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From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: oleg@redhat.com, tj@kernel.org
Cc: rusty@rustcorp.com.au, akpm@linux-foundation.org,
	arjan@linux.intel.com, linux-kernel@vger.kernel.org
Subject: Re: + kmod-avoid-deadlock-by-recursive-kmod-call.patch added to-mm tree
Date: Sat, 4 Feb 2012 21:56:49 +0900	[thread overview]
Message-ID: <201202042156.HCJ57836.OQMFSVJHLtFOFO@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20120203180030.GA8842@redhat.com>

Oleg Nesterov wrote:
> What do you think about s/khelper/system/ instead of this patch?

I'm not catching up with this topic. But I'm fine with any solution provided
that it can handle

  some kernel function calls request_module()

    request_module() triggers call_usermodehelper("/sbin/modprobe", UMH_WAIT_PROC)

      /sbin/modprobe loads a kernel module

        loading a kernel module triggers kobject_uevent_env()

          kobject_uevent_env() calls call_usermodehelper("/sbin/hotplug", UMH_WAIT_EXEC)

            do_execve("/sbin/hotplug") calls request_module("binfmt-0000")

              request_module("binfmt-0000") triggers call_usermodehelper("/sbin/modprobe", UMH_WAIT_PROC)

                /sbin/modprobe fails to load binfmt-0000 module

call trace on an UP machine.

kmod-avoid-deadlock-by-recursive-kmod-call.patch is for avoiding
call_usermodehelper("/sbin/modprobe", UMH_WAIT_PROC) called from
call_usermodehelper("/sbin/hotplug", UMH_WAIT_EXEC).

  parent reply	other threads:[~2012-02-04 12:57 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-26 17:56 + kmod-avoid-deadlock-by-recursive-kmod-call.patch added to -mm tree Oleg Nesterov
2012-01-27  2:55 ` Rusty Russell
2012-01-27 14:32   ` Oleg Nesterov
2012-01-29  0:49     ` Rusty Russell
2012-01-29 16:31       ` Oleg Nesterov
2012-01-29 23:26         ` Rusty Russell
2012-01-30  0:25           ` Tejun Heo
2012-01-30 13:03             ` Oleg Nesterov
2012-01-30 17:28               ` Tejun Heo
2012-02-03 18:00                 ` Oleg Nesterov
2012-02-03 19:26                   ` Tejun Heo
2012-02-04 12:56                   ` Tetsuo Handa [this message]
2012-02-06 17:19                     ` + kmod-avoid-deadlock-by-recursive-kmod-call.patch added to-mm tree Oleg Nesterov
2012-01-30 12:38           ` + kmod-avoid-deadlock-by-recursive-kmod-call.patch added to -mm tree Oleg Nesterov

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