Date: Fri, 3 Jun 2005 18:10:05 GMT From: =?ISO-8859-1?Q?Se=E1n_C=2E_Farley?= <sean-freebsd@farley.org> To: freebsd-bugs@FreeBSD.org Subject: Re: gnu/77818: GDB locks in wait4() when running applications Message-ID: <200506031810.j53IA5NR074196@freefall.freebsd.org>
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The following reply was made to PR gnu/77818; it has been noted by GNATS.
From: =?ISO-8859-1?Q?Se=E1n_C=2E_Farley?= <sean-freebsd@farley.org>
To: David Xu <davidxu@freebsd.org>
Cc: bug-followup@freebsd.org
Subject: Re: gnu/77818: GDB locks in wait4() when running applications
Date: Fri, 3 Jun 2005 13:01:06 -0500 (CDT)
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On Fri, 3 Jun 2005, David Xu wrote:
> Please try following patch, this patch fixes nanosleep problem,
> the patch just removed some unnecessary code.
>
> Index: kern_sig.c
<snip>
Thank you. That fixed the nanosleep() bug for me. I had to apply the
patch by hand since it was against 6-CURRENT. Also, I unsquished some
comments. Here is the patch against 5-STABLE:
--------------------------------------------------------------
--- kern_sig.c.orig=09Fri Jun 3 07:32:03 2005
+++ kern_sig.c=09Fri Jun 3 07:50:56 2005
@@ -1689,34 +1689,23 @@
=09}
=09/*
-=09 * If proc is traced, always give parent a chance;
-=09 * if signal event is tracked by procfs, give *that*
-=09 * a chance, as well.
+=09 * If the signal is being ignored, then we forget about it immediately.
+=09 * (Note: we don't set SIGCONT in ps_sigignore, and if it is set to
+=09 * SIG_IGN, action will be SIG_DFL here.)
=09 */
-=09if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
-=09=09action =3D SIG_DFL;
-=09} else {
-=09=09/*
-=09=09 * If the signal is being ignored,
-=09=09 * then we forget about it immediately.
-=09=09 * (Note: we don't set SIGCONT in ps_sigignore,
-=09=09 * and if it is set to SIG_IGN,
-=09=09 * action will be SIG_DFL here.)
-=09=09 */
-=09=09mtx_lock(&ps->ps_mtx);
-=09=09if (SIGISMEMBER(ps->ps_sigignore, sig) ||
-=09=09 (p->p_flag & P_WEXIT)) {
-=09=09=09mtx_unlock(&ps->ps_mtx);
-=09=09=09return;
-=09=09}
-=09=09if (SIGISMEMBER(td->td_sigmask, sig))
-=09=09=09action =3D SIG_HOLD;
-=09=09else if (SIGISMEMBER(ps->ps_sigcatch, sig))
-=09=09=09action =3D SIG_CATCH;
-=09=09else
-=09=09=09action =3D SIG_DFL;
+=09mtx_lock(&ps->ps_mtx);
+=09if (SIGISMEMBER(ps->ps_sigignore, sig) ||
+=09 (p->p_flag & P_WEXIT)) {
=09=09mtx_unlock(&ps->ps_mtx);
+=09=09return;
=09}
+=09if (SIGISMEMBER(td->td_sigmask, sig))
+=09=09action =3D SIG_HOLD;
+=09else if (SIGISMEMBER(ps->ps_sigcatch, sig))
+=09=09action =3D SIG_CATCH;
+=09else
+=09=09action =3D SIG_DFL;
+=09mtx_unlock(&ps->ps_mtx);
=09if (prop & SA_CONT) {
=09=09SIG_STOPSIGMASK(p->p_siglist);
@@ -1865,14 +1854,16 @@
=09=09 * Mutexes are short lived. Threads waiting on them will
=09=09 * hit thread_suspend_check() soon.
=09=09 */
-=09} else if (p->p_state =3D=3D PRS_NORMAL) {
-=09=09if ((p->p_flag & P_TRACED) || (action !=3D SIG_DFL) ||
-=09=09=09!(prop & SA_STOP)) {
+=09} else if (p->p_state =3D=3D PRS_NORMAL) {
+=09=09if ((p->p_flag & P_TRACED) || action =3D=3D SIG_CATCH) {
=09=09=09mtx_lock_spin(&sched_lock);
=09=09=09tdsigwakeup(td, sig, action);
=09=09=09mtx_unlock_spin(&sched_lock);
=09=09=09goto out;
=09=09}
+
+=09=09MPASS(action =3D=3D SIG_DFL);
+
=09=09if (prop & SA_STOP) {
=09=09=09if (p->p_flag & P_PPWAIT)
=09=09=09=09goto out;
@@ -1955,35 +1946,27 @@
=09=09 */
=09=09if ((td->td_flags & TDF_SINTR) =3D=3D 0)
=09=09=09return;
+
=09=09/*
-=09=09 * Process is sleeping and traced. Make it runnable
-=09=09 * so it can discover the signal in issignal() and stop
-=09=09 * for its parent.
+=09=09 * If SIGCONT is default (or ignored) and process is asleep, we
+=09=09 * are finished; the process should not be awakened.
=09=09 */
-=09=09if (p->p_flag & P_TRACED) {
-=09=09=09p->p_flag &=3D ~P_STOPPED_TRACE;
-=09=09} else {
+=09=09if ((prop & SA_CONT) && action =3D=3D SIG_DFL) {
+=09=09=09SIGDELSET(p->p_siglist, sig);
=09=09=09/*
-=09=09=09 * If SIGCONT is default (or ignored) and process is
-=09=09=09 * asleep, we are finished; the process should not
-=09=09=09 * be awakened.
+=09=09=09 * It may be on either list in this state.
+=09=09=09 * Remove from both for now.
=09=09=09 */
-=09=09=09if ((prop & SA_CONT) && action =3D=3D SIG_DFL) {
-=09=09=09=09SIGDELSET(p->p_siglist, sig);
-=09=09=09=09/*
-=09=09=09=09 * It may be on either list in this state.
-=09=09=09=09 * Remove from both for now.
-=09=09=09=09 */
-=09=09=09=09SIGDELSET(td->td_siglist, sig);
-=09=09=09=09return;
-=09=09=09}
-
-=09=09=09/*
-=09=09=09 * Give low priority threads a better chance to run.
-=09=09=09 */
-=09=09=09if (td->td_priority > PUSER)
-=09=09=09=09td->td_priority =3D PUSER;
+=09=09=09SIGDELSET(td->td_siglist, sig);
+=09=09=09return;
=09=09}
+
+=09=09/*
+=09=09 * Give low priority threads a better chance to run.
+=09=09 */
+=09=09if (td->td_priority > PUSER)
+=09=09=09td->td_priority =3D PUSER;
+
=09=09sleepq_abort(td);
=09} else {
=09=09/*
--------------------------------------------------------------
Now that you have fixed my bugs, I will now have to go find some more to
play with. :)
Se=E1n
--=20
sean-freebsd@farley.org
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