diff options
Diffstat (limited to 'src/alloc.c')
| -rw-r--r-- | src/alloc.c | 60 |
1 files changed, 29 insertions, 31 deletions
diff --git a/src/alloc.c b/src/alloc.c index ebaff38..f505eda 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -1,11 +1,13 @@ // Copyright © Tavian Barnes <tavianator@tavianator.com> // SPDX-License-Identifier: 0BSD -#include "prelude.h" #include "alloc.h" + +#include "bfs.h" #include "bit.h" #include "diag.h" #include "sanity.h" + #include <errno.h> #include <stdlib.h> #include <stdint.h> @@ -18,24 +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; @@ -51,7 +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; @@ -71,8 +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); @@ -106,10 +103,10 @@ void *reserve(void *ptr, size_t align, size_t size, size_t count) { size_t old_size = size * count; // Capacity is doubled every power of two, from 0→1, 1→2, 2→4, etc. - // If we stayed within the same size class, re-use ptr. + // If we stayed within the same size class, reuse ptr. if (count & (count - 1)) { // Tell sanitizers about the new array element - sanitize_alloc((char *)ptr + old_size, size); + sanitize_resize(ptr, old_size, old_size + size, bit_ceil(count) * size); errno = 0; return ptr; } @@ -124,7 +121,7 @@ void *reserve(void *ptr, size_t align, size_t size, size_t count) { } // Pretend we only allocated one more element - sanitize_free((char *)ret + old_size + size, new_size - old_size - size); + sanitize_resize(ret, new_size, old_size + size, new_size); errno = 0; return ret; } @@ -176,7 +173,7 @@ void arena_init(struct arena *arena, size_t align, size_t size) { } /** Allocate a new slab. */ -attr(cold) +_cold static int slab_alloc(struct arena *arena) { // Make the initial allocation size ~4K size_t size = 4096; @@ -231,6 +228,7 @@ void arena_free(struct arena *arena, void *ptr) { union chunk *chunk = ptr; chunk_set_next(arena, chunk, arena->chunks); arena->chunks = chunk; + sanitize_uninit(chunk, arena->size); sanitize_free(chunk, arena->size); } @@ -250,7 +248,7 @@ void arena_destroy(struct arena *arena) { sanitize_uninit(arena); } -void varena_init(struct varena *varena, size_t align, size_t min, size_t offset, size_t size) { +void varena_init(struct varena *varena, size_t align, size_t offset, size_t size) { varena->align = align; varena->offset = offset; varena->size = size; @@ -259,7 +257,7 @@ void varena_init(struct varena *varena, size_t align, size_t min, size_t offset, // The smallest size class is at least as many as fit in the smallest // aligned allocation size - size_t min_count = (flex_size(align, min, offset, size, 1) - offset + size - 1) / size; + size_t min_count = (flex_size(align, offset, size, 1) - offset + size - 1) / size; varena->shift = bit_width(min_count - 1); } @@ -272,7 +270,7 @@ static size_t varena_size_class(struct varena *varena, size_t count) { /** Get the exact size of a flexible struct. */ static size_t varena_exact_size(const struct varena *varena, size_t count) { - return flex_size(varena->align, 0, varena->offset, varena->size, count); + return flex_size(varena->align, varena->offset, varena->size, count); } /** Get the arena for the given array length. */ @@ -306,8 +304,7 @@ void *varena_alloc(struct varena *varena, size_t count) { } // Tell the sanitizers the exact size of the allocated struct - sanitize_free(ret, arena->size); - sanitize_alloc(ret, varena_exact_size(varena, count)); + sanitize_resize(ret, arena->size, varena_exact_size(varena, count), arena->size); return ret; } @@ -319,15 +316,14 @@ void *varena_realloc(struct varena *varena, void *ptr, size_t old_count, size_t return NULL; } - size_t new_exact_size = varena_exact_size(varena, new_count); - size_t old_exact_size = varena_exact_size(varena, old_count); + size_t old_size = old_arena->size; + size_t new_size = new_arena->size; if (new_arena == old_arena) { - if (new_count < old_count) { - sanitize_free((char *)ptr + new_exact_size, old_exact_size - new_exact_size); - } else if (new_count > old_count) { - sanitize_alloc((char *)ptr + old_exact_size, new_exact_size - old_exact_size); - } + sanitize_resize(ptr, + varena_exact_size(varena, old_count), + varena_exact_size(varena, new_count), + new_size); return ptr; } @@ -336,16 +332,18 @@ void *varena_realloc(struct varena *varena, void *ptr, size_t old_count, size_t return NULL; } - size_t old_size = old_arena->size; - sanitize_alloc((char *)ptr + old_exact_size, old_size - old_exact_size); + // Non-sanitized builds don't bother computing exact sizes, and just use + // the potentially-larger arena size for each size class instead. To + // allow the below memcpy() to work with the less-precise sizes, expand + // the old allocation to its full capacity. + sanitize_resize(ptr, varena_exact_size(varena, old_count), old_size, old_size); - size_t new_size = new_arena->size; size_t min_size = new_size < old_size ? new_size : old_size; memcpy(ret, ptr, min_size); arena_free(old_arena, ptr); - sanitize_free((char *)ret + new_exact_size, new_size - new_exact_size); + sanitize_resize(ret, new_size, varena_exact_size(varena, new_count), new_size); return ret; } |