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authorVegard Nossum <vegard.nossum@gmail.com>2008-04-04 00:53:23 +0200
committerVegard Nossum <vegard.nossum@gmail.com>2009-06-15 12:40:02 +0200
commitf85612967c93b67b10dd240e3e8bf8a0eee9def7 (patch)
tree184a70bc888b35235ee0b1805a06f90fd45295d8 /arch/x86/include/asm/string_64.h
parentf8b4ece2a94693b7d2dd32ea716cb92545b5dce6 (diff)
x86: add hooks for kmemcheck
The hooks that we modify are: - Page fault handler (to handle kmemcheck faults) - Debug exception handler (to hide pages after single-stepping the instruction that caused the page fault) Also redefine memset() to use the optimized version if kmemcheck is enabled. (Thanks to Pekka Enberg for minimizing the impact on the page fault handler.) As kmemcheck doesn't handle MMX/SSE instructions (yet), we also disable the optimized xor code, and rely instead on the generic C implementation in order to avoid false-positive warnings. Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no> [whitespace fixlet] Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> [rebased for mainline inclusion] Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Diffstat (limited to 'arch/x86/include/asm/string_64.h')
-rw-r--r--arch/x86/include/asm/string_64.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 2afe164bf1e6..19e2c468fc2c 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -27,6 +27,7 @@ static __always_inline void *__inline_memcpy(void *to, const void *from, size_t
function. */
#define __HAVE_ARCH_MEMCPY 1
+#ifndef CONFIG_KMEMCHECK
#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
extern void *memcpy(void *to, const void *from, size_t len);
#else
@@ -42,6 +43,13 @@ 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
#define __HAVE_ARCH_MEMSET
void *memset(void *s, int c, size_t n);