diff --git a/src/alloc-aligned.c b/src/alloc-aligned.c index 7eeb9e92..0882ecc9 100644 --- a/src/alloc-aligned.c +++ b/src/alloc-aligned.c @@ -14,13 +14,16 @@ terms of the MIT license. A copy of the license can be found in the file // Aligned Allocation // ------------------------------------------------------ -static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* const heap, const size_t size, const size_t alignment, const size_t offset, const bool zero) mi_attr_noexcept { +static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* const heap, const size_t size, size_t alignment, const size_t offset, const bool zero) mi_attr_noexcept { // note: we don't require `size > offset`, we just guarantee that // the address at offset is aligned regardless of the allocated size. - mi_assert(alignment > 0 && alignment % sizeof(void*) == 0); if (mi_unlikely(size > PTRDIFF_MAX)) return NULL; // we don't allocate more than PTRDIFF_MAX (see ) if (mi_unlikely(alignment==0 || !_mi_is_power_of_two(alignment))) return NULL; // require power-of-two (see ) + + // if the passed alignment is too small, correct it upwards to the minimal internal required alignment + // fixes issues in user code calling aligned variants for types with small alignment requirements below pointer alignment + alignment = alignment < sizeof(void*) ? sizeof(void*) : alignment; const uintptr_t align_mask = alignment-1; // for any x, `(x & align_mask) == (x % alignment)` // try if there is a small block available with just the right alignment