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(left + right)/2 can overflow in cases where left + (right-left)/2 wouldn't.
See, for example left=2 and right=2^32-1.

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Just saw the Documentation/SubmittingPatches file; will resubmit properly.

@mutexlox mutexlox closed this Sep 30, 2011
torvalds pushed a commit that referenced this pull request Feb 8, 2012
Overly indented code should be refactored.

Suggest refactoring excessive indentation of of
if/else/for/do/while/switch statements.

For example:

$ cat t.c
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv)
{

	if (1)
		if (2)
			if (3)
				if (4)
					if (5)
						if (6)
							if (7)
								if (8)
									;
	return 0;
}

$ ./scripts/checkpatch.pl -f t.c
WARNING: Too many leading tabs - consider code refactoring
#12: FILE: t.c:12:
+						if (6)

WARNING: Too many leading tabs - consider code refactoring
#13: FILE: t.c:13:
+							if (7)

WARNING: Too many leading tabs - consider code refactoring
#14: FILE: t.c:14:
+								if (8)

total: 0 errors, 3 warnings, 17 lines checked

t.c has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Signed-off-by: Joe Perches <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
jkstrick pushed a commit to jkstrick/linux that referenced this pull request Feb 11, 2012
If the netdev is already in NETREG_UNREGISTERING/_UNREGISTERED state, do not
update the real num tx queues. netdev_queue_update_kobjects() is already
called via remove_queue_kobjects() at NETREG_UNREGISTERING time. So, when
upper layer driver, e.g., FCoE protocol stack is monitoring the netdev
event of NETDEV_UNREGISTER and calls back to LLD ndo_fcoe_disable() to remove
extra queues allocated for FCoE, the associated txq sysfs kobjects are already
removed, and trying to update the real num queues would cause something like
below:

...
PID: 25138  TASK: ffff88021e64c440  CPU: 3   COMMAND: "kworker/3:3"
 #0 [ffff88021f007760] machine_kexec at ffffffff810226d9
 #1 [ffff88021f0077d0] crash_kexec at ffffffff81089d2d
 #2 [ffff88021f0078a0] oops_end at ffffffff813bca78
 #3 [ffff88021f0078d0] no_context at ffffffff81029e72
 #4 [ffff88021f007920] __bad_area_nosemaphore at ffffffff8102a155
 #5 [ffff88021f0079f0] bad_area_nosemaphore at ffffffff8102a23e
 torvalds#6 [ffff88021f007a00] do_page_fault at ffffffff813bf32e
 torvalds#7 [ffff88021f007b10] page_fault at ffffffff813bc045
    [exception RIP: sysfs_find_dirent+17]
    RIP: ffffffff81178611  RSP: ffff88021f007bc0  RFLAGS: 00010246
    RAX: ffff88021e64c440  RBX: ffffffff8156cc63  RCX: 0000000000000004
    RDX: ffffffff8156cc63  RSI: 0000000000000000  RDI: 0000000000000000
    RBP: ffff88021f007be0   R8: 0000000000000004   R9: 0000000000000008
    R10: ffffffff816fed00  R11: 0000000000000004  R12: 0000000000000000
    R13: ffffffff8156cc63  R14: 0000000000000000  R15: ffff8802222a0000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 torvalds#8 [ffff88021f007be8] sysfs_get_dirent at ffffffff81178c07
 torvalds#9 [ffff88021f007c18] sysfs_remove_group at ffffffff8117ac27
torvalds#10 [ffff88021f007c48] netdev_queue_update_kobjects at ffffffff813178f9
torvalds#11 [ffff88021f007c88] netif_set_real_num_tx_queues at ffffffff81303e38
torvalds#12 [ffff88021f007cc8] ixgbe_set_num_queues at ffffffffa0249763 [ixgbe]
torvalds#13 [ffff88021f007cf8] ixgbe_init_interrupt_scheme at ffffffffa024ea89 [ixgbe]
torvalds#14 [ffff88021f007d48] ixgbe_fcoe_disable at ffffffffa0267113 [ixgbe]
torvalds#15 [ffff88021f007d68] vlan_dev_fcoe_disable at ffffffffa014fef5 [8021q]
torvalds#16 [ffff88021f007d78] fcoe_interface_cleanup at ffffffffa02b7dfd [fcoe]
torvalds#17 [ffff88021f007df8] fcoe_destroy_work at ffffffffa02b7f08 [fcoe]
torvalds#18 [ffff88021f007e18] process_one_work at ffffffff8105d7ca
torvalds#19 [ffff88021f007e68] worker_thread at ffffffff81060513
torvalds#20 [ffff88021f007ee8] kthread at ffffffff810648b6
torvalds#21 [ffff88021f007f48] kernel_thread_helper at ffffffff813c40f4

Signed-off-by: Yi Zou <[email protected]>
Tested-by: Ross Brattain <[email protected]>
Tested-by: Stephen Ko <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>
zachariasmaladroit pushed a commit to galaxys-cm7miui-kernel/linux that referenced this pull request Feb 11, 2012
If the netdev is already in NETREG_UNREGISTERING/_UNREGISTERED state, do not
update the real num tx queues. netdev_queue_update_kobjects() is already
called via remove_queue_kobjects() at NETREG_UNREGISTERING time. So, when
upper layer driver, e.g., FCoE protocol stack is monitoring the netdev
event of NETDEV_UNREGISTER and calls back to LLD ndo_fcoe_disable() to remove
extra queues allocated for FCoE, the associated txq sysfs kobjects are already
removed, and trying to update the real num queues would cause something like
below:

...
PID: 25138  TASK: ffff88021e64c440  CPU: 3   COMMAND: "kworker/3:3"
 #0 [ffff88021f007760] machine_kexec at ffffffff810226d9
 #1 [ffff88021f0077d0] crash_kexec at ffffffff81089d2d
 #2 [ffff88021f0078a0] oops_end at ffffffff813bca78
 #3 [ffff88021f0078d0] no_context at ffffffff81029e72
 #4 [ffff88021f007920] __bad_area_nosemaphore at ffffffff8102a155
 #5 [ffff88021f0079f0] bad_area_nosemaphore at ffffffff8102a23e
 torvalds#6 [ffff88021f007a00] do_page_fault at ffffffff813bf32e
 torvalds#7 [ffff88021f007b10] page_fault at ffffffff813bc045
    [exception RIP: sysfs_find_dirent+17]
    RIP: ffffffff81178611  RSP: ffff88021f007bc0  RFLAGS: 00010246
    RAX: ffff88021e64c440  RBX: ffffffff8156cc63  RCX: 0000000000000004
    RDX: ffffffff8156cc63  RSI: 0000000000000000  RDI: 0000000000000000
    RBP: ffff88021f007be0   R8: 0000000000000004   R9: 0000000000000008
    R10: ffffffff816fed00  R11: 0000000000000004  R12: 0000000000000000
    R13: ffffffff8156cc63  R14: 0000000000000000  R15: ffff8802222a0000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 torvalds#8 [ffff88021f007be8] sysfs_get_dirent at ffffffff81178c07
 torvalds#9 [ffff88021f007c18] sysfs_remove_group at ffffffff8117ac27
torvalds#10 [ffff88021f007c48] netdev_queue_update_kobjects at ffffffff813178f9
torvalds#11 [ffff88021f007c88] netif_set_real_num_tx_queues at ffffffff81303e38
torvalds#12 [ffff88021f007cc8] ixgbe_set_num_queues at ffffffffa0249763 [ixgbe]
torvalds#13 [ffff88021f007cf8] ixgbe_init_interrupt_scheme at ffffffffa024ea89 [ixgbe]
torvalds#14 [ffff88021f007d48] ixgbe_fcoe_disable at ffffffffa0267113 [ixgbe]
torvalds#15 [ffff88021f007d68] vlan_dev_fcoe_disable at ffffffffa014fef5 [8021q]
torvalds#16 [ffff88021f007d78] fcoe_interface_cleanup at ffffffffa02b7dfd [fcoe]
torvalds#17 [ffff88021f007df8] fcoe_destroy_work at ffffffffa02b7f08 [fcoe]
torvalds#18 [ffff88021f007e18] process_one_work at ffffffff8105d7ca
torvalds#19 [ffff88021f007e68] worker_thread at ffffffff81060513
torvalds#20 [ffff88021f007ee8] kthread at ffffffff810648b6
torvalds#21 [ffff88021f007f48] kernel_thread_helper at ffffffff813c40f4

Signed-off-by: Yi Zou <[email protected]>
Tested-by: Ross Brattain <[email protected]>
Tested-by: Stephen Ko <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>
tworaz pushed a commit to tworaz/linux that referenced this pull request Feb 13, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a
 torvalds#7 [d72d3d1] zone_watermark_ok at c02d26cb
 torvalds#8 [d72d3d2c] compact_zone at c030b8d
 torvalds#9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
xXorAa pushed a commit to xXorAa/linux that referenced this pull request Feb 17, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a
 torvalds#7 [d72d3d1] zone_watermark_ok at c02d26cb
 torvalds#8 [d72d3d2c] compact_zone at c030b8d
 torvalds#9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Feb 23, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Mar 1, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Mar 19, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Mar 22, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Apr 2, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Apr 9, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Apr 11, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Apr 12, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
psanford pushed a commit to retailnext/linux that referenced this pull request Apr 16, 2012
…S block during isolation for migration

BugLink: http://bugs.launchpad.net/bugs/931719

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a
 torvalds#7 [d72d3d1] zone_watermark_ok at c02d26cb
 torvalds#8 [d72d3d2c] compact_zone at c030b8d
 torvalds#9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tim Gardner <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request Apr 19, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 4, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 4, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 5, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ssvb pushed a commit to ssvb/linux-n810 that referenced this pull request May 6, 2012
commit 3d2606f upstream.

