Fix: handle sys_futex() FUTEX_WAIT interrupted by signal

[urcu.git] / compat_futex.c

diff --git a/compat_futex.c b/compat_futex.c
index 6ec0b3912b34afbda58c873371f83aec55d35f68..a3571343ca37d086e77620da1ed0dd5e9fd71778 100644 (file)
--- a/compat_futex.c
+++ b/compat_futex.c
@@ -54,7 +54,7 @@ pthread_cond_t __urcu_compat_futex_cond = PTHREAD_COND_INITIALIZER;
 int compat_futex_noasync(int32_t *uaddr, int op, int32_t val,
        const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
 {
-       int ret, gret = 0;
+       int ret;
 
        /*
         * Check if NULL. Don't let users expect that they are taken into
@@ -70,7 +70,11 @@ int compat_futex_noasync(int32_t *uaddr, int op, int32_t val,
        cmm_smp_mb();
 
        ret = pthread_mutex_lock(&__urcu_compat_futex_lock);
-       assert(!ret);
+       if (ret) {
+               errno = ret;
+               ret = -1;
+               goto end;
+       }
        switch (op) {
        case FUTEX_WAIT:
                /*
@@ -91,11 +95,16 @@ int compat_futex_noasync(int32_t *uaddr, int op, int32_t val,
                pthread_cond_broadcast(&__urcu_compat_futex_cond);
                break;
        default:
-               gret = -EINVAL;
+               errno = EINVAL;
+               ret = -1;
        }
        ret = pthread_mutex_unlock(&__urcu_compat_futex_lock);
-       assert(!ret);
-       return gret;
+       if (ret) {
+               errno = ret;
+               ret = -1;
+       }
+end:
+       return ret;
 }
 
 /*
@@ -107,6 +116,8 @@ int compat_futex_noasync(int32_t *uaddr, int op, int32_t val,
 int compat_futex_async(int32_t *uaddr, int op, int32_t val,
        const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
 {
+       int ret = 0;
+
        /*
         * Check if NULL. Don't let users expect that they are taken into
         * account. 
@@ -122,13 +133,20 @@ int compat_futex_async(int32_t *uaddr, int op, int32_t val,
 
        switch (op) {
        case FUTEX_WAIT:
-               while (CMM_LOAD_SHARED(*uaddr) == val)
-                       poll(NULL, 0, 10);
+               while (CMM_LOAD_SHARED(*uaddr) == val) {
+                       if (poll(NULL, 0, 10) < 0) {
+                               ret = -1;
+                               /* Keep poll errno. Caller handles EINTR. */
+                               goto end;
+                       }
+               }
                break;
        case FUTEX_WAKE:
                break;
        default:
-               return -EINVAL;
+               errno = EINVAL;
+               ret = -1;
        }
-       return 0;
+end:
+       return ret;
 }