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hardened_malloc
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avoid reading thread_local more than once

pull/87/head
Daniel Micay 2019-04-14 19:57:22 -04:00
parent 7e465c621e
commit e7eeb3f35c
1 changed files with 29 additions and 30 deletions
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59
h_malloc.c
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@ -56,7 +56,7 @@ static_assert(N_ARENA <= 4, "currently only support up to 4 arenas (as an initia
#if N_ARENA > 1
__attribute__((tls_model("initial-exec")))
static thread_local unsigned thread_arena = N_ARENA;
static _Atomic unsigned thread_arena_counter = 0;
static atomic_uint thread_arena_counter = 0;
#else
static const unsigned thread_arena = 0;
#endif
@ -473,11 +473,11 @@ static inline void stats_slab_deallocate(UNUSED struct size_class *c, UNUSED siz
#endif
}
static inline void *allocate_small(size_t requested_size) {
static inline void *allocate_small(unsigned arena, size_t requested_size) {
struct size_info info = get_size_info(requested_size);
size_t size = info.size ? info.size : 16;
struct size_class *c = &ro.size_class_metadata[thread_arena][info.class];
struct size_class *c = &ro.size_class_metadata[arena][info.class];
size_t slots = size_class_slots[info.class];
size_t slab_size = get_slab_size(slots, size);
@ -1151,19 +1151,18 @@ COLD static void init_slow_path(void) {
}
}
static inline void init(void) {
static inline unsigned init(void) {
unsigned arena = thread_arena;
#if N_ARENA > 1
if (unlikely(thread_arena >= N_ARENA)) {
thread_arena = thread_arena_counter++ % N_ARENA;
if (unlikely(!is_init())) {
init_slow_path();
}
if (likely(arena < N_ARENA)) {
return arena;
}
#else
thread_arena = arena = thread_arena_counter++ % N_ARENA;
#endif
if (unlikely(!is_init())) {
init_slow_path();
}
#endif
return arena;
}
// trigger early initialization to set up pthread_atfork and protect state as soon as possible
@ -1225,8 +1224,8 @@ static void *allocate_large(size_t size) {
return p;
}
static inline void *allocate(size_t size) {
return size <= max_slab_size_class ? allocate_small(size) : allocate_large(size);
static inline void *allocate(unsigned arena, size_t size) {
return size <= max_slab_size_class ? allocate_small(arena, size) : allocate_large(size);
}
static void deallocate_large(void *p, const size_t *expected_size) {
@ -1252,7 +1251,7 @@ static void deallocate_large(void *p, const size_t *expected_size) {
regions_quarantine_deallocate_pages(p, size, guard_size);
}
static int alloc_aligned(void **memptr, size_t alignment, size_t size, size_t min_alignment) {
static int alloc_aligned(unsigned arena, void **memptr, size_t alignment, size_t size, size_t min_alignment) {
if ((alignment - 1) & alignment || alignment < min_alignment) {
return EINVAL;
}
@ -1262,7 +1261,7 @@ static int alloc_aligned(void **memptr, size_t alignment, size_t size, size_t mi
size = get_size_info_align(size, alignment).size;
}
void *p = allocate(size);
void *p = allocate(arena, size);
if (p == NULL) {
return ENOMEM;
}
@ -1298,9 +1297,9 @@ static int alloc_aligned(void **memptr, size_t alignment, size_t size, size_t mi
return 0;
}
static void *alloc_aligned_simple(size_t alignment, size_t size) {
static void *alloc_aligned_simple(unsigned arena, size_t alignment, size_t size) {
void *ptr;
int ret = alloc_aligned(&ptr, alignment, size, 1);
int ret = alloc_aligned(arena, &ptr, alignment, size, 1);
if (ret) {
errno = ret;
return NULL;
@ -1316,10 +1315,10 @@ static size_t adjust_size_for_canaries(size_t size) {
}
static inline void *alloc(size_t size) {
init();
unsigned arena = init();
thread_unseal_metadata();
size = adjust_size_for_canaries(size);
void *p = allocate(size);
void *p = allocate(arena, size);
thread_seal_metadata();
return p;
}
@ -1334,10 +1333,10 @@ EXPORT void *h_calloc(size_t nmemb, size_t size) {
errno = ENOMEM;
return NULL;
}
init();
unsigned arena = init();
thread_unseal_metadata();
total_size = adjust_size_for_canaries(total_size);
void *p = allocate(total_size);
void *p = allocate(arena, total_size);
thread_seal_metadata();
if (!ZERO_ON_FREE && likely(p != NULL) && total_size && total_size <= max_slab_size_class) {
memset(p, 0, total_size - canary_size);
@ -1463,7 +1462,7 @@ EXPORT void *h_realloc(void *old, size_t size) {
}
}
void *new = allocate(size);
void *new = allocate(thread_arena, size);
if (new == NULL) {
thread_seal_metadata();
return NULL;
@ -1483,19 +1482,19 @@ EXPORT void *h_realloc(void *old, size_t size) {
}
EXPORT int h_posix_memalign(void **memptr, size_t alignment, size_t size) {
init();
unsigned arena = init();
thread_unseal_metadata();
size = adjust_size_for_canaries(size);
int ret = alloc_aligned(memptr, alignment, size, sizeof(void *));
int ret = alloc_aligned(arena, memptr, alignment, size, sizeof(void *));
thread_seal_metadata();
return ret;
}
EXPORT void *h_aligned_alloc(size_t alignment, size_t size) {
init();
unsigned arena = init();
thread_unseal_metadata();
size = adjust_size_for_canaries(size);
void *p = alloc_aligned_simple(alignment, size);
void *p = alloc_aligned_simple(arena, alignment, size);
thread_seal_metadata();
return p;
}
@ -1504,10 +1503,10 @@ EXPORT void *h_memalign(size_t alignment, size_t size) ALIAS(h_aligned_alloc);
#ifndef __ANDROID__
EXPORT void *h_valloc(size_t size) {
init();
unsigned arena = init();
thread_unseal_metadata();
size = adjust_size_for_canaries(size);
void *p = alloc_aligned_simple(PAGE_SIZE, size);
void *p = alloc_aligned_simple(arena, PAGE_SIZE, size);
thread_seal_metadata();
return p;
}
@ -1518,10 +1517,10 @@ EXPORT void *h_pvalloc(size_t size) {
errno = ENOMEM;
return NULL;
}
init();
unsigned arena = init();
thread_unseal_metadata();
size = adjust_size_for_canaries(size);
void *p = alloc_aligned_simple(PAGE_SIZE, size);
void *p = alloc_aligned_simple(arena, PAGE_SIZE, size);
thread_seal_metadata();
return p;
}