IBS initialization is a mix of per-core register access and per-node
pci device setup. Register access should be pinned to the cpu, but pci
setup must run with preemption enabled.

This patch better separates the code into non-/preemptible sections
and fixes sleeping with preemption disabled. See bug message below.

Fixes also freeing the eilvt entry by introducing put_eilvt().

BUG: sleeping function called from invalid context at mm/slub.c:824
in_atomic(): 1, irqs_disabled(): 0, pid: 32357, name: modprobe
INFO: lockdep is turned off.
Pid: 32357, comm: modprobe Not tainted 2.6.39-rc7+ torvalds#14
Call Trace:
 [<ffffffff8104bdc8>] __might_sleep+0x112/0x117
 [<ffffffff81129693>] kmem_cache_alloc_trace+0x4b/0xe7
 [<ffffffff81278f14>] kzalloc.constprop.0+0x29/0x2b
 [<ffffffff81278f4c>] pci_get_subsys+0x36/0x78
 [<ffffffff81022689>] ? setup_APIC_eilvt+0xfb/0x139
 [<ffffffff81278fa4>] pci_get_device+0x16/0x18
 [<ffffffffa06c8b5d>] op_amd_init+0xd3/0x211 [oprofile]
 [<ffffffffa064d000>] ? 0xffffffffa064cfff
 [<ffffffffa064d298>] op_nmi_init+0x21e/0x26a [oprofile]
 [<ffffffffa064d062>] oprofile_arch_init+0xe/0x26 [oprofile]
 [<ffffffffa064d010>] oprofile_init+0x10/0x42 [oprofile]
 [<ffffffff81002099>] do_one_initcall+0x7f/0x13a
 [<ffffffff81096524>] sys_init_module+0x132/0x281
 [<ffffffff814cc682>] system_call_fastpath+0x16/0x1b

Reported-by: Dave Jones <[email protected]>
Signed-off-by: Robert Richter <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 7, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 9, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 14, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 16, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 17, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 21, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 22, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
koenkooi pushed a commit to koenkooi/linux that referenced this pull request May 22, 2012
…S block during isolation for migration

commit 0bf380b upstream.

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72e
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d1] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8d
 #9 [d72d3d68] compact_zone_order at c030bba1
torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84
torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845
torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6
torvalds#17 [d72d3f30] do_page_fault at c05c70ed
torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.

Reported-by: Herbert van den Bergh <[email protected]>
Tested-by: Herbert van den Bergh <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Jul 14, 2025
…void Priority Inversion in SRIOV

commit dc0297f upstream.

RLCG Register Access is a way for virtual functions to safely access GPU
registers in a virtualized environment., including TLB flushes and
register reads. When multiple threads or VFs try to access the same
registers simultaneously, it can lead to race conditions. By using the
RLCG interface, the driver can serialize access to the registers. This
means that only one thread can access the registers at a time,
preventing conflicts and ensuring that operations are performed
correctly. Additionally, when a low-priority task holds a mutex that a
high-priority task needs, ie., If a thread holding a spinlock tries to
acquire a mutex, it can lead to priority inversion. register access in
amdgpu_virt_rlcg_reg_rw especially in a fast code path is critical.

The call stack shows that the function amdgpu_virt_rlcg_reg_rw is being
called, which attempts to acquire the mutex. This function is invoked
from amdgpu_sriov_wreg, which in turn is called from
gmc_v11_0_flush_gpu_tlb.

The [ BUG: Invalid wait context ] indicates that a thread is trying to
acquire a mutex while it is in a context that does not allow it to sleep
(like holding a spinlock).

Fixes the below:

[  253.013423] =============================
[  253.013434] [ BUG: Invalid wait context ]
[  253.013446] 6.12.0-amdstaging-drm-next-lol-050225 torvalds#14 Tainted: G     U     OE
[  253.013464] -----------------------------
[  253.013475] kworker/0:1/10 is trying to lock:
[  253.013487] ffff9f30542e3cf8 (&adev->virt.rlcg_reg_lock){+.+.}-{3:3}, at: amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.013815] other info that might help us debug this:
[  253.013827] context-{4:4}
[  253.013835] 3 locks held by kworker/0:1/10:
[  253.013847]  #0: ffff9f3040050f58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  253.013877]  #1: ffffb789c008be40 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  253.013905]  #2: ffff9f3054281838 (&adev->gmc.invalidate_lock){+.+.}-{2:2}, at: gmc_v11_0_flush_gpu_tlb+0x198/0x4f0 [amdgpu]
[  253.014154] stack backtrace:
[  253.014164] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G     U     OE      6.12.0-amdstaging-drm-next-lol-050225 torvalds#14
[  253.014189] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  253.014203] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/18/2024
[  253.014224] Workqueue: events work_for_cpu_fn
[  253.014241] Call Trace:
[  253.014250]  <TASK>
[  253.014260]  dump_stack_lvl+0x9b/0xf0
[  253.014275]  dump_stack+0x10/0x20
[  253.014287]  __lock_acquire+0xa47/0x2810
[  253.014303]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014321]  lock_acquire+0xd1/0x300
[  253.014333]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014562]  ? __lock_acquire+0xa6b/0x2810
[  253.014578]  __mutex_lock+0x85/0xe20
[  253.014591]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014782]  ? sched_clock_noinstr+0x9/0x10
[  253.014795]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014808]  ? local_clock_noinstr+0xe/0xc0
[  253.014822]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015012]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.015029]  mutex_lock_nested+0x1b/0x30
[  253.015044]  ? mutex_lock_nested+0x1b/0x30
[  253.015057]  amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015249]  amdgpu_sriov_wreg+0xc5/0xd0 [amdgpu]
[  253.015435]  gmc_v11_0_flush_gpu_tlb+0x44b/0x4f0 [amdgpu]
[  253.015667]  gfx_v11_0_hw_init+0x499/0x29c0 [amdgpu]
[  253.015901]  ? __pfx_smu_v13_0_update_pcie_parameters+0x10/0x10 [amdgpu]
[  253.016159]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.016173]  ? smu_hw_init+0x18d/0x300 [amdgpu]
[  253.016403]  amdgpu_device_init+0x29ad/0x36a0 [amdgpu]
[  253.016614]  amdgpu_driver_load_kms+0x1a/0xc0 [amdgpu]
[  253.017057]  amdgpu_pci_probe+0x1c2/0x660 [amdgpu]
[  253.017493]  local_pci_probe+0x4b/0xb0
[  253.017746]  work_for_cpu_fn+0x1a/0x30
[  253.017995]  process_one_work+0x21e/0x680
[  253.018248]  worker_thread+0x190/0x330
[  253.018500]  ? __pfx_worker_thread+0x10/0x10
[  253.018746]  kthread+0xe7/0x120
[  253.018988]  ? __pfx_kthread+0x10/0x10
[  253.019231]  ret_from_fork+0x3c/0x60
[  253.019468]  ? __pfx_kthread+0x10/0x10
[  253.019701]  ret_from_fork_asm+0x1a/0x30
[  253.019939]  </TASK>

v2: s/spin_trylock/spin_lock_irqsave to be safe (Christian).

Fixes: e864180 ("drm/amdgpu: Add lock around VF RLCG interface")
Cc: lin cao <[email protected]>
Cc: Jingwen Chen <[email protected]>
Cc: Victor Skvortsov <[email protected]>
Cc: Zhigang Luo <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
[ Minor context change fixed. ]
Signed-off-by: Wenshan Lan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Jul 14, 2025
commit fa787ac upstream.

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Jul 15, 2025
…void Priority Inversion in SRIOV

commit dc0297f upstream.

RLCG Register Access is a way for virtual functions to safely access GPU
registers in a virtualized environment., including TLB flushes and
register reads. When multiple threads or VFs try to access the same
registers simultaneously, it can lead to race conditions. By using the
RLCG interface, the driver can serialize access to the registers. This
means that only one thread can access the registers at a time,
preventing conflicts and ensuring that operations are performed
correctly. Additionally, when a low-priority task holds a mutex that a
high-priority task needs, ie., If a thread holding a spinlock tries to
acquire a mutex, it can lead to priority inversion. register access in
amdgpu_virt_rlcg_reg_rw especially in a fast code path is critical.

The call stack shows that the function amdgpu_virt_rlcg_reg_rw is being
called, which attempts to acquire the mutex. This function is invoked
from amdgpu_sriov_wreg, which in turn is called from
gmc_v11_0_flush_gpu_tlb.

