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#include <atomic.h> // for LIBC_UNLOCK, LIBC_LOCK
#include <libc.h> // for libc, libc::(anonymous)
#include <malloc.h> // for page, page::(anonymous), __malloc_pvec, LARGE_...
#include <stddef.h> // for NULL
#include <stdint.h> // for uintptr_t
#include <stdlib.h> // for free
#include <sys/mman.h> // for size_t, munmap
void free(void *ptr)
{
if (ptr == NULL) {
return;
}
LIBC_LOCK(__libc.lock.malloc);
struct page *p = __malloc_pvec;
int found_in_pages = 0;
while (p) {
if ((uintptr_t)ptr >= (uintptr_t)p->heap &&
(uintptr_t)ptr < (uintptr_t)(p->heap + (p->block.size * p->block.count))) {
size_t offset = (uintptr_t)ptr - (uintptr_t)p->heap;
size_t index = offset / p->block.size;
size_t byte_index = index / 8;
size_t bit_index = index % 8;
LIBC_LOCK(p->lock);
if (p->bitmap[byte_index] & (1 << bit_index)) {
p->bitmap[byte_index] &= ~(1 << bit_index);
p->block.used--;
found_in_pages = 1;
}
LIBC_UNLOCK(p->lock);
if (found_in_pages && p->block.used == 0) {
if (p->prev)
p->prev->next = p->next;
if (p->next)
p->next->prev = p->prev;
if (p == __malloc_pvec)
__malloc_pvec = p->next;
munmap(p, (p->flags == PAGE_SMALL) ? SMALL_PAGE_SIZE :
(p->flags == PAGE_MEDIUM) ? MEDIUM_PAGE_SIZE :
LARGE_PAGE_SIZE);
}
LIBC_UNLOCK(__libc.lock.malloc);
return;
}
p = p->next;
}
void **orig_ptr_slot = (void **)((uintptr_t)ptr - sizeof(void *));
void *potential_orig = *orig_ptr_slot;
p = __malloc_pvec;
while (p) {
if ((uintptr_t)potential_orig >= (uintptr_t)p->heap &&
(uintptr_t)potential_orig < (uintptr_t)(p->heap + (p->block.size * p->block.count))) {
size_t offset = (uintptr_t)potential_orig - (uintptr_t)p->heap;
size_t index = offset / p->block.size;
size_t byte_index = index / 8;
size_t bit_index = index % 8;
LIBC_LOCK(p->lock);
if (p->bitmap[byte_index] & (1 << bit_index)) {
p->bitmap[byte_index] &= ~(1 << bit_index);
p->block.used--;
}
LIBC_UNLOCK(p->lock);
if (p->block.used == 0) {
if (p->prev)
p->prev->next = p->next;
if (p->next)
p->next->prev = p->prev;
if (p == __malloc_pvec)
__malloc_pvec = p->next;
munmap(p, (p->flags == PAGE_SMALL) ? SMALL_PAGE_SIZE :
(p->flags == PAGE_MEDIUM) ? MEDIUM_PAGE_SIZE :
LARGE_PAGE_SIZE);
}
LIBC_UNLOCK(__libc.lock.malloc);
return;
}
p = p->next;
}
LIBC_UNLOCK(__libc.lock.malloc);
}
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