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From: Chris Wright <chrisw@sous-sol.org>
To: linux-kernel@vger.kernel.org, stable@kernel.org
Cc: Justin Forbes <jmforbes@linuxtx.org>,
	Zwane Mwaikambo <zwane@arm.linux.org.uk>,
	"Theodore Ts'o" <tytso@mit.edu>,
	Randy Dunlap <rdunlap@xenotime.net>,
	Dave Jones <davej@redhat.com>,
	Chuck Wolber <chuckw@quantumlinux.com>,
	Chris Wedgwood <reviews@ml.cw.f00f.org>,
	Michael Krufky <mkrufky@linuxtv.org>,
	torvalds@linux-foundation.org, akpm@linux-foundation.org,
	alan@lxorguk.ukuu.org.uk,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Mike Galbraith <efault@gmx.de>,
	Albert Cahalan <acahalan@gmail.com>,
	Andrew Morton <akpm@osdl.org>, Roland McGrath <roland@redhat.com>,
	Ingo Molnar <mingo@elte.hu>, Coywolf Qi Hunt <qiyong@fc-cn.com>,
	Oleg Nesterov <oleg@tv-sign.ru>,
	Linus Torvalds <torvalds@osdl.org>
Subject: [patch 12/59] [PATCH] Fix reparenting to the same thread group. (take 2)
Date: Fri, 02 Feb 2007 18:35:16 -0800	[thread overview]
Message-ID: <20070203023928.378027000@sous-sol.org> (raw)
In-Reply-To: <20070203023504.435051000@sous-sol.org>

[-- Attachment #1: fix-reparenting-to-the-same-thread-group.patch --]
[-- Type: text/plain, Size: 2962 bytes --]

-stable review patch.  If anyone has any objections, please let us know.
------------------

From: Eric W. Biederman <ebiederm@xmission.com>

This patch fixes the case when we reparent to a different thread in the
same thread group.  This modifies the code so that we do not send
signals and do not change the signal to send to SIGCHLD unless we have
change the thread group of our parents.  It also suppresses sending
pdeath_sig in this cas as well since the result of geppid doesn't
change.

Thanks to Oleg for spotting my bug of only fixing this for non-ptraced
tasks.

This fixes the issues identified by Albert Cahalan in thread
http://lkml.org/lkml/2006/12/21/22.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Mike Galbraith <efault@gmx.de>
Cc: Albert Cahalan <acahalan@gmail.com>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Coywolf Qi Hunt <qiyong@fc-cn.com>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[chrisw: fold in 241ceee0b442, Oleg's fix to restore user visible behaviour]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---
 kernel/exit.c |   29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

--- linux-2.6.19.2.orig/kernel/exit.c
+++ linux-2.6.19.2/kernel/exit.c
@@ -603,10 +603,6 @@ choose_new_parent(struct task_struct *p,
 static void
 reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
 {
-	/* We don't want people slaying init.  */
-	if (p->exit_signal != -1)
-		p->exit_signal = SIGCHLD;
-
 	if (p->pdeath_signal)
 		/* We already hold the tasklist_lock here.  */
 		group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
@@ -626,13 +622,7 @@ reparent_thread(struct task_struct *p, s
 		p->parent = p->real_parent;
 		add_parent(p);
 
-		/* If we'd notified the old parent about this child's death,
-		 * also notify the new parent.
-		 */
-		if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
-		    thread_group_empty(p))
-			do_notify_parent(p, p->exit_signal);
-		else if (p->state == TASK_TRACED) {
+		if (p->state == TASK_TRACED) {
 			/*
 			 * If it was at a trace stop, turn it into
 			 * a normal stop since it's no longer being
@@ -642,6 +632,23 @@ reparent_thread(struct task_struct *p, s
 		}
 	}
 
+	/* If this is a threaded reparent there is no need to
+	 * notify anyone anything has happened.
+	 */
+	if (p->real_parent->group_leader == father->group_leader)
+		return;
+
+	/* We don't want people slaying init.  */
+	if (p->exit_signal != -1)
+		p->exit_signal = SIGCHLD;
+
+	/* If we'd notified the old parent about this child's death,
+	 * also notify the new parent.
+	 */
+	if (!traced && p->exit_state == EXIT_ZOMBIE &&
+	    p->exit_signal != -1 && thread_group_empty(p))
+		do_notify_parent(p, p->exit_signal);
+
 	/*
 	 * process group orphan check
 	 * Case ii: Our child is in a different pgrp

