kmemcheck: remove annotations

Patch series "kmemcheck: kill kmemcheck", v2.

As discussed at LSF/MM, kill kmemcheck.

KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow).  KASan is already upstream.

We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).

The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.

Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.

This patch (of 4):

Remove kmemcheck annotations, and calls to kmemcheck from the kernel.

[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
  Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 1 insertions, 21 deletions

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index a20eacd9c7e9..3e73bc255e4e 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -158,11 +158,6 @@ ifdef CONFIG_X86_X32
 endif
 export CONFIG_X86_X32_ABI
 
-# Don't unroll struct assignments with kmemcheck enabled
-ifeq ($(CONFIG_KMEMCHECK),y)
-	KBUILD_CFLAGS += $(call cc-option,-fno-builtin-memcpy)
-endif
-
 #
 # If the function graph tracer is used with mcount instead of fentry,
 # '-maccumulate-outgoing-args' is needed to prevent a GCC bug
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 43cbe843de8d..0350d99bb8fd 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -7,7 +7,6 @@
  * Documentation/DMA-API.txt for documentation.
  */
 
-#include <linux/kmemcheck.h>
 #include <linux/scatterlist.h>
 #include <linux/dma-debug.h>
 #include <asm/io.h>
diff --git a/arch/x86/include/asm/xor.h b/arch/x86/include/asm/xor.h
index 1f5c5161ead6..45c8605467f1 100644
--- a/arch/x86/include/asm/xor.h
+++ b/arch/x86/include/asm/xor.h
@@ -1,7 +1,4 @@
-#ifdef CONFIG_KMEMCHECK
-/* kmemcheck doesn't handle MMX/SSE/SSE2 instructions */
-# include <asm-generic/xor.h>
-#elif !defined(_ASM_X86_XOR_H)
+#ifndef _ASM_X86_XOR_H
 #define _ASM_X86_XOR_H
 
 /*
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index b7b0f74a2150..989514c94a55 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -42,7 +42,6 @@
 #include <linux/edac.h>
 #endif
 
-#include <asm/kmemcheck.h>
 #include <asm/stacktrace.h>
 #include <asm/processor.h>
 #include <asm/debugreg.h>
@@ -749,10 +748,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
 	if (!dr6 && user_mode(regs))
 		user_icebp = 1;
 
-	/* Catch kmemcheck conditions! */
-	if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
-		goto exit;
-
 	/* Store the virtualized DR6 value */
 	tsk->thread.debugreg6 = dr6;
 
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 3109ba6c6ede..78ca9a8ee454 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -20,7 +20,6 @@
 #include <asm/cpufeature.h>		/* boot_cpu_has, ...		*/
 #include <asm/traps.h>			/* dotraplinkage, ...		*/
 #include <asm/pgalloc.h>		/* pgd_*(), ...			*/
-#include <asm/kmemcheck.h>		/* kmemcheck_*(), ...		*/
 #include <asm/fixmap.h>			/* VSYSCALL_ADDR		*/
 #include <asm/vsyscall.h>		/* emulate_vsyscall		*/
 #include <asm/vm86.h>			/* struct vm86			*/
@@ -1256,8 +1255,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 	 * Detect and handle instructions that would cause a page fault for
 	 * both a tracked kernel page and a userspace page.
 	 */
-	if (kmemcheck_active(regs))
-		kmemcheck_hide(regs);
 	prefetchw(&mm->mmap_sem);
 
 	if (unlikely(kmmio_fault(regs, address)))
@@ -1280,9 +1277,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 		if (!(error_code & (X86_PF_RSVD | X86_PF_USER | X86_PF_PROT))) {
 			if (vmalloc_fault(address) >= 0)
 				return;
-
-			if (kmemcheck_fault(regs, address, error_code))
-				return;
 		}
 
 		/* Can handle a stale RO->RW TLB: */