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Pull request for series with
subject: bpf: don't check against device MTU in __bpf_skb_max_len
version: 1
url: https://patchwork.ozlabs.org/project/netdev/list/?series=199469

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kernel-patches-bot and others added 2 commits September 9, 2020 13:11
… uses

__bpf_skb_max_len() as the max-length. This function limit size against the
current net_device MTU (skb->dev->mtu).

Often packets gets redirected to another net_device, that can have a larger
MTU, and this is the MTU that should count. The MTU limiting at this stage
seems wrong and redundant as the netstack will handle MTU checking
elsewhere.

Redirecting into sockmap by sk_skb programs already skip this MTU check.
Keep what commit 0c6bc6e ("bpf: fix sk_skb programs without skb->dev
assigned") did, and limit the max_len to SKB_MAX_ALLOC.

Also notice that the max_len MTU check is already skipped for GRO SKBs
(skb_is_gso), in both bpf_skb_adjust_room() and bpf_skb_change_head().
Thus, it is clearly safe to remove this check.

Signed-off-by: Jesper Dangaard Brouer <[email protected]>
---
 net/core/filter.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
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At least one diff in series https://patchwork.ozlabs.org/project/netdev/list/?series=199469 expired. Closing PR.

@kernel-patches-bot kernel-patches-bot deleted the series/199469 branch September 15, 2020 17:49
kernel-patches-bot pushed a commit that referenced this pull request Sep 16, 2020
I got the following lockdep splat while testing:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc7-00172-g021118712e59 #932 Not tainted
  ------------------------------------------------------
  btrfs/229626 is trying to acquire lock:
  ffffffff828513f0 (cpu_hotplug_lock){++++}-{0:0}, at: alloc_workqueue+0x378/0x450

  but task is already holding lock:
  ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #7 (&fs_info->scrub_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_scrub_dev+0x11c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #6 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_run_dev_stats+0x49/0x480
	 commit_cowonly_roots+0xb5/0x2a0
	 btrfs_commit_transaction+0x516/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #5 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_commit_transaction+0x4bb/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #4 (&fs_info->reloc_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_record_root_in_trans+0x43/0x70
	 start_transaction+0xd1/0x5d0
	 btrfs_dirty_inode+0x42/0xd0
	 touch_atime+0xa1/0xd0
	 btrfs_file_mmap+0x3f/0x60
	 mmap_region+0x3a4/0x640
	 do_mmap+0x376/0x580
	 vm_mmap_pgoff+0xd5/0x120
	 ksys_mmap_pgoff+0x193/0x230
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #3 (&mm->mmap_lock#2){++++}-{3:3}:
	 __might_fault+0x68/0x90
	 _copy_to_user+0x1e/0x80
	 perf_read+0x141/0x2c0
	 vfs_read+0xad/0x1b0
	 ksys_read+0x5f/0xe0
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #2 (&cpuctx_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x88/0x150
	 perf_event_init+0x1db/0x20b
	 start_kernel+0x3ae/0x53c
	 secondary_startup_64+0xa4/0xb0

  -> #1 (pmus_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x4f/0x150
	 cpuhp_invoke_callback+0xb1/0x900
	 _cpu_up.constprop.26+0x9f/0x130
	 cpu_up+0x7b/0xc0
	 bringup_nonboot_cpus+0x4f/0x60
	 smp_init+0x26/0x71
	 kernel_init_freeable+0x110/0x258
	 kernel_init+0xa/0x103
	 ret_from_fork+0x1f/0x30

  -> #0 (cpu_hotplug_lock){++++}-{0:0}:
	 __lock_acquire+0x1272/0x2310
	 lock_acquire+0x9e/0x360
	 cpus_read_lock+0x39/0xb0
	 alloc_workqueue+0x378/0x450
	 __btrfs_alloc_workqueue+0x15d/0x200
	 btrfs_alloc_workqueue+0x51/0x160
	 scrub_workers_get+0x5a/0x170
	 btrfs_scrub_dev+0x18c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    cpu_hotplug_lock --> &fs_devs->device_list_mutex --> &fs_info->scrub_lock

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&fs_info->scrub_lock);
				 lock(&fs_devs->device_list_mutex);
				 lock(&fs_info->scrub_lock);
    lock(cpu_hotplug_lock);

   *** DEADLOCK ***

  2 locks held by btrfs/229626:
   #0: ffff88bfe8bb86e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_scrub_dev+0xbd/0x630
   #1: ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  stack backtrace:
  CPU: 15 PID: 229626 Comm: btrfs Kdump: loaded Not tainted 5.8.0-rc7-00172-g021118712e59 #932
  Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
  Call Trace:
   dump_stack+0x78/0xa0
   check_noncircular+0x165/0x180
   __lock_acquire+0x1272/0x2310
   lock_acquire+0x9e/0x360
   ? alloc_workqueue+0x378/0x450
   cpus_read_lock+0x39/0xb0
   ? alloc_workqueue+0x378/0x450
   alloc_workqueue+0x378/0x450
   ? rcu_read_lock_sched_held+0x52/0x80
   __btrfs_alloc_workqueue+0x15d/0x200
   btrfs_alloc_workqueue+0x51/0x160
   scrub_workers_get+0x5a/0x170
   btrfs_scrub_dev+0x18c/0x630
   ? start_transaction+0xd1/0x5d0
   btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
   btrfs_ioctl+0x2799/0x30a0
   ? do_sigaction+0x102/0x250
   ? lockdep_hardirqs_on_prepare+0xca/0x160
   ? _raw_spin_unlock_irq+0x24/0x30
   ? trace_hardirqs_on+0x1c/0xe0
   ? _raw_spin_unlock_irq+0x24/0x30
   ? do_sigaction+0x102/0x250
   ? ksys_ioctl+0x83/0xc0
   ksys_ioctl+0x83/0xc0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x50/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This happens because we're allocating the scrub workqueues under the
scrub and device list mutex, which brings in a whole host of other
dependencies.

Because the work queue allocation is done with GFP_KERNEL, it can
trigger reclaim, which can lead to a transaction commit, which in turns
needs the device_list_mutex, it can lead to a deadlock. A different
problem for which this fix is a solution.

Fix this by moving the actual allocation outside of the
scrub lock, and then only take the lock once we're ready to actually
assign them to the fs_info.  We'll now have to cleanup the workqueues in
a few more places, so I've added a helper to do the refcount dance to
safely free the workqueues.

