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Fix xallocx() bugs.

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Fix xallocx() bugs related to the 'extra' parameter when specified as
non-zero.
This commit is contained in:
Jason Evans 2015-09-11 16:18:53 -07:00
parent a00b10735a
commit 560a4e1e01
9 changed files with 399 additions and 184 deletions
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111
src/huge.c
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@ -126,18 +126,19 @@ huge_dalloc_junk_t *huge_dalloc_junk = JEMALLOC_N(huge_dalloc_junk_impl);
#endif
static void
huge_ralloc_no_move_similar(void *ptr, size_t oldsize, size_t usize,
size_t size, size_t extra, bool zero)
huge_ralloc_no_move_similar(void *ptr, size_t oldsize, size_t usize_min,
size_t usize_max, bool zero)
{
size_t usize_next;
size_t usize, usize_next;
extent_node_t *node;
arena_t *arena;
chunk_hooks_t chunk_hooks = CHUNK_HOOKS_INITIALIZER;
bool zeroed;
/* Increase usize to incorporate extra. */
while (usize < s2u(size+extra) && (usize_next = s2u(usize+1)) < oldsize)
usize = usize_next;
for (usize = usize_min; usize < usize_max && (usize_next = s2u(usize+1))
<= oldsize; usize = usize_next)
; /* Do nothing. */
if (oldsize == usize)
return;
@ -195,6 +196,8 @@ huge_ralloc_no_move_shrink(void *ptr, size_t oldsize, size_t usize)
arena = extent_node_arena_get(node);
chunk_hooks = chunk_hooks_get(arena);
assert(oldsize > usize);
/* Split excess chunks. */
cdiff = CHUNK_CEILING(oldsize) - CHUNK_CEILING(usize);
if (cdiff != 0 && chunk_hooks.split(ptr, CHUNK_CEILING(oldsize),
@ -230,18 +233,11 @@ huge_ralloc_no_move_shrink(void *ptr, size_t oldsize, size_t usize)
}
static bool
huge_ralloc_no_move_expand(void *ptr, size_t oldsize, size_t size, bool zero) {
size_t usize;
huge_ralloc_no_move_expand(void *ptr, size_t oldsize, size_t usize, bool zero) {
extent_node_t *node;
arena_t *arena;
bool is_zeroed_subchunk, is_zeroed_chunk;
usize = s2u(size);
if (usize == 0) {
/* size_t overflow. */
return (true);
}
node = huge_node_get(ptr);
arena = extent_node_arena_get(node);
malloc_mutex_lock(&arena->huge_mtx);
@ -282,89 +278,76 @@ huge_ralloc_no_move_expand(void *ptr, size_t oldsize, size_t size, bool zero) {
}
bool
huge_ralloc_no_move(void *ptr, size_t oldsize, size_t size, size_t extra,
bool zero)
huge_ralloc_no_move(void *ptr, size_t oldsize, size_t usize_min,
size_t usize_max, bool zero)
{
size_t usize;
/* Both allocations must be huge to avoid a move. */
if (oldsize < chunksize)
return (true);
assert(s2u(oldsize) == oldsize);
usize = s2u(size);
if (usize == 0) {
/* size_t overflow. */
/* Both allocations must be huge to avoid a move. */
if (oldsize < chunksize || usize_max < chunksize)
return (true);
if (CHUNK_CEILING(usize_max) > CHUNK_CEILING(oldsize)) {
/* Attempt to expand the allocation in-place. */
if (!huge_ralloc_no_move_expand(ptr, oldsize, usize_max, zero))
return (false);
/* Try again, this time with usize_min. */
if (usize_min < usize_max && CHUNK_CEILING(usize_min) >
CHUNK_CEILING(oldsize) && huge_ralloc_no_move_expand(ptr,
oldsize, usize_min, zero))
return (false);
}
/*
* Avoid moving the allocation if the existing chunk size accommodates
* the new size.
*/
if (CHUNK_CEILING(oldsize) >= CHUNK_CEILING(usize)
&& CHUNK_CEILING(oldsize) <= CHUNK_CEILING(s2u(size+extra))) {
huge_ralloc_no_move_similar(ptr, oldsize, usize, size, extra,
if (CHUNK_CEILING(oldsize) >= CHUNK_CEILING(usize_min)
&& CHUNK_CEILING(oldsize) <= CHUNK_CEILING(usize_max)) {
huge_ralloc_no_move_similar(ptr, oldsize, usize_min, usize_max,
zero);
return (false);
}
/* Attempt to shrink the allocation in-place. */
if (CHUNK_CEILING(oldsize) >= CHUNK_CEILING(usize))
return (huge_ralloc_no_move_shrink(ptr, oldsize, usize));
if (CHUNK_CEILING(oldsize) > CHUNK_CEILING(usize_max))
return (huge_ralloc_no_move_shrink(ptr, oldsize, usize_max));
return (true);
}
/* Attempt to expand the allocation in-place. */
if (huge_ralloc_no_move_expand(ptr, oldsize, size + extra, zero)) {
if (extra == 0)
return (true);
static void *
huge_ralloc_move_helper(tsd_t *tsd, arena_t *arena, size_t usize,
size_t alignment, bool zero, tcache_t *tcache)
{
/* Try again, this time without extra. */
return (huge_ralloc_no_move_expand(ptr, oldsize, size, zero));
}
return (false);
if (alignment <= chunksize)
return (huge_malloc(tsd, arena, usize, zero, tcache));
return (huge_palloc(tsd, arena, usize, alignment, zero, tcache));
}
void *
huge_ralloc(tsd_t *tsd, arena_t *arena, void *ptr, size_t oldsize, size_t size,
size_t extra, size_t alignment, bool zero, tcache_t *tcache)
huge_ralloc(tsd_t *tsd, arena_t *arena, void *ptr, size_t oldsize, size_t usize,
size_t alignment, bool zero, tcache_t *tcache)
{
void *ret;
size_t copysize;
/* Try to avoid moving the allocation. */
if (!huge_ralloc_no_move(ptr, oldsize, size, extra, zero))
if (!huge_ralloc_no_move(ptr, oldsize, usize, usize, zero))
return (ptr);
/*
* size and oldsize are different enough that we need to use a
* usize and oldsize are different enough that we need to use a
* different size class. In that case, fall back to allocating new
* space and copying.
*/
if (alignment > chunksize) {
ret = huge_palloc(tsd, arena, size + extra, alignment, zero,
tcache);
} else
ret = huge_malloc(tsd, arena, size + extra, zero, tcache);
ret = huge_ralloc_move_helper(tsd, arena, usize, alignment, zero,
tcache);
if (ret == NULL)
return (NULL);
if (ret == NULL) {
if (extra == 0)
return (NULL);
/* Try again, this time without extra. */
if (alignment > chunksize) {
ret = huge_palloc(tsd, arena, size, alignment, zero,
tcache);
} else
ret = huge_malloc(tsd, arena, size, zero, tcache);
if (ret == NULL)
return (NULL);
}
/*
* Copy at most size bytes (not size+extra), since the caller has no
* expectation that the extra bytes will be reliably preserved.
*/
copysize = (size < oldsize) ? size : oldsize;
copysize = (usize < oldsize) ? usize : oldsize;
memcpy(ret, ptr, copysize);
isqalloc(tsd, ptr, oldsize, tcache);
return (ret);