From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752915Ab1HMAUH (ORCPT ); Fri, 12 Aug 2011 20:20:07 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:44541 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751817Ab1HMAUE (ORCPT ); Fri, 12 Aug 2011 20:20:04 -0400 Date: Fri, 12 Aug 2011 17:19:59 -0700 From: Matt Helsley To: Daniel Lezcano Cc: akpm@linux-foundation.org, containers@lists.linux-foundation.org, bonbons@linux-vserver.org, oleg@tv-sign.ru, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] Notify container-init parent a 'reboot' occured Message-ID: <20110813001959.GB5777@count0.beaverton.ibm.com> References: <1313094241-3674-1-git-send-email-daniel.lezcano@free.fr> <1313094241-3674-3-git-send-email-daniel.lezcano@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1313094241-3674-3-git-send-email-daniel.lezcano@free.fr> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 11, 2011 at 10:24:01PM +0200, Daniel Lezcano wrote: > When the reboot syscall is called and the pid namespace where the calling > process belongs to is not from the init pidns, we send a SIGCHLD with CLD_REBOOTED > to the parent of this pid namespace. Shouldn't we honor the exit_signal set via clone() here rather than hardcode SIGCHLD? More below... > > Signed-off-by: Daniel Lezcano > --- > include/asm-generic/siginfo.h | 3 ++- > include/linux/sched.h | 1 + > kernel/signal.c | 40 ++++++++++++++++++++++++++++++++++++++++ > kernel/sys.c | 20 ++++++++++++++++++-- > 4 files changed, 61 insertions(+), 3 deletions(-) > > diff --git a/include/asm-generic/siginfo.h b/include/asm-generic/siginfo.h > index 0dd4e87..9bff4a2 100644 > --- a/include/asm-generic/siginfo.h > +++ b/include/asm-generic/siginfo.h > @@ -218,7 +218,8 @@ typedef struct siginfo { > #define CLD_TRAPPED (__SI_CHLD|4) /* traced child has trapped */ > #define CLD_STOPPED (__SI_CHLD|5) /* child has stopped */ > #define CLD_CONTINUED (__SI_CHLD|6) /* stopped child has continued */ > -#define NSIGCHLD 6 > +#define CLD_REBOOTED (__SI_CHLD|7) /* process was killed by a reboot */ > +#define NSIGCHLD 7 > > /* > * SIGPOLL si_codes > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 20b03bf..c62dc9e 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -2170,6 +2170,7 @@ extern int kill_pgrp(struct pid *pid, int sig, int priv); > extern int kill_pid(struct pid *pid, int sig, int priv); > extern int kill_proc_info(int, struct siginfo *, pid_t); > extern __must_check bool do_notify_parent(struct task_struct *, int); > +extern void do_notify_parent_cldreboot(struct task_struct *, int, char *); > extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent); > extern void force_sig(int, struct task_struct *); > extern int send_sig(int, struct task_struct *, int); > diff --git a/kernel/signal.c b/kernel/signal.c > index 291c970..7d3d44c 100644 > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -1668,6 +1668,46 @@ bool do_notify_parent(struct task_struct *tsk, int sig) > return autoreap; > } > > +void do_notify_parent_cldreboot(struct task_struct *tsk, int why, char *buffer) > +{ > + struct siginfo info = { }; > + struct task_struct *parent; > + struct sighand_struct *sighand; > + unsigned long flags; > + > + if (tsk->ptrace) > + parent = tsk->parent; > + else { > + tsk = tsk->group_leader; > + parent = tsk->real_parent; > + } > + > + info.si_signo = SIGCHLD; should this be: info.si_signo = tsk->exit_signal == -1 ? SIGCHLD : tsk->exit_signal; ? > + info.si_errno = 0; > + info.si_status = why; > + > + rcu_read_lock(); > + info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns); > + info.si_uid = __task_cred(tsk)->uid; > + rcu_read_unlock(); > + > + info.si_utime = cputime_to_clock_t(tsk->utime); > + info.si_stime = cputime_to_clock_t(tsk->stime); > + > + info.si_code = CLD_REBOOTED; > + > + sighand = parent->sighand; > + spin_lock_irqsave(&sighand->siglock, flags); > + if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && > + sighand->action[SIGCHLD-1].sa.sa_flags & SA_CLDREBOOT) > + __group_send_sig_info(SIGCHLD, &info, parent); (with corresponding changes above...) > + /* > + * Even if SIGCHLD is not generated, we must wake up wait4 calls. > + */