Fix: compat futex duplicated lock and completion

[urcu.git] / urcu-bp.c

diff --git a/urcu-bp.c b/urcu-bp.c
index 67eae07b6e1b3f69c9cc4739d524dd45de899daf..f28ef89df4de7a6c5723c13f964d452aa72d5969 100644 (file)
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -42,6 +42,8 @@
 #include "urcu-pointer.h"
 #include "urcu/tls-compat.h"
 
+#include "urcu-die.h"
+
 /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
 #undef _LGPL_SOURCE
 #include "urcu-bp.h"
@@ -142,17 +144,12 @@ static void mutex_lock(pthread_mutex_t *mutex)
 
 #ifndef DISTRUST_SIGNALS_EXTREME
        ret = pthread_mutex_lock(mutex);
-       if (ret) {
-               perror("Error in pthread mutex lock");
-               exit(-1);
-       }
+       if (ret)
+               urcu_die(ret);
 #else /* #ifndef DISTRUST_SIGNALS_EXTREME */
        while ((ret = pthread_mutex_trylock(mutex)) != 0) {
-               if (ret != EBUSY && ret != EINTR) {
-                       printf("ret = %d, errno = %d\n", ret, errno);
-                       perror("Error in pthread mutex lock");
-                       exit(-1);
-               }
+               if (ret != EBUSY && ret != EINTR)
+                       urcu_die(ret);
                poll(NULL,0,10);
        }
 #endif /* #else #ifndef DISTRUST_SIGNALS_EXTREME */
@@ -163,10 +160,8 @@ static void mutex_unlock(pthread_mutex_t *mutex)
        int ret;
 
        ret = pthread_mutex_unlock(mutex);
-       if (ret) {
-               perror("Error in pthread mutex unlock");
-               exit(-1);
-       }
+       if (ret)
+               urcu_die(ret);
 }
 
 void update_counter_and_wait(void)
@@ -220,9 +215,9 @@ void synchronize_rcu(void)
        sigset_t newmask, oldmask;
        int ret;
 
-       ret = sigemptyset(&newmask);
+       ret = sigfillset(&newmask);
        assert(!ret);
-       ret = pthread_sigmask(SIG_SETMASK, &newmask, &oldmask);
+       ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
        assert(!ret);
 
        mutex_lock(&rcu_gp_lock);
@@ -285,26 +280,37 @@ void rcu_read_unlock(void)
  */
 static void resize_arena(struct registry_arena *arena, size_t len)
 {
-       void *new_arena;
+       void *new_p;
+       size_t old_len;
+
+       old_len = arena->len;
 
        if (!arena->p)
-               new_arena = mmap(arena->p, len,
-                                PROT_READ | PROT_WRITE,
-                                MAP_ANONYMOUS | MAP_PRIVATE,
-                                -1, 0);
+               new_p = mmap(arena->p, len,
+                       PROT_READ | PROT_WRITE,
+                       MAP_ANONYMOUS | MAP_PRIVATE,
+                       -1, 0);
        else
-               new_arena = mremap_wrapper(arena->p, arena->len,
-                                       len, MREMAP_MAYMOVE);
-       assert(new_arena != MAP_FAILED);
+               new_p = mremap_wrapper(arena->p, old_len,
+                       len, MREMAP_MAYMOVE);
+       assert(new_p != MAP_FAILED);
+
+       /*
+        * Zero the newly allocated memory. Since mmap() does not
+        * clearly specify if memory is zeroed or not (although it is
+        * very likely that it is), be extra careful by not expecting
+        * the new range to be zeroed by mremap.
+        */
+       bzero(new_p + old_len, len - old_len);
 
        /*
-        * re-used the same region ?
+        * If we did not re-use the same region, we need to update the
+        * arena pointer.
         */
-       if (new_arena == arena->p)
-               return;
+       if (new_p != arena->p)
+               arena->p = new_p;
 
-       bzero(new_arena + arena->len, len - arena->len);
-       arena->p = new_arena;
+       arena->len = len;
 }
 
 /* Called with signals off and mutex locked */
@@ -365,9 +371,9 @@ void rcu_bp_register(void)
        sigset_t newmask, oldmask;
        int ret;
 
-       ret = sigemptyset(&newmask);
+       ret = sigfillset(&newmask);
        assert(!ret);
-       ret = pthread_sigmask(SIG_SETMASK, &newmask, &oldmask);
+       ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
        assert(!ret);
 
        /*
@@ -400,9 +406,9 @@ void rcu_bp_before_fork(void)
        sigset_t newmask, oldmask;
        int ret;
 
-       ret = sigemptyset(&newmask);
+       ret = sigfillset(&newmask);
        assert(!ret);
-       ret = pthread_sigmask(SIG_SETMASK, &newmask, &oldmask);
+       ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
        assert(!ret);
        mutex_lock(&rcu_gp_lock);
        saved_fork_signal_mask = oldmask;