Re: + kmod-avoid-deadlock-by-recursive-kmod-call.patch added to-mm tree

From: Tetsuo Handa
Date: Sat Feb 04 2012 - 07:57:33 EST

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).
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at