CC: [email protected] # 5.4+
Reviewed-by: Filipe Manana <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 16, 2020
…s metrics" test

Linux 5.9 introduced perf test case "Parse and process metrics" and
on s390 this test case always dumps core:

  [root@t35lp67 perf]# ./perf test -vvvv -F 67
  67: Parse and process metrics                             :
  --- start ---
  metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC
  parsing metric: inst_retired.any / cpu_clk_unhalted.thread
  Segmentation fault (core dumped)
  [root@t35lp67 perf]#

I debugged this core dump and gdb shows this call chain:

  (gdb) where
   #0  0x000003ffabc3192a in __strnlen_c_1 () from /lib64/libc.so.6
   #1  0x000003ffabc293de in strcasestr () from /lib64/libc.so.6
   #2  0x0000000001102ba2 in match_metric(list=0x1e6ea20 "inst_retired.any",
            n=<optimized out>)
       at util/metricgroup.c:368
   #3  find_metric (map=<optimized out>, map=<optimized out>,
           metric=0x1e6ea20 "inst_retired.any")
      at util/metricgroup.c:765
   #4  __resolve_metric (ids=0x0, map=<optimized out>, metric_list=0x0,
           metric_no_group=<optimized out>, m=<optimized out>)
      at util/metricgroup.c:844
   #5  resolve_metric (ids=0x0, map=0x0, metric_list=0x0,
          metric_no_group=<optimized out>)
      at util/metricgroup.c:881
   #6  metricgroup__add_metric (metric=<optimized out>,
        metric_no_group=metric_no_group@entry=false, events=<optimized out>,
        events@entry=0x3ffd84fb878, metric_list=0x0,
        metric_list@entry=0x3ffd84fb868, map=0x0)
      at util/metricgroup.c:943
   #7  0x00000000011034ae in metricgroup__add_metric_list (map=0x13f9828 <map>,
        metric_list=0x3ffd84fb868, events=0x3ffd84fb878,
        metric_no_group=<optimized out>, list=<optimized out>)
      at util/metricgroup.c:988
   #8  parse_groups (perf_evlist=perf_evlist@entry=0x1e70260,
          str=str@entry=0x12f34b2 "IPC", metric_no_group=<optimized out>,
          metric_no_merge=<optimized out>,
          fake_pmu=fake_pmu@entry=0x1462f18 <perf_pmu.fake>,
          metric_events=0x3ffd84fba58, map=0x1)
      at util/metricgroup.c:1040
   #9  0x0000000001103eb2 in metricgroup__parse_groups_test(
  	evlist=evlist@entry=0x1e70260, map=map@entry=0x13f9828 <map>,
  	str=str@entry=0x12f34b2 "IPC",
  	metric_no_group=metric_no_group@entry=false,
  	metric_no_merge=metric_no_merge@entry=false,
  	metric_events=0x3ffd84fba58)
      at util/metricgroup.c:1082
   #10 0x00000000010c84d8 in __compute_metric (ratio2=0x0, name2=0x0,
          ratio1=<synthetic pointer>, name1=0x12f34b2 "IPC",
  	vals=0x3ffd84fbad8, name=0x12f34b2 "IPC")
      at tests/parse-metric.c:159
   #11 compute_metric (ratio=<synthetic pointer>, vals=0x3ffd84fbad8,
  	name=0x12f34b2 "IPC")
      at tests/parse-metric.c:189
   #12 test_ipc () at tests/parse-metric.c:208
.....
..... omitted many more lines

This test case was added with
commit 218ca91 ("perf tests: Add parse metric test for frontend metric").

When I compile with make DEBUG=y it works fine and I do not get a core dump.

It turned out that the above listed function call chain worked on a struct
pmu_event array which requires a trailing element with zeroes which was
missing. The marco map_for_each_event() loops over that array tests for members
metric_expr/metric_name/metric_group being non-NULL. Adding this element fixes
the issue.

Output after:

  [root@t35lp46 perf]# ./perf test 67
  67: Parse and process metrics                             : Ok
  [root@t35lp46 perf]#

Committer notes:

As Ian remarks, this is not s390 specific:

<quote Ian>
  This also shows up with address sanitizer on all architectures
  (perhaps change the patch title) and perhaps add a "Fixes: <commit>"
  tag.

  =================================================================
  ==4718==ERROR: AddressSanitizer: global-buffer-overflow on address
  0x55c93b4d59e8 at pc 0x55c93a1541e2 bp 0x7ffd24327c60 sp
  0x7ffd24327c58
  READ of size 8 at 0x55c93b4d59e8 thread T0
      #0 0x55c93a1541e1 in find_metric tools/perf/util/metricgroup.c:764:2
      #1 0x55c93a153e6c in __resolve_metric tools/perf/util/metricgroup.c:844:9
      #2 0x55c93a152f18 in resolve_metric tools/perf/util/metricgroup.c:881:9
      #3 0x55c93a1528db in metricgroup__add_metric
  tools/perf/util/metricgroup.c:943:9
      #4 0x55c93a151996 in metricgroup__add_metric_list
  tools/perf/util/metricgroup.c:988:9
      #5 0x55c93a1511b9 in parse_groups tools/perf/util/metricgroup.c:1040:8
      #6 0x55c93a1513e1 in metricgroup__parse_groups_test
  tools/perf/util/metricgroup.c:1082:9
      #7 0x55c93a0108ae in __compute_metric tools/perf/tests/parse-metric.c:159:8
      #8 0x55c93a010744 in compute_metric tools/perf/tests/parse-metric.c:189:9
      #9 0x55c93a00f5ee in test_ipc tools/perf/tests/parse-metric.c:208:2
      #10 0x55c93a00f1e8 in test__parse_metric
  tools/perf/tests/parse-metric.c:345:2
      #11 0x55c939fd7202 in run_test tools/perf/tests/builtin-test.c:410:9
      #12 0x55c939fd6736 in test_and_print tools/perf/tests/builtin-test.c:440:9
      #13 0x55c939fd58c3 in __cmd_test tools/perf/tests/builtin-test.c:661:4
      #14 0x55c939fd4e02 in cmd_test tools/perf/tests/builtin-test.c:807:9
      #15 0x55c939e4763d in run_builtin tools/perf/perf.c:313:11
      #16 0x55c939e46475 in handle_internal_command tools/perf/perf.c:365:8
      #17 0x55c939e4737e in run_argv tools/perf/perf.c:409:2
      #18 0x55c939e45f7e in main tools/perf/perf.c:539:3

  0x55c93b4d59e8 is located 0 bytes to the right of global variable
  'pme_test' defined in 'tools/perf/tests/parse-metric.c:17:25'
  (0x55c93b4d54a0) of size 1352
  SUMMARY: AddressSanitizer: global-buffer-overflow
  tools/perf/util/metricgroup.c:764:2 in find_metric
  Shadow bytes around the buggy address:
    0x0ab9a7692ae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692af0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  =>0x0ab9a7692b30: 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 f9
    0x0ab9a7692b40: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b50: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b60: f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
    0x0ab9a7692b70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:	   fa
    Freed heap region:	   fd
    Stack left redzone:	   f1
    Stack mid redzone:	   f2
    Stack right redzone:     f3
    Stack after return:	   f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:	   f6
    Poisoned by user:        f7
    Container overflow:	   fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
    Shadow gap:              cc
</quote>

I'm also adding the missing "Fixes" tag and setting just .name to NULL,
as doing it that way is more compact (the compiler will zero out
everything else) and the table iterators look for .name being NULL as
the sentinel marking the end of the table.

Fixes: 0a507af ("perf tests: Add parse metric test for ipc metric")
Signed-off-by: Thomas Richter <[email protected]>
Reviewed-by: Sumanth Korikkar <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
Krzysztof Kozlowski says:

====================
nfc: s3fwrn5: Few cleanups

Changes since v2:
1. Fix dtschema ID after rename (patch 1/8).
2. Apply patch 9/9 (defconfig change).

