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add further zero initialization checks

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This commit is contained in:
daanx 2023-04-22 10:18:57 -07:00
parent e90ad987cc
commit 2a6352fef2
6 changed files with 42 additions and 14 deletions
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14
src/alloc-aligned.c
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@ -218,19 +218,13 @@ static void* mi_heap_realloc_zero_aligned_at(mi_heap_t* heap, void* p, size_t ne
return p; // reallocation still fits, is aligned and not more than 50% waste
}
else {
// note: we don't zero allocate upfront so we only zero initialize the expanded part
void* newp = mi_heap_malloc_aligned_at(heap,newsize,alignment,offset);
if (newp != NULL) {
if (zero && newsize > size) {
const mi_page_t* page = _mi_ptr_page(newp);
if (page->free_is_zero) {
// already zero initialized
mi_assert_expensive(mi_mem_is_zero(newp,newsize));
}
else {
// also set last word in the previous allocation to zero to ensure any padding is zero-initialized
size_t start = (size >= sizeof(intptr_t) ? size - sizeof(intptr_t) : 0);
memset((uint8_t*)newp + start, 0, newsize - start);
}
// also set last word in the previous allocation to zero to ensure any padding is zero-initialized
size_t start = (size >= sizeof(intptr_t) ? size - sizeof(intptr_t) : 0);
_mi_memzero((uint8_t*)newp + start, newsize - start);
}
_mi_memcpy_aligned(newp, p, (newsize > size ? size : newsize));
mi_free(p); // only free if successful

8
src/page.c
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@ -66,6 +66,14 @@ static bool mi_page_list_is_valid(mi_page_t* page, mi_block_t* p) {
if (p < start || p >= end) return false;
p = mi_block_next(page, p);
}
#if MI_DEBUG>3 // generally too expensive to check this
if (page->free_is_zero) {
const size_t ubsize = mi_page_usable_block_size(page);
for (mi_block_t* block = page->free; block != NULL; block = mi_block_next(page, block)) {
mi_assert_expensive(mi_mem_is_zero(block + 1, ubsize - sizeof(mi_block_t)));
}
}
#endif
return true;
}