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author | Alexander Monakov <amonakov@ispras.ru> | 2018-04-16 20:54:36 +0300 |
---|---|---|
committer | Rich Felker <dalias@aerifal.cx> | 2018-04-17 19:23:00 -0400 |
commit | ce7ae11acfd9db8eb92cc6823c132e1825918d92 (patch) | |
tree | 209dc86f7454ff68af570afb3ad29e2bbc1a1a27 /src | |
parent | d889cc3463edc92869676c1eec34a8f52d942adb (diff) | |
download | musl-ce7ae11acfd9db8eb92cc6823c132e1825918d92.tar.gz musl-ce7ae11acfd9db8eb92cc6823c132e1825918d92.tar.bz2 musl-ce7ae11acfd9db8eb92cc6823c132e1825918d92.tar.xz musl-ce7ae11acfd9db8eb92cc6823c132e1825918d92.zip |
ldso, malloc: implement reclaim_gaps via __malloc_donate
Split 'free' into unmap_chunk and bin_chunk, use the latter to introduce
__malloc_donate and use it in reclaim_gaps instead of calling 'free'.
Diffstat (limited to 'src')
-rw-r--r-- | src/malloc/malloc.c | 61 |
1 files changed, 43 insertions, 18 deletions
diff --git a/src/malloc/malloc.c b/src/malloc/malloc.c index db19bc34..6605ec3a 100644 --- a/src/malloc/malloc.c +++ b/src/malloc/malloc.c @@ -299,6 +299,8 @@ static int pretrim(struct chunk *self, size_t n, int i, int j) return 1; } +static void bin_chunk(struct chunk *); + static void trim(struct chunk *self, size_t n) { size_t n1 = CHUNK_SIZE(self); @@ -314,7 +316,7 @@ static void trim(struct chunk *self, size_t n) next->psize = n1-n | C_INUSE; self->csize = n | C_INUSE; - free(CHUNK_TO_MEM(split)); + bin_chunk(split); } void *malloc(size_t n) @@ -465,29 +467,14 @@ copy_free_ret: return new; } -void free(void *p) +static void bin_chunk(struct chunk *self) { - struct chunk *self, *next; + struct chunk *next = NEXT_CHUNK(self); size_t final_size, new_size, size; int reclaim=0; int i; - if (!p) return; - - self = MEM_TO_CHUNK(p); - - if (IS_MMAPPED(self)) { - size_t extra = self->psize; - char *base = (char *)self - extra; - size_t len = CHUNK_SIZE(self) + extra; - /* Crash on double free */ - if (extra & 1) a_crash(); - __munmap(base, len); - return; - } - final_size = new_size = CHUNK_SIZE(self); - next = NEXT_CHUNK(self); /* Crash on corrupted footer (likely from buffer overflow) */ if (next->psize != self->csize) a_crash(); @@ -548,3 +535,41 @@ void free(void *p) unlock_bin(i); } + +static void unmap_chunk(struct chunk *self) +{ + size_t extra = self->psize; + char *base = (char *)self - extra; + size_t len = CHUNK_SIZE(self) + extra; + /* Crash on double free */ + if (extra & 1) a_crash(); + __munmap(base, len); +} + +void free(void *p) +{ + if (!p) return; + + struct chunk *self = MEM_TO_CHUNK(p); + + if (IS_MMAPPED(self)) + unmap_chunk(self); + else + bin_chunk(self); +} + +void __malloc_donate(char *start, char *end) +{ + size_t align_start_up = (SIZE_ALIGN-1) & (-(uintptr_t)start - OVERHEAD); + size_t align_end_down = (SIZE_ALIGN-1) & (uintptr_t)end; + + if (end - start <= OVERHEAD + align_start_up + align_end_down) + return; + start += align_start_up + OVERHEAD; + end -= align_end_down; + + struct chunk *c = MEM_TO_CHUNK(start), *n = MEM_TO_CHUNK(end); + c->psize = n->csize = C_INUSE; + c->csize = n->psize = C_INUSE | (end-start); + bin_chunk(c); +} |