diff options
Diffstat (limited to 'mm/kmsan/core.c')
| -rw-r--r-- | mm/kmsan/core.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/mm/kmsan/core.c b/mm/kmsan/core.c index cf2d70e9c9a5..95f859e38c53 100644 --- a/mm/kmsan/core.c +++ b/mm/kmsan/core.c @@ -196,8 +196,7 @@ void kmsan_internal_set_shadow_origin(void *addr, size_t size, int b, u32 origin, bool checked) { u64 address = (u64)addr; - void *shadow_start; - u32 *origin_start; + u32 *shadow_start, *origin_start; size_t pad = 0; KMSAN_WARN_ON(!kmsan_metadata_is_contiguous(addr, size)); @@ -225,8 +224,16 @@ void kmsan_internal_set_shadow_origin(void *addr, size_t size, int b, origin_start = (u32 *)kmsan_get_metadata((void *)address, KMSAN_META_ORIGIN); - for (int i = 0; i < size / KMSAN_ORIGIN_SIZE; i++) - origin_start[i] = origin; + /* + * If the new origin is non-zero, assume that the shadow byte is also non-zero, + * and unconditionally overwrite the old origin slot. + * If the new origin is zero, overwrite the old origin slot iff the + * corresponding shadow slot is zero. + */ + for (int i = 0; i < size / KMSAN_ORIGIN_SIZE; i++) { + if (origin || !shadow_start[i]) + origin_start[i] = origin; + } } struct page *kmsan_vmalloc_to_page_or_null(void *vaddr) |