diff options
Diffstat (limited to 'libc-top-half/musl/src/malloc/oldmalloc/aligned_alloc.c')
-rw-r--r-- | libc-top-half/musl/src/malloc/oldmalloc/aligned_alloc.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/malloc/oldmalloc/aligned_alloc.c b/libc-top-half/musl/src/malloc/oldmalloc/aligned_alloc.c new file mode 100644 index 0000000..4adca3b --- /dev/null +++ b/libc-top-half/musl/src/malloc/oldmalloc/aligned_alloc.c @@ -0,0 +1,53 @@ +#include <stdlib.h> +#include <stdint.h> +#include <errno.h> +#include "malloc_impl.h" + +void *aligned_alloc(size_t align, size_t len) +{ + unsigned char *mem, *new; + + if ((align & -align) != align) { + errno = EINVAL; + return 0; + } + + if (len > SIZE_MAX - align || + (__malloc_replaced && !__aligned_alloc_replaced)) { + errno = ENOMEM; + return 0; + } + + if (align <= SIZE_ALIGN) + return malloc(len); + + if (!(mem = malloc(len + align-1))) + return 0; + + new = (void *)((uintptr_t)mem + align-1 & -align); + if (new == mem) return mem; + + struct chunk *c = MEM_TO_CHUNK(mem); + struct chunk *n = MEM_TO_CHUNK(new); + + if (IS_MMAPPED(c)) { + /* Apply difference between aligned and original + * address to the "extra" field of mmapped chunk. */ + n->psize = c->psize + (new-mem); + n->csize = c->csize - (new-mem); + return new; + } + + struct chunk *t = NEXT_CHUNK(c); + + /* Split the allocated chunk into two chunks. The aligned part + * that will be used has the size in its footer reduced by the + * difference between the aligned and original addresses, and + * the resulting size copied to its header. A new header and + * footer are written for the split-off part to be freed. */ + n->psize = c->csize = C_INUSE | (new-mem); + n->csize = t->psize -= new-mem; + + __bin_chunk(c); + return new; +} |