The [ BUG: Invalid wait context ] indicates that a thread is trying to
acquire a mutex while it is in a context that does not allow it to sleep
(like holding a spinlock).

Fixes the below:

[  253.013423] =============================
[  253.013434] [ BUG: Invalid wait context ]
[  253.013446] 6.12.0-amdstaging-drm-next-lol-050225 torvalds#14 Tainted: G     U     OE
[  253.013464] -----------------------------
[  253.013475] kworker/0:1/10 is trying to lock:
[  253.013487] ffff9f30542e3cf8 (&adev->virt.rlcg_reg_lock){+.+.}-{3:3}, at: amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.013815] other info that might help us debug this:
[  253.013827] context-{4:4}
[  253.013835] 3 locks held by kworker/0:1/10:
[  253.013847]  #0: ffff9f3040050f58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  253.013877]  #1: ffffb789c008be40 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  253.013905]  #2: ffff9f3054281838 (&adev->gmc.invalidate_lock){+.+.}-{2:2}, at: gmc_v11_0_flush_gpu_tlb+0x198/0x4f0 [amdgpu]
[  253.014154] stack backtrace:
[  253.014164] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G     U     OE      6.12.0-amdstaging-drm-next-lol-050225 torvalds#14
[  253.014189] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  253.014203] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/18/2024
[  253.014224] Workqueue: events work_for_cpu_fn
[  253.014241] Call Trace:
[  253.014250]  <TASK>
[  253.014260]  dump_stack_lvl+0x9b/0xf0
[  253.014275]  dump_stack+0x10/0x20
[  253.014287]  __lock_acquire+0xa47/0x2810
[  253.014303]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014321]  lock_acquire+0xd1/0x300
[  253.014333]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014562]  ? __lock_acquire+0xa6b/0x2810
[  253.014578]  __mutex_lock+0x85/0xe20
[  253.014591]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014782]  ? sched_clock_noinstr+0x9/0x10
[  253.014795]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014808]  ? local_clock_noinstr+0xe/0xc0
[  253.014822]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015012]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.015029]  mutex_lock_nested+0x1b/0x30
[  253.015044]  ? mutex_lock_nested+0x1b/0x30
[  253.015057]  amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015249]  amdgpu_sriov_wreg+0xc5/0xd0 [amdgpu]
[  253.015435]  gmc_v11_0_flush_gpu_tlb+0x44b/0x4f0 [amdgpu]
[  253.015667]  gfx_v11_0_hw_init+0x499/0x29c0 [amdgpu]
[  253.015901]  ? __pfx_smu_v13_0_update_pcie_parameters+0x10/0x10 [amdgpu]
[  253.016159]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.016173]  ? smu_hw_init+0x18d/0x300 [amdgpu]
[  253.016403]  amdgpu_device_init+0x29ad/0x36a0 [amdgpu]
[  253.016614]  amdgpu_driver_load_kms+0x1a/0xc0 [amdgpu]
[  253.017057]  amdgpu_pci_probe+0x1c2/0x660 [amdgpu]
[  253.017493]  local_pci_probe+0x4b/0xb0
[  253.017746]  work_for_cpu_fn+0x1a/0x30
[  253.017995]  process_one_work+0x21e/0x680
[  253.018248]  worker_thread+0x190/0x330
[  253.018500]  ? __pfx_worker_thread+0x10/0x10
[  253.018746]  kthread+0xe7/0x120
[  253.018988]  ? __pfx_kthread+0x10/0x10
[  253.019231]  ret_from_fork+0x3c/0x60
[  253.019468]  ? __pfx_kthread+0x10/0x10
[  253.019701]  ret_from_fork_asm+0x1a/0x30
[  253.019939]  </TASK>

v2: s/spin_trylock/spin_lock_irqsave to be safe (Christian).

Fixes: e864180 ("drm/amdgpu: Add lock around VF RLCG interface")
Cc: lin cao <[email protected]>
Cc: Jingwen Chen <[email protected]>
Cc: Victor Skvortsov <[email protected]>
Cc: Zhigang Luo <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
[ Minor context change fixed. ]
Signed-off-by: Wenshan Lan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Jul 15, 2025
commit fa787ac upstream.

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Jul 16, 2025
…void Priority Inversion in SRIOV

commit dc0297f upstream.

RLCG Register Access is a way for virtual functions to safely access GPU
registers in a virtualized environment., including TLB flushes and
register reads. When multiple threads or VFs try to access the same
registers simultaneously, it can lead to race conditions. By using the
RLCG interface, the driver can serialize access to the registers. This
means that only one thread can access the registers at a time,
preventing conflicts and ensuring that operations are performed
correctly. Additionally, when a low-priority task holds a mutex that a
high-priority task needs, ie., If a thread holding a spinlock tries to
acquire a mutex, it can lead to priority inversion. register access in
amdgpu_virt_rlcg_reg_rw especially in a fast code path is critical.

The call stack shows that the function amdgpu_virt_rlcg_reg_rw is being
called, which attempts to acquire the mutex. This function is invoked
from amdgpu_sriov_wreg, which in turn is called from
gmc_v11_0_flush_gpu_tlb.

The [ BUG: Invalid wait context ] indicates that a thread is trying to
acquire a mutex while it is in a context that does not allow it to sleep
(like holding a spinlock).

Fixes the below:

[  253.013423] =============================
[  253.013434] [ BUG: Invalid wait context ]
[  253.013446] 6.12.0-amdstaging-drm-next-lol-050225 torvalds#14 Tainted: G     U     OE
[  253.013464] -----------------------------
[  253.013475] kworker/0:1/10 is trying to lock:
[  253.013487] ffff9f30542e3cf8 (&adev->virt.rlcg_reg_lock){+.+.}-{3:3}, at: amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.013815] other info that might help us debug this:
[  253.013827] context-{4:4}
[  253.013835] 3 locks held by kworker/0:1/10:
[  253.013847]  #0: ffff9f3040050f58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  253.013877]  #1: ffffb789c008be40 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  253.013905]  #2: ffff9f3054281838 (&adev->gmc.invalidate_lock){+.+.}-{2:2}, at: gmc_v11_0_flush_gpu_tlb+0x198/0x4f0 [amdgpu]
[  253.014154] stack backtrace:
[  253.014164] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G     U     OE      6.12.0-amdstaging-drm-next-lol-050225 torvalds#14
[  253.014189] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  253.014203] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/18/2024
[  253.014224] Workqueue: events work_for_cpu_fn
[  253.014241] Call Trace:
[  253.014250]  <TASK>
[  253.014260]  dump_stack_lvl+0x9b/0xf0
[  253.014275]  dump_stack+0x10/0x20
[  253.014287]  __lock_acquire+0xa47/0x2810
[  253.014303]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014321]  lock_acquire+0xd1/0x300
[  253.014333]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014562]  ? __lock_acquire+0xa6b/0x2810
[  253.014578]  __mutex_lock+0x85/0xe20
[  253.014591]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014782]  ? sched_clock_noinstr+0x9/0x10
[  253.014795]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014808]  ? local_clock_noinstr+0xe/0xc0
[  253.014822]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015012]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.015029]  mutex_lock_nested+0x1b/0x30
[  253.015044]  ? mutex_lock_nested+0x1b/0x30
[  253.015057]  amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015249]  amdgpu_sriov_wreg+0xc5/0xd0 [amdgpu]
[  253.015435]  gmc_v11_0_flush_gpu_tlb+0x44b/0x4f0 [amdgpu]
[  253.015667]  gfx_v11_0_hw_init+0x499/0x29c0 [amdgpu]
[  253.015901]  ? __pfx_smu_v13_0_update_pcie_parameters+0x10/0x10 [amdgpu]
[  253.016159]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.016173]  ? smu_hw_init+0x18d/0x300 [amdgpu]
[  253.016403]  amdgpu_device_init+0x29ad/0x36a0 [amdgpu]
[  253.016614]  amdgpu_driver_load_kms+0x1a/0xc0 [amdgpu]
[  253.017057]  amdgpu_pci_probe+0x1c2/0x660 [amdgpu]
[  253.017493]  local_pci_probe+0x4b/0xb0
[  253.017746]  work_for_cpu_fn+0x1a/0x30
[  253.017995]  process_one_work+0x21e/0x680
[  253.018248]  worker_thread+0x190/0x330
[  253.018500]  ? __pfx_worker_thread+0x10/0x10
[  253.018746]  kthread+0xe7/0x120
[  253.018988]  ? __pfx_kthread+0x10/0x10
[  253.019231]  ret_from_fork+0x3c/0x60
[  253.019468]  ? __pfx_kthread+0x10/0x10
[  253.019701]  ret_from_fork_asm+0x1a/0x30
[  253.019939]  </TASK>

v2: s/spin_trylock/spin_lock_irqsave to be safe (Christian).

Fixes: e864180 ("drm/amdgpu: Add lock around VF RLCG interface")
Cc: lin cao <[email protected]>
Cc: Jingwen Chen <[email protected]>
Cc: Victor Skvortsov <[email protected]>
Cc: Zhigang Luo <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
[ Minor context change fixed. ]
Signed-off-by: Wenshan Lan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
ptr1337 pushed a commit to CachyOS/linux that referenced this pull request Jul 17, 2025
commit fa787ac upstream.

