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| author | Rich Felker <dalias@aerifal.cx> | 2018-04-19 22:19:29 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2018-04-19 22:22:11 -0400 |
| commit | b4b1e10364c8737a632be61582e05a8d3acf5690 (patch) | |
| tree | 68c07893e646a5e94c47afb7f8b01317c143968b /src/malloc/malloc.c | |
| parent | 72141795d4edd17f88da192447395a48444afa10 (diff) | |
| download | musl-b4b1e10364c8737a632be61582e05a8d3acf5690.tar.gz | |
reintroduce hardening against partially-replaced allocator
commit 618b18c78e33acfe54a4434e91aa57b8e171df89 removed the previous
detection and hardening since it was incorrect. commit
72141795d4edd17f88da192447395a48444afa10 already handled all that
remained for hardening the static-linked case. in the dynamic-linked
case, have the dynamic linker check whether malloc was replaced and
make that information available.
with these changes, the properties documented in commit
c9f415d7ea2dace5bf77f6518b6afc36bb7a5732 are restored: if calloc is
not provided, it will behave as malloc+memset, and any of the
memalign-family functions not provided will fail with ENOMEM.
Diffstat (limited to 'src/malloc/malloc.c')
| -rw-r--r-- | src/malloc/malloc.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/src/malloc/malloc.c b/src/malloc/malloc.c index 239ab9c6..d72883e1 100644 --- a/src/malloc/malloc.c +++ b/src/malloc/malloc.c @@ -20,6 +20,8 @@ static struct { volatile int free_lock[2]; } mal; +int __malloc_replaced; + /* Synchronization tools */ static inline void lock(volatile int *lk) @@ -356,10 +358,13 @@ void *calloc(size_t m, size_t n) } n *= m; void *p = malloc(n); - if (!p || IS_MMAPPED(MEM_TO_CHUNK(p))) - return p; - if (n >= PAGE_SIZE) - n = mal0_clear(p, PAGE_SIZE, n); + if (!p) return p; + if (!__malloc_replaced) { + if (IS_MMAPPED(MEM_TO_CHUNK(p))) + return p; + if (n >= PAGE_SIZE) + n = mal0_clear(p, PAGE_SIZE, n); + } return memset(p, 0, n); } |