Changes since v1:
1. Rename dtschema file and add additionalProperties:false, as Rob
   suggested,
2. Add Marek's tested-by,
3. New patches: #4, #5, #6, #7 and #9.
====================

Signed-off-by: David S. Miller <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
When compiling with DEBUG=1 on Fedora 32 I'm getting crash for 'perf
test signal':

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000c68548 in __test_function ()
  (gdb) bt
  #0  0x0000000000c68548 in __test_function ()
  #1  0x00000000004d62e9 in test_function () at tests/bp_signal.c:61
  #2  0x00000000004d689a in test__bp_signal (test=0xa8e280 <generic_ ...
  #3  0x00000000004b7d49 in run_test (test=0xa8e280 <generic_tests+1 ...
  #4  0x00000000004b7e7f in test_and_print (t=0xa8e280 <generic_test ...
  #5  0x00000000004b8927 in __cmd_test (argc=1, argv=0x7fffffffdce0, ...
  ...

It's caused by the symbol __test_function being in the ".bss" section:

  $ readelf -a ./perf | less
    [Nr] Name              Type             Address           Offset
         Size              EntSize          Flags  Link  Info  Align
    ...
    [28] .bss              NOBITS           0000000000c356a0  008346a0
         00000000000511f8  0000000000000000  WA       0     0     32

  $ nm perf | grep __test_function
  0000000000c68548 B __test_function

I guess most of the time we're just lucky the inline asm ended up in the
".text" section, so making it specific explicit with push and pop
section clauses.

  $ readelf -a ./perf | less
    [Nr] Name              Type             Address           Offset
         Size              EntSize          Flags  Link  Info  Align
    ...
    [13] .text             PROGBITS         0000000000431240  00031240
         0000000000306faa  0000000000000000  AX       0     0     16

  $ nm perf | grep __test_function
  00000000004d62c8 T __test_function

Committer testing:

  $ readelf -wi ~/bin/perf | grep producer -m1
    <c>   DW_AT_producer    : (indirect string, offset: 0x254a): GNU C99 10.2.1 20200723 (Red Hat 10.2.1-1) -mtune=generic -march=x86-64 -ggdb3 -std=gnu99 -fno-omit-frame-pointer -funwind-tables -fstack-protector-all
                                                                                                                                         ^^^^^
                                                                                                                                         ^^^^^
                                                                                                                                         ^^^^^
  $

Before:

  $ perf test signal
  20: Breakpoint overflow signal handler                    : FAILED!
  $

After:

  $ perf test signal
  20: Breakpoint overflow signal handler                    : Ok
  $

Fixes: 8fd34e1 ("perf test: Improve bp_signal")
Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
Ido Schimmel says:

====================
mlxsw: Derive SBIB from maximum port speed & MTU

Petr says:

Internal buffer is a part of port headroom used for packets that are
mirrored due to triggers that the Spectrum ASIC considers "egress". Besides
ACL mirroring on port egresss this includes also packets mirrored due to
ECN marking.

This patchset changes the way the internal mirroring buffer is reserved.
Currently the buffer reflects port MTU and speed accurately. In the future,
mlxsw should support dcbnl_setbuffer hook to allow the users to set buffer
sizes by hand. In that case, there might not be enough space for growth of
the internal mirroring buffer due to MTU and speed changes. While vetoing
MTU changes would be merely confusing, port speed changes cannot be vetoed,
and such change would simply lead to issues in packet mirroring.

For these reasons, with these patches the internal mirroring buffer is
derived from maximum MTU and maximum speed achievable on the port.

Patches #1 and #2 introduce a new callback to determine the maximum speed a
given port can achieve.

With patches #3 and #4, the information about, respectively, maximum MTU
and maximum port speed, is kept in struct mlxsw_sp_port.

In patch #5, maximum MTU and maximum speed are used to determine the size
of the internal buffer. MTU update and speed update hooks are dropped,
because they are no longer necessary.
====================

Signed-off-by: David S. Miller <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
The aliases were never released causing the following leaks:

  Indirect leak of 1224 byte(s) in 9 object(s) allocated from:
    #0 0x7feefb830628 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x107628)
    #1 0x56332c8f1b62 in __perf_pmu__new_alias util/pmu.c:322
    #2 0x56332c8f401f in pmu_add_cpu_aliases_map util/pmu.c:778
    #3 0x56332c792ce9 in __test__pmu_event_aliases tests/pmu-events.c:295
    #4 0x56332c792ce9 in test_aliases tests/pmu-events.c:367
    #5 0x56332c76a09b in run_test tests/builtin-test.c:410
    #6 0x56332c76a09b in test_and_print tests/builtin-test.c:440
    #7 0x56332c76ce69 in __cmd_test tests/builtin-test.c:695
    #8 0x56332c76ce69 in cmd_test tests/builtin-test.c:807
    #9 0x56332c7d2214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #10 0x56332c6701a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #11 0x56332c6701a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #12 0x56332c6701a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #13 0x7feefb359cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 956a783 ("perf test: Test pmu-events aliases")
Signed-off-by: Namhyung Kim <[email protected]>
Reviewed-by: John Garry <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
The evsel->unit borrows a pointer of pmu event or alias instead of
owns a string.  But tool event (duration_time) passes a result of
strdup() caused a leak.

It was found by ASAN during metric test:

  Direct leak of 210 byte(s) in 70 object(s) allocated from:
    #0 0x7fe366fca0b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
    #1 0x559fbbcc6ea3 in add_event_tool util/parse-events.c:414
    #2 0x559fbbcc6ea3 in parse_events_add_tool util/parse-events.c:1414
    #3 0x559fbbd8474d in parse_events_parse util/parse-events.y:439
    #4 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096
    #5 0x559fbbcc95da in __parse_events util/parse-events.c:2141
    #6 0x559fbbc28555 in check_parse_id tests/pmu-events.c:406
    #7 0x559fbbc28555 in check_parse_id tests/pmu-events.c:393
    #8 0x559fbbc28555 in check_parse_cpu tests/pmu-events.c:415
    #9 0x559fbbc28555 in test_parsing tests/pmu-events.c:498
    #10 0x559fbbc0109b in run_test tests/builtin-test.c:410
    #11 0x559fbbc0109b in test_and_print tests/builtin-test.c:440
    #12 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695
    #13 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807
    #14 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #15 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #16 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #17 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #18 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: f0fbb11 ("perf stat: Implement duration_time as a proper event")
Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
The test_generic_metric() missed to release entries in the pctx.  Asan
reported following leak (and more):

  Direct leak of 128 byte(s) in 1 object(s) allocated from:
    #0 0x7f4c9396980e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x55f7e748cc14 in hashmap_grow (/home/namhyung/project/linux/tools/perf/perf+0x90cc14)
    #2 0x55f7e748d497 in hashmap__insert (/home/namhyung/project/linux/tools/perf/perf+0x90d497)
    #3 0x55f7e7341667 in hashmap__set /home/namhyung/project/linux/tools/perf/util/hashmap.h:111
    #4 0x55f7e7341667 in expr__add_ref util/expr.c:120
    #5 0x55f7e7292436 in prepare_metric util/stat-shadow.c:783
    #6 0x55f7e729556d in test_generic_metric util/stat-shadow.c:858
    #7 0x55f7e712390b in compute_single tests/parse-metric.c:128
    #8 0x55f7e712390b in __compute_metric tests/parse-metric.c:180
    #9 0x55f7e712446d in compute_metric tests/parse-metric.c:196
    #10 0x55f7e712446d in test_dcache_l2 tests/parse-metric.c:295
    #11 0x55f7e712446d in test__parse_metric tests/parse-metric.c:355
    #12 0x55f7e70be09b in run_test tests/builtin-test.c:410
    #13 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
    #14 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
    #15 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
    #16 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #17 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #18 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #19 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #20 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 6d432c4 ("perf tools: Add test_generic_metric function")
Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
The metricgroup__add_metric() can find multiple match for a metric group
and it's possible to fail.  Also it can fail in the middle like in
resolve_metric() even for single metric.