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
1054009064 pushed a commit to 1054009064/linux that referenced this pull request Jul 17, 2025
…void Priority Inversion in SRIOV

commit dc0297f upstream.

RLCG Register Access is a way for virtual functions to safely access GPU
registers in a virtualized environment., including TLB flushes and
register reads. When multiple threads or VFs try to access the same
registers simultaneously, it can lead to race conditions. By using the
RLCG interface, the driver can serialize access to the registers. This
means that only one thread can access the registers at a time,
preventing conflicts and ensuring that operations are performed
correctly. Additionally, when a low-priority task holds a mutex that a
high-priority task needs, ie., If a thread holding a spinlock tries to
acquire a mutex, it can lead to priority inversion. register access in
amdgpu_virt_rlcg_reg_rw especially in a fast code path is critical.

The call stack shows that the function amdgpu_virt_rlcg_reg_rw is being
called, which attempts to acquire the mutex. This function is invoked
from amdgpu_sriov_wreg, which in turn is called from
gmc_v11_0_flush_gpu_tlb.

The [ BUG: Invalid wait context ] indicates that a thread is trying to
acquire a mutex while it is in a context that does not allow it to sleep
(like holding a spinlock).

Fixes the below:

[  253.013423] =============================
[  253.013434] [ BUG: Invalid wait context ]
[  253.013446] 6.12.0-amdstaging-drm-next-lol-050225 torvalds#14 Tainted: G     U     OE
[  253.013464] -----------------------------
[  253.013475] kworker/0:1/10 is trying to lock:
[  253.013487] ffff9f30542e3cf8 (&adev->virt.rlcg_reg_lock){+.+.}-{3:3}, at: amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.013815] other info that might help us debug this:
[  253.013827] context-{4:4}
[  253.013835] 3 locks held by kworker/0:1/10:
[  253.013847]  #0: ffff9f3040050f58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  253.013877]  #1: ffffb789c008be40 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  253.013905]  #2: ffff9f3054281838 (&adev->gmc.invalidate_lock){+.+.}-{2:2}, at: gmc_v11_0_flush_gpu_tlb+0x198/0x4f0 [amdgpu]
[  253.014154] stack backtrace:
[  253.014164] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G     U     OE      6.12.0-amdstaging-drm-next-lol-050225 torvalds#14
[  253.014189] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  253.014203] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/18/2024
[  253.014224] Workqueue: events work_for_cpu_fn
[  253.014241] Call Trace:
[  253.014250]  <TASK>
[  253.014260]  dump_stack_lvl+0x9b/0xf0
[  253.014275]  dump_stack+0x10/0x20
[  253.014287]  __lock_acquire+0xa47/0x2810
[  253.014303]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014321]  lock_acquire+0xd1/0x300
[  253.014333]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014562]  ? __lock_acquire+0xa6b/0x2810
[  253.014578]  __mutex_lock+0x85/0xe20
[  253.014591]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.014782]  ? sched_clock_noinstr+0x9/0x10
[  253.014795]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.014808]  ? local_clock_noinstr+0xe/0xc0
[  253.014822]  ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015012]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.015029]  mutex_lock_nested+0x1b/0x30
[  253.015044]  ? mutex_lock_nested+0x1b/0x30
[  253.015057]  amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[  253.015249]  amdgpu_sriov_wreg+0xc5/0xd0 [amdgpu]
[  253.015435]  gmc_v11_0_flush_gpu_tlb+0x44b/0x4f0 [amdgpu]
[  253.015667]  gfx_v11_0_hw_init+0x499/0x29c0 [amdgpu]
[  253.015901]  ? __pfx_smu_v13_0_update_pcie_parameters+0x10/0x10 [amdgpu]
[  253.016159]  ? srso_alias_return_thunk+0x5/0xfbef5
[  253.016173]  ? smu_hw_init+0x18d/0x300 [amdgpu]
[  253.016403]  amdgpu_device_init+0x29ad/0x36a0 [amdgpu]
[  253.016614]  amdgpu_driver_load_kms+0x1a/0xc0 [amdgpu]
[  253.017057]  amdgpu_pci_probe+0x1c2/0x660 [amdgpu]
[  253.017493]  local_pci_probe+0x4b/0xb0
[  253.017746]  work_for_cpu_fn+0x1a/0x30
[  253.017995]  process_one_work+0x21e/0x680
[  253.018248]  worker_thread+0x190/0x330
[  253.018500]  ? __pfx_worker_thread+0x10/0x10
[  253.018746]  kthread+0xe7/0x120
[  253.018988]  ? __pfx_kthread+0x10/0x10
[  253.019231]  ret_from_fork+0x3c/0x60
[  253.019468]  ? __pfx_kthread+0x10/0x10
[  253.019701]  ret_from_fork_asm+0x1a/0x30
[  253.019939]  </TASK>

v2: s/spin_trylock/spin_lock_irqsave to be safe (Christian).

Fixes: e864180 ("drm/amdgpu: Add lock around VF RLCG interface")
Cc: lin cao <[email protected]>
Cc: Jingwen Chen <[email protected]>
Cc: Victor Skvortsov <[email protected]>
Cc: Zhigang Luo <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
[ Minor context change fixed. ]
Signed-off-by: Wenshan Lan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
TianyouLi pushed a commit to TianyouLi/linux that referenced this pull request Jul 21, 2025
In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Jul 30, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
1054009064 pushed a commit to 1054009064/linux that referenced this pull request Aug 1, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
sean-jc pushed a commit to sean-jc/linux that referenced this pull request Aug 14, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Aug 18, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Aug 18, 2025
hfsplus_bmap_alloc can trigger a crash if a
record offset or length is larger than node_size

[   15.264282] BUG: KASAN: slab-out-of-bounds in hfsplus_bmap_alloc+0x887/0x8b0
[   15.265192] Read of size 8 at addr ffff8881085ca188 by task test/183
[   15.265949]
[   15.266163] CPU: 0 UID: 0 PID: 183 Comm: test Not tainted 6.17.0-rc2-gc17b750b3ad9 torvalds#14 PREEMPT(voluntary)
[   15.266165] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   15.266167] Call Trace:
[   15.266168]  <TASK>
[   15.266169]  dump_stack_lvl+0x53/0x70
[   15.266173]  print_report+0xd0/0x660
[   15.266181]  kasan_report+0xce/0x100
[   15.266185]  hfsplus_bmap_alloc+0x887/0x8b0
[   15.266208]  hfs_btree_inc_height.isra.0+0xd5/0x7c0
[   15.266217]  hfsplus_brec_insert+0x870/0xb00
[   15.266222]  __hfsplus_ext_write_extent+0x428/0x570
[   15.266225]  __hfsplus_ext_cache_extent+0x5e/0x910
[   15.266227]  hfsplus_ext_read_extent+0x1b2/0x200
[   15.266233]  hfsplus_file_extend+0x5a7/0x1000
[   15.266237]  hfsplus_get_block+0x12b/0x8c0
[   15.266238]  __block_write_begin_int+0x36b/0x12c0
[   15.266251]  block_write_begin+0x77/0x110
[   15.266252]  cont_write_begin+0x428/0x720
[   15.266259]  hfsplus_write_begin+0x51/0x100
[   15.266262]  cont_write_begin+0x272/0x720
[   15.266270]  hfsplus_write_begin+0x51/0x100
[   15.266274]  generic_perform_write+0x321/0x750
[   15.266285]  generic_file_write_iter+0xc3/0x310
[   15.266289]  __kernel_write_iter+0x2fd/0x800
[   15.266296]  dump_user_range+0x2ea/0x910
[   15.266301]  elf_core_dump+0x2a94/0x2ed0
[   15.266320]  vfs_coredump+0x1d85/0x45e0
[   15.266349]  get_signal+0x12e3/0x1990
[   15.266357]  arch_do_signal_or_restart+0x89/0x580
[   15.266362]  irqentry_exit_to_user_mode+0xab/0x110
[   15.266364]  asm_exc_page_fault+0x26/0x30
[   15.266366] RIP: 0033:0x41bd35
[   15.266367] Code: bc d1 f3 0f 7f 27 f3 0f 7f 6f 10 f3 0f 7f 77 20 f3 0f 7f 7f 30 49 83 c0 0f 49 29 d0 48 8d 7c 17 31 e9 9f 0b 00 00 66 0f ef c0 <f3> 0f 6f 0e f3 0f 6f 56 10 66 0f 74 c1 66 0f d7 d0 49 83 f8f
[   15.266369] RSP: 002b:00007ffc9e62d078 EFLAGS: 00010283
[   15.266371] RAX: 00007ffc9e62d100 RBX: 0000000000000000 RCX: 0000000000000000
[   15.266372] RDX: 00000000000000e0 RSI: 0000000000000000 RDI: 00007ffc9e62d100
[   15.266373] RBP: 0000400000000040 R08: 00000000000000e0 R09: 0000000000000000
[   15.266374] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[   15.266375] R13: 0000000000000000 R14: 0000000000000000 R15: 0000400000000000
[   15.266376]  </TASK>

When calling hfsplus_bmap_alloc to allocate a free node, this function
first retrieves the bitmap from header node and map node using node->page
together with the offset and length from hfs_brec_lenoff

```
len = hfs_brec_lenoff(node, 2, &off16);
off = off16;

off += node->page_offset;
pagep = node->page + (off >> PAGE_SHIFT);
data = kmap_local_page(*pagep);
```

However, if the retrieved offset or length is invalid(i.e. exceeds
node_size), the code may end up accessing pages outside the allocated
range for this node.

