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-rw-r--r--src/thread/pthread_create.c29
-rw-r--r--src/thread/pthread_mutexattr_setrobust.c24
2 files changed, 27 insertions, 26 deletions
diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index b6a7a5ef..893773fa 100644
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -4,10 +4,13 @@
#include "libc.h"
#include <sys/mman.h>
#include <string.h>
+#include <stddef.h>
void *__mmap(void *, size_t, int, int, int, off_t);
int __munmap(void *, size_t);
int __mprotect(void *, size_t, int);
+void __vm_lock_impl(int);
+void __vm_unlock_impl(void);
static void dummy_0()
{
@@ -15,7 +18,6 @@ static void dummy_0()
weak_alias(dummy_0, __acquire_ptc);
weak_alias(dummy_0, __release_ptc);
weak_alias(dummy_0, __pthread_tsd_run_dtors);
-weak_alias(dummy_0, __do_private_robust_list);
weak_alias(dummy_0, __do_orphaned_stdio_locks);
_Noreturn void __pthread_exit(void *result)
@@ -72,7 +74,25 @@ _Noreturn void __pthread_exit(void *result)
a_dec(&libc.bytelocale_cnt_minus_1);
}
- __do_private_robust_list();
+ /* Process robust list in userspace to handle non-pshared mutexes
+ * and the detached thread case where the robust list head will
+ * be invalid when the kernel would process it. */
+ __vm_lock_impl(+1);
+ volatile void *volatile *rp;
+ while ((rp=self->robust_list.head) && rp != &self->robust_list.head) {
+ pthread_mutex_t *m = (void *)((char *)rp
+ - offsetof(pthread_mutex_t, _m_next));
+ int waiters = m->_m_waiters;
+ int priv = (m->_m_type & 128) ^ 128;
+ self->robust_list.pending = rp;
+ self->robust_list.head = *rp;
+ int cont = a_swap(&m->_m_lock, self->tid|0x40000000);
+ self->robust_list.pending = 0;
+ if (cont < 0 || waiters)
+ __wake(&m->_m_lock, 1, priv);
+ }
+ __vm_unlock_impl();
+
__do_orphaned_stdio_locks();
if (self->detached && self->map_base) {
@@ -85,6 +105,11 @@ _Noreturn void __pthread_exit(void *result)
* detached later (== 2), we need to clear it here. */
if (self->detached == 2) __syscall(SYS_set_tid_address, 0);
+ /* Robust list will no longer be valid, and was already
+ * processed above, so unregister it with the kernel. */
+ if (self->robust_list.off)
+ __syscall(SYS_set_robust_list, 0, 3*sizeof(long));
+
/* The following call unmaps the thread's stack mapping
* and then exits without touching the stack. */
__unmapself(self->map_base, self->map_size);
diff --git a/src/thread/pthread_mutexattr_setrobust.c b/src/thread/pthread_mutexattr_setrobust.c
index d0627889..dcfa4cf1 100644
--- a/src/thread/pthread_mutexattr_setrobust.c
+++ b/src/thread/pthread_mutexattr_setrobust.c
@@ -1,28 +1,4 @@
#include "pthread_impl.h"
-#include <stddef.h>
-
-void __do_private_robust_list()
-{
- pthread_t self = __pthread_self();
- volatile void *volatile *p;
- volatile void *volatile *prev;
- volatile void *volatile *next;
- pthread_mutex_t *m;
-
- prev = &self->robust_list.head;
- for (p=self->robust_list.head; p&&p!=&self->robust_list.head; p=next) {
- next = *p;
- m = (void *)((char *)p - offsetof(pthread_mutex_t, _m_next));
- if (!(m->_m_type & 128)) {
- int waiters = m->_m_waiters;
- *prev = next;
- int cont = a_swap(&m->_m_lock, self->tid|0x40000000);
- if (cont < 0 || waiters) __wake(&m->_m_lock, 1, 1);
- } else {
- prev = p;
- }
- }
-}
int pthread_mutexattr_setrobust(pthread_mutexattr_t *a, int robust)
{