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strengthen alignment check for memalign and aligned_alloc

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daan 2020-02-17 09:59:11 -08:00
parent 16ebb70e4c
commit f2ac272baa
4 changed files with 732 additions and 6 deletions
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2
src/alloc-aligned.c
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@ -20,7 +20,7 @@ static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* const heap, const size_t
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 <https://sourceware.org/ml/libc-announce/2019/msg00001.html>)
if (mi_unlikely(alignment==0 || !_mi_is_power_of_two(alignment))) return NULL; // require power-of-two (see <https://en.cppreference.com/w/c/memory/aligned_alloc>)
if (mi_unlikely(alignment==0 || !_mi_is_power_of_two(alignment))) return NULL; // require power-of-two (see <https://en.cppreference.com/w/c/memory/aligned_alloc>)
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

10
src/alloc-posix.c
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@ -48,7 +48,7 @@ int mi_posix_memalign(void** p, size_t alignment, size_t size) mi_attr_noexcept
if (p == NULL) return EINVAL;
if (alignment % sizeof(void*) != 0) return EINVAL; // natural alignment
if (!_mi_is_power_of_two(alignment)) return EINVAL; // not a power of 2
void* q = (alignment <= MI_MAX_ALIGN_SIZE ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
void* q = (mi_malloc_satisfies_alignment(alignment, size) ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
if (q==NULL && size != 0) return ENOMEM;
mi_assert_internal(((uintptr_t)q % alignment) == 0);
*p = q;
@ -56,26 +56,26 @@ int mi_posix_memalign(void** p, size_t alignment, size_t size) mi_attr_noexcept
}
mi_decl_restrict void* mi_memalign(size_t alignment, size_t size) mi_attr_noexcept {
void* p = (alignment <= MI_MAX_ALIGN_SIZE ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
void* p = (mi_malloc_satisfies_alignment(alignment,size) ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
mi_assert_internal(((uintptr_t)p % alignment) == 0);
return p;
}
mi_decl_restrict void* mi_valloc(size_t size) mi_attr_noexcept {
return mi_malloc_aligned(size, _mi_os_page_size());
return mi_memalign( _mi_os_page_size(), size );
}
mi_decl_restrict void* mi_pvalloc(size_t size) mi_attr_noexcept {
size_t psize = _mi_os_page_size();
if (size >= SIZE_MAX - psize) return NULL; // overflow
size_t asize = ((size + psize - 1) / psize) * psize;
size_t asize = _mi_align_up(size, psize);
return mi_malloc_aligned(asize, psize);
}
mi_decl_restrict void* mi_aligned_alloc(size_t alignment, size_t size) mi_attr_noexcept {
if (alignment==0 || !_mi_is_power_of_two(alignment)) return NULL;
if ((size&(alignment-1)) != 0) return NULL; // C11 requires integral multiple, see <https://en.cppreference.com/w/c/memory/aligned_alloc>
void* p = (alignment <= MI_MAX_ALIGN_SIZE ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
void* p = (mi_malloc_satisfies_alignment(alignment, size) ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
mi_assert_internal(((uintptr_t)p % alignment) == 0);
return p;
}