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 X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B96E2C48BCD for ; Wed, 9 Jun 2021 14:42:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FEA7613AD for ; Wed, 9 Jun 2021 14:42:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238102AbhFIOoh (ORCPT ); Wed, 9 Jun 2021 10:44:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:55240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237065AbhFIOoh (ORCPT ); Wed, 9 Jun 2021 10:44:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E181E60C41; Wed, 9 Jun 2021 14:42:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623249763; bh=Lp60OTlEpA4K5hhgaDeUeuOpwZLJTceSMA4AcexQtDY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=i1N60SBwy3hhUI46/fN+kdehhpeImnmtscq8b13N5KLlfhHalhL19DyhtSNBX8S9Z 9CDaDA17auI1RHJuJhRandVrmoAUs9Ph/YqROiIXoT93L0j0Cj+uQX8RwvA2axRHbk sRDx1WA1oBUErIq/+qinZXUbEAu+M3PyM8+47TIzPp7/yz1lpM9YdW7FRSfc05H+pJ u6fRahWU12idNUlBHvjO4ayKFNkaVp8eZfmu8N3H3PIw5HRNWvyQh3ajAtV/ztZ3Fq fBM1KRCuEtzYnd3P+8L8iu1D5NBLfIOLZuczMlCdSriyWae17OK0ve/Ld0uMweQbPQ yDYLChHfcaeUg== Date: Wed, 9 Jun 2021 23:42:39 +0900 From: Masami Hiramatsu To: Punit Agrawal Cc: naveen.n.rao@linux.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, linux-kernel@vger.kernel.org, guoren@kernel.org, linux-csky@vger.kernel.org Subject: Re: [RFC PATCH 3/5] kprobe: Simplify prepare_kprobe() by dropping redundant version Message-Id: <20210609234239.8b61d29b7f12fb1307048e6c@kernel.org> In-Reply-To: <20210609105019.3626677-4-punitagrawal@gmail.com> References: <20210609105019.3626677-1-punitagrawal@gmail.com> <20210609105019.3626677-4-punitagrawal@gmail.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; 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-csky@vger.kernel.org On Wed, 9 Jun 2021 19:50:17 +0900 Punit Agrawal wrote: > The function prepare_kprobe() is called during kprobe registration and > is responsible for ensuring any architecture related preparation for > the kprobe is done before returning. > > One of two versions of prepare_kprobe() is chosen depending on the > availability of KPROBE_ON_FTRACE in the kernel configuration. > > Simplify the code by dropping the version when KPROBE_ON_FTRACE is not > selected - instead relying on kprobe_ftrace() to return false when > KPROBE_ON_FTRACE is not set. > OK, since kprobe_ftrace() just checks a flag is set or not, it is always usable in kprobes.c. Looks good to me :) Acked-by: Masami Hiramatsu Thank you! > No functional change. > > Signed-off-by: Punit Agrawal > --- > include/linux/kprobes.h | 5 +++++ > kernel/kprobes.c | 23 +++++++++-------------- > 2 files changed, 14 insertions(+), 14 deletions(-) > > diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h > index 1883a4a9f16a..771013bab18a 100644 > --- a/include/linux/kprobes.h > +++ b/include/linux/kprobes.h > @@ -362,6 +362,11 @@ static inline void wait_for_kprobe_optimizer(void) { } > extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, > struct ftrace_ops *ops, struct ftrace_regs *fregs); > extern int arch_prepare_kprobe_ftrace(struct kprobe *p); > +#else > +static inline int arch_prepare_kprobe_ftrace(struct kprobe *p) > +{ > + return -EINVAL; > +} > #endif > > int arch_check_ftrace_location(struct kprobe *p); > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 1a11d3c411bf..54d37d4ab897 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1022,15 +1022,6 @@ static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = { > static int kprobe_ipmodify_enabled; > static int kprobe_ftrace_enabled; > > -/* Must ensure p->addr is really on ftrace */ > -static int prepare_kprobe(struct kprobe *p) > -{ > - if (!kprobe_ftrace(p)) > - return arch_prepare_kprobe(p); > - > - return arch_prepare_kprobe_ftrace(p); > -} > - > /* Caller must lock kprobe_mutex */ > static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > int *cnt) > @@ -1102,11 +1093,6 @@ static int disarm_kprobe_ftrace(struct kprobe *p) > ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled); > } > #else /* !CONFIG_KPROBES_ON_FTRACE */ > -static inline int prepare_kprobe(struct kprobe *p) > -{ > - return arch_prepare_kprobe(p); > -} > - > static inline int arm_kprobe_ftrace(struct kprobe *p) > { > return -ENODEV; > @@ -1118,6 +1104,15 @@ static inline int disarm_kprobe_ftrace(struct kprobe *p) > } > #endif > > +static int prepare_kprobe(struct kprobe *p) > +{ > + /* Must ensure p->addr is really on ftrace */ > + if (kprobe_ftrace(p)) > + return arch_prepare_kprobe_ftrace(p); > + > + return arch_prepare_kprobe(p); > +} > + > /* Arm a kprobe with text_mutex */ > static int arm_kprobe(struct kprobe *kp) > { > -- > 2.30.2 > -- Masami Hiramatsu