In those cases, the intermediate list and ids will be leaked like:

  Direct leak of 3 byte(s) in 1 object(s) allocated from:
    #0 0x7f4c938f40b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
    #1 0x55f7e71c1bef in __add_metric util/metricgroup.c:683
    #2 0x55f7e71c31d0 in add_metric util/metricgroup.c:906
    #3 0x55f7e71c3844 in metricgroup__add_metric util/metricgroup.c:940
    #4 0x55f7e71c488d in metricgroup__add_metric_list util/metricgroup.c:993
    #5 0x55f7e71c488d in parse_groups util/metricgroup.c:1045
    #6 0x55f7e71c60a4 in metricgroup__parse_groups_test util/metricgroup.c:1087
    #7 0x55f7e71235ae in __compute_metric tests/parse-metric.c:164
    #8 0x55f7e7124650 in compute_metric tests/parse-metric.c:196
    #9 0x55f7e7124650 in test_recursion_fail tests/parse-metric.c:318
    #10 0x55f7e7124650 in test__parse_metric tests/parse-metric.c:356
    #11 0x55f7e70be09b in run_test tests/builtin-test.c:410
    #12 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
    #13 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
    #14 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
    #15 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #16 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #17 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #18 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #19 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 83de0b7 ("perf metric: Collect referenced metrics in struct metric_ref_node")
Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
The following leaks were detected by ASAN:

  Indirect leak of 360 byte(s) in 9 object(s) allocated from:
    #0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333
    #2 0x560578f752fc in perf_pmu_parse util/pmu.y:59
    #3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73
    #4 0x560578e07045 in test__pmu tests/pmu.c:155
    #5 0x560578de109b in run_test tests/builtin-test.c:410
    #6 0x560578de109b in test_and_print tests/builtin-test.c:440
    #7 0x560578de401a in __cmd_test tests/builtin-test.c:661
    #8 0x560578de401a in cmd_test tests/builtin-test.c:807
    #9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: cff7f95 ("perf tests: Move pmu tests into separate object")
Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
kernel-patches-bot pushed a commit that referenced this pull request Oct 2, 2020
Ido Schimmel says:

====================
mlxsw: Expose transceiver overheat counter

Amit says:

An overheated transceiver can be the root cause of various network
problems such as link flapping. Counting the number of times a
transceiver's temperature was higher than its configured threshold can
therefore help in debugging such issues.

This patch set exposes a transceiver overheat counter via ethtool. This
is achieved by configuring the Spectrum ASIC to generate events whenever
a transceiver is overheated. The temperature thresholds are queried from
the transceiver (if available) and set to the default otherwise.

Example:

...
transceiver_overheat: 2

Patch set overview:

Patches #1-#3 add required device registers
Patches #4-#5 add required infrastructure in mlxsw to configure and
count overheat events
Patches #6-#9 gradually add support for the transceiver overheat counter
Patch #10 exposes the transceiver overheat counter via ethtool
====================

Signed-off-by: David S. Miller <[email protected]>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 12, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

This isn't a problem in itself, the problem is that the list can be
very long, so it may lock a LOT of mutexes, but lockdep engine can only
deal with MAX_LOCK_DEPTH held locks:

unshare -n bash -c 'for i in $(seq 1 100);do  ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ffff8880010b7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350
 kernel-patches#1: ffffc900004a7d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350
 kernel-patches#2: ffffffff8bc6fbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x7f0
 kernel-patches#3: ffffffff8bc8daa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x7e/0x2e0
 kernel-patches#4: ffff88800b5e9cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1056/0x1b00
[..]

Work around this limitation by chopping the list into smaller chunks
and process them individually for LOCKDEP enabled kernels.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 12, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

This isn't a problem in itself, the problem is that the list can be
very long, so it may lock a LOT of mutexes, but lockdep engine can only
deal with MAX_LOCK_DEPTH held locks:

unshare -n bash -c 'for i in $(seq 1 100);do  ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ffff8880010b7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350
 kernel-patches#1: ffffc900004a7d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350
 kernel-patches#2: ffffffff8bc6fbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x7f0
 kernel-patches#3: ffffffff8bc8daa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x7e/0x2e0
 kernel-patches#4: ffff88800b5e9cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1056/0x1b00
[..]

Work around this limitation by chopping the list into smaller chunks
and process them individually for LOCKDEP enabled kernels.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 12, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

This isn't a problem in itself, the problem is that the list can be
very long, so it may lock a LOT of mutexes, but lockdep engine can only
deal with MAX_LOCK_DEPTH held locks:

unshare -n bash -c 'for i in $(seq 1 100);do  ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ffff8880010b7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350
 kernel-patches#1: ffffc900004a7d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350
 kernel-patches#2: ffffffff8bc6fbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x7f0
 kernel-patches#3: ffffffff8bc8daa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x7e/0x2e0
 kernel-patches#4: ffff88800b5e9cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1056/0x1b00
[..]

Work around this limitation by chopping the list into smaller chunks
and process them individually for LOCKDEP enabled kernels.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 12, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

This isn't a problem in itself, the problem is that the list can be
very long, so it may lock a LOT of mutexes, but lockdep engine can only
deal with MAX_LOCK_DEPTH held locks:

unshare -n bash -c 'for i in $(seq 1 100);do  ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ffff8880010b7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350
 kernel-patches#1: ffffc900004a7d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350
 kernel-patches#2: ffffffff8bc6fbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x7f0
 kernel-patches#3: ffffffff8bc8daa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x7e/0x2e0
 kernel-patches#4: ffff88800b5e9cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1056/0x1b00
[..]

Work around this limitation by chopping the list into smaller chunks
and process them individually for LOCKDEP enabled kernels.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 12, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

This isn't a problem in itself, the problem is that the list can be
very long, so it may lock a LOT of mutexes, but lockdep engine can only
deal with MAX_LOCK_DEPTH held locks:

unshare -n bash -c 'for i in $(seq 1 100);do  ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ffff8880010b7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350
 kernel-patches#1: ffffc900004a7d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350
 kernel-patches#2: ffffffff8bc6fbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x7f0
 kernel-patches#3: ffffffff8bc8daa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x7e/0x2e0
 kernel-patches#4: ffff88800b5e9cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1056/0x1b00
[..]

