mm/kasan: print name of mem[set,cpy,move]() caller in report

When bogus memory access happens in mem[set,cpy,move]() it's usually
caller's fault.  So don't blame mem[set,cpy,move]() in bug report, blame
the caller instead.

Before:
  BUG: KASAN: out-of-bounds access in memset+0x23/0x40 at <address>
After:
  BUG: KASAN: out-of-bounds access in <memset_caller> at <address>

Link: http://lkml.kernel.org/r/1462538722-1574-2-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 8df666bb23be76dcbf1be0948089519be0dabb7f..e5beb40d97b1c90d3ddc4fc6c47c170060efcdf7 100644 (file)
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -273,32 +273,36 @@ static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
        return memory_is_poisoned_n(addr, size);
 }
 
-
-static __always_inline void check_memory_region(unsigned long addr,
-                                               size_t size, bool write)
+static __always_inline void check_memory_region_inline(unsigned long addr,
+                                               size_t size, bool write,
+                                               unsigned long ret_ip)
 {
        if (unlikely(size == 0))
                return;
 
        if (unlikely((void *)addr <
                kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
-               kasan_report(addr, size, write, _RET_IP_);
+               kasan_report(addr, size, write, ret_ip);
                return;
        }
 
        if (likely(!memory_is_poisoned(addr, size)))
                return;
 
-       kasan_report(addr, size, write, _RET_IP_);
+       kasan_report(addr, size, write, ret_ip);
 }
 
-void __asan_loadN(unsigned long addr, size_t size);
-void __asan_storeN(unsigned long addr, size_t size);
+static void check_memory_region(unsigned long addr,
+                               size_t size, bool write,
+                               unsigned long ret_ip)
+{
+       check_memory_region_inline(addr, size, write, ret_ip);
+}
 
 #undef memset
 void *memset(void *addr, int c, size_t len)
 {
-       __asan_storeN((unsigned long)addr, len);
+       check_memory_region((unsigned long)addr, len, true, _RET_IP_);
 
        return __memset(addr, c, len);
 }
@@ -306,8 +310,8 @@ void *memset(void *addr, int c, size_t len)
 #undef memmove
 void *memmove(void *dest, const void *src, size_t len)
 {
-       __asan_loadN((unsigned long)src, len);
-       __asan_storeN((unsigned long)dest, len);
+       check_memory_region((unsigned long)src, len, false, _RET_IP_);
+       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
 
        return __memmove(dest, src, len);
 }
@@ -315,8 +319,8 @@ void *memmove(void *dest, const void *src, size_t len)
 #undef memcpy
 void *memcpy(void *dest, const void *src, size_t len)
 {
-       __asan_loadN((unsigned long)src, len);
-       __asan_storeN((unsigned long)dest, len);
+       check_memory_region((unsigned long)src, len, false, _RET_IP_);
+       check_memory_region((unsigned long)dest, len, true, _RET_IP_);
 
        return __memcpy(dest, src, len);
 }
@@ -690,22 +694,22 @@ void __asan_unregister_globals(struct kasan_global *globals, size_t size)
 }
 EXPORT_SYMBOL(__asan_unregister_globals);
 
-#define DEFINE_ASAN_LOAD_STORE(size)                           \
-       void __asan_load##size(unsigned long addr)              \
-       {                                                       \
-               check_memory_region(addr, size, false);         \
-       }                                                       \
-       EXPORT_SYMBOL(__asan_load##size);                       \
-       __alias(__asan_load##size)                              \
-       void __asan_load##size##_noabort(unsigned long);        \
-       EXPORT_SYMBOL(__asan_load##size##_noabort);             \
-       void __asan_store##size(unsigned long addr)             \
-       {                                                       \
-               check_memory_region(addr, size, true);          \
-       }                                                       \
-       EXPORT_SYMBOL(__asan_store##size);                      \
-       __alias(__asan_store##size)                             \
-       void __asan_store##size##_noabort(unsigned long);       \
+#define DEFINE_ASAN_LOAD_STORE(size)                                   \
+       void __asan_load##size(unsigned long addr)                      \
+       {                                                               \
+               check_memory_region_inline(addr, size, false, _RET_IP_);\
+       }                                                               \
+       EXPORT_SYMBOL(__asan_load##size);                               \
+       __alias(__asan_load##size)                                      \
+       void __asan_load##size##_noabort(unsigned long);                \
+       EXPORT_SYMBOL(__asan_load##size##_noabort);                     \
+       void __asan_store##size(unsigned long addr)                     \
+       {                                                               \
+               check_memory_region_inline(addr, size, true, _RET_IP_); \
+       }                                                               \
+       EXPORT_SYMBOL(__asan_store##size);                              \
+       __alias(__asan_store##size)                                     \
+       void __asan_store##size##_noabort(unsigned long);               \
        EXPORT_SYMBOL(__asan_store##size##_noabort)
 
 DEFINE_ASAN_LOAD_STORE(1);
@@ -716,7 +720,7 @@ DEFINE_ASAN_LOAD_STORE(16);
 
 void __asan_loadN(unsigned long addr, size_t size)
 {
-       check_memory_region(addr, size, false);
+       check_memory_region(addr, size, false, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_loadN);
 
@@ -726,7 +730,7 @@ EXPORT_SYMBOL(__asan_loadN_noabort);
 
 void __asan_storeN(unsigned long addr, size_t size)
 {
-       check_memory_region(addr, size, true);
+       check_memory_region(addr, size, true, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_storeN);