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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B7FF2C433DB for ; Fri, 26 Mar 2021 14:12:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4823B61A02 for ; Fri, 26 Mar 2021 14:12:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4823B61A02 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CE3016B0070; Fri, 26 Mar 2021 10:12:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CB9B66B0071; Fri, 26 Mar 2021 10:12:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B58526B0072; Fri, 26 Mar 2021 10:12:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0126.hostedemail.com [216.40.44.126]) by kanga.kvack.org (Postfix) with ESMTP id 9A9ED6B0070 for ; Fri, 26 Mar 2021 10:12:50 -0400 (EDT) Received: from smtpin40.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 5AA6818065949 for ; Fri, 26 Mar 2021 14:12:50 +0000 (UTC) X-FDA: 77962216500.40.6A74534 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by imf18.hostedemail.com (Postfix) with ESMTP id 566152000248 for ; Fri, 26 Mar 2021 14:12:47 +0000 (UTC) Received: from [192.168.1.111] (unknown [175.152.148.180]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9CxqcnC611gzhgBAA--.1090S2; Fri, 26 Mar 2021 22:12:19 +0800 (CST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.4\)) Subject: Re: [PATCH 4/6] kprobes/ftrace: Use ftrace_location() when [dis]arming probes From: Huang Pei In-Reply-To: <20210325154433.7ed7e56a@gandalf.local.home> Date: Fri, 26 Mar 2021 22:12:18 +0800 Cc: Thomas Bogendoerfer , ambrosehua@gmail.com, Bibo Mao , linux-mips@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Jiaxun Yang , Paul Burton , Li Xuefeng , Yang Tiezhu , Gao Juxin , Huacai Chen , Jinyang He , "Maciej W . Rozycki" , Jisheng Zhang , Masami Hiramatsu , "Naveen N . Rao" Content-Transfer-Encoding: quoted-printable Message-Id: References: <20210313064149.29276-1-huangpei@loongson.cn> <20210313064149.29276-5-huangpei@loongson.cn> <20210325154433.7ed7e56a@gandalf.local.home> To: Steven Rostedt X-Mailer: Apple Mail (2.3608.120.23.2.4) X-CM-TRANSID:AQAAf9CxqcnC611gzhgBAA--.1090S2 X-Coremail-Antispam: 1UD129KBjvJXoWxZr48CrWfCw1rAw45uFy8Zrb_yoW5Cw45pF 95Kan8tF48JFWjgF9Fgw45Zr10yrW5t347KrZ2ya4FvrnrXr13WFWI9w4UArnxCr9YkFWS vFsFvFyqk3WxZ3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvK14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xII jxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr 1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxa n2IY04v7MxkIecxEwVAFwVW5XwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJV W8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF 1VAFwI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6x IIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6rWUJVWrZr1UMIIF 0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxh VjvjDU0xZFpf9x0JUJKsUUUUUU= X-CM-SenderInfo: xkxd0whshlqz5rrqw2lrqou0/ X-Stat-Signature: soguepb6q9bw3gpxq5pny7ngz49f9z5a X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 566152000248 Received-SPF: none (loongson.cn>: No applicable sender policy available) receiver=imf18; identity=mailfrom; envelope-from=""; helo=loongson.cn; client-ip=114.242.206.163 X-HE-DKIM-Result: none/none X-HE-Tag: 1616767967-211006 X-Bogosity: Ham, tests=bogofilter, spamicity=0.006874, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Patch 4/5 is from arm64=E2=80=99s KPROBES_ON_FTRACE, I think which is = needed by all RISC with both KPROBES_ON_FTRACE and -fpatchable-function-entry. But since V7, no further patches are released, what protocol should I = follow if I need these two patches? > On Mar 26, 2021, at 3:44 AM, Steven Rostedt = wrote: >=20 > On Sat, 13 Mar 2021 14:41:47 +0800 > Huang Pei wrote: >=20 >> From: Jisheng Zhang >>=20 >=20 > Looks like this was sent before, but was missing the proper authorship > (which is not Jisheng). >=20 > = https://lore.kernel.org/linux-arm-kernel/20191225173219.4f9db436@xhacker.d= ebian/ >=20 > -- Steve >=20 >=20 >> Ftrace location could include more than a single instruction in case >> of some architectures (powerpc64, for now). In this case, kprobe is >> permitted on any of those instructions, and uses ftrace = infrastructure >> for functioning. >>=20 >> However, [dis]arm_kprobe_ftrace() uses the kprobe address when = setting >> up ftrace filter IP. This won't work if the address points to any >> instruction apart from the one that has a branch to _mcount(). To >> resolve this, have [dis]arm_kprobe_ftrace() use ftrace_function() to >> identify the filter IP. >>=20 >> Signed-off-by: Naveen N. Rao >> Acked-by: Masami Hiramatsu >> --- >> kernel/kprobes.c | 8 +++++--- >> 1 file changed, 5 insertions(+), 3 deletions(-) >>=20 >> diff --git a/kernel/kprobes.c b/kernel/kprobes.c >> index 41fdbb7953c6..66ee28b071c2 100644 >> --- a/kernel/kprobes.c >> +++ b/kernel/kprobes.c >> @@ -1045,9 +1045,10 @@ static int prepare_kprobe(struct kprobe *p) >> static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops = *ops, >> int *cnt) >> { >> + unsigned long ftrace_ip =3D ftrace_location((unsigned = long)p->addr); >> int ret =3D 0; >>=20 >> - ret =3D ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0); >> + ret =3D ftrace_set_filter_ip(ops, ftrace_ip, 0, 0); >> if (ret) { >> pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n", >> p->addr, ret); >> @@ -1070,7 +1071,7 @@ static int __arm_kprobe_ftrace(struct kprobe = *p, struct ftrace_ops *ops, >> * At this point, sinec ops is not registered, we should be sefe = from >> * registering empty filter. >> */ >> - ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); >> + ftrace_set_filter_ip(ops, ftrace_ip, 1, 0); >> return ret; >> } >>=20 >> @@ -1087,6 +1088,7 @@ static int arm_kprobe_ftrace(struct kprobe *p) >> static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops = *ops, >> int *cnt) >> { >> + unsigned long ftrace_ip =3D ftrace_location((unsigned = long)p->addr); >> int ret =3D 0; >>=20 >> if (*cnt =3D=3D 1) { >> @@ -1097,7 +1099,7 @@ static int __disarm_kprobe_ftrace(struct kprobe = *p, struct ftrace_ops *ops, >>=20 >> (*cnt)--; >>=20 >> - ret =3D ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); >> + ret =3D ftrace_set_filter_ip(ops, ftrace_ip, 1, 0); >> WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS = (%d)\n", >> p->addr, ret); >> return ret; Huang Pei huangpei@loongson.cn