- fix deadlock in blogd that happens on shutdown (bnc#730193730193)

OBS-URL: https://build.opensuse.org/package/show/Base:System/sysvinit?expand=0&rev=177

showconsole-1.16-deadlock.diff

@@ -0,0 +1,78 @@
+From 05c3f60fe02370f4c8d15b996bcc8d6f3dc57e12 Mon Sep 17 00:00:00 2001
+From: Ludwig Nussel <ludwig.nussel@suse.de>
+Date: Thu, 21 Jun 2012 09:09:19 +0200
+Subject: [PATCH] fix deadlock
+
+writelog() must not call pthread_yield() with the lock held that the
+main thread tries to get to cancel the writer thread. writelog()
+on the other hand needs to empty the buffer always to make sure
+poll() blocks again an doesn't cause a loop.
+---
+ libconsole.c |   25 +++++++++++++++++--------
+ 1 files changed, 17 insertions(+), 8 deletions(-)
+
+diff --git a/libconsole.c b/libconsole.c
+index b962032..54b353a 100644
+--- a/libconsole.c
++++ b/libconsole.c
+@@ -429,21 +429,28 @@ xout:
+ 
+ static inline void writelog(void)
+ {
+-    if (!flog)
++    lock(&llock);
++    if (!flog) { /* log file closed, reset buffer */
++	resetlog();
++	unlock(&llock);
+ 	return;
++    }
+     clearerr(flog);
+-    lock(&llock);
+     while (avail > 0) {
+ 	size_t ret = (size_t)avail;
+ 
+ 	if (avail > TRANS_BUFFER_SIZE)
+ 	    ret = TRANS_BUFFER_SIZE;
+ 
+-	if (!flog || nsigsys)
++	if (!flog || nsigsys) { /* log file closed, reset buffer */
++	    resetlog();
+ 	    break;
++	}
+ 	ret = fwrite(head, sizeof(unsigned char), ret, flog);
+-	if (!ret && ferror(flog))
++	if (!ret && ferror(flog)) { /* cannot write anymore, reset buffer */
++	    resetlog();
+ 	    break;
++	}
+ 	head += ret;
+ 
+ 	if (head >= tail) {		/* empty, reset buffer */
+@@ -498,8 +505,13 @@ static inline int poll(int msec, mutex_t *outer)
+ 	    if (err == ETIMEDOUT || err == EBUSY)
+ 		ret = 0;
+ 	}
+-    } else
++#if 0
++    } else {
++	unlock(&ljoin);
+ 	pthread_yield();
++	lock(&ljoin);
++#endif
++    }
+ 
+     return ret;
+ }
+@@ -772,9 +784,6 @@ static void *action(void *dummy attribute((unused)))
+ 	if (!poll(30, &ljoin))
+ 	    continue;
+ 
+-	if (!flog)
+-	    break;
+-
+ 	writelog();
+     }
+     unlock(&ljoin);
+-- 
+1.7.7
+

sysvinit.changes

@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Thu Jun 21 07:16:05 UTC 2012 - lnussel@suse.de
+
+- fix deadlock in blogd that happens on shutdown (bnc#730193730193)
+
 -------------------------------------------------------------------
 Wed May 23 10:45:13 UTC 2012 - werner@suse.de
 

sysvinit.spec

@@ -16,6 +16,7 @@
 #
 
 
+
 Name:           sysvinit
 %define PDVER  2.0.2
 %define KPVER  2.21
@@ -59,6 +60,7 @@ Patch20:        powerd-%{PDVER}.dif
 Patch21:        powerd-%{PDVER}-getaddrinfo.patch
 Patch30:        killproc-%{KPVER}.dif
 Patch40:        showconsole-%{SCVER}.dif
+Patch41:        showconsole-1.16-deadlock.diff
 Patch50:        startpar-%{START}.dif
 Requires:       mingetty
 Requires:       sysvinit-tools
@@ -126,6 +128,7 @@ ln -t../%{name}-%{SIVER}dsf/doc/killproc README
 popd
 pushd ../showconsole-%{SCVER}
 %patch40
+%patch41 -p1
 ln -t../%{name}-%{SIVER}dsf/doc/showconsole README
 popd
 pushd ../startpar-%{START}