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commit c9c3598eaf41d8c95ccf5eae8fe26c37ca88747d
parent dfeb089a5def8b30d5c8b8a485d7c473032d7c2c
Author: sin <sin@2f30.org>
Date:   Tue Jul 30 12:20:41 +0100

Fix posix_memalign()

Use PAGESIZE instead of 0x1000.

Diffstat:
alloc.c | 47++++++++++++++++++++++++++---------------------
1 file changed, 26 insertions(+), 21 deletions(-)
diff --git a/alloc.c b/alloc.c @@ -15,6 +15,10 @@ enum { NALLOC = 65536 * 128, }; +enum { + PAGESIZE = 0x1000, +}; + /* Only needed because we have to implement * realloc() */ struct chunk { @@ -23,26 +27,26 @@ struct chunk { enum chunk_state state; } chunks[NALLOC]; -/* Align on a 0x1000 boundary */ +/* Align on a PAGESIZE boundary */ void * mmap_page_aligned(size_t nbytes) { void *addr; int ret; - if (nbytes % 0x1000) - nbytes = (nbytes + 0x1000) & ~(0x1000 - 1); + if (nbytes % PAGESIZE) + nbytes = (nbytes + PAGESIZE) & ~(PAGESIZE - 1); - addr = mmap(0, nbytes + 0x1000, + addr = mmap(0, nbytes + PAGESIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); if (addr == MAP_FAILED) return NULL; /* Guard page at the end of the allocation */ - ret = mprotect((char *)addr + nbytes, 0x1000, + ret = mprotect((char *)addr + nbytes, PAGESIZE, PROT_NONE); if (ret < 0) { - munmap(addr, nbytes + 0x1000); + munmap(addr, nbytes + PAGESIZE); return NULL; } return addr; @@ -89,7 +93,7 @@ realloc(void *oldp, size_t nbytes) n = chunks[i].size < nbytes ? chunks[i].size : nbytes; memcpy(p, chunks[i].base, n); chunks[i].state = FREE; - munmap(chunks[i].base, chunks[i].size + 0x1000); + munmap(chunks[i].base, chunks[i].size + PAGESIZE); return p; } } @@ -118,7 +122,7 @@ free(void *p) for (i = 0; i < NALLOC; i++) { if (chunks[i].base == p) { chunks[i].state = FREE; - munmap(chunks[i].base, chunks[i].size + 0x1000); + munmap(chunks[i].base, chunks[i].size + PAGESIZE); break; } } @@ -150,24 +154,25 @@ malloc_size(void *p) } int -posix_memalign(void **memptr, size_t alignment, size_t size) +posix_memalign(void **memptr, size_t align, size_t size) { - void *result; + void *mem; - /* Make sure that alignment is a large enough power of 2. */ - if (((alignment - 1) & alignment) != 0 || alignment < sizeof(void *)) + if (((align - 1) & align)) return EINVAL; + if (align < sizeof(void *)) + return EINVAL; + + if (PAGESIZE % align) { + fprintf(stderr, "%s: %zu alignment not supported!\n", + __func__, align); + abort(); + } - /* - * max(size, alignment) is enough to assure the requested alignment, - * since the allocator always allocates power-of-two blocks. - */ - if (size < alignment) - size = alignment; - result = malloc(size); - if (!result) + mem = malloc(size); + if (!mem) return ENOMEM; - *memptr = result; + *memptr = mem; return 0; }