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| author | Marco Elver <elver@google.com> | 2021-03-12 21:08:00 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-03-13 11:27:30 -0800 |
| commit | 0aa41cae92c1e2e61ae5b3a2dde8e674172e40ac (patch) | |
| tree | ac5e4d06e1703059b8f87899665ebf521fbfdb6d | |
| parent | df3ae2c9941d38106afd67d7816b58f6dc7405e8 (diff) | |
| download | lwn-0aa41cae92c1e2e61ae5b3a2dde8e674172e40ac.tar.gz lwn-0aa41cae92c1e2e61ae5b3a2dde8e674172e40ac.zip | |
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>
| -rw-r--r-- | mm/kfence/report.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/mm/kfence/report.c b/mm/kfence/report.c index 519f037720f5..e3f71451ad9e 100644 --- a/mm/kfence/report.c +++ b/mm/kfence/report.c @@ -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) |