From 6f8326cacd08bf7d1966743086855fc36574bf74 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Thu, 30 Jun 2011 20:41:34 -0400 Subject: [PATCH] Fix robust mutex handling after fork --- nptl/ChangeLog | 10 +++++++ nptl/nptl-init.c | 22 ++++++++++++++-- nptl/pthreadP.h | 13 ++++++---- nptl/sysdeps/pthread/pthread-functions.h | 3 ++- nptl/sysdeps/unix/sysv/linux/fork.c | 33 +++++++++++++++++++----- 5 files changed, 66 insertions(+), 15 deletions(-) diff --git a/nptl/ChangeLog b/nptl/ChangeLog index e0526fa7b8..c545b079f4 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -1,3 +1,13 @@ +2011-06-30 Ulrich Drepper + + * 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 * pthread_rwlock_init.c: Include for memset declaration. diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c index 851bab2bf1..33492c1602 100644 --- 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 , 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 43ca44c829..df4f4d769b 100644 --- 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 , 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 0c404fcbb3..15a4dff142 100644 --- 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 , 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 524d72c587..80fb147788 100644 --- 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 , 2002. @@ -29,6 +29,7 @@ #include #include #include +#include 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