Fix robust mutex handling after fork

diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index e0526fa7b89665472f0699fe2f4538f1d3b89273..c545b079f4e066868acc911745ed4efaff29c023 100644 (file)
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,3 +1,13 @@
+2011-06-30  Ulrich Drepper  <drepper@gmail.com>
+
+       * nptl-init.c (__nptl_set_robust): New function.
+       (pthread_functions): Add reference.
+       * npthreadP.h: Declare __nptl_set_robust.
+       * sysdeps/pthread/pthread-functions.h (pthread_functions): Add
+       ptr_set_robust member.
+       * sysdeps/unix/sysv/linux/fork.c: Call set_robust_list syscall in
+       child if threads are used.
+
 2011-06-14  Andreas Jaeger  <aj@suse.de>
 
        * pthread_rwlock_init.c: Include <string.h> for memset declaration.

diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index 851bab2bf1998d4ef772768d39efddf76d13cad2..33492c1602126b9fb7b8d7fecce16826ec49e395 100644 (file)
--- a/nptl/nptl-init.c
+++ b/nptl/nptl-init.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002-2007, 2008, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2007, 2008, 2009, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -67,6 +67,13 @@ static const char nptl_version[] __attribute_used__ = VERSION;
 extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
 #endif
 
+#ifdef SHARED
+static
+#else
+extern
+#endif
+void __nptl_set_robust (struct pthread *);
+
 #ifdef SHARED
 static void nptl_freeres (void);
 
@@ -130,7 +137,8 @@ static const struct pthread_functions pthread_functions =
     .ptr__nptl_deallocate_tsd = __nptl_deallocate_tsd,
     .ptr__nptl_setxid = __nptl_setxid,
     /* For now only the stack cache needs to be freed.  */
-    .ptr_freeres = nptl_freeres
+    .ptr_freeres = nptl_freeres,
+    .ptr_set_robust = __nptl_set_robust
   };
 # define ptr_pthread_functions &pthread_functions
 #else
@@ -147,7 +155,17 @@ nptl_freeres (void)
   __unwind_freeres ();
   __free_stacks (0);
 }
+
+
+static
 #endif
+void
+__nptl_set_robust (struct pthread *self)
+{
+  INTERNAL_SYSCALL_DECL (err);
+  INTERNAL_SYSCALL (set_robust_list, err, 2, &self->robust_head,
+                   sizeof (struct robust_list_head));
+}
 
 
 /* For asynchronous cancellation we use a signal.  This is the handler.  */

diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index 43ca44c8296f17f97baeda18cf50f2367ff19651..df4f4d769b0cc3aed1f0db4908560658d0f3a252 100644 (file)
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002-2007, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2007, 2009, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -555,17 +555,20 @@ extern void __pthread_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffe
 
 /* Old cleanup interfaces, still used in libc.so.  */
 extern void _pthread_cleanup_push (struct _pthread_cleanup_buffer *buffer,
-                                   void (*routine) (void *), void *arg);
+                                  void (*routine) (void *), void *arg);
 extern void _pthread_cleanup_pop (struct _pthread_cleanup_buffer *buffer,
-                                  int execute);
+                                 int execute);
 extern void _pthread_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer,
-                                         void (*routine) (void *), void *arg);
+                                        void (*routine) (void *), void *arg);
 extern void _pthread_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer,
-                                          int execute);
+                                         int execute);
 
 extern void __nptl_deallocate_tsd (void) attribute_hidden;
 
 extern int __nptl_setxid (struct xid_command *cmdp) attribute_hidden;
+#ifndef SHARED
+extern void __nptl_set_robust (struct pthread *self);
+#endif
 
 extern void __free_stacks (size_t limit) attribute_hidden;
 

diff --git a/nptl/sysdeps/pthread/pthread-functions.h b/nptl/sysdeps/pthread/pthread-functions.h
index 0c404fcbb3c9bc57c65f54fdee956396898f9cba..15a4dff1428aa7422cf7d89e618b721c098f954c 100644 (file)
--- a/nptl/sysdeps/pthread/pthread-functions.h
+++ b/nptl/sysdeps/pthread/pthread-functions.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2003, 2004, 2005, 2006, 2007, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
 
@@ -97,6 +97,7 @@ struct pthread_functions
   void (*ptr__nptl_deallocate_tsd) (void);
   int (*ptr__nptl_setxid) (struct xid_command *);
   void (*ptr_freeres) (void);
+  void (*ptr_set_robust) (struct pthread *);
 };
 
 /* Variable in libc.so.  */

diff --git a/nptl/sysdeps/unix/sysv/linux/fork.c b/nptl/sysdeps/unix/sysv/linux/fork.c
index 524d72c5874eab52427403e28dbde4219509b5d5..80fb147788dcad893227fac4d434148585160f61 100644 (file)
--- a/nptl/sysdeps/unix/sysv/linux/fork.c
+++ b/nptl/sysdeps/unix/sysv/linux/fork.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003, 2007, 2008 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2007, 2008, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -29,6 +29,7 @@
 #include <ldsodefs.h>
 #include <bits/stdio-lock.h>
 #include <atomic.h>
+#include <pthreadP.h>
 
 
 unsigned long int *__fork_generation_pointer;
@@ -86,8 +87,8 @@ __libc_fork (void)
         just go away.  The unloading code works in the order of the
         list.
 
-         While executing the registered handlers we are building a
-         list of all the entries so that we can go backward later on.  */
+        While executing the registered handlers we are building a
+        list of all the entries so that we can go backward later on.  */
       while (1)
        {
          /* Execute the handler if there is one.  */
@@ -154,6 +155,24 @@ __libc_fork (void)
       GL(dl_cpuclock_offset) = now;
 #endif
 
+#ifdef __NR_set_robust_list
+      /* Initialize the robust mutex list which has been reset during
+        the fork.  We do not check for errors since if it fails here
+        it failed at process start as well and noone could have used
+        robust mutexes.  We also do not have to set
+        self->robust_head.futex_offset since we inherit the correct
+        value from the parent.  */
+# ifdef SHARED
+      if (__builtin_expect (__libc_pthread_functions_init, 0))
+       PTHFCT_CALL (ptr_set_robust, (self));
+# else
+      extern __typeof (__nptl_set_robust) __nptl_set_robust
+       __attribute__((weak));
+      if (__builtin_expect (__nptl_set_robust != NULL, 0))
+       __nptl_set_robust (self);
+# endif
+#endif
+
       /* Reset the file list.  These are recursive mutexes.  */
       fresetlockfiles ();
 
@@ -170,10 +189,10 @@ __libc_fork (void)
            allp->handler->child_handler ();
 
          /* Note that we do not have to wake any possible waiter.
-            This is the only thread in the new process.  The count
-            may have been bumped up by other threads doing a fork.
-            We reset it to 1, to avoid waiting for non-existing
-            thread(s) to release the count.  */
+            This is the only thread in the new process.  The count
+            may have been bumped up by other threads doing a fork.
+            We reset it to 1, to avoid waiting for non-existing
+            thread(s) to release the count.  */
          allp->handler->refcntr = 1;
 
          /* XXX We could at this point look through the object pool