Re: FAILED: patch "[PATCH] kprobes: Fix to protect kick_kprobe_optimizer() by" failed to apply to 4.9-stable tree

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jun 23, 2020 at 09:26:28AM -0400, Sasha Levin wrote:
> On Tue, Jun 23, 2020 at 01:57:26PM +0200, gregkh@linuxfoundation.org wrote:
> > 
> > The patch below does not apply to the 4.9-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> > 
> > thanks,
> > 
> > greg k-h
> > 
> > ------------------ original commit in Linus's tree ------------------
> > 
> > > From 1a0aa991a6274161c95a844c58cfb801d681eb59 Mon Sep 17 00:00:00 2001
> > From: Masami Hiramatsu <mhiramat@kernel.org>
> > Date: Tue, 12 May 2020 17:02:56 +0900
> > Subject: [PATCH] kprobes: Fix to protect kick_kprobe_optimizer() by
> > kprobe_mutex
> > 
> > In kprobe_optimizer() kick_kprobe_optimizer() is called
> > without kprobe_mutex, but this can race with other caller
> > which is protected by kprobe_mutex.
> > 
> > To fix that, expand kprobe_mutex protected area to protect
> > kick_kprobe_optimizer() call.
> > 
> > Link: http://lkml.kernel.org/r/158927057586.27680.5036330063955940456.stgit@devnote2
> > 
> > Fixes: cd7ebe2298ff ("kprobes: Use text_poke_smp_batch for optimizing")
> > Cc: Ingo Molnar <mingo@kernel.org>
> > Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>
> > Cc: Anders Roxell <anders.roxell@linaro.org>
> > Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
> > Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
> > Cc: David Miller <davem@davemloft.net>
> > Cc: Ingo Molnar <mingo@elte.hu>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Ziqian SUN <zsun@redhat.com>
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> 
> The conflict happened because we don't have 2d1e38f56622 ("kprobes: Cure
> hotplug lock ordering issues") on 4.9 and 4.4. I've fixed it up and
> queued for both branches.

Thanks for fixing this, and the other FAILED patches up as well.

greg k-h