Work around this limitation by chopping the list into smaller chunks
and process them individually for LOCKDEP enabled kernels.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 12, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

This isn't a problem in itself, the problem is that the list can be
very long, so it may lock a LOT of mutexes, but lockdep engine can only
deal with MAX_LOCK_DEPTH held locks:

unshare -n bash -c 'for i in $(seq 1 100);do  ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ffff8880010b7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350
 kernel-patches#1: ffffc900004a7d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350
 kernel-patches#2: ffffffff8bc6fbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x7f0
 kernel-patches#3: ffffffff8bc8daa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x7e/0x2e0
 kernel-patches#4: ffff88800b5e9cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1056/0x1b00
[..]

Work around this limitation by chopping the list into smaller chunks
and process them individually for LOCKDEP enabled kernels.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 12, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

This isn't a problem in itself, the problem is that the list can be
very long, so it may lock a LOT of mutexes, but lockdep engine can only
deal with MAX_LOCK_DEPTH held locks:

unshare -n bash -c 'for i in $(seq 1 100);do  ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ffff8880010b7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350
 kernel-patches#1: ffffc900004a7d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350
 kernel-patches#2: ffffffff8bc6fbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x7f0
 kernel-patches#3: ffffffff8bc8daa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x7e/0x2e0
 kernel-patches#4: ffff88800b5e9cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1056/0x1b00
[..]

Work around this limitation by chopping the list into smaller chunks
and process them individually for LOCKDEP enabled kernels.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 13, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 14, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 14, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 14, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 14, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 14, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 14, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 14, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 14, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 14, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 15, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 15, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 kernel-patches#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 kernel-patches#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 kernel-patches#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 kernel-patches#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 15, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 15, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 16, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 16, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 17, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 19, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 19, 2025
With latest llvm22, I hit the verif_scale_strobemeta selftest failure
below:
  $ ./test_progs -n 618
  libbpf: prog 'on_event': BPF program load failed: -E2BIG
  libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
  BPF program is too large. Processed 1000001 insn
  verification time 7019091 usec
  stack depth 488
  processed 1000001 insns (limit 1000000) max_states_per_insn 28 total_states 33927 peak_states 12813 mark_read 0
  -- END PROG LOAD LOG --
  libbpf: prog 'on_event': failed to load: -E2BIG
  libbpf: failed to load object 'strobemeta.bpf.o'
  scale_test:FAIL:expect_success unexpected error: -7 (errno 7)
  #618     verif_scale_strobemeta:FAIL

But if I increase the verificaiton insn limit from 1M to 10M, the above
test_progs run actually will succeed. The below is the result from veristat:
  $ ./veristat strobemeta.bpf.o
  Processing 'strobemeta.bpf.o'...
  File              Program   Verdict  Duration (us)    Insns  States  Program size  Jited size
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  strobemeta.bpf.o  on_event  success       90250893  9777685  358230         15954       80794
  ----------------  --------  -------  -------------  -------  ------  ------------  ----------
  Done. Processed 1 files, 0 programs. Skipped 1 files, 0 programs.

Further debugging shows the llvm commit [1] is responsible for the verificaiton
failure as it tries to convert certain switch statement to if-condition. Such
change may cause different transformation compared to original switch statement.

In bpf program strobemeta.c case, the initial llvm ir for read_int_var() function is
  define internal void @read_int_var(ptr noundef %0, i64 noundef %1, ptr noundef %2,
      ptr noundef %3, ptr noundef %4) #2 !dbg !535 {
    %6 = alloca ptr, align 8
    %7 = alloca i64, align 8
    %8 = alloca ptr, align 8
    %9 = alloca ptr, align 8
    %10 = alloca ptr, align 8
    %11 = alloca ptr, align 8
    %12 = alloca i32, align 4
    ...
    %20 = icmp ne ptr %19, null, !dbg !561
    br i1 %20, label %22, label %21, !dbg !562

  21:                                               ; preds = %5
    store i32 1, ptr %12, align 4
    br label %48, !dbg !563

  22:
    %23 = load ptr, ptr %9, align 8, !dbg !564
    ...

  47:                                               ; preds = %38, %22
    store i32 0, ptr %12, align 4, !dbg !588
    br label %48, !dbg !588

  48:                                               ; preds = %47, %21
    call void @llvm.lifetime.end.p0(ptr %11) #4, !dbg !588
    %49 = load i32, ptr %12, align 4
    switch i32 %49, label %51 [
      i32 0, label %50
      i32 1, label %50
    ]

  50:                                               ; preds = %48, %48
    ret void, !dbg !589

  51:                                               ; preds = %48
    unreachable
  }

Note that the above 'switch' statement is added by clang frontend.
Without [1], the switch statement will survive until SelectionDag,
so the switch statement acts like a 'barrier' and prevents some
transformation involved with both 'before' and 'after' the switch statement.

But with [1], the switch statement will be removed during middle end
optimization and later middle end passes (esp. after inlining) have more
freedom to reorder the code.

The following is the related source code:

  static void *calc_location(struct strobe_value_loc *loc, void *tls_base):
        bpf_probe_read_user(&tls_ptr, sizeof(void *), dtv);
        /* if pointer has (void *)-1 value, then TLS wasn't initialized yet */
        return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;

  In read_int_var() func, we have:
        void *location = calc_location(&cfg->int_locs[idx], tls_base);
        if (!location)
                return;

        bpf_probe_read_user(value, sizeof(struct strobe_value_generic), location);
        ...

The static func calc_location() is called inside read_int_var(). The asm code
without [1]:
     77: .123....89 (85) call bpf_probe_read_user#112
     78: ........89 (79) r1 = *(u64 *)(r10 -368)
     79: .1......89 (79) r2 = *(u64 *)(r10 -8)
     80: .12.....89 (bf) r3 = r2
     81: .123....89 (0f) r3 += r1
     82: ..23....89 (07) r2 += 1
     83: ..23....89 (79) r4 = *(u64 *)(r10 -464)
     84: ..234...89 (a5) if r2 < 0x2 goto pc+13
     85: ...34...89 (15) if r3 == 0x0 goto pc+12
     86: ...3....89 (bf) r1 = r10
     87: .1.3....89 (07) r1 += -400
     88: .1.3....89 (b4) w2 = 16
In this case, 'r2 < 0x2' and 'r3 == 0x0' go to null 'locaiton' place,
so the verifier actually prefers to do verification first at 'r1 = r10' etc.

The asm code with [1]:
    119: .123....89 (85) call bpf_probe_read_user#112
    120: ........89 (79) r1 = *(u64 *)(r10 -368)
    121: .1......89 (79) r2 = *(u64 *)(r10 -8)
    122: .12.....89 (bf) r3 = r2
    123: .123....89 (0f) r3 += r1
    124: ..23....89 (07) r2 += -1
    125: ..23....89 (a5) if r2 < 0xfffffffe goto pc+6
    126: ........89 (05) goto pc+17
    ...
    144: ........89 (b4) w1 = 0
    145: .1......89 (6b) *(u16 *)(r8 +80) = r1
In this case, if 'r2 < 0xfffffffe' is true, the control will go to
non-null 'location' branch, so 'goto pc+17' will actually go to
null 'location' branch. This seems causing tremendous amount of
verificaiton state.

To fix the issue, rewrite the following code
  return tls_ptr && tls_ptr != (void *)-1
                ? tls_ptr + tls_index.offset
                : NULL;
to if/then statement and hopefully these explicit if/then statements
are sticky during middle-end optimizations.