This patch adds proper validation of both offset and length before use,
preventing out-of-bounds page access. Move is_bnode_offset_valid and
check_and_correct_requested_length to hfsplus_fs.h, as they may be
required by other functions.

Reported-by: [email protected]
Closes: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Yang Chenzhi <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Aug 22, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Aug 24, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Aug 24, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
aman-ahuja-fortanix pushed a commit to fortanix/linux that referenced this pull request Aug 25, 2025
…faces

BugLink: https://bugs.launchpad.net/bugs/2115616

commit 2240fed upstream.

Robert Morris created a test program which can cause
usb_hub_to_struct_hub() to dereference a NULL or inappropriate
pointer:

Oops: general protection fault, probably for non-canonical address
0xcccccccccccccccc: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
CPU: 7 UID: 0 PID: 117 Comm: kworker/7:1 Not tainted 6.13.0-rc3-00017-gf44d154d6e3d torvalds#14
Hardware name: FreeBSD BHYVE/BHYVE, BIOS 14.0 10/17/2021
Workqueue: usb_hub_wq hub_event
RIP: 0010:usb_hub_adjust_deviceremovable+0x78/0x110
...
Call Trace:
 <TASK>
 ? die_addr+0x31/0x80
 ? exc_general_protection+0x1b4/0x3c0
 ? asm_exc_general_protection+0x26/0x30
 ? usb_hub_adjust_deviceremovable+0x78/0x110
 hub_probe+0x7c7/0xab0
 usb_probe_interface+0x14b/0x350
 really_probe+0xd0/0x2d0
 ? __pfx___device_attach_driver+0x10/0x10
 __driver_probe_device+0x6e/0x110
 driver_probe_device+0x1a/0x90
 __device_attach_driver+0x7e/0xc0
 bus_for_each_drv+0x7f/0xd0
 __device_attach+0xaa/0x1a0
 bus_probe_device+0x8b/0xa0
 device_add+0x62e/0x810
 usb_set_configuration+0x65d/0x990
 usb_generic_driver_probe+0x4b/0x70
 usb_probe_device+0x36/0xd0

The cause of this error is that the device has two interfaces, and the
hub driver binds to interface 1 instead of interface 0, which is where
usb_hub_to_struct_hub() looks.

We can prevent the problem from occurring by refusing to accept hub
devices that violate the USB spec by having more than one
configuration or interface.

Reported-and-tested-by: Robert Morris <[email protected]>
Cc: stable <[email protected]>
Closes: https://lore.kernel.org/linux-usb/95564.1737394039@localhost/
Signed-off-by: Alan Stern <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Noah Wager <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Aug 25, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
mj22226 pushed a commit to mj22226/linux that referenced this pull request Aug 26, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ruzickajakub pushed a commit to ruzickajakub/linux that referenced this pull request Aug 28, 2025
1054009064 pushed a commit to 1054009064/linux that referenced this pull request Aug 28, 2025
[ Upstream commit fa787ac ]

In KVM guests with Hyper-V hypercalls enabled, the hypercalls
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST and HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX
allow a guest to request invalidation of portions of a virtual TLB.
For this, the hypercall parameter includes a list of GVAs that are supposed
to be invalidated.

However, when non-canonical GVAs are passed, there is currently no
filtering in place and they are eventually passed to checked invocations of
INVVPID on Intel / INVLPGA on AMD.  While AMD's INVLPGA silently ignores
non-canonical addresses (effectively a no-op), Intel's INVVPID explicitly
signals VM-Fail and ultimately triggers the WARN_ONCE in invvpid_error():

  invvpid failed: ext=0x0 vpid=1 gva=0xaaaaaaaaaaaaa000
  WARNING: CPU: 6 PID: 326 at arch/x86/kvm/vmx/vmx.c:482
  invvpid_error+0x91/0xa0 [kvm_intel]
  Modules linked in: kvm_intel kvm 9pnet_virtio irqbypass fuse
  CPU: 6 UID: 0 PID: 326 Comm: kvm-vm Not tainted 6.15.0 torvalds#14 PREEMPT(voluntary)
  RIP: 0010:invvpid_error+0x91/0xa0 [kvm_intel]
  Call Trace:
    vmx_flush_tlb_gva+0x320/0x490 [kvm_intel]
    kvm_hv_vcpu_flush_tlb+0x24f/0x4f0 [kvm]
    kvm_arch_vcpu_ioctl_run+0x3013/0x5810 [kvm]

Hyper-V documents that invalid GVAs (those that are beyond a partition's
GVA space) are to be ignored.  While not completely clear whether this
ruling also applies to non-canonical GVAs, it is likely fine to make that
assumption, and manual testing on Azure confirms "real" Hyper-V interprets
the specification in the same way.

Skip non-canonical GVAs when processing the list of address to avoid
tripping the INVVPID failure.  Alternatively, KVM could filter out "bad"
GVAs before inserting into the FIFO, but practically speaking the only
downside of pushing validation to the final processing is that doing so
is suboptimal for the guest, and no well-behaved guest will request TLB
flushes for non-canonical addresses.

Fixes: 2609708 ("KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently")
Cc: [email protected]
Signed-off-by: Manuel Andreas <[email protected]>
Suggested-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
[sean: use plain is_noncanonical_address()]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Sep 2, 2025
Patch series "mm: remove nth_page()", v2.

As discussed recently with Linus, nth_page() is just nasty and we would
like to remove it.

To recap, the reason we currently need nth_page() within a folio is
because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the
memmap is allocated per memory section.

While buddy allocations cannot cross memory section boundaries, hugetlb
and dax folios can.

So crossing a memory section means that "page++" could do the wrong thing.
Instead, nth_page() on these problematic configs always goes from
page->pfn, to the go from (++pfn)->page, which is rather nasty.

Likely, many people have no idea when nth_page() is required and when it
might be dropped.

We refer to such problematic PFN ranges and "non-contiguous pages".  If we
only deal with "contiguous pages", there is not need for nth_page().

Besides that "obvious" folio case, we might end up using nth_page() within
CMA allocations (again, could span memory sections), and in one corner
case (kfence) when processing memblock allocations (again, could span
memory sections).

So let's handle all that, add sanity checks, and remove nth_page().

Patch #1 -> #5   : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups
Patch torvalds#6 -> torvalds#13  : disallow folios to have non-contiguous pages
Patch torvalds#14 -> torvalds#20 : remove nth_page() usage within folios
Patch torvalds#22        : disallow CMA allocations of non-contiguous pages
Patch torvalds#23 -> torvalds#33 : sanity+check + remove nth_page() usage within SG entry
Patch torvalds#34        : sanity-check + remove nth_page() usage in
                   unpin_user_page_range_dirty_lock()
Patch torvalds#35        : remove nth_page() in kfence
Patch torvalds#36        : adjust stale comment regarding nth_page
Patch torvalds#37        : mm: remove nth_page()

A lot of this is inspired from the discussion at [1] between Linus, Jason
and me, so cudos to them.


This patch (of 37):

In an ideal world, we wouldn't have to deal with SPARSEMEM without
SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is
considered too costly and consequently not supported.

However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP,
let's forbid the user to disable VMEMMAP: just like we already do for
arm64, s390 and x86.

So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without
SPARSEMEM_VMEMMAP.

This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone
for loongarch, powerpc, riscv and sparc.  All architectures only enable
SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big
downside to using the VMEMMAP (quite the contrary).

This is a preparation for not supporting

(1) folio sizes that exceed a single memory section

(2) CMA allocations of non-contiguous page ranges

in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit
possible impact as much as possible (e.g., gigantic hugetlb page
allocations suddenly fails).

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Zi Yan <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: SeongJae Park <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Alexandru Elisei <[email protected]>
Cc: Alex Dubov <[email protected]>
Cc: Alex Willamson <[email protected]>
Cc: Bart van Assche <[email protected]>
Cc: Borislav Betkov <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Brett Creeley <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter (Ampere) <[email protected]>
Cc: Damien Le Maol <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Doug Gilbert <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Inki Dae <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Jason A. Donenfeld <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonas Lahtinen <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Lars Persson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: Maxim Levitky <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Niklas Cassel <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Begunkov <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Robin Murohy <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Shameerali Kolothum Thodi <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleinxer <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yishai Hadas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
vincent-mailhol added a commit to vincent-mailhol/linux that referenced this pull request Sep 3, 2025
In November last year, I sent an RFC to introduce CAN XL [1]. That
RFC, despite positive feedback, was put on hold due to some unanswered
question concerning the PWM encoding [2].