--

  parent reply	other threads:[~2007-02-03  2:35 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-03  2:35 [patch 00/59] -stable review Chris Wright
2007-02-03  2:35 ` [patch 01/59] i2c-mv64xxx: Fix random oops at boot Chris Wright
2007-02-03  2:35 ` [patch 02/59] i2c/m41t00: Do not forget to write year Chris Wright
2007-02-03  2:35 ` [patch 03/59] Check for populated zone in __drain_pages Chris Wright
2007-02-03  2:35 ` [patch 04/59] Fix HWRNG built-in initcalls priority Chris Wright
2007-02-03  2:35 ` [patch 05/59] md: pass down BIO_RW_SYNC in raid{1,10} Chris Wright
2007-02-03  2:35 ` [patch 06/59] NETFILTER: Fix routing of REJECT target generated packets in output chain Chris Wright
2007-02-03  2:35 ` [patch 07/59] NETFILTER: nf_conntrack_ipv6: fix crash when handling fragments Chris Wright
2007-02-03  2:35 ` [patch 08/59] NETFILTER: tcp conntrack: fix IP_CT_TCP_FLAG_CLOSE_INIT value Chris Wright
2007-02-03  2:35 ` [patch 09/59] NETFILTER: arp_tables: fix userspace compilation Chris Wright
2007-02-03  2:35 ` [patch 10/59] Repair snd-usb-usx2y over OHCI Chris Wright
2007-02-03  2:35 ` [patch 11/59] [stable] [PATCH] IB/mthca: Fix off-by-one in FMR handling on memfree Chris Wright
2007-02-03  2:35 ` Chris Wright [this message]
2007-02-03  2:35 ` [patch 13/59] ieee1394: sbp2: fix probing of some DVD-ROM/RWs Chris Wright
2007-02-03  2:35 ` [patch 14/59] sched: tasks cannot run on cpus onlined after boot Chris Wright
2007-02-03  2:35 ` [patch 15/59] Fix up CIFS for "test_clear_page_dirty()" removal Chris Wright
2007-02-03  2:35 ` [patch 16/59] start_kernel: test if irqs got enabled early, barf, and disable them again Chris Wright
2007-02-03  2:35 ` [patch 17/59] PCI: prevent down_read when pci_devices is empty Chris Wright
2007-02-03 16:16   ` Kumar Gala
2007-02-05 17:04     ` Chris Wright
2007-02-03  2:35 ` [patch 18/59] IPV6 MCAST: Fix joining all-node multicast group on device initialization Chris Wright
2007-02-03  2:35 ` [patch 19/59] NETFILTER: ctnetlink: check for status attribute existence on conntrack creation Chris Wright
2007-02-03  2:35 ` [patch 20/59] NETFILTER: ctnetlink: fix leak in ctnetlink_create_conntrack error path Chris Wright
2007-02-03  2:35 ` [patch 21/59] IPSEC: Policy list disorder Chris Wright
2007-02-03  2:35 ` [patch 22/59] ALSA hda-codec - Fix NULL dereference in generic hda code Chris Wright
2007-02-03  2:35 ` [patch 23/59] SELinux: fix an oops with NetLabel and non-MLS SELinux policy Chris Wright
2007-02-03  2:35 ` [patch 24/59] IB/iser: return error code when PDUs may not be sent Chris Wright
2007-02-03  2:35 ` [patch 25/59] Fix UML on non-standard VM split hosts Chris Wright
2007-02-04  1:06   ` Randy Dunlap
2007-02-04  3:11     ` Jeff Dike
2007-02-04  4:19       ` Randy Dunlap
2007-02-03  2:35 ` [patch 26/59] ACPI: fix cpufreq regression Chris Wright
2007-02-03  2:35 ` [patch 27/59] x86: Work around gcc 4.2 over aggressive optimizer Chris Wright
2007-02-03  2:35 ` [patch 28/59] NETFILTER: Fix iptables ABI breakage on (at least) CRIS Chris Wright
2007-02-03  2:35 ` [patch 29/59] elevator: move clearing of unplug flag earlier Chris Wright
