From fc242bef00206c3bab4117345734ce744f0b7eff Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Thu, 21 Dec 2006 21:50:33 +0000 Subject: * include/atomic.h (atomic_forced_read): New macro. --- nptl/ChangeLog | 5 +++++ nptl/sysdeps/unix/sysv/linux/pthread_kill.c | 18 +++++++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-) (limited to 'nptl') diff --git a/nptl/ChangeLog b/nptl/ChangeLog index 510693d..631e20d 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -1,3 +1,8 @@ +2006-12-21 Jakub Jelinek + + * sysdeps/unix/sysv/linux/pthread_kill.c (pthread_kill): Make sure + tid isn't reread from pd->tid in between ESRCH test and the syscall. + 2006-12-06 Jakub Jelinek * sysdeps/unix/sysv/linux/s390/s390-32/sysdep-cancel.h (PSEUDO): Handle diff --git a/nptl/sysdeps/unix/sysv/linux/pthread_kill.c b/nptl/sysdeps/unix/sysv/linux/pthread_kill.c index 9115d6f..259c954 100644 --- a/nptl/sysdeps/unix/sysv/linux/pthread_kill.c +++ b/nptl/sysdeps/unix/sysv/linux/pthread_kill.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2004, 2006 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -33,7 +33,15 @@ __pthread_kill (threadid, signo) struct pthread *pd = (struct pthread *) threadid; /* Make sure the descriptor is valid. */ - if (INVALID_TD_P (pd)) + if (DEBUGGING_P && INVALID_TD_P (pd)) + /* Not a valid thread handle. */ + return ESRCH; + + /* Force load of pd->tid into local variable or register. Oherwise + if a thread exits between ESRCH test and tgkill, we might return + EINVAL, because pd->tid would be cleared by the kernel. */ + pid_t tid = atomic_forced_read (pd->tid); + if (__builtin_expect (tid <= 0, 0)) /* Not a valid thread handle. */ return ESRCH; @@ -53,15 +61,15 @@ __pthread_kill (threadid, signo) int val; #if __ASSUME_TGKILL val = INTERNAL_SYSCALL (tgkill, err, 3, THREAD_GETMEM (THREAD_SELF, pid), - pd->tid, signo); + tid, signo); #else # ifdef __NR_tgkill val = INTERNAL_SYSCALL (tgkill, err, 3, THREAD_GETMEM (THREAD_SELF, pid), - pd->tid, signo); + tid, signo); if (INTERNAL_SYSCALL_ERROR_P (val, err) && INTERNAL_SYSCALL_ERRNO (val, err) == ENOSYS) # endif - val = INTERNAL_SYSCALL (tkill, err, 2, pd->tid, signo); + val = INTERNAL_SYSCALL (tkill, err, 2, tid, signo); #endif return (INTERNAL_SYSCALL_ERROR_P (val, err) -- cgit v1.1