Test with llvm20 and llvm21 as well and all strobemeta related selftests
are passed.

  [1] llvm/llvm-project#161000

Signed-off-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 23, 2025
…ked_roots()

If fs_info->super_copy or fs_info->super_for_commit allocated failed in
btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().
Otherwise btrfs_check_leaked_roots() would access NULL pointer because
fs_info->allocated_roots had not been initialised.

syzkaller reported the following information:
  ------------[ cut here ]------------
  BUG: unable to handle page fault for address: fffffffffffffbb0
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0
  Oops: Oops: 0000 [kernel-patches#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 kernel-patches#4 PREEMPT(lazy)
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)
  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]
  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230
  [...]
  Call Trace:
   <TASK>
   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280
   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029
   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097
   vfs_get_tree+0x98/0x320 fs/super.c:1759
   do_new_mount+0x357/0x660 fs/namespace.c:3899
   path_mount+0x716/0x19c0 fs/namespace.c:4226
   do_mount fs/namespace.c:4239 [inline]
   __do_sys_mount fs/namespace.c:4450 [inline]
   __se_sys_mount fs/namespace.c:4427 [inline]
   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f032eaffa8d
  [...]

Fixes: 3bb17a2 ("btrfs: add get_tree callback for new mount API")
CC: [email protected] # 6.12+
Reviewed-by: Daniel Vacek <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Dewei Meng <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Oct 31, 2025
The original code causes a circular locking dependency found by lockdep.

======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc6-lgci-xe-xe-pw-151626v3+ kernel-patches#1 Tainted: G S   U
------------------------------------------------------
xe_fault_inject/5091 is trying to acquire lock:
ffff888156815688 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}, at: __flush_work+0x25d/0x660

but task is already holding lock:

ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> kernel-patches#2 (&devcd->mutex){+.+.}-{3:3}:
       mutex_lock_nested+0x4e/0xc0
       devcd_data_write+0x27/0x90
       sysfs_kf_bin_write+0x80/0xf0
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> kernel-patches#1 (kn->active#236){++++}-{0:0}:
       kernfs_drain+0x1e2/0x200
       __kernfs_remove+0xae/0x400
       kernfs_remove_by_name_ns+0x5d/0xc0
       remove_files+0x54/0x70
       sysfs_remove_group+0x3d/0xa0
       sysfs_remove_groups+0x2e/0x60
       device_remove_attrs+0xc7/0x100
       device_del+0x15d/0x3b0
       devcd_del+0x19/0x30
       process_one_work+0x22b/0x6f0
       worker_thread+0x1e8/0x3d0
       kthread+0x11c/0x250
       ret_from_fork+0x26c/0x2e0
       ret_from_fork_asm+0x1a/0x30
-> #0 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}:
       __lock_acquire+0x1661/0x2860
       lock_acquire+0xc4/0x2f0
       __flush_work+0x27a/0x660
       flush_delayed_work+0x5d/0xa0
       dev_coredump_put+0x63/0xa0
       xe_driver_devcoredump_fini+0x12/0x20 [xe]
       devm_action_release+0x12/0x30
       release_nodes+0x3a/0x120
       devres_release_all+0x8a/0xd0
       device_unbind_cleanup+0x12/0x80
       device_release_driver_internal+0x23a/0x280
       device_driver_detach+0x14/0x20
       unbind_store+0xaf/0xc0
       drv_attr_store+0x21/0x50
       sysfs_kf_write+0x4a/0x80
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of: (work_completion)(&(&devcd->del_wk)->work) --> kn->active#236 --> &devcd->mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&devcd->mutex);
                               lock(kn->active#236);
                               lock(&devcd->mutex);
  lock((work_completion)(&(&devcd->del_wk)->work));
 *** DEADLOCK ***
5 locks held by xe_fault_inject/5091:
 #0: ffff8881129f9488 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x72/0xf0
 kernel-patches#1: ffff88810c755078 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x123/0x220
 kernel-patches#2: ffff8881054811a0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x55/0x280
 kernel-patches#3: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
 kernel-patches#4: ffffffff8359e020 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x72/0x660
stack backtrace:
CPU: 14 UID: 0 PID: 5091 Comm: xe_fault_inject Tainted: G S   U              6.16.0-rc6-lgci-xe-xe-pw-151626v3+ kernel-patches#1 PREEMPT_{RT,(lazy)}
Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Micro-Star International Co., Ltd. MS-7D25/PRO Z690-A DDR4(MS-7D25), BIOS 1.10 12/13/2021
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xf0
 dump_stack+0x10/0x20
 print_circular_bug+0x285/0x360
 check_noncircular+0x135/0x150
 ? register_lock_class+0x48/0x4a0
 __lock_acquire+0x1661/0x2860
 lock_acquire+0xc4/0x2f0
 ? __flush_work+0x25d/0x660
 ? mark_held_locks+0x46/0x90
 ? __flush_work+0x25d/0x660
 __flush_work+0x27a/0x660
 ? __flush_work+0x25d/0x660
 ? trace_hardirqs_on+0x1e/0xd0
 ? __pfx_wq_barrier_func+0x10/0x10
 flush_delayed_work+0x5d/0xa0
 dev_coredump_put+0x63/0xa0
 xe_driver_devcoredump_fini+0x12/0x20 [xe]
 devm_action_release+0x12/0x30
 release_nodes+0x3a/0x120
 devres_release_all+0x8a/0xd0
 device_unbind_cleanup+0x12/0x80
 device_release_driver_internal+0x23a/0x280
 ? bus_find_device+0xa8/0xe0
 device_driver_detach+0x14/0x20
 unbind_store+0xaf/0xc0
 drv_attr_store+0x21/0x50
 sysfs_kf_write+0x4a/0x80
 kernfs_fop_write_iter+0x169/0x220
 vfs_write+0x293/0x560
 ksys_write+0x72/0xf0
 __x64_sys_write+0x19/0x30
 x64_sys_call+0x2bf/0x2660
 do_syscall_64+0x93/0xb60
 ? __f_unlock_pos+0x15/0x20
 ? __x64_sys_getdents64+0x9b/0x130
 ? __pfx_filldir64+0x10/0x10
 ? do_syscall_64+0x1a2/0xb60
 ? clear_bhb_loop+0x30/0x80
 ? clear_bhb_loop+0x30/0x80
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x76e292edd574
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007fffe247a828 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000076e292edd574
RDX: 000000000000000c RSI: 00006267f6306063 RDI: 000000000000000b
RBP: 000000000000000c R08: 000076e292fc4b20 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00006267f6306063
R13: 000000000000000b R14: 00006267e6859c00 R15: 000076e29322a000
 </TASK>
xe 0000:03:00.0: [drm] Xe device coredump has been deleted.

