Reserve enough user request stack space in pthread_create.
Bug: 18830897
Change-Id: I1ba4aaeaf66a7ff99c5d82ad45469011171b0a3b
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index c47b750..9b45161 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -106,25 +106,25 @@
return error;
}
-static void* __create_thread_stack(const pthread_attr_t& attr) {
+static void* __create_thread_stack(size_t stack_size, size_t guard_size) {
// Create a new private anonymous map.
int prot = PROT_READ | PROT_WRITE;
int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
- void* stack = mmap(NULL, attr.stack_size, prot, flags, -1, 0);
+ void* stack = mmap(NULL, stack_size, prot, flags, -1, 0);
if (stack == MAP_FAILED) {
__libc_format_log(ANDROID_LOG_WARN,
"libc",
"pthread_create failed: couldn't allocate %zd-byte stack: %s",
- attr.stack_size, strerror(errno));
+ stack_size, strerror(errno));
return NULL;
}
// Set the guard region at the end of the stack to PROT_NONE.
- if (mprotect(stack, attr.guard_size, PROT_NONE) == -1) {
+ if (mprotect(stack, guard_size, PROT_NONE) == -1) {
__libc_format_log(ANDROID_LOG_WARN, "libc",
"pthread_create failed: couldn't mprotect PROT_NONE %zd-byte stack guard region: %s",
- attr.guard_size, strerror(errno));
- munmap(stack, attr.stack_size);
+ guard_size, strerror(errno));
+ munmap(stack, stack_size);
return NULL;
}
@@ -132,30 +132,36 @@
}
static int __allocate_thread(pthread_attr_t* attr, pthread_internal_t** threadp, void** child_stack) {
+ size_t allocate_stack_size;
+ uint8_t* stack_top;
+
if (attr->stack_base == NULL) {
// The caller didn't provide a stack, so allocate one.
// Make sure the stack size and guard size are multiples of PAGE_SIZE.
- attr->stack_size = BIONIC_ALIGN(attr->stack_size, PAGE_SIZE);
+ allocate_stack_size = BIONIC_ALIGN(attr->stack_size + sizeof(pthread_internal_t), PAGE_SIZE);
attr->guard_size = BIONIC_ALIGN(attr->guard_size, PAGE_SIZE);
- attr->stack_base = __create_thread_stack(*attr);
+ attr->stack_base = __create_thread_stack(allocate_stack_size, attr->guard_size);
if (attr->stack_base == NULL) {
return EAGAIN;
}
+ stack_top = reinterpret_cast<uint8_t*>(attr->stack_base) + allocate_stack_size;
} else {
// The caller did provide a stack, so remember we're not supposed to free it.
attr->flags |= PTHREAD_ATTR_FLAG_USER_ALLOCATED_STACK;
+ allocate_stack_size = 0;
+ stack_top = reinterpret_cast<uint8_t*>(attr->stack_base) + attr->stack_size;
}
// Thread stack is used for two sections:
// pthread_internal_t.
// regular stack, from top to down.
- uint8_t* stack_top = reinterpret_cast<uint8_t*>(attr->stack_base) + attr->stack_size;
stack_top -= sizeof(pthread_internal_t);
pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(stack_top);
// No need to check stack_top alignment. The size of pthread_internal_t is 16-bytes aligned,
// and user allocated stack is guaranteed by pthread_attr_setstack.
+ thread->allocated_stack_size = allocate_stack_size;
thread->attr = *attr;
__init_tls(thread);
@@ -243,7 +249,7 @@
// reminder that you can't rewrite this function to use a ScopedPthreadMutexLocker.
pthread_mutex_unlock(&thread->startup_handshake_mutex);
if (!thread->user_allocated_stack()) {
- munmap(thread->attr.stack_base, thread->attr.stack_size);
+ munmap(thread->attr.stack_base, thread->allocated_stack_size);
}
__libc_format_log(ANDROID_LOG_WARN, "libc", "pthread_create failed: clone failed: %s", strerror(errno));
return clone_errno;
diff --git a/libc/bionic/pthread_exit.cpp b/libc/bionic/pthread_exit.cpp
index e04cf8e..ee76e2b 100644
--- a/libc/bionic/pthread_exit.cpp
+++ b/libc/bionic/pthread_exit.cpp
@@ -89,7 +89,7 @@
// Keep track of what we need to know about the stack before we lose the pthread_internal_t.
void* stack_base = thread->attr.stack_base;
- size_t stack_size = thread->attr.stack_size;
+ size_t stack_size = thread->allocated_stack_size;
bool free_stack = false;
pthread_mutex_lock(&g_thread_list_lock);
diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index 95097b7..62ec543 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -86,6 +86,9 @@
pthread_mutex_t startup_handshake_mutex;
+ /* Store real allocated stack size, including thread stack and pthread_internal_t. */
+ int allocated_stack_size;
+
void* tls[BIONIC_TLS_SLOTS];
/*
diff --git a/libc/bionic/pthread_internals.cpp b/libc/bionic/pthread_internals.cpp
index 7c30e6e..a0a8df0 100644
--- a/libc/bionic/pthread_internals.cpp
+++ b/libc/bionic/pthread_internals.cpp
@@ -53,9 +53,9 @@
// For threads using user allocated stack (including the main thread), the pthread_internal_t
// can't be freed since it is on the stack.
- if (free_thread && !(thread->attr.flags & PTHREAD_ATTR_FLAG_USER_ALLOCATED_STACK)) {
- // Use one munmap to free the whole thread stack, including pthread_internal_t.
- munmap(thread->attr.stack_base, thread->attr.stack_size);
+ if (free_thread && !thread->user_allocated_stack()) {
+ // Use one munmap to free allocated stack size, including thread stack and pthread_internal_t.
+ munmap(thread->attr.stack_base, thread->allocated_stack_size);
}
}