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Fix calloc to really return zeroed memory.

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This commit is contained in:
Ulrich Drepper 1998-11-04 11:59:59 +00:00
parent 070a0c7e6c
commit 58c14234b7
1 changed files with 15 additions and 9 deletions
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24
malloc/malloc.c
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@ -1761,15 +1761,15 @@ __malloc_check_init()
static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */
#define MMAP(size, prot, flags) ((dev_zero_fd < 0) ? \
#define MMAP(addr, size, prot, flags) ((dev_zero_fd < 0) ? \
(dev_zero_fd = open("/dev/zero", O_RDWR), \
mmap(0, (size), (prot), (flags), dev_zero_fd, 0)) : \
mmap(0, (size), (prot), (flags), dev_zero_fd, 0))
mmap((addr), (size), (prot), (flags), dev_zero_fd, 0)) : \
mmap((addr), (size), (prot), (flags), dev_zero_fd, 0))
#else
#define MMAP(size, prot, flags) \
(mmap(0, (size), (prot), (flags)|MAP_ANONYMOUS, -1, 0))
#define MMAP(addr, size, prot, flags) \
(mmap((addr), (size), (prot), (flags)|MAP_ANONYMOUS, -1, 0))
#endif
@ -1789,7 +1789,7 @@ static mchunkptr mmap_chunk(size) size_t size;
*/
size = (size + SIZE_SZ + page_mask) & ~page_mask;
p = (mchunkptr)MMAP(size, PROT_READ|PROT_WRITE, MAP_PRIVATE);
p = (mchunkptr)MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE);
if(p == (mchunkptr)-1) return 0;
n_mmaps++;
@ -1921,7 +1921,7 @@ new_heap(size) size_t size;
No swap space needs to be reserved for the following large
mapping (on Linux, this is the case for all non-writable mappings
anyway). */
p1 = (char *)MMAP(HEAP_MAX_SIZE<<1, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE);
p1 = (char *)MMAP(0, HEAP_MAX_SIZE<<1, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE);
if(p1 == (char *)-1)
return 0;
p2 = (char *)(((unsigned long)p1 + HEAP_MAX_SIZE) & ~(HEAP_MAX_SIZE-1));
@ -1962,7 +1962,10 @@ grow_heap(h, diff) heap_info *h; long diff;
new_size = (long)h->size + diff;
if(new_size < (long)sizeof(*h))
return -1;
if(mprotect((char *)h + new_size, -diff, PROT_NONE) != 0)
/* Try to re-map the extra heap space freshly to save memory, and
make it inaccessible. */
if((char *)MMAP((char *)h + new_size, -diff, PROT_NONE,
MAP_PRIVATE|MAP_FIXED) == (char *)-1)
return -2;
}
h->size = new_size;
@ -2117,7 +2120,10 @@ static void do_check_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p;
if(ar_ptr != &main_arena) {
heap_info *heap = heap_for_ptr(p);
assert(heap->ar_ptr == ar_ptr);
assert((char *)p + sz <= (char *)heap + heap->size);
if(p != top(ar_ptr))
assert((char *)p + sz <= (char *)heap + heap->size);
else
assert((char *)p + sz == (char *)heap + heap->size);
return;
}
#endif