2007-02-03  2:35 ` [patch 30/59] Revert "[PATCH] Fix up mmap_kmem" Chris Wright
2007-02-03  2:35 ` [patch 31/59] remove __devinit markings from rtc_sysfs_add_device() Chris Wright
2007-02-03  2:35 ` [patch 32/59] SPARC64: Set g4/g5 properly in sun4v dtlb-prot handling Chris Wright
2007-02-03  2:35 ` [patch 33/59] sis190: failure to set the MAC address from EEPROM Chris Wright
2007-02-03  2:35 ` [patch 34/59] knfsd: fix setting of ACL server versions Chris Wright
2007-02-03  2:35 ` [patch 35/59] knfsd: fix an NFSD bug with full sized, non-page-aligned reads Chris Wright
2007-02-03  2:35 ` [patch 36/59] knfsd: fix type mismatch with filldir_t used by nfsd Chris Wright
2007-02-03  2:35 ` [patch 37/59] knfsd: fix up some bit-rot in exp_export Chris Wright
2007-02-03  2:35 ` [patch 38/59] md: assorted md and raid1 one-liners Chris Wright
2007-02-03  2:35 ` [patch 39/59] md: make repair actually work for raid1 Chris Wright
2007-02-03  2:35 ` [patch 40/59] md: fix a few problems with the interface (sysfs and ioctl) to md Chris Wright
2007-02-03  2:35 ` [patch 41/59] md: fix potential memalloc deadlock in md Chris Wright
2007-02-03  2:35 ` [patch 42/59] libata: use kmap_atomic(KM_IRQ0) in SCSI simulator Chris Wright
2007-02-03  2:35 ` [patch 43/59] Dont allow the stack to grow into hugetlb reserved regions Chris Wright
2007-02-03  2:35 ` [patch 44/59] uml: fix signal frame alignment Chris Wright
2007-02-03  2:35 ` [patch 45/59] bonding: ARP monitoring broken on x86_64 Chris Wright
2007-02-03  2:35 ` [patch 46/59] jmicron: 40/80pin primary detection Chris Wright
2007-02-03  2:35 ` [patch 47/59] DECNET: Handle a failure in neigh_parms_alloc (take 2) Chris Wright
2007-02-03  2:35 ` [patch 48/59] SPARC32: Fix over-optimization by GCC near ip_fast_csum Chris Wright
2007-02-03  2:35 ` [patch 49/59] IPV4: Fix the fib trie iterator to work with a single entry routing tables Chris Wright
2007-02-03  2:35 ` [patch 50/59] IPV4: Fix single-entry /proc/net/fib_trie output Chris Wright
2007-02-03  2:35 ` [patch 51/59] AF_PACKET: Fix BPF handling Chris Wright
2007-02-03  2:35 ` [patch 52/59] AF_PACKET: Check device down state before hard header callbacks Chris Wright
2007-02-03  2:35 ` [patch 53/59] TCP: rare bad TCP checksum with 2.6.19 Chris Wright
2007-02-03  2:35 ` [patch 54/59] TCP: Fix sorting of SACK blocks Chris Wright
2007-02-03  2:35 ` [patch 55/59] TCP: skb is unexpectedly freed Chris Wright
2007-02-03  2:36 ` [patch 56/59] NETFILTER: xt_connbytes: fix division by zero Chris Wright
2007-02-03  2:36 ` [patch 57/59] SUNRPC: Give cloned RPC clients their own rpc_pipefs directory Chris Wright
2007-02-03  2:36 ` [patch 58/59] move_task_off_dead_cpu() should be called with disabled ints Chris Wright
2007-02-03  2:36 ` [patch 59/59] sched: fix cond_resched_softirq() offset Chris Wright
2007-02-03  2:59 ` [stable] [patch 00/59] -stable review Chris Wright
2007-02-04  6:08   ` Randy Dunlap
2007-02-04 13:36     ` Dave Jones
2007-02-04 17:30       ` Randy Dunlap

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