diff options
| -rw-r--r-- | build/has/aligned-alloc.c | 8 | ||||
| -rw-r--r-- | build/header.mk | 1 | ||||
| -rw-r--r-- | src/alloc.c | 15 | ||||
| -rw-r--r-- | src/alloc.h | 34 | ||||
| -rw-r--r-- | tests/alloc.c | 8 |
5 files changed, 27 insertions, 39 deletions
diff --git a/build/has/aligned-alloc.c b/build/has/aligned-alloc.c deleted file mode 100644 index 4460038..0000000 --- a/build/has/aligned-alloc.c +++ /dev/null @@ -1,8 +0,0 @@ -// Copyright © Tavian Barnes <tavianator@tavianator.com> -// SPDX-License-Identifier: 0BSD - -#include <stdlib.h> - -int main(void) { - return !aligned_alloc(_Alignof(void *), sizeof(void *)); -} diff --git a/build/header.mk b/build/header.mk index 88a8986..e9f1abc 100644 --- a/build/header.mk +++ b/build/header.mk @@ -18,7 +18,6 @@ HEADERS := \ gen/has/acl-get-tag-type.h \ gen/has/acl-is-trivial-np.h \ gen/has/acl-trivial.h \ - gen/has/aligned-alloc.h \ gen/has/builtin-riscv-pause.h \ gen/has/confstr.h \ gen/has/extattr-get-file.h \ diff --git a/src/alloc.c b/src/alloc.c index 779e1d7..4e68e13 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -20,24 +20,22 @@ # define ALLOC_MAX (SIZE_MAX / 2) #endif -/** Portable aligned_alloc()/posix_memalign(). */ +/** posix_memalign() wrapper. */ static void *xmemalign(size_t align, size_t size) { bfs_assert(has_single_bit(align)); bfs_assert(align >= sizeof(void *)); - bfs_assert(is_aligned(align, size)); -#if BFS_HAS_ALIGNED_ALLOC - return aligned_alloc(align, size); -#else + // Since https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2072.htm, + // aligned_alloc() doesn't require the size to be a multiple of align. + // But the sanitizers don't know about that yet, so always use + // posix_memalign(). void *ptr = NULL; errno = posix_memalign(&ptr, align, size); return ptr; -#endif } void *alloc(size_t align, size_t size) { bfs_assert(has_single_bit(align)); - bfs_assert(is_aligned(align, size)); if (size > ALLOC_MAX) { errno = EOVERFLOW; @@ -53,7 +51,6 @@ void *alloc(size_t align, size_t size) { void *zalloc(size_t align, size_t size) { bfs_assert(has_single_bit(align)); - bfs_assert(is_aligned(align, size)); if (size > ALLOC_MAX) { errno = EOVERFLOW; @@ -73,8 +70,6 @@ void *zalloc(size_t align, size_t size) { void *xrealloc(void *ptr, size_t align, size_t old_size, size_t new_size) { bfs_assert(has_single_bit(align)); - bfs_assert(is_aligned(align, old_size)); - bfs_assert(is_aligned(align, new_size)); if (new_size == 0) { free(ptr); diff --git a/src/alloc.h b/src/alloc.h index 4f119e0..7865d5d 100644 --- a/src/alloc.h +++ b/src/alloc.h @@ -30,25 +30,24 @@ static inline size_t align_ceil(size_t align, size_t size) { } /** - * Saturating array size. - * - * @align - * Array element alignment. - * @size - * Array element size. - * @count - * Array element count. - * @return - * size * count, saturating to the maximum aligned value on overflow. + * Saturating size addition. */ -static inline size_t array_size(size_t align, size_t size, size_t count) { +static inline size_t size_add(size_t lhs, size_t rhs) { + size_t ret = lhs + rhs; + return ret >= lhs ? ret : (size_t)-1; +} + +/** + * Saturating size multiplication. + */ +static inline size_t size_mul(size_t size, size_t count) { size_t ret = size * count; - return ret / size == count ? ret : ~(align - 1); + return ret / size == count ? ret : (size_t)-1; } /** Saturating array sizeof. */ #define sizeof_array(type, count) \ - array_size(alignof(type), sizeof(type), count) + size_mul(sizeof(type), count) /** Size of a struct/union field. */ #define sizeof_member(type, member) \ @@ -72,13 +71,8 @@ static inline size_t array_size(size_t align, size_t size, size_t count) { * to the maximum aligned value on overflow. */ static inline size_t flex_size(size_t align, size_t min, size_t offset, size_t size, size_t count) { - size_t ret = size * count; - size_t overflow = ret / size != count; - - size_t extra = offset + align - 1; - ret += extra; - overflow |= ret < extra; - ret |= -overflow; + size_t ret = size_mul(size, count); + ret = size_add(ret, offset + align - 1); ret = align_floor(align, ret); // Make sure flex_sizeof(type, member, 0) >= sizeof(type), even if the diff --git a/tests/alloc.c b/tests/alloc.c index f91b428..046613a 100644 --- a/tests/alloc.c +++ b/tests/alloc.c @@ -11,6 +11,14 @@ #include <stdint.h> void check_alloc(void) { + // Check aligned allocation + void *ptr; + bfs_everify((ptr = zalloc(64, 129))); + bfs_check((uintptr_t)ptr % 64 == 0); + bfs_echeck((ptr = xrealloc(ptr, 64, 129, 65))); + bfs_check((uintptr_t)ptr % 64 == 0); + free(ptr); + // Check sizeof_flex() struct flexible { alignas(64) int foo[8]; |