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| author | Andrey Konovalov <andreyknvl@google.com> | 2023-02-10 22:16:03 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-16 20:43:51 -0800 |
| commit | 36aa1e6779c3c6f8e0d4552544214f5cffe3c287 (patch) | |
| tree | 1639d4bb581f0baab0ebed256c8e2af3a0fa6c5e /mm/kmsan | |
| parent | d11a5621f3252120dfc7cef7600a90bd8e605caf (diff) | |
| download | linux-36aa1e6779c3c6f8e0d4552544214f5cffe3c287.tar.gz linux-36aa1e6779c3c6f8e0d4552544214f5cffe3c287.tar.bz2 linux-36aa1e6779c3c6f8e0d4552544214f5cffe3c287.zip | |
lib/stacktrace, kasan, kmsan: rework extra_bits interface
The current implementation of the extra_bits interface is confusing:
passing extra_bits to __stack_depot_save makes it seem that the extra
bits are somehow stored in stack depot. In reality, they are only
embedded into a stack depot handle and are not used within stack depot.
Drop the extra_bits argument from __stack_depot_save and instead provide
a new stack_depot_set_extra_bits function (similar to the exsiting
stack_depot_get_extra_bits) that saves extra bits into a stack depot
handle.
Update the callers of __stack_depot_save to use the new interace.
This change also fixes a minor issue in the old code: __stack_depot_save
does not return NULL if saving stack trace fails and extra_bits is used.
Link: https://lkml.kernel.org/r/317123b5c05e2f82854fc55d8b285e0869d3cb77.1676063693.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kmsan')
| -rw-r--r-- | mm/kmsan/core.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/mm/kmsan/core.c b/mm/kmsan/core.c index 112dce135c7f..f710257d6867 100644 --- a/mm/kmsan/core.c +++ b/mm/kmsan/core.c @@ -69,13 +69,15 @@ depot_stack_handle_t kmsan_save_stack_with_flags(gfp_t flags, { unsigned long entries[KMSAN_STACK_DEPTH]; unsigned int nr_entries; + depot_stack_handle_t handle; nr_entries = stack_trace_save(entries, KMSAN_STACK_DEPTH, 0); /* Don't sleep (see might_sleep_if() in __alloc_pages_nodemask()). */ flags &= ~__GFP_DIRECT_RECLAIM; - return __stack_depot_save(entries, nr_entries, extra, flags, true); + handle = __stack_depot_save(entries, nr_entries, flags, true); + return stack_depot_set_extra_bits(handle, extra); } /* Copy the metadata following the memmove() behavior. */ @@ -215,6 +217,7 @@ depot_stack_handle_t kmsan_internal_chain_origin(depot_stack_handle_t id) u32 extra_bits; int depth; bool uaf; + depot_stack_handle_t handle; if (!id) return id; @@ -250,8 +253,9 @@ depot_stack_handle_t kmsan_internal_chain_origin(depot_stack_handle_t id) * positives when __stack_depot_save() passes it to instrumented code. */ kmsan_internal_unpoison_memory(entries, sizeof(entries), false); - return __stack_depot_save(entries, ARRAY_SIZE(entries), extra_bits, - GFP_ATOMIC, true); + handle = __stack_depot_save(entries, ARRAY_SIZE(entries), GFP_ATOMIC, + true); + return stack_depot_set_extra_bits(handle, extra_bits); } void kmsan_internal_set_shadow_origin(void *addr, size_t size, int b, |