Attachment 5586 Details for Bug 7317 – Patch for v3-5

[patch] Patch for v3-5

tmp.diff (text/plain), 3.46 KB, created by Stefan Metzmacher on 2010-04-01 10:41:02 UTC

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Creator: Stefan Metzmacher

Created: 2010-04-01 10:41:02 UTC

Size: 3.46 KB

patch

obsolete

>From 71fbf9366442ff06f50b3a6f5f48c0e95ec920fb Mon Sep 17 00:00:00 2001
>From: Stefan Metzmacher <metze@samba.org>
>Date: Thu, 1 Apr 2010 16:23:06 +0200
>Subject: [PATCH] s3:winbindd: fix problems with SIGCHLD handling (bug #7317)
>
>The main problem is that we call CatchChild() within the
>parent winbindd, which overwrites the signal handler
>that was registered by winbindd_setup_sig_chld_handler().
>
>That means winbindd_sig_chld_handler() and winbind_child_died()
>are never triggered when a winbindd domain child dies.
>As a result will get "broken pipe" for all requests to that domain.
>
>To reduce the risk of similar bugs in future we call
>CatchChild() in winbindd_reinit_after_fork() now.
>
>We also use a full winbindd_reinit_after_fork() in the
>cache validation child now instead instead of just resetting
>the SIGCHLD handler by hand. This will also fix possible
>tdb problems on systems without pread/pwrite and disabled mmap
>as we now correctly reopen the tdb handle for the child.
>
>metze
>(cherry picked from commit 73577205cf81644e7fe853eaf3e6459f7f443096)
>---
> source3/winbindd/winbindd.c      |   14 +++-----------
> source3/winbindd/winbindd_cm.c   |    3 ---
> source3/winbindd/winbindd_dual.c |    6 +++---
> 3 files changed, 6 insertions(+), 17 deletions(-)
>
>diff --git a/source3/winbindd/winbindd.c b/source3/winbindd/winbindd.c
>index 9684a34..6e02b7d 100644
>--- a/source3/winbindd/winbindd.c
>+++ b/source3/winbindd/winbindd.c
>@@ -384,7 +384,6 @@ static void winbind_msg_validate_cache(struct messaging_context *msg_ctx,
> 	 * so we don't block the main winbindd and the validation
> 	 * code can safely use fork/waitpid...
> 	 */
>-	CatchChild();
> 	child_pid = sys_fork();
> 
> 	if (child_pid == -1) {
>@@ -402,16 +401,9 @@ static void winbind_msg_validate_cache(struct messaging_context *msg_ctx,
> 
> 	/* child */
> 
>-	/* install default SIGCHLD handler: validation code uses fork/waitpid */
>-	ZERO_STRUCT(act);
>-	act.sa_handler = SIG_DFL;
>-#ifdef SA_RESTART
>-	/* We *want* SIGALRM to interrupt a system call. */
>-	act.sa_flags = SA_RESTART;
>-#endif
>-	sigemptyset(&act.sa_mask);
>-	sigaddset(&act.sa_mask,SIGCHLD);
>-	sigaction(SIGCHLD,&act,&oldact);
>+	if (!winbindd_reinit_after_fork(NULL)) {
>+		_exit(0);
>+	}
> 
> 	ret = (uint8)winbindd_validate_cache_nobackup();
> 	DEBUG(10, ("winbindd_msg_validata_cache: got return value %d\n", ret));
>diff --git a/source3/winbindd/winbindd_cm.c b/source3/winbindd/winbindd_cm.c
>index e43a431..66da35f 100644
>--- a/source3/winbindd/winbindd_cm.c
>+++ b/source3/winbindd/winbindd_cm.c
>@@ -179,9 +179,6 @@ static bool fork_child_dc_connect(struct winbindd_domain *domain)
> 	pid_t parent_pid = sys_getpid();
> 	char *lfile = NULL;
> 
>-	/* Stop zombies */
>-	CatchChild();
>-
> 	if (domain->dc_probe_pid != (pid_t)-1) {
> 		/*
> 		 * We might already have a DC probe
>diff --git a/source3/winbindd/winbindd_dual.c b/source3/winbindd/winbindd_dual.c
>index dff9652..291b2d1 100644
>--- a/source3/winbindd/winbindd_dual.c
>+++ b/source3/winbindd/winbindd_dual.c
>@@ -1219,6 +1219,9 @@ bool winbindd_reinit_after_fork(const char *logfilename)
> 					    logfilename))
> 		return false;
> 
>+	/* Stop zombies in children */
>+	CatchChild();
>+
> 	/* Don't handle the same messages as our parent. */
> 	messaging_deregister(winbind_messaging_context(),
> 			     MSG_SMB_CONF_UPDATED, NULL);
>@@ -1342,9 +1345,6 @@ static bool fork_domain_child(struct winbindd_child *child)
> 
> 	DEBUG(10, ("Child process %d\n", (int)sys_getpid()));
> 
>-	/* Stop zombies in children */
>-	CatchChild();
>-
> 	state.sock = fdpair[0];
> 	close(fdpair[1]);
> 
>-- 
>1.6.3.3
>

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