While stuck, some small preparation work was done in parallel in [3]
by refactoring the struct can_priv and doing some trivial clean-up and
renaming. [3] received zero feedback but was eventually merged after
splitting it in smaller parts and resending it.

Finally, in July this year, we clarified the remaining mysteries about
PWM calculation, thus unlocking the series. Summer being a bit busy
because of some personal matters brings us to now.

After doing all the refactoring and adding all the CAN XL features,
the final result is roughly 30 patches, probably too much for a single
series. So I am splitting it in two:

  - preparation (this series)
  - CAN XL

And so, this series continues and finishes the preparation work done
in [3]. It contains all the refactoring needed to smoothly introduce
CAN XL. The goal is to:

  - split the function in smaller pieces: CAN XL will introduce a fair
    amount of code. And some functions which are already fairly long
    (86 lines for can_validate(), 216 lines for can_changelink())
    would grow to disproportionate sizes if the CAN XL logic were to
    be inlined in those functions.

  - repurpose the existing code to handle both CAN FD and CAN XL: a
    huge part of CAN XL simply reuses the CAN FD logic. All the
    existing CAN FD logic is made more generic to handle both CAN FD
    and XL.

In more details:

  - Patch #1 moves struct data_bittiming_params from dev.h to
    bittiming.h and patch #2 makes can_get_relative_tdco() FD agnostic
    before also moving it to bittiming.h.

  - Patch #3 adds some comments to netlink.h tagging which IFLA
    symbols are FD specific.

  - Patch #4 to torvalds#7 are refactoring can_validate() and
    can_validate_bittiming().

  - Patch torvalds#8 to torvalds#12 are refactoring can_changelink() and
    can_tdc_changelink().

  - Patch torvalds#13 and torvalds#14 are refactoring can_get_size() and
    can_tdc_get_size().

  - Patch torvalds#15 to torvalds#18 are refactoring can_fill_info() and
    can_tdc_fill_info().

  - Patch torvalds#19 makes can_calc_tdco() FD agnostic.

  - Patch torvalds#20 adds can_get_ctrlmode_str() which converts control mode
    flags into strings. This is done in preparation of patch torvalds#20.

  - Patch torvalds#21 is the final patch and improves the user experience by
    providing detailed error messages whenever invalid parameters are
    provided. All those error messages came into handy when debugging
    the upcoming CAN XL patches.

Aside from the last patch, the other changes do not impact any of the
existing functionalities.

The follow up series which introduces CAN XL is nearly completed but
will be sent only once this one is approved: one thing at a time, I do
not want to overwhelm people (including myself).

[1] https://lore.kernel.org/linux-can/[email protected]/
[2] https://lore.kernel.org/linux-can/[email protected]/
[3] https://lore.kernel.org/linux-can/[email protected]/

To: Marc Kleine-Budde <[email protected]>
To: Oliver Hartkopp <[email protected]>
Cc: Vincent Mailhol <[email protected]>
Cc: Stéphane Grosjean <[email protected]>
Cc: Robert Nawrath <[email protected]>
Cc: Minh Le <[email protected]>
Cc: Duy Nguyen <[email protected]>
Cc: [email protected]
Cc: [email protected]

Signed-off-by: Vincent Mailhol <[email protected]>

---
Changes in v2:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v1: https://lore.kernel.org/r/[email protected]



--- b4-submit-tracking ---
# This section is used internally by b4 prep for tracking purposes.
{
  "series": {
    "revision": 2,
    "change-id": "20250831-canxl-netlink-prep-9dbf8498fd9d",
    "prefixes": [],
    "prerequisites": [
      "base-commit: net-next/main"
    ],
    "history": {
      "v1": [
        "[email protected]"
      ]
    }
  }
}
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Sep 4, 2025
Patch series "mm: remove nth_page()", v2.

As discussed recently with Linus, nth_page() is just nasty and we would
like to remove it.

To recap, the reason we currently need nth_page() within a folio is
because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the
memmap is allocated per memory section.

While buddy allocations cannot cross memory section boundaries, hugetlb
and dax folios can.

So crossing a memory section means that "page++" could do the wrong thing.
Instead, nth_page() on these problematic configs always goes from
page->pfn, to the go from (++pfn)->page, which is rather nasty.

Likely, many people have no idea when nth_page() is required and when it
might be dropped.

We refer to such problematic PFN ranges and "non-contiguous pages".  If we
only deal with "contiguous pages", there is not need for nth_page().

Besides that "obvious" folio case, we might end up using nth_page() within
CMA allocations (again, could span memory sections), and in one corner
case (kfence) when processing memblock allocations (again, could span
memory sections).

So let's handle all that, add sanity checks, and remove nth_page().

Patch #1 -> #5   : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups
Patch torvalds#6 -> torvalds#13  : disallow folios to have non-contiguous pages
Patch torvalds#14 -> torvalds#20 : remove nth_page() usage within folios
Patch torvalds#22        : disallow CMA allocations of non-contiguous pages
Patch torvalds#23 -> torvalds#33 : sanity+check + remove nth_page() usage within SG entry
Patch torvalds#34        : sanity-check + remove nth_page() usage in
                   unpin_user_page_range_dirty_lock()
Patch torvalds#35        : remove nth_page() in kfence
Patch torvalds#36        : adjust stale comment regarding nth_page
Patch torvalds#37        : mm: remove nth_page()

A lot of this is inspired from the discussion at [1] between Linus, Jason
and me, so cudos to them.


This patch (of 37):

In an ideal world, we wouldn't have to deal with SPARSEMEM without
SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is
considered too costly and consequently not supported.

However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP,
let's forbid the user to disable VMEMMAP: just like we already do for
arm64, s390 and x86.

So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without
SPARSEMEM_VMEMMAP.

This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone
for loongarch, powerpc, riscv and sparc.  All architectures only enable
SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big
downside to using the VMEMMAP (quite the contrary).

This is a preparation for not supporting

(1) folio sizes that exceed a single memory section

(2) CMA allocations of non-contiguous page ranges

in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit
possible impact as much as possible (e.g., gigantic hugetlb page
allocations suddenly fails).

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Zi Yan <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: SeongJae Park <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Alexandru Elisei <[email protected]>
Cc: Alex Dubov <[email protected]>
Cc: Alex Willamson <[email protected]>
Cc: Bart van Assche <[email protected]>
Cc: Borislav Betkov <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Brett Creeley <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter (Ampere) <[email protected]>
Cc: Damien Le Maol <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Doug Gilbert <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Inki Dae <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Jason A. Donenfeld <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonas Lahtinen <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Lars Persson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: Maxim Levitky <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Niklas Cassel <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Begunkov <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Robin Murohy <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Shameerali Kolothum Thodi <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleinxer <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yishai Hadas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
ioworker0 pushed a commit to ioworker0/linux that referenced this pull request Sep 4, 2025
Patch series "mm: remove nth_page()", v2.

As discussed recently with Linus, nth_page() is just nasty and we would
like to remove it.

To recap, the reason we currently need nth_page() within a folio is
because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the
memmap is allocated per memory section.

While buddy allocations cannot cross memory section boundaries, hugetlb
and dax folios can.

So crossing a memory section means that "page++" could do the wrong thing.
Instead, nth_page() on these problematic configs always goes from
page->pfn, to the go from (++pfn)->page, which is rather nasty.

Likely, many people have no idea when nth_page() is required and when it
might be dropped.

We refer to such problematic PFN ranges and "non-contiguous pages".  If we
only deal with "contiguous pages", there is not need for nth_page().

Besides that "obvious" folio case, we might end up using nth_page() within
CMA allocations (again, could span memory sections), and in one corner
case (kfence) when processing memblock allocations (again, could span
memory sections).

So let's handle all that, add sanity checks, and remove nth_page().

Patch #1 -> #5   : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups
Patch torvalds#6 -> torvalds#13  : disallow folios to have non-contiguous pages
Patch torvalds#14 -> torvalds#20 : remove nth_page() usage within folios
Patch torvalds#22        : disallow CMA allocations of non-contiguous pages
Patch torvalds#23 -> torvalds#33 : sanity+check + remove nth_page() usage within SG entry
Patch torvalds#34        : sanity-check + remove nth_page() usage in
                   unpin_user_page_range_dirty_lock()
Patch torvalds#35        : remove nth_page() in kfence
Patch torvalds#36        : adjust stale comment regarding nth_page
Patch torvalds#37        : mm: remove nth_page()

A lot of this is inspired from the discussion at [1] between Linus, Jason
and me, so cudos to them.


This patch (of 37):

In an ideal world, we wouldn't have to deal with SPARSEMEM without
SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is
considered too costly and consequently not supported.

However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP,
let's forbid the user to disable VMEMMAP: just like we already do for
arm64, s390 and x86.

So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without
SPARSEMEM_VMEMMAP.

This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone
for loongarch, powerpc, riscv and sparc.  All architectures only enable
SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big
downside to using the VMEMMAP (quite the contrary).

