Date: Sun, 22 Oct 2006 09:30:18 -0700 (PDT) From: mjacob@freebsd.org To: src-committers@freebsd.org Cc: cvs-src@freebsd.org, cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/kern kern_exit.c Message-ID: <20061022092642.Y18042@ns1.feral.com> In-Reply-To: <200610221354.57273.davidxu@freebsd.org> References: <200610220014.k9M0E5mG061752@gw.catspoiler.org> <200610221354.57273.davidxu@freebsd.org>
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Are these changes why 9 out of ten reboots for me go into panic with: panic: signal pending ? On Sun, 22 Oct 2006, David Xu wrote: > On Sunday 22 October 2006 08:14, Don Lewis wrote: >> On 21 Oct, David Xu wrote: >>> davidxu 2006-10-21 23:59:15 UTC >>> >>> FreeBSD src repository >>> >>> Modified files: >>> sys/kern kern_exit.c >>> Log: >>> Since revision 1.333 of kern_sig.c no longer uses P_WEXIT, the change >>> opened a race window which can cause memory leak in signal queue. >>> Here we free memory for signal queue when process state is set to >>> PRS_ZOMBIE. >>> >>> Revision Changes Path >>> 1.291 +8 -2 src/sys/kern/kern_exit.c >> >> I wonder if the earlier change is what broke portupgrade after I >> upgraded from an August 31st version of current to yesterday's version. >> The symptoms were random processes dying from SIGHUP. It was easy to >> reproduce by just going to a port directory and running >> script foo make clean >> a few times. I'd randomly see make complain about a non-zero exit >> status from uname or some other sub-process. I tracked the problem back >> to the SIGHUP bit being set in td2's sigqueue in fork1(). As a >> workaround, I added a call to sigqueue_init() where td2 gets bzero'ed. >> >> Disappearing back into the void ... > > But I am still worrried by these signal changes, if an exiting process > can be sent a signal, and msleep will interrupted in cleanup code, where the > code will return to ? in normal case, code will return to userland, and > signal will be removed and delivered, but if a thread is in exit1(), where > the code can be returned to ? if a cleanup procedure is interrupted, isn't > there is any resource leak or dead-loop if it is retried because signal is > never removed ? > > David Xu >
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