diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2024-06-21 13:35:03 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-07-04 04:30:23 +0200 |
| commit | 4d7b5a2cec6efb4dfd42a3fddf321d4d828e794d (patch) | |
| tree | 6338b3def34732ebbba03ddd5e686f595094b309 /mm/kfence | |
| parent | mm: slub: disable KMSAN when checking the padding bytes (diff) | |
| download | linux-4d7b5a2cec6efb4dfd42a3fddf321d4d828e794d.tar.xz linux-4d7b5a2cec6efb4dfd42a3fddf321d4d828e794d.zip | |
mm: kfence: disable KMSAN when checking the canary
KMSAN warns about check_canary() accessing the canary.
The reason is that, even though set_canary() is properly instrumented and
sets shadow, slub explicitly poisons the canary's address range
afterwards.
Unpoisoning the canary is not the right thing to do: only check_canary()
is supposed to ever touch it. Instead, disable KMSAN checks around canary
read accesses.
Link: https://lkml.kernel.org/r/20240621113706.315500-20-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kfence')
| -rw-r--r-- | mm/kfence/core.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 964b8482275b..83f8e78827c0 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -305,8 +305,14 @@ metadata_update_state(struct kfence_metadata *meta, enum kfence_object_state nex WRITE_ONCE(meta->state, next); } +#ifdef CONFIG_KMSAN +#define check_canary_attributes noinline __no_kmsan_checks +#else +#define check_canary_attributes inline +#endif + /* Check canary byte at @addr. */ -static inline bool check_canary_byte(u8 *addr) +static check_canary_attributes bool check_canary_byte(u8 *addr) { struct kfence_metadata *meta; unsigned long flags; @@ -341,7 +347,8 @@ static inline void set_canary(const struct kfence_metadata *meta) *((u64 *)addr) = KFENCE_CANARY_PATTERN_U64; } -static inline void check_canary(const struct kfence_metadata *meta) +static check_canary_attributes void +check_canary(const struct kfence_metadata *meta) { const unsigned long pageaddr = ALIGN_DOWN(meta->addr, PAGE_SIZE); unsigned long addr = pageaddr; |