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kfence: fix reports if constant function prefixes exist 

Some architectures prefix all functions with a constant string ('.' on
ppc64).  Add ARCH_FUNC_PREFIX, which may optionally be defined in
<asm/kfence.h>, so that get_stack_skipnr() can work properly.

Link: https://lkml.kernel.org/r/f036c53d-7e81-763c-47f4-6024c6c5f058@csgroup.eu
Link: https://lkml.kernel.org/r/20210304144000.1148590-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rM2-mainline
Marco Elver 2021-03-12 21:08:00 -08:00 committed by Linus Torvalds
parent df3ae2c994
commit 0aa41cae92
1 changed files with 12 additions and 6 deletions
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18
mm/kfence/report.c
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@ -20,6 +20,11 @@
#include "kfence.h"
/* May be overridden by <asm/kfence.h>. */
#ifndef ARCH_FUNC_PREFIX
#define ARCH_FUNC_PREFIX ""
#endif
extern bool no_hash_pointers;
/* Helper function to either print to a seq_file or to console. */
@ -67,8 +72,9 @@ static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries
for (skipnr = 0; skipnr < num_entries; skipnr++) {
int len = scnprintf(buf, sizeof(buf), "%ps", (void *)stack_entries[skipnr]);
if (str_has_prefix(buf, "kfence_") || str_has_prefix(buf, "__kfence_") ||
!strncmp(buf, "__slab_free", len)) {
if (str_has_prefix(buf, ARCH_FUNC_PREFIX "kfence_") ||
str_has_prefix(buf, ARCH_FUNC_PREFIX "__kfence_") ||
!strncmp(buf, ARCH_FUNC_PREFIX "__slab_free", len)) {
/*
* In case of tail calls from any of the below
* to any of the above.
@ -77,10 +83,10 @@ static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries
}
/* Also the *_bulk() variants by only checking prefixes. */
if (str_has_prefix(buf, "kfree") ||
str_has_prefix(buf, "kmem_cache_free") ||
str_has_prefix(buf, "__kmalloc") ||
str_has_prefix(buf, "kmem_cache_alloc"))
if (str_has_prefix(buf, ARCH_FUNC_PREFIX "kfree") ||
str_has_prefix(buf, ARCH_FUNC_PREFIX "kmem_cache_free") ||
str_has_prefix(buf, ARCH_FUNC_PREFIX "__kmalloc") ||
str_has_prefix(buf, ARCH_FUNC_PREFIX "kmem_cache_alloc"))
goto found;
}
if (fallback < num_entries)