From ce081b037e7a762f0dd090a207cafc5121f39f51 Mon Sep 17 00:00:00 2001 From: kib Date: Tue, 27 Oct 2009 10:47:58 +0000 Subject: In r197963, a race with thread being selected for signal delivery while in kernel mode, and later changing signal mask to block the signal, was fixed for sigprocmask(2) and ptread_exit(3). The same race exists for sigreturn(2), setcontext(2) and swapcontext(2) syscalls. Use kern_sigprocmask() instead of direct manipulation of td_sigmask to reschedule newly blocked signals, closing the race. Reviewed by: davidxu Tested by: pho MFC after: 1 month --- sys/compat/freebsd32/freebsd32_misc.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) (limited to 'sys/compat') diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c index 9f6b16d..37fa079 100644 --- a/sys/compat/freebsd32/freebsd32_misc.c +++ b/sys/compat/freebsd32/freebsd32_misc.c @@ -2482,7 +2482,7 @@ ofreebsd32_sigprocmask(struct thread *td, int error; OSIG2SIG(uap->mask, set); - error = kern_sigprocmask(td, uap->how, &set, &oset, 1); + error = kern_sigprocmask(td, uap->how, &set, &oset, SIGPROCMASK_OLD); SIG2OSIG(oset, td->td_retval[0]); return (error); } @@ -2546,15 +2546,11 @@ int ofreebsd32_sigblock(struct thread *td, struct ofreebsd32_sigblock_args *uap) { - struct proc *p = td->td_proc; - sigset_t set; + sigset_t set, oset; OSIG2SIG(uap->mask, set); - SIG_CANTMASK(set); - PROC_LOCK(p); - SIG2OSIG(td->td_sigmask, td->td_retval[0]); - SIGSETOR(td->td_sigmask, set); - PROC_UNLOCK(p); + kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); + SIG2OSIG(oset, td->td_retval[0]); return (0); } @@ -2562,16 +2558,11 @@ int ofreebsd32_sigsetmask(struct thread *td, struct ofreebsd32_sigsetmask_args *uap) { - struct proc *p = td->td_proc; - sigset_t set; + sigset_t set, oset; OSIG2SIG(uap->mask, set); - SIG_CANTMASK(set); - PROC_LOCK(p); - SIG2OSIG(td->td_sigmask, td->td_retval[0]); - SIGSETLO(td->td_sigmask, set); - signotify(td); - PROC_UNLOCK(p); + kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); + SIG2OSIG(oset, td->td_retval[0]); return (0); } -- cgit v1.1