From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1419AC7EE2A for ; Wed, 17 May 2023 12:00:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231429AbjEQMAB (ORCPT ); Wed, 17 May 2023 08:00:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231423AbjEQL74 (ORCPT ); Wed, 17 May 2023 07:59:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30E29421D; Wed, 17 May 2023 04:59:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B9D7D638AE; Wed, 17 May 2023 11:59:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E8FEC4339B; Wed, 17 May 2023 11:59:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684324794; bh=+KJCyW8UcBpWC8n/rNnAChXGAO9waLTlJQG8Dp7ZVa0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=A3wxgK//Fl+HRbw82WER6yeLjIrBy7NjkG7nKzaC9v+P1fj78NXLtyfTUYg6p8RW3 bcAK0NdVb6cmJkcuG45bfXlMqsGuVB3TLoZ9orpTFPY1byepkeSx7xQjtgNU8zrKKD wTdJxIXAMwBx6Iy/a0uF9S1BYxfeG0GyYWMfIWmHRxsQhRcHkH1v9LzjA+kNLKpqv7 e8r084YNf5nre8CudRHdqPB1LnJmYIUgarQqld+w/Od+y+7vBvaKV14OCnreYJC/FG 6y/C9GMB3OgNGppJUtg0r4xA4tjwSUsps1xz2PWr2TMPKYhtqmtc7D/8CKGwlHTkOb B2qnlglxsW41Q== Date: Wed, 17 May 2023 20:59:47 +0900 From: Masami Hiramatsu (Google) To: Ze Gao Cc: Steven Rostedt , Albert Ou , Alexander Gordeev , Alexei Starovoitov , Borislav Petkov , Christian Borntraeger , Dave Hansen , Heiko Carstens , "H. Peter Anvin" , Ingo Molnar , Palmer Dabbelt , Paul Walmsley , Sven Schnelle , Thomas Gleixner , Vasily Gorbik , x86@kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Conor Dooley , Jiri Olsa , Yonghong Song , Ze Gao , stable@vger.kernel.org Subject: Re: [PATCH v3 1/4] rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler Message-Id: <20230517205947.c1710ed175519b59f56e09b1@kernel.org> In-Reply-To: <20230517034510.15639-2-zegao@tencent.com> References: <20230517034510.15639-1-zegao@tencent.com> <20230517034510.15639-2-zegao@tencent.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org Hi Ze Gao, On Wed, 17 May 2023 11:45:06 +0800 Ze Gao wrote: > This patch replaces preempt_{disable, enable} with its corresponding > notrace version in rethook_trampoline_handler so no worries about stack > recursion or overflow introduced by preempt_count_{add, sub} under > fprobe + rethook context. > > Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook") > Signed-off-by: Ze Gao > Acked-by: Masami Hiramatsu (Google) > Cc: > Link: https://lore.kernel.org/linux-trace-kernel/20230516071830.8190-2-zegao@tencent.com Note that you don't need to add Link tag of the previous version for each patch. I'll add it when I pick it :) Thank you, > --- > kernel/trace/rethook.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c > index 32c3dfdb4d6a..60f6cb2b486b 100644 > --- a/kernel/trace/rethook.c > +++ b/kernel/trace/rethook.c > @@ -288,7 +288,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, > * These loops must be protected from rethook_free_rcu() because those > * are accessing 'rhn->rethook'. > */ > - preempt_disable(); > + preempt_disable_notrace(); > > /* > * Run the handler on the shadow stack. Do not unlink the list here because > @@ -321,7 +321,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, > first = first->next; > rethook_recycle(rhn); > } > - preempt_enable(); > + preempt_enable_notrace(); > > return correct_ret_addr; > } > -- > 2.40.1 > -- Masami Hiramatsu (Google)