diff options
| author | Dylan Noblesmith <nobled@dreamwidth.org> | 2012-04-01 18:21:47 +0000 |
|---|---|---|
| committer | Dylan Noblesmith <nobled@dreamwidth.org> | 2012-04-29 11:22:15 +0000 |
| commit | 546abd25038dc4ad9af17a0f99bae818b980436e (patch) | |
| tree | b5b6223bd360389bb41abf731f2c4b7f133ec09f | |
| parent | bcc5caf642a9beec324657becac501944ce4dc23 (diff) | |
util: fix undefined behavior
container_of() can legally return anything, even invalid addresses
that cause segfaults, when 'sample' is an uninitialized pointer.
Bug exposed by clang.
NOTE: This is a candidate for the 8.0 branch.
(cherry picked from commit ccff74971203b533bf16b46b49a9e61753f75e6c)
| -rw-r--r-- | src/gallium/auxiliary/util/u_double_list.h | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/src/gallium/auxiliary/util/u_double_list.h b/src/gallium/auxiliary/util/u_double_list.h index 2384c36cb13..9d1129b185d 100644 --- a/src/gallium/auxiliary/util/u_double_list.h +++ b/src/gallium/auxiliary/util/u_double_list.h @@ -105,6 +105,11 @@ static INLINE void list_delinit(struct list_head *item) #define LIST_IS_EMPTY(__list) \ ((__list)->next == (__list)) +/** + * Cast from a pointer to a member of a struct back to the containing struct. + * + * 'sample' MUST be initialized, or else the result is undefined! + */ #ifndef container_of #define container_of(ptr, sample, member) \ (void *)((char *)(ptr) \ @@ -112,29 +117,29 @@ static INLINE void list_delinit(struct list_head *item) #endif #define LIST_FOR_EACH_ENTRY(pos, head, member) \ - for (pos = container_of((head)->next, pos, member); \ + for (pos = NULL, pos = container_of((head)->next, pos, member); \ &pos->member != (head); \ pos = container_of(pos->member.next, pos, member)) #define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member) \ - for (pos = container_of((head)->next, pos, member), \ + for (pos = NULL, pos = container_of((head)->next, pos, member), \ storage = container_of(pos->member.next, pos, member); \ &pos->member != (head); \ pos = storage, storage = container_of(storage->member.next, storage, member)) #define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member) \ - for (pos = container_of((head)->prev, pos, member), \ + for (pos = NULL, pos = container_of((head)->prev, pos, member), \ storage = container_of(pos->member.prev, pos, member); \ &pos->member != (head); \ pos = storage, storage = container_of(storage->member.prev, storage, member)) #define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member) \ - for (pos = container_of((start), pos, member); \ + for (pos = NULL, pos = container_of((start), pos, member); \ &pos->member != (head); \ pos = container_of(pos->member.next, pos, member)) #define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member) \ - for (pos = container_of((start), pos, member); \ + for (pos = NULL, pos = container_of((start), pos, member); \ &pos->member != (head); \ pos = container_of(pos->member.prev, pos, member)) |