From: Szabolcs Nagy Date: Tue, 16 Feb 2021 14:12:25 +0000 (+0000) Subject: malloc: Refactor TAG_ macros to avoid indirection X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=2689b5c71b4c5ca4bddb011a5ca62c586f62bc58;p=glibc.git malloc: Refactor TAG_ macros to avoid indirection This does not change behaviour, just removes one layer of indirection in the internal memory tagging logic. Use tag_ and mtag_ prefixes instead of __tag_ and __mtag_ since these are all symbols with internal linkage, private to malloc.c, so there is no user namespace pollution issue. Reviewed-by: DJ Delorie --- diff --git a/malloc/arena.c b/malloc/arena.c index 0777dc70c6..d0778fea92 100644 --- a/malloc/arena.c +++ b/malloc/arena.c @@ -332,12 +332,12 @@ ptmalloc_init (void) if (__MTAG_SBRK_UNTAGGED) __morecore = __failing_morecore; - __mtag_mmap_flags = __MTAG_MMAP_FLAGS; - __tag_new_memset = __mtag_tag_new_memset; - __tag_region = __libc_mtag_tag_region; - __tag_new_usable = __mtag_tag_new_usable; - __tag_at = __libc_mtag_address_get_tag; - __mtag_granule_mask = ~(size_t)(__MTAG_GRANULE_SIZE - 1); + mtag_mmap_flags = __MTAG_MMAP_FLAGS; + tag_new_memset = __mtag_tag_new_memset; + tag_region = __libc_mtag_tag_region; + tag_new_usable = __mtag_tag_new_usable; + tag_at = __libc_mtag_address_get_tag; + mtag_granule_mask = ~(size_t)(__MTAG_GRANULE_SIZE - 1); } #endif @@ -557,7 +557,7 @@ new_heap (size_t size, size_t top_pad) } } } - if (__mprotect (p2, size, MTAG_MMAP_FLAGS | PROT_READ | PROT_WRITE) != 0) + if (__mprotect (p2, size, mtag_mmap_flags | PROT_READ | PROT_WRITE) != 0) { __munmap (p2, HEAP_MAX_SIZE); return 0; @@ -587,7 +587,7 @@ grow_heap (heap_info *h, long diff) { if (__mprotect ((char *) h + h->mprotect_size, (unsigned long) new_size - h->mprotect_size, - MTAG_MMAP_FLAGS | PROT_READ | PROT_WRITE) != 0) + mtag_mmap_flags | PROT_READ | PROT_WRITE) != 0) return -2; h->mprotect_size = new_size; diff --git a/malloc/hooks.c b/malloc/hooks.c index efec05f0a8..d8e304c31c 100644 --- a/malloc/hooks.c +++ b/malloc/hooks.c @@ -68,7 +68,7 @@ __malloc_check_init (void) tags, so fetch the tag at each location before dereferencing it. */ #define SAFE_CHAR_OFFSET(p,offset) \ - ((unsigned char *) TAG_AT (((unsigned char *) p) + offset)) + ((unsigned char *) tag_at (((unsigned char *) p) + offset)) /* A simple, standard set of debugging hooks. Overhead is `only' one byte per chunk; still this will catch most cases of double frees or @@ -249,7 +249,7 @@ malloc_check (size_t sz, const void *caller) top_check (); victim = _int_malloc (&main_arena, nb); __libc_lock_unlock (main_arena.mutex); - return mem2mem_check (TAG_NEW_USABLE (victim), sz); + return mem2mem_check (tag_new_usable (victim), sz); } static void @@ -280,7 +280,7 @@ free_check (void *mem, const void *caller) else { /* Mark the chunk as belonging to the library again. */ - (void)TAG_REGION (chunk2rawmem (p), CHUNK_AVAILABLE_SIZE (p) + (void)tag_region (chunk2rawmem (p), CHUNK_AVAILABLE_SIZE (p) - CHUNK_HDR_SZ); _int_free (&main_arena, p, 1); __libc_lock_unlock (main_arena.mutex); @@ -375,7 +375,7 @@ invert: __libc_lock_unlock (main_arena.mutex); - return mem2mem_check (TAG_NEW_USABLE (newmem), bytes); + return mem2mem_check (tag_new_usable (newmem), bytes); } static void * @@ -417,7 +417,7 @@ memalign_check (size_t alignment, size_t bytes, const void *caller) top_check (); mem = _int_memalign (&main_arena, alignment, bytes + 1); __libc_lock_unlock (main_arena.mutex); - return mem2mem_check (TAG_NEW_USABLE (mem), bytes); + return mem2mem_check (tag_new_usable (mem), bytes); } #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_25) diff --git a/malloc/malloc.c b/malloc/malloc.c index ecb87350b0..62d00f54cc 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -413,26 +413,26 @@ void *(*__morecore)(ptrdiff_t) = __default_morecore; operations can continue to be used. Support macros are used to do this: - void *TAG_NEW_MEMSET (void *ptr, int, val, size_t size) + void *tag_new_memset (void *ptr, int, val, size_t size) Has the same interface as memset(), but additionally allocates a new tag, colors the memory with that tag and returns a pointer that is correctly colored for that location. The non-tagging version will simply call memset. - void *TAG_REGION (void *ptr, size_t size) + void *tag_region (void *ptr, size_t size) Color the region of memory pointed to by PTR and size SIZE with the color of PTR. Returns the original pointer. - void *TAG_NEW_USABLE (void *ptr) + void *tag_new_usable (void *ptr) Allocate a new random color and use it to color the user region of a chunk; this may include data from the subsequent chunk's header if tagging is sufficiently fine grained. Returns PTR suitably recolored for accessing the memory there. - void *TAG_AT (void *ptr) + void *tag_at (void *ptr) Read the current color of the memory at the address pointed to by PTR (ignoring it's current color) and return PTR recolored to that @@ -455,25 +455,20 @@ __default_tag_nop (void *ptr) return ptr; } -static int __mtag_mmap_flags = 0; -static size_t __mtag_granule_mask = ~(size_t)0; +static int mtag_mmap_flags = 0; +static size_t mtag_granule_mask = ~(size_t)0; -static void *(*__tag_new_memset)(void *, int, size_t) = memset; -static void *(*__tag_region)(void *, size_t) = __default_tag_region; -static void *(*__tag_new_usable)(void *) = __default_tag_nop; -static void *(*__tag_at)(void *) = __default_tag_nop; +static void *(*tag_new_memset)(void *, int, size_t) = memset; +static void *(*tag_region)(void *, size_t) = __default_tag_region; +static void *(*tag_new_usable)(void *) = __default_tag_nop; +static void *(*tag_at)(void *) = __default_tag_nop; -# define MTAG_MMAP_FLAGS __mtag_mmap_flags -# define TAG_NEW_MEMSET(ptr, val, size) __tag_new_memset (ptr, val, size) -# define TAG_REGION(ptr, size) __tag_region (ptr, size) -# define TAG_NEW_USABLE(ptr) __tag_new_usable (ptr) -# define TAG_AT(ptr) __tag_at (ptr) #else -# define MTAG_MMAP_FLAGS 0 -# define TAG_NEW_MEMSET(ptr, val, size) memset (ptr, val, size) -# define TAG_REGION(ptr, size) (ptr) -# define TAG_NEW_USABLE(ptr) (ptr) -# define TAG_AT(ptr) (ptr) +# define mtag_mmap_flags 0 +# define tag_new_memset(ptr, val, size) memset (ptr, val, size) +# define tag_region(ptr, size) (ptr) +# define tag_new_usable(ptr) (ptr) +# define tag_at(ptr) (ptr) #endif #include @@ -1305,8 +1300,8 @@ nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /* Convert between user mem pointers and chunk pointers, updating any memory tags on the pointer to