Date: Wed, 20 Feb 2013 17:55:17 +0000 (UTC) From: "Justin T. Gibbs" <gibbs@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r247049 - head/sys/cddl/contrib/opensolaris/uts/common/dtrace Message-ID: <201302201755.r1KHtHA6068794@svn.freebsd.org>
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Author: gibbs Date: Wed Feb 20 17:55:17 2013 New Revision: 247049 URL: http://svnweb.freebsd.org/changeset/base/247049 Log: Avoid panic when tearing down the DTrace pid provider for a process that has crashed. sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c: In fasttrap_pid_disable(), we cannot PHOLD the proc structure for a process that no longer exists, but we still have other, fasttrap specific, state that must be cleaned up for probes that existed in the dead process. Instead of returning early if the process related to our probes isn't found, conditionalize the locking and carry on with a NULL proc pointer. The rest of the fasttrap code already understands that a NULL proc is possible and does the right things in this case. Sponsored by: Spectra Logic Corporation Reviewed by: rpaulo, gnn MFC after: 1 week Modified: head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c Wed Feb 20 17:46:38 2013 (r247048) +++ head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c Wed Feb 20 17:55:17 2013 (r247049) @@ -1124,14 +1124,12 @@ fasttrap_pid_disable(void *arg, dtrace_i * provider lock as a point of mutual exclusion to prevent other * DTrace consumers from disabling this probe. */ - if ((p = pfind(probe->ftp_pid)) == NULL) { - mutex_exit(&provider->ftp_mtx); - return; - } + if ((p = pfind(probe->ftp_pid)) != NULL) { #ifdef __FreeBSD__ - _PHOLD(p); - PROC_UNLOCK(p); + _PHOLD(p); + PROC_UNLOCK(p); #endif + } /* * Disable all the associated tracepoints (for fully enabled probes). @@ -1168,7 +1166,8 @@ fasttrap_pid_disable(void *arg, dtrace_i fasttrap_pid_cleanup(); #ifdef __FreeBSD__ - PRELE(p); + if (p != NULL) + PRELE(p); #endif if (!probe->ftp_enabled) return;
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