Fixes: 01daccf ("devcoredump : Serialize devcd_del work")
Cc: Mukesh Ojha <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: [email protected]
Cc: [email protected] # v6.1+
Signed-off-by: Maarten Lankhorst <[email protected]>
Cc: Matthew Brost <[email protected]>
Acked-by: Mukesh Ojha <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
kuba-moo added a commit to linux-netdev/testing-bpf-ci that referenced this pull request Nov 5, 2025
Michael Chan says:

====================
bnxt_en: Bug fixes

Patches 1, 3, and 4 are bug fixes related to the FW log tracing driver
coredump feature recently added in 6.13.  Patch kernel-patches#1 adds the necessary
call to shutdown the FW logging DMA during PCI shutdown.  Patch kernel-patches#3 fixes
a possible null pointer derefernce when using early versions of the FW
with this feature.  Patch kernel-patches#4 adds the coredump header information
unconditionally to make it more robust.

Patch kernel-patches#2 fixes a possible memory leak during PTP shutdown.  Patch kernel-patches#5
eliminates a dmesg warning when doing devlink reload.
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Nov 13, 2025
On completion of i915_vma_pin_ww(), a synchronous variant of
dma_fence_work_commit() is called.  When pinning a VMA to GGTT address
space on a Cherry View family processor, or on a Broxton generation SoC
with VTD enabled, i.e., when stop_machine() is then called from
intel_ggtt_bind_vma(), that can potentially lead to lock inversion among
reservation_ww and cpu_hotplug locks.