respect the tag value at that location. */ -#define chunk2mem(p) ((void*)TAG_AT (((char*)(p) + CHUNK_HDR_SZ))) -#define mem2chunk(mem) ((mchunkptr)TAG_AT (((char*)(mem) - CHUNK_HDR_SZ))) +#define chunk2mem(p) ((void *)tag_at (((char*)(p) + CHUNK_HDR_SZ))) +#define mem2chunk(mem) ((mchunkptr)tag_at (((char*)(mem) - CHUNK_HDR_SZ))) /* The smallest possible chunk */ #define MIN_CHUNK_SIZE (offsetof(struct malloc_chunk, fd_nextsize)) @@ -1337,7 +1332,7 @@ nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ #ifdef USE_MTAG #define CHUNK_AVAILABLE_SIZE(p) \ ((chunksize (p) + (chunk_is_mmapped (p) ? 0 : SIZE_SZ)) \ - & __mtag_granule_mask) + & mtag_granule_mask) #else #define CHUNK_AVAILABLE_SIZE(p) \ (chunksize (p) + (chunk_is_mmapped (p) ? 0 : SIZE_SZ)) @@ -1361,7 +1356,7 @@ checked_request2size (size_t req, size_t *sz) __nonnull (1) number. Ideally, this would be part of request2size(), but that must be a macro that produces a compile time constant if passed a constant literal. */ - req = (req + ~__mtag_granule_mask) & __mtag_granule_mask; + req = (req + ~mtag_granule_mask) & mtag_granule_mask; #endif *sz = request2size (req); @@ -2467,7 +2462,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av) if ((unsigned long) (size) > (unsigned long) (nb)) { mm = (char *) (MMAP (0, size, - MTAG_MMAP_FLAGS | PROT_READ | PROT_WRITE, 0)); + mtag_mmap_flags | PROT_READ | PROT_WRITE, 0)); if (mm != MAP_FAILED) { @@ -2665,7 +2660,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av) if ((unsigned long) (size) > (unsigned long) (nb)) { char *mbrk = (char *) (MMAP (0, size, - MTAG_MMAP_FLAGS | PROT_READ | PROT_WRITE, + mtag_mmap_flags | PROT_READ | PROT_WRITE, 0)); if (mbrk != MAP_FAILED) @@ -3221,14 +3216,14 @@ __libc_malloc (size_t bytes) && tcache->counts[tc_idx] > 0) { victim = tcache_get (tc_idx); - return TAG_NEW_USABLE (victim); + return tag_new_usable (victim); } DIAG_POP_NEEDS_COMMENT; #endif if (SINGLE_THREAD_P) { - victim = TAG_NEW_USABLE (_int_malloc (&main_arena, bytes)); + victim = tag_new_usable (_int_malloc (&main_arena, bytes)); assert (!victim || chunk_is_mmapped (mem2chunk (victim)) || &main_arena == arena_for_chunk (mem2chunk (victim))); return victim; @@ -3249,7 +3244,7 @@ __libc_malloc (size_t bytes) if (ar_ptr != NULL) __libc_lock_unlock (ar_ptr->mutex); - victim = TAG_NEW_USABLE (victim); + victim = tag_new_usable (victim); assert (!victim || chunk_is_mmapped (mem2chunk (victim)) || ar_ptr == arena_for_chunk (mem2chunk (victim))); @@ -3305,7 +3300,7 @@ __libc_free (void *mem) MAYBE_INIT_TCACHE (); /* Mark the chunk as belonging to the library again. */ - (void)TAG_REGION (chunk2rawmem (p), + (void)tag_region (chunk2rawmem (p), CHUNK_AVAILABLE_SIZE (p) - CHUNK_HDR_SZ); ar_ptr = arena_for_chunk (p); @@ -3408,7 +3403,7 @@ __libc_realloc (void *oldmem, size_t bytes) reused. There's a performance hit for both us and the caller for doing this, so we might want to reconsider. */ - return TAG_NEW_USABLE (newmem); + return tag_new_usable (newmem); } #endif /* Note the extra SIZE_SZ overhead. */ @@ -3451,7 +3446,7 @@ __libc_realloc (void *oldmem, size_t bytes) { size_t sz = CHUNK_AVAILABLE_SIZE (oldp) - CHUNK_HDR_SZ; memcpy (newp, oldmem, sz); - (void) TAG_REGION (chunk2rawmem (oldp), sz); + (void) tag_region (chunk2rawmem (oldp), sz); _int_free (ar_ptr, oldp, 0); } } @@ -3509,7 +3504,7 @@ _mid_memalign (size_t alignment, size_t bytes, void *address) p = _int_memalign (&main_arena, alignment, bytes); assert (!p || chunk_is_mmapped (mem2chunk (p)) || &main_arena == arena_for_chunk (mem2chunk (p))); - return TAG_NEW_USABLE (p); + return tag_new_usable (p); } arena_get (ar_ptr, bytes + alignment + MINSIZE); @@ -3527,7 +3522,7 @@ _mid_memalign (size_t alignment, size_t bytes, void *address) assert (!p || chunk_is_mmapped (mem2chunk (p)) || ar_ptr == arena_for_chunk (mem2chunk (p))); - return TAG_NEW_USABLE (p); + return tag_new_usable (p); } /* For ISO C11. */ weak_alias (__libc_memalign, aligned_alloc) @@ -3544,7 +3539,7 @@ __libc_valloc (size_t bytes) void *address = RETURN_ADDRESS (0); size_t pagesize = GLRO (dl_pagesize); p = _mid_memalign (pagesize, bytes, address); - return TAG_NEW_USABLE (p); + return tag_new_usable (p); } void * @@ -3569,7 +3564,7 @@ __libc_pvalloc (size_t bytes) rounded_bytes = rounded_bytes & -(pagesize - 1); p = _mid_memalign (pagesize, rounded_bytes, address); - return TAG_NEW_USABLE (p); + return tag_new_usable (p); } void * @@ -3666,7 +3661,7 @@ __libc_calloc (size_t n, size_t elem_size) regardless of MORECORE_CLEARS, so we zero the whole block while doing so. */ #ifdef USE_MTAG - return TAG_NEW_MEMSET (mem, 0, CHUNK_AVAILABLE_SIZE (p) - CHUNK_HDR_SZ); + return tag_new_memset (mem, 0, CHUNK_AVAILABLE_SIZE (p) - CHUNK_HDR_SZ); #else INTERNAL_SIZE_T csz = chunksize (p); @@ -4821,7 +4816,7 @@ _int_realloc(mstate av, mchunkptr oldp, INTERNAL_SIZE_T oldsize, av->top = chunk_at_offset (oldp, nb); set_head (av->top, (newsize - nb) | PREV_INUSE); check_inuse_chunk (av, oldp); - return TAG_NEW_USABLE (chunk2rawmem (oldp)); + return tag_new_usable (chunk2rawmem (oldp)); } /* Try to expand forward into next chunk; split off remainder below */ @@ -4856,8 +4851,8 @@ _int_realloc(mstate av, mchunkptr oldp, INTERNAL_SIZE_T oldsize, { void *oldmem = chunk2rawmem (oldp); size_t sz = CHUNK_AVAILABLE_SIZE (oldp) - CHUNK_HDR_SZ; - (void) TAG_REGION (oldmem, sz); - newmem = TAG_NEW_USABLE (newmem); + (void) tag_region (oldmem, sz); + newmem = tag_new_usable (newmem); memcpy (newmem, oldmem, sz); _int_free (av, oldp, 1); check_inuse_chunk (av, newp); @@ -4881,7 +4876,7 @@ _int_realloc(mstate av, mchunkptr oldp, INTERNAL_SIZE_T oldsize, { remainder = chunk_at_offset (newp, nb); /* Clear any user-space tags before writing the header. */ - remainder = TAG_REGION (remainder, remainder_size); + remainder = tag_region (remainder, remainder_size); set_head_size (newp, nb | (av != &main_arena ? NON_MAIN_ARENA : 0)); set_head (remainder, remainder_size | PREV_INUSE | (av != &main_arena ? NON_MAIN_ARENA : 0)); @@ -4891,7 +4886,7 @@ _int_realloc(mstate av, mchunkptr oldp, INTERNAL_SIZE_T oldsize, } check_inuse_chunk (av, newp); - return TAG_NEW_USABLE (chunk2rawmem (newp)); + return tag_new_usable (chunk2rawmem (newp)); } /* @@ -5108,7 +5103,7 @@ musable (void *mem) /* The usable space may be reduced if memory tagging is needed, since we cannot share the user-space data with malloc's internal data structure. */ - result &= __mtag_granule_mask; + result &= mtag_granule_mask; #endif return result; }