From: Peter Eisentraut <peter_e@gmx.net>
Date: Wed, 16 Dec 2009 23:05:00 +0000 (+0000)
Subject: Don't unblock SIGQUIT in the SIGQUIT handler
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=17f99595bcd8a7761764ee5447738adfddf86d38;p=users%2Fandresfreund%2Fpostgres.git

Don't unblock SIGQUIT in the SIGQUIT handler

This was possibly linked to a deadlock-like situation in glibc syslog code
invoked by the ereport call in quickdie().  In any case, a signal handler
should not unblock its own signal unless there is a specific reason to.
---

diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index c7906bfa1b..b2fb501882 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -2538,6 +2538,7 @@ drop_unnamed_stmt(void)
 void
 quickdie(SIGNAL_ARGS)
 {
+	sigaddset(&BlockSig, SIGQUIT); /* prevent nested calls */
 	PG_SETMASK(&BlockSig);
 
 	/*
diff --git a/src/include/libpq/pqsignal.h b/src/include/libpq/pqsignal.h
index 82414d62d7..4659ae21d1 100644
--- a/src/include/libpq/pqsignal.h
+++ b/src/include/libpq/pqsignal.h
@@ -38,6 +38,7 @@ extern int	UnBlockSig,
 int			pqsigsetmask(int mask);
 #endif
 
+#define sigaddset(set, signum)	(*(set) |= (sigmask(signum)))
 #define sigdelset(set, signum)	(*(set) &= ~(sigmask(signum)))
 #endif /* not HAVE_SIGPROCMASK */