[86.861179] ======================================================
[86.861193] WARNING: possible circular locking dependency detected
[86.861209] 6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ kernel-patches#1 Tainted: G     U
[86.861226] ------------------------------------------------------
[86.861238] i915_module_loa/1432 is trying to acquire lock:
[86.861252] ffffffff83489090 (cpu_hotplug_lock){++++}-{0:0}, at: stop_machine+0x1c/0x50
[86.861290]
but task is already holding lock:
[86.861303] ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.862233]
which lock already depends on the new lock.
[86.862251]
the existing dependency chain (in reverse order) is:
[86.862265]
-> kernel-patches#5 (reservation_ww_class_mutex){+.+.}-{3:3}:
[86.862292]        dma_resv_lockdep+0x19a/0x390
[86.862315]        do_one_initcall+0x60/0x3f0
[86.862334]        kernel_init_freeable+0x3cd/0x680
[86.862353]        kernel_init+0x1b/0x200
[86.862369]        ret_from_fork+0x47/0x70
[86.862383]        ret_from_fork_asm+0x1a/0x30
[86.862399]
-> kernel-patches#4 (reservation_ww_class_acquire){+.+.}-{0:0}:
[86.862425]        dma_resv_lockdep+0x178/0x390
[86.862440]        do_one_initcall+0x60/0x3f0
[86.862454]        kernel_init_freeable+0x3cd/0x680
[86.862470]        kernel_init+0x1b/0x200
[86.862482]        ret_from_fork+0x47/0x70
[86.862495]        ret_from_fork_asm+0x1a/0x30
[86.862509]
-> kernel-patches#3 (&mm->mmap_lock){++++}-{3:3}:
[86.862531]        down_read_killable+0x46/0x1e0
[86.862546]        lock_mm_and_find_vma+0xa2/0x280
[86.862561]        do_user_addr_fault+0x266/0x8e0
[86.862578]        exc_page_fault+0x8a/0x2f0
[86.862593]        asm_exc_page_fault+0x27/0x30
[86.862607]        filldir64+0xeb/0x180
[86.862620]        kernfs_fop_readdir+0x118/0x480
[86.862635]        iterate_dir+0xcf/0x2b0
[86.862648]        __x64_sys_getdents64+0x84/0x140
[86.862661]        x64_sys_call+0x1058/0x2660
[86.862675]        do_syscall_64+0x91/0xe90
[86.862689]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.862703]
-> kernel-patches#2 (&root->kernfs_rwsem){++++}-{3:3}:
[86.862725]        down_write+0x3e/0xf0
[86.862738]        kernfs_add_one+0x30/0x3c0
[86.862751]        kernfs_create_dir_ns+0x53/0xb0
[86.862765]        internal_create_group+0x134/0x4c0
[86.862779]        sysfs_create_group+0x13/0x20
[86.862792]        topology_add_dev+0x1d/0x30
[86.862806]        cpuhp_invoke_callback+0x4b5/0x850
[86.862822]        cpuhp_issue_call+0xbf/0x1f0
[86.862836]        __cpuhp_setup_state_cpuslocked+0x111/0x320
[86.862852]        __cpuhp_setup_state+0xb0/0x220
[86.862866]        topology_sysfs_init+0x30/0x50
[86.862879]        do_one_initcall+0x60/0x3f0
[86.862893]        kernel_init_freeable+0x3cd/0x680
[86.862908]        kernel_init+0x1b/0x200
[86.862921]        ret_from_fork+0x47/0x70
[86.862934]        ret_from_fork_asm+0x1a/0x30
[86.862947]
-> kernel-patches#1 (cpuhp_state_mutex){+.+.}-{3:3}:
[86.862969]        __mutex_lock+0xaa/0xed0
[86.862982]        mutex_lock_nested+0x1b/0x30
[86.862995]        __cpuhp_setup_state_cpuslocked+0x67/0x320
[86.863012]        __cpuhp_setup_state+0xb0/0x220
[86.863026]        page_alloc_init_cpuhp+0x2d/0x60
[86.863041]        mm_core_init+0x22/0x2d0
[86.863054]        start_kernel+0x576/0xbd0
[86.863068]        x86_64_start_reservations+0x18/0x30
[86.863084]        x86_64_start_kernel+0xbf/0x110
[86.863098]        common_startup_64+0x13e/0x141
[86.863114]
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
[86.863135]        __lock_acquire+0x1635/0x2810
[86.863152]        lock_acquire+0xc4/0x2f0
[86.863166]        cpus_read_lock+0x41/0x100
[86.863180]        stop_machine+0x1c/0x50
[86.863194]        bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.863987]        intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.864735]        __vma_bind+0x55/0x70 [i915]
[86.865510]        fence_work+0x26/0xa0 [i915]
[86.866248]        fence_notify+0xa1/0x140 [i915]
[86.866983]        __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.867719]        i915_sw_fence_commit+0x39/0x60 [i915]
[86.868453]        i915_vma_pin_ww+0x462/0x1360 [i915]
[86.869228]        i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.870001]        initial_plane_vma+0x307/0x840 [i915]
[86.870774]        intel_initial_plane_config+0x33f/0x670 [i915]
[86.871546]        intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.872330]        i915_driver_probe+0x7fa/0xe80 [i915]
[86.873057]        i915_pci_probe+0xe6/0x220 [i915]
[86.873782]        local_pci_probe+0x47/0xb0
[86.873802]        pci_device_probe+0xf3/0x260
[86.873817]        really_probe+0xf1/0x3c0
[86.873833]        __driver_probe_device+0x8c/0x180
[86.873848]        driver_probe_device+0x24/0xd0
[86.873862]        __driver_attach+0x10f/0x220
[86.873876]        bus_for_each_dev+0x7f/0xe0
[86.873892]        driver_attach+0x1e/0x30
[86.873904]        bus_add_driver+0x151/0x290
[86.873917]        driver_register+0x5e/0x130
[86.873931]        __pci_register_driver+0x7d/0x90
[86.873945]        i915_pci_register_driver+0x23/0x30 [i915]
[86.874678]        i915_init+0x37/0x120 [i915]
[86.875347]        do_one_initcall+0x60/0x3f0
[86.875369]        do_init_module+0x97/0x2a0
[86.875385]        load_module+0x2c54/0x2d80
[86.875398]        init_module_from_file+0x96/0xe0
[86.875413]        idempotent_init_module+0x117/0x330
[86.875426]        __x64_sys_finit_module+0x77/0x100
[86.875440]        x64_sys_call+0x24de/0x2660
[86.875454]        do_syscall_64+0x91/0xe90
[86.875470]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.875486]
other info that might help us debug this:
[86.875502] Chain exists of:
  cpu_hotplug_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex
[86.875539]  Possible unsafe locking scenario:
[86.875552]        CPU0                    CPU1
[86.875563]        ----                    ----
[86.875573]   lock(reservation_ww_class_mutex);
[86.875588]                                lock(reservation_ww_class_acquire);
[86.875606]                                lock(reservation_ww_class_mutex);
[86.875624]   rlock(cpu_hotplug_lock);
[86.875637]
 *** DEADLOCK ***
[86.875650] 3 locks held by i915_module_loa/1432:
[86.875663]  #0: ffff888101f5c1b0 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x104/0x220
[86.875699]  kernel-patches#1: ffffc90002e0b4a0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.876512]  kernel-patches#2: ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915]
[86.877305]
stack backtrace:
[86.877326] CPU: 0 UID: 0 PID: 1432 Comm: i915_module_loa Tainted: G     U              6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ kernel-patches#1 PREEMPT(voluntary)
[86.877334] Tainted: [U]=USER
[86.877336] Hardware name:  /NUC5CPYB, BIOS PYBSWCEL.86A.0079.2020.0420.1316 04/20/2020
[86.877339] Call Trace:
[86.877344]  <TASK>
[86.877353]  dump_stack_lvl+0x91/0xf0
[86.877364]  dump_stack+0x10/0x20
[86.877369]  print_circular_bug+0x285/0x360
[86.877379]  check_noncircular+0x135/0x150
[86.877390]  __lock_acquire+0x1635/0x2810
[86.877403]  lock_acquire+0xc4/0x2f0
[86.877408]  ? stop_machine+0x1c/0x50
[86.877422]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878173]  cpus_read_lock+0x41/0x100
[86.878182]  ? stop_machine+0x1c/0x50
[86.878191]  ? __pfx_bxt_vtd_ggtt_insert_entries__cb+0x10/0x10 [i915]
[86.878916]  stop_machine+0x1c/0x50
[86.878927]  bxt_vtd_ggtt_insert_entries__BKL+0x3b/0x60 [i915]
[86.879652]  intel_ggtt_bind_vma+0x43/0x70 [i915]
[86.880375]  __vma_bind+0x55/0x70 [i915]
[86.881133]  fence_work+0x26/0xa0 [i915]
[86.881851]  fence_notify+0xa1/0x140 [i915]
[86.882566]  __i915_sw_fence_complete+0x8f/0x270 [i915]
[86.883286]  i915_sw_fence_commit+0x39/0x60 [i915]
[86.884003]  i915_vma_pin_ww+0x462/0x1360 [i915]
[86.884756]  ? i915_vma_pin.constprop.0+0x6c/0x1d0 [i915]
[86.885513]  i915_vma_pin.constprop.0+0x133/0x1d0 [i915]
[86.886281]  initial_plane_vma+0x307/0x840 [i915]
[86.887049]  intel_initial_plane_config+0x33f/0x670 [i915]
[86.887819]  intel_display_driver_probe_nogem+0x1c6/0x260 [i915]
[86.888587]  i915_driver_probe+0x7fa/0xe80 [i915]
[86.889293]  ? mutex_unlock+0x12/0x20
[86.889301]  ? drm_privacy_screen_get+0x171/0x190
[86.889308]  ? acpi_dev_found+0x66/0x80
[86.889321]  i915_pci_probe+0xe6/0x220 [i915]
[86.890038]  local_pci_probe+0x47/0xb0
[86.890049]  pci_device_probe+0xf3/0x260
[86.890058]  really_probe+0xf1/0x3c0
[86.890067]  __driver_probe_device+0x8c/0x180
[86.890072]  driver_probe_device+0x24/0xd0
[86.890078]  __driver_attach+0x10f/0x220
[86.890083]  ? __pfx___driver_attach+0x10/0x10
[86.890088]  bus_for_each_dev+0x7f/0xe0
[86.890097]  driver_attach+0x1e/0x30
[86.890101]  bus_add_driver+0x151/0x290
[86.890107]  driver_register+0x5e/0x130
[86.890113]  __pci_register_driver+0x7d/0x90
[86.890119]  i915_pci_register_driver+0x23/0x30 [i915]
[86.890833]  i915_init+0x37/0x120 [i915]
[86.891482]  ? __pfx_i915_init+0x10/0x10 [i915]
[86.892135]  do_one_initcall+0x60/0x3f0
[86.892145]  ? __kmalloc_cache_noprof+0x33f/0x470
[86.892157]  do_init_module+0x97/0x2a0
[86.892164]  load_module+0x2c54/0x2d80
[86.892168]  ? __kernel_read+0x15c/0x300
[86.892185]  ? kernel_read_file+0x2b1/0x320
[86.892195]  init_module_from_file+0x96/0xe0
[86.892199]  ? init_module_from_file+0x96/0xe0
[86.892211]  idempotent_init_module+0x117/0x330
[86.892224]  __x64_sys_finit_module+0x77/0x100
[86.892230]  x64_sys_call+0x24de/0x2660
[86.892236]  do_syscall_64+0x91/0xe90
[86.892243]  ? irqentry_exit+0x77/0xb0
[86.892249]  ? sysvec_apic_timer_interrupt+0x57/0xc0
[86.892256]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[86.892261] RIP: 0033:0x7303e1b2725d
[86.892271] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48
[86.892276] RSP: 002b:00007ffddd1fdb38 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[86.892281] RAX: ffffffffffffffda RBX: 00005d771d88fd90 RCX: 00007303e1b2725d
[86.892285] RDX: 0000000000000000 RSI: 00005d771d893aa0 RDI: 000000000000000c
[86.892287] RBP: 00007ffddd1fdbf0 R08: 0000000000000040 R09: 00007ffddd1fdb80
[86.892289] R10: 00007303e1c03b20 R11: 0000000000000246 R12: 00005d771d893aa0
[86.892292] R13: 0000000000000000 R14: 00005d771d88f0d0 R15: 00005d771d895710
[86.892304]  </TASK>

Call asynchronous variant of dma_fence_work_commit() in that case.

v3: Provide more verbose in-line comment (Andi),
  - mention target environments in commit message.

Fixes: 7d1c261 ("drm/i915: Take reservation lock around i915_vma_pin.")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14985
Cc: Andi Shyti <[email protected]>
Signed-off-by: Janusz Krzysztofik <[email protected]>
Reviewed-by: Sebastian Brzezinka <[email protected]>
Reviewed-by: Krzysztof Karas <[email protected]>
Acked-by: Andi Shyti <[email protected]>
Signed-off-by: Andi Shyti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
(cherry picked from commit 648ef1324add1c2e2b6041cdf0b28d31fbca5f13)
Signed-off-by: Rodrigo Vivi <[email protected]>
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