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hardened_malloc
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add CSPRNGs for regions and slabs

pull/50/head
Daniel Micay 2018-08-25 00:21:02 -04:00
parent 510291646b
commit f3c8502509
1 changed files with 9 additions and 1 deletions
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10
malloc.c
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@ -193,6 +193,7 @@ static struct size_class {
struct slab_metadata *free_slabs;
struct slab_metadata *slab_info;
pthread_mutex_t mutex;
struct random_state rng;
} size_class_metadata[N_SIZE_CLASSES];
static const size_t class_region_size = 128ULL * 1024 * 1024 * 1024;
@ -440,6 +441,7 @@ struct region_info {
static const size_t initial_region_table_size = 256;
static struct random_state regions_rng;
static struct region_info *regions;
static size_t regions_total = initial_region_table_size;
static size_t regions_free = initial_region_table_size;
@ -560,10 +562,13 @@ static void post_fork_child(void) {
if (pthread_mutex_init(&regions_lock, NULL)) {
fatal_error("mutex initialization failed");
}
random_state_init(&regions_rng);
for (unsigned i = 0; i < N_SIZE_CLASSES; i++) {
if (pthread_mutex_init(&size_class_metadata[i].mutex, NULL)) {
struct size_class *c = &size_class_metadata[i];
if (pthread_mutex_init(&c->mutex, NULL)) {
fatal_error("mutex initialization failed");
}
random_state_init(&c->rng);
}
}
@ -586,6 +591,7 @@ COLD static void init_slow_path(void) {
if (regions == NULL) {
fatal_error("failed to set up allocator");
}
random_state_init(&regions_rng);
ro.slab_region_start = memory_map(slab_region_size);
if (ro.slab_region_start == NULL) {
@ -600,6 +606,8 @@ COLD static void init_slow_path(void) {
fatal_error("mutex initialization failed");
}
random_state_init(&c->rng);
size_t bound = (real_class_region_size - class_region_size) / PAGE_SIZE - 1;
size_t gap = (get_random_size_uniform(&rng, bound) + 1) * PAGE_SIZE;
c->class_region_start = (char *)ro.slab_region_start + real_class_region_size * i + gap;