This is a preparation for not supporting

(1) folio sizes that exceed a single memory section

(2) CMA allocations of non-contiguous page ranges

in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit
possible impact as much as possible (e.g., gigantic hugetlb page
allocations suddenly fails).

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Zi Yan <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: SeongJae Park <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Alexandru Elisei <[email protected]>
Cc: Alex Dubov <[email protected]>
Cc: Alex Willamson <[email protected]>
Cc: Bart van Assche <[email protected]>
Cc: Borislav Betkov <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Brett Creeley <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter (Ampere) <[email protected]>
Cc: Damien Le Maol <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Doug Gilbert <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Inki Dae <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Jason A. Donenfeld <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonas Lahtinen <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Lars Persson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: Maxim Levitky <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Niklas Cassel <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Begunkov <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Robin Murohy <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Shameerali Kolothum Thodi <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleinxer <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yishai Hadas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
ioworker0 pushed a commit to ioworker0/linux that referenced this pull request Sep 5, 2025
Patch series "mm: remove nth_page()", v2.

As discussed recently with Linus, nth_page() is just nasty and we would
like to remove it.

To recap, the reason we currently need nth_page() within a folio is
because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the
memmap is allocated per memory section.

While buddy allocations cannot cross memory section boundaries, hugetlb
and dax folios can.

So crossing a memory section means that "page++" could do the wrong thing.
Instead, nth_page() on these problematic configs always goes from
page->pfn, to the go from (++pfn)->page, which is rather nasty.

Likely, many people have no idea when nth_page() is required and when it
might be dropped.

We refer to such problematic PFN ranges and "non-contiguous pages".  If we
only deal with "contiguous pages", there is not need for nth_page().

Besides that "obvious" folio case, we might end up using nth_page() within
CMA allocations (again, could span memory sections), and in one corner
case (kfence) when processing memblock allocations (again, could span
memory sections).

So let's handle all that, add sanity checks, and remove nth_page().

Patch #1 -> #5   : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups
Patch torvalds#6 -> torvalds#13  : disallow folios to have non-contiguous pages
Patch torvalds#14 -> torvalds#20 : remove nth_page() usage within folios
Patch torvalds#22        : disallow CMA allocations of non-contiguous pages
Patch torvalds#23 -> torvalds#33 : sanity+check + remove nth_page() usage within SG entry
Patch torvalds#34        : sanity-check + remove nth_page() usage in
                   unpin_user_page_range_dirty_lock()
Patch torvalds#35        : remove nth_page() in kfence
Patch torvalds#36        : adjust stale comment regarding nth_page
Patch torvalds#37        : mm: remove nth_page()

A lot of this is inspired from the discussion at [1] between Linus, Jason
and me, so cudos to them.


This patch (of 37):

In an ideal world, we wouldn't have to deal with SPARSEMEM without
SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is
considered too costly and consequently not supported.

However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP,
let's forbid the user to disable VMEMMAP: just like we already do for
arm64, s390 and x86.

So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without
SPARSEMEM_VMEMMAP.

This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone
for loongarch, powerpc, riscv and sparc.  All architectures only enable
SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big
downside to using the VMEMMAP (quite the contrary).

This is a preparation for not supporting

(1) folio sizes that exceed a single memory section

(2) CMA allocations of non-contiguous page ranges

in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit
possible impact as much as possible (e.g., gigantic hugetlb page
allocations suddenly fails).

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Zi Yan <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: SeongJae Park <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Alexandru Elisei <[email protected]>
Cc: Alex Dubov <[email protected]>
Cc: Alex Willamson <[email protected]>
Cc: Bart van Assche <[email protected]>
Cc: Borislav Betkov <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Brett Creeley <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter (Ampere) <[email protected]>
Cc: Damien Le Maol <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Doug Gilbert <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Inki Dae <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Jason A. Donenfeld <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonas Lahtinen <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Lars Persson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: Maxim Levitky <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Niklas Cassel <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Begunkov <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Robin Murohy <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Shameerali Kolothum Thodi <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleinxer <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yishai Hadas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
vincent-mailhol added a commit to vincent-mailhol/linux that referenced this pull request Sep 7, 2025
In November last year, I sent an RFC to introduce CAN XL [1]. That
RFC, despite positive feedback, was put on hold due to some unanswered
question concerning the PWM encoding [2].

While stuck, some small preparation work was done in parallel in [3]
by refactoring the struct can_priv and doing some trivial clean-up and
renaming. [3] received zero feedback but was eventually merged after
splitting it in smaller parts and resending it.

Finally, in July this year, we clarified the remaining mysteries about
PWM calculation, thus unlocking the series. Summer being a bit busy
because of some personal matters brings us to now.

After doing all the refactoring and adding all the CAN XL features,
the final result is roughly 30 patches, probably too much for a single
series. So I am splitting it in two:

  - preparation (this series)
  - CAN XL

And so, this series continues and finishes the preparation work done
in [3]. It contains all the refactoring needed to smoothly introduce
CAN XL. The goal is to:

  - split the function in smaller pieces: CAN XL will introduce a fair
    amount of code. And some functions which are already fairly long
    (86 lines for can_validate(), 216 lines for can_changelink())
    would grow to disproportionate sizes if the CAN XL logic were to
    be inlined in those functions.

  - repurpose the existing code to handle both CAN FD and CAN XL: a
    huge part of CAN XL simply reuses the CAN FD logic. All the
    existing CAN FD logic is made more generic to handle both CAN FD
    and XL.

In more details:

  - Patch #1 moves struct data_bittiming_params from dev.h to
    bittiming.h and patch #2 makes can_get_relative_tdco() FD agnostic
    before also moving it to bittiming.h.

  - Patch #3 adds some comments to netlink.h tagging which IFLA
    symbols are FD specific.

  - Patch #4 to torvalds#6 are refactoring can_validate() and
    can_validate_bittiming().

  - Patch torvalds#7 to torvalds#11 are refactoring can_changelink() and
    can_tdc_changelink().

  - Patch torvalds#12 and torvalds#13 are refactoring can_get_size() and
    can_tdc_get_size().

  - Patch torvalds#14 to torvalds#17 are refactoring can_fill_info() and
    can_tdc_fill_info().

  - Patch torvalds#18 makes can_calc_tdco() FD agnostic.

  - Patch torvalds#19 adds can_get_ctrlmode_str() which converts control mode
    flags into strings. This is done in preparation of patch torvalds#20.

  - Patch torvalds#20 is the final patch and improves the user experience by
    providing detailed error messages whenever invalid parameters are
    provided. All those error messages came into handy when debugging
    the upcoming CAN XL patches.

Aside from the last patch, the other changes do not impact any of the
existing functionalities.

The follow up series which introduces CAN XL is nearly completed but
will be sent only once this one is approved: one thing at a time, I do
not want to overwhelm people (including myself).

[1] https://lore.kernel.org/linux-can/[email protected]/
[2] https://lore.kernel.org/linux-can/[email protected]/
[3] https://lore.kernel.org/linux-can/[email protected]/

To: Marc Kleine-Budde <[email protected]>
To: Oliver Hartkopp <[email protected]>
Cc: Vincent Mailhol <[email protected]>
Cc: Stéphane Grosjean <[email protected]>
Cc: Robert Nawrath <[email protected]>
Cc: Minh Le <[email protected]>
Cc: Duy Nguyen <[email protected]>
Cc: [email protected]
Cc: [email protected]

Signed-off-by: Vincent Mailhol <[email protected]>

---
Changes in v2:

  - Move can_validate()'s comment block to can_validate_databittiming().
    Consequently,

      [PATCH 07/21] can: netlink: remove comment in can_validate()

    from v1 is removed.

  - Change any occurrences of WARN_ON(1) into return -EOPNOTSUPP to
    suppress the three gcc warnings which were reported by the kernel
    test robot:
    Link: https://lore.kernel.org/linux-can/[email protected]/
    Link: https://lore.kernel.org/linux-can/[email protected]/
    Link: https://lore.kernel.org/linux-can/[email protected]/

  - Link to v1: https://lore.kernel.org/r/[email protected]

--- b4-submit-tracking ---
{
  "series": {
    "revision": 2,
    "change-id": "20250831-canxl-netlink-prep-9dbf8498fd9d",
    "prefixes": [],
    "prerequisites": [
      "base-commit: net-next/main"
    ],
    "history": {
      "v1": [
        "[email protected]"
      ]
    }
  }
}
krzk added a commit to krzk/linux that referenced this pull request Sep 8, 2025
Hi,

Continuing changelog from "drm/msm: Add support for SM8750" where this
was part of.

