diff options
| -rw-r--r-- | thread_pthread_mn.c | 39 |
1 files changed, 22 insertions, 17 deletions
diff --git a/thread_pthread_mn.c b/thread_pthread_mn.c index 5c21f212e4..569def6c0c 100644 --- a/thread_pthread_mn.c +++ b/thread_pthread_mn.c @@ -194,7 +194,7 @@ nt_alloc_thread_stack_chunk(void) mmap_flags |= MAP_STACK; #endif - const char *m = (void *)mmap(NULL, MSTACK_CHUNK_SIZE, PROT_READ | PROT_WRITE, mmap_flags, -1, 0); + const char *m = (void *)mmap(NULL, MSTACK_CHUNK_SIZE, PROT_NONE, mmap_flags, -1, 0); if (m == MAP_FAILED) { return NULL; } @@ -213,6 +213,12 @@ nt_alloc_thread_stack_chunk(void) VM_ASSERT(stack_count <= UINT16_MAX); + // Enable read/write for the header pages + if (mprotect((void *)m, (size_t)header_page_cnt * MSTACK_PAGE_SIZE, PROT_READ | PROT_WRITE) != 0) { + munmap((void *)m, MSTACK_CHUNK_SIZE); + return NULL; + } + struct nt_stack_chunk_header *ch = (struct nt_stack_chunk_header *)m; ch->start_page = header_page_cnt; @@ -241,7 +247,7 @@ nt_stack_chunk_get_msf(const rb_vm_t *vm, const char *mstack) return (struct nt_machine_stack_footer *)&mstack[msz - sizeof(struct nt_machine_stack_footer)]; } -static void * +static void nt_stack_chunk_get_stack(const rb_vm_t *vm, struct nt_stack_chunk_header *ch, size_t idx, void **vm_stack, void **machine_stack) { // TODO: only support stack going down @@ -266,8 +272,6 @@ nt_stack_chunk_get_stack(const rb_vm_t *vm, struct nt_stack_chunk_header *ch, si *vm_stack = (void *)vstack; *machine_stack = (void *)mstack; - - return (void *)guard_page; } RBIMPL_ATTR_MAYBE_UNUSED() @@ -291,17 +295,6 @@ nt_stack_chunk_dump(void) } static int -nt_guard_page(const char *p, size_t len) -{ - if (mprotect((void *)p, len, PROT_NONE) != -1) { - return 0; - } - else { - return errno; - } -} - -static int nt_alloc_stack(rb_vm_t *vm, void **vm_stack, void **machine_stack) { int err = 0; @@ -319,8 +312,20 @@ nt_alloc_stack(rb_vm_t *vm, void **vm_stack, void **machine_stack) RUBY_DEBUG_LOG("uninitialized_stack_count:%d", ch->uninitialized_stack_count); size_t idx = ch->stack_count - ch->uninitialized_stack_count--; - void *guard_page = nt_stack_chunk_get_stack(vm, ch, idx, vm_stack, machine_stack); - err = nt_guard_page(guard_page, MSTACK_PAGE_SIZE); + + // The chunk was mapped PROT_NONE; enable the VM stack and + // machine stack pages, leaving the guard page as PROT_NONE. + char *stack_start = nt_stack_chunk_get_stack_start(ch, idx); + size_t vm_stack_size = vm->default_params.thread_vm_stack_size; + size_t mstack_size = nt_thread_stack_size() - vm_stack_size - MSTACK_PAGE_SIZE; + + if (mprotect(stack_start, vm_stack_size, PROT_READ | PROT_WRITE) != 0 || + mprotect(stack_start + vm_stack_size + MSTACK_PAGE_SIZE, mstack_size, PROT_READ | PROT_WRITE) != 0) { + err = errno; + } + else { + nt_stack_chunk_get_stack(vm, ch, idx, vm_stack, machine_stack); + } } else { nt_free_stack_chunks = ch->prev_free_chunk; |