kmemcheck: rip it out

Fix up makefiles, remove references, and git rm kmemcheck.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Vegard Nossum <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Tim Hansen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Levin, Alexander (Sasha Levin)

Documentation/admin-guide/kernel-parameters.txt

@@ -1864,13 +1864,6 @@
 			Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
 			the default is off.
 
-	kmemcheck=	[X86] Boot-time kmemcheck enable/disable/one-shot mode
-			Valid arguments: 0, 1, 2
-			kmemcheck=0 (disabled)
-			kmemcheck=1 (enabled)
-			kmemcheck=2 (one-shot mode)
-			Default: 2 (one-shot mode)
-
 	kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
 			Default is 0 (don't ignore, but inject #GP)
 

Documentation/dev-tools/index.rst

@@ -21,7 +21,6 @@ whole; patches welcome!
    kasan
    ubsan
    kmemleak
-   kmemcheck
    gdb-kernel-debugging
    kgdb
    kselftest

Documentation/dev-tools/kmemcheck.rst

@@ -7688,16 +7688,6 @@ F:	include/linux/kdb.h
 F:	include/linux/kgdb.h
 F:	kernel/debug/
 
-KMEMCHECK
-M:	Vegard Nossum <[email protected]>
-M:	Pekka Enberg <[email protected]>
-S:	Maintained
-F:	Documentation/dev-tools/kmemcheck.rst
-F:	arch/x86/include/asm/kmemcheck.h
-F:	arch/x86/mm/kmemcheck/
-F:	include/linux/kmemcheck.h
-F:	mm/kmemcheck.c
-
 KMEMLEAK
 M:	Catalin Marinas <[email protected]>
 S:	Maintained

MAINTAINERS

@@ -112,7 +112,6 @@ config X86
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_KASAN			if X86_64 && SPARSEMEM_VMEMMAP
 	select HAVE_ARCH_KGDB
-	select HAVE_ARCH_KMEMCHECK
 	select HAVE_ARCH_MMAP_RND_BITS		if MMU
 	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
 	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
@@ -1430,7 +1429,7 @@ config ARCH_DMA_ADDR_T_64BIT
 
 config X86_DIRECT_GBPAGES
 	def_bool y
-	depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
+	depends on X86_64 && !DEBUG_PAGEALLOC
 	---help---
 	  Certain kernel features effectively disable kernel
 	  linear 1 GB mappings (even if the CPU otherwise

arch/x86/Kconfig

@@ -1,43 +1 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef ASM_X86_KMEMCHECK_H
-#define ASM_X86_KMEMCHECK_H
-
-#include <linux/types.h>
-#include <asm/ptrace.h>
-
-#ifdef CONFIG_KMEMCHECK
-bool kmemcheck_active(struct pt_regs *regs);
-
-void kmemcheck_show(struct pt_regs *regs);
-void kmemcheck_hide(struct pt_regs *regs);
-
-bool kmemcheck_fault(struct pt_regs *regs,
-	unsigned long address, unsigned long error_code);
-bool kmemcheck_trap(struct pt_regs *regs);
-#else
-static inline bool kmemcheck_active(struct pt_regs *regs)
-{
-	return false;
-}
-
-static inline void kmemcheck_show(struct pt_regs *regs)
-{
-}
-
-static inline void kmemcheck_hide(struct pt_regs *regs)
-{
-}
-
-static inline bool kmemcheck_fault(struct pt_regs *regs,
-	unsigned long address, unsigned long error_code)
-{
-	return false;
-}
-
-static inline bool kmemcheck_trap(struct pt_regs *regs)
-{
-	return false;
-}
-#endif /* CONFIG_KMEMCHECK */
-
-#endif

arch/x86/include/asm/kmemcheck.h

@@ -179,8 +179,6 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
  *	No 3D Now!
  */
 
-#ifndef CONFIG_KMEMCHECK
-
 #if (__GNUC__ >= 4)
 #define memcpy(t, f, n) __builtin_memcpy(t, f, n)
 #else
@@ -189,13 +187,6 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
 	 ? __constant_memcpy((t), (f), (n))	\
 	 : __memcpy((t), (f), (n)))
 #endif
-#else
-/*
- * kmemcheck becomes very happy if we use the REP instructions unconditionally,
- * because it means that we know both memory operands in advance.
- */
-#define memcpy(t, f, n) __memcpy((t), (f), (n))
-#endif
 
 #endif
 #endif /* !CONFIG_FORTIFY_SOURCE */

arch/x86/include/asm/string_32.h

@@ -33,7 +33,6 @@ extern void *memcpy(void *to, const void *from, size_t len);
 extern void *__memcpy(void *to, const void *from, size_t len);
 
 #ifndef CONFIG_FORTIFY_SOURCE
-#ifndef CONFIG_KMEMCHECK
 #if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4
 #define memcpy(dst, src, len)					\
 ({								\
@@ -46,13 +45,6 @@ extern void *__memcpy(void *to, const void *from, size_t len);
 	__ret;							\
 })
 #endif
-#else
-/*
- * kmemcheck becomes very happy if we use the REP instructions unconditionally,
- * because it means that we know both memory operands in advance.
- */
-#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
-#endif
 #endif /* !CONFIG_FORTIFY_SOURCE */
 
 #define __HAVE_ARCH_MEMSET

arch/x86/include/asm/string_64.h

@@ -187,21 +187,6 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 	if (c->x86 == 6 && c->x86_model < 15)
 		clear_cpu_cap(c, X86_FEATURE_PAT);
 
-#ifdef CONFIG_KMEMCHECK
-	/*
-	 * P4s have a "fast strings" feature which causes single-
-	 * stepping REP instructions to only generate a #DB on
-	 * cache-line boundaries.
-	 *
-	 * Ingo Molnar reported a Pentium D (model 6) and a Xeon
-	 * (model 2) with the same problem.
-	 */
-	if (c->x86 == 15)
-		if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
-				  MSR_IA32_MISC_ENABLE_FAST_STRING_BIT) > 0)
-			pr_info("kmemcheck: Disabling fast string operations\n");
-#endif
-
 	/*
 	 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
 	 * clear the fast string and enhanced fast string CPU capabilities.

arch/x86/kernel/cpu/intel.c

@@ -29,8 +29,6 @@ obj-$(CONFIG_X86_PTDUMP)	+= debug_pagetables.o
 
 obj-$(CONFIG_HIGHMEM)		+= highmem_32.o
 
-obj-$(CONFIG_KMEMCHECK)		+= kmemcheck/
-
 KASAN_SANITIZE_kasan_init_$(BITS).o := n
 obj-$(CONFIG_KASAN)		+= kasan_init_$(BITS).o