Changes in v7:
- Drop all applied patches.
- Remaining patches - no changes
- Patch #3: I did not remove ndelay(250) as discussed with Dmitry,
  because:
  1. Indeed the HPG does not mention any delay needed, unlike PHY 10 nm.
  2. However downstream source code for PHY 3+4+5 nm has exactly these
     delays. This could be copy-paste or could be intentional workaround
     for some issue about which I have no clue. Timings are tricky and
     I don't think I should be introducing changes without actually
     knowing them.
- Add Rb tags
- Link to v6: https://lore.kernel.org/r/[email protected]


Changes in v6:
=============
- Add ack/rb tags
- Dropped dispcc-sm8750 patch, because I sent it separately.
- Several changes due to rebasing on updagted Dmitry's "dpu drop
  features" rework.
- Drop applied patches.
- New patch: drm/msm/dpu: Consistently use u32 instead of uint32_t
- Fix dimmed display issue (thanks Abel Vesa) in patch "Implement 10-bit
  color alpha for v12.0 DPU".
- Implement remaining comments from Dmitry like code style (blank line),
  see also individual changelogs.
- Link to v5: https://lore.kernel.org/r/[email protected]

Changes in v5:
=============
- Add ack/rb tags
- New patches:
  torvalds#6: clk: qcom: dispcc-sm8750: Fix setting rate byte and pixel clocks
  torvalds#14: drm/msm/dsi/phy: Toggle back buffer resync after preparing PLL
  torvalds#15: drm/msm/dsi/phy: Define PHY_CMN_CTRL_0 bitfields
  torvalds#16: drm/msm/dsi/phy: Fix reading zero as PLL rates when unprepared
  torvalds#17: drm/msm/dsi/phy: Fix missing initial VCO rate

- Patch drm/msm/dsi: Add support for SM8750:
  - Only reparent byte and pixel clocks while PLLs is prepared. Setting
    rate works fine with earlier DISP CC patch for enabling their parents
    during rate change.

- Link to v4: https://lore.kernel.org/r/[email protected]

Changes in v4
=============
- Add ack/rb tags
- Implement Dmitry's feedback (lower-case hex, indentation, pass
  mdss_ver instead of ctl), patches:
  drm/msm/dpu: Implement 10-bit color alpha for v12.0 DPU
  drm/msm/dpu: Implement CTL_PIPE_ACTIVE for v12.0 DPU

- Rebase on latest next
- Drop applied two first patches
- Link to v3: https://lore.kernel.org/r/[email protected]

Changes in v3
=============
- Add ack/rb tags
- #5: dt-bindings: display/msm: dp-controller: Add SM8750:
  Extend commit msg

- torvalds#7: dt-bindings: display/msm: qcom,sm8750-mdss: Add SM8750:
  - Properly described interconnects
  - Use only one compatible and contains for the sub-blocks (Rob)

- torvalds#12: drm/msm/dsi: Add support for SM8750:
  Drop 'struct msm_dsi_config sm8750_dsi_cfg' and use sm8650 one.
- drm/msm/dpu: Implement new v12.0 DPU differences
  Split into several patches
- Link to v2: https://lore.kernel.org/r/[email protected]

Changes in v2
=============
- Implement LM crossbar, 10-bit alpha and active layer changes:
  New patch: drm/msm/dpu: Implement new v12.0 DPU differences
- New patch: drm/msm/dpu: Add missing "fetch" name to set_active_pipes()
- Add CDM
- Split some DPU patch pieces into separate patches:
  drm/msm/dpu: Drop useless comments
  drm/msm/dpu: Add LM_7, DSC_[67], PP_[67] and MERGE_3D_5
  drm/msm/dpu: Add handling of LM_6 and LM_7 bits in pending flush mask
- Split DSI and DSI PHY patches
- Mention CLK_OPS_PARENT_ENABLE in DSI commit
- Mention DSI PHY PLL work:
  https://patchwork.freedesktop.org/patch/542000/?series=119177&rev=1
- DPU: Drop SSPP_VIG4 comments
- DPU: Add CDM
- Link to v1: https://lore.kernel.org/r/[email protected]

Best regards,
Krzysztof

To: Abhinav Kumar <[email protected]>
To: Sean Paul <[email protected]>
To: Marijn Suijten <[email protected]>
To: David Airlie <[email protected]>
To: Simona Vetter <[email protected]>
To: Maarten Lankhorst <[email protected]>
To: Maxime Ripard <[email protected]>
To: Thomas Zimmermann <[email protected]>
To: Rob Herring <[email protected]>
To: Krzysztof Kozlowski <[email protected]>
To: Conor Dooley <[email protected]>
To: Krishna Manikandan <[email protected]>
To: Jonathan Marek <[email protected]>
To: Kuogee Hsieh <[email protected]>
To: Neil Armstrong <[email protected]>
To: Dmitry Baryshkov <[email protected]>
To: Rob Clark <[email protected]>
To: Bjorn Andersson <[email protected]>
To: Michael Turquette <[email protected]>
To: Stephen Boyd <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Krzysztof Kozlowski <[email protected]>
Cc: Srini Kandagatla <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: [email protected]
Cc: Abel Vesa <[email protected]>

--- b4-submit-tracking ---
# This section is used internally by b4 prep for tracking purposes.
{
  "series": {
    "revision": 7,
    "change-id": "20250109-b4-sm8750-display-6ea537754af1",
    "prefixes": [],
    "history": {
      "v1": [
        "[email protected]"
      ],
      "v2": [
        "[email protected]"
      ],
      "v3": [
        "[email protected]"
      ],
      "v4": [
        "[email protected]"
      ],
      "v5": [
        "[email protected]"
      ],
      "v6": [
        "[email protected]"
      ]
    },
    "prerequisites": [
      "change-id: 20241213-dpu-drop-features-7603dc3ee189:v5",
      "base-commit: next-20250610"
    ]
  }
}
intel-lab-lkp pushed a commit to intel-lab-lkp/linux that referenced this pull request Sep 9, 2025
Patch series "mm: remove nth_page()", v2.

As discussed recently with Linus, nth_page() is just nasty and we would
like to remove it.

To recap, the reason we currently need nth_page() within a folio is
because on some kernel configs (SPARSEMEM without SPARSEMEM_VMEMMAP), the
memmap is allocated per memory section.

While buddy allocations cannot cross memory section boundaries, hugetlb
and dax folios can.

So crossing a memory section means that "page++" could do the wrong thing.
Instead, nth_page() on these problematic configs always goes from
page->pfn, to the go from (++pfn)->page, which is rather nasty.

Likely, many people have no idea when nth_page() is required and when it
might be dropped.

We refer to such problematic PFN ranges and "non-contiguous pages".  If we
only deal with "contiguous pages", there is not need for nth_page().

Besides that "obvious" folio case, we might end up using nth_page() within
CMA allocations (again, could span memory sections), and in one corner
case (kfence) when processing memblock allocations (again, could span
memory sections).

So let's handle all that, add sanity checks, and remove nth_page().

Patch #1 -> #5   : stop making SPARSEMEM_VMEMMAP user-selectable + cleanups
Patch torvalds#6 -> torvalds#13  : disallow folios to have non-contiguous pages
Patch torvalds#14 -> torvalds#20 : remove nth_page() usage within folios
Patch torvalds#22        : disallow CMA allocations of non-contiguous pages
Patch torvalds#23 -> torvalds#33 : sanity+check + remove nth_page() usage within SG entry
Patch torvalds#34        : sanity-check + remove nth_page() usage in
                   unpin_user_page_range_dirty_lock()
Patch torvalds#35        : remove nth_page() in kfence
Patch torvalds#36        : adjust stale comment regarding nth_page
Patch torvalds#37        : mm: remove nth_page()

A lot of this is inspired from the discussion at [1] between Linus, Jason
and me, so cudos to them.


This patch (of 37):

In an ideal world, we wouldn't have to deal with SPARSEMEM without
SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is
considered too costly and consequently not supported.

However, if an architecture does support SPARSEMEM with SPARSEMEM_VMEMMAP,
let's forbid the user to disable VMEMMAP: just like we already do for
arm64, s390 and x86.

So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without
SPARSEMEM_VMEMMAP.

This implies that the option to not use SPARSEMEM_VMEMMAP will now be gone
for loongarch, powerpc, riscv and sparc.  All architectures only enable
SPARSEMEM_VMEMMAP with 64bit support, so there should not really be a big
downside to using the VMEMMAP (quite the contrary).

This is a preparation for not supporting

(1) folio sizes that exceed a single memory section

(2) CMA allocations of non-contiguous page ranges

in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we want to limit
possible impact as much as possible (e.g., gigantic hugetlb page
allocations suddenly fails).

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/CAHk-=wiCYfNp4AJLBORU-c7ZyRBUp66W2-Et6cdQ4REx-GyQ_A@mail.gmail.com/T/#u [1]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Zi Yan <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Acked-by: SeongJae Park <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Alexandru Elisei <[email protected]>
Cc: Alex Dubov <[email protected]>
Cc: Alex Willamson <[email protected]>
Cc: Bart van Assche <[email protected]>
Cc: Borislav Betkov <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Brett Creeley <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter (Ampere) <[email protected]>
Cc: Damien Le Maol <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Doug Gilbert <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Inki Dae <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Jason A. Donenfeld <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jonas Lahtinen <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Lars Persson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: Maxim Levitky <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Niklas Cassel <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Begunkov <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Robin Murohy <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Shameerali Kolothum Thodi <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleinxer <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yishai Hadas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
hbirth pushed a commit to hbirth/linux that referenced this pull request Sep 9, 2025
…locksize

Increase dlm locksize and change DLM lock request and return to start and end values, rather than offset and length as a preparation for byte range locks
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