From nobody Sun Apr 26 08:21:08 2026 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 50971CCA480 for ; Mon, 20 Jun 2022 21:32:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243657AbiFTVc0 (ORCPT ); Mon, 20 Jun 2022 17:32:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241677AbiFTVcZ (ORCPT ); Mon, 20 Jun 2022 17:32:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6313C13CFE; Mon, 20 Jun 2022 14:32:24 -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 F1E34611FC; Mon, 20 Jun 2022 21:32:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47ED3C341C5; Mon, 20 Jun 2022 21:32:23 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1o3P0Q-003o1G-4h; Mon, 20 Jun 2022 17:32:22 -0400 Message-ID: <20220620213221.981855209@goodmis.org> User-Agent: quilt/0.66 Date: Mon, 20 Jun 2022 17:31:59 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Yonghong Song , Peter Zijlstra , bpf , Kernel Team , stable@vger.kernel.org, "Masami Hiramatsu (Google)" , Jiri Olsa Subject: [for-linus][PATCH 1/4] tracing/kprobes: Check whether get_kretprobe() returns NULL in kretprobe_dispatcher() References: <20220620213158.468216113@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Masami Hiramatsu (Google)" There is a small chance that get_kretprobe(ri) returns NULL in kretprobe_dispatcher() when another CPU unregisters the kretprobe right after __kretprobe_trampoline_handler(). To avoid this issue, kretprobe_dispatcher() checks the get_kretprobe() return value again. And if it is NULL, it returns soon because that kretprobe is under unregistering process. This issue has been introduced when the kretprobe is decoupled from the struct kretprobe_instance by commit d741bf41d7c7 ("kprobes: Remove kretprobe hash"). Before that commit, the struct kretprob_instance::rp directly points the kretprobe and it is never be NULL. Link: https://lkml.kernel.org/r/165366693881.797669.16926184644089588731.st= git@devnote2 Reported-by: Yonghong Song Fixes: d741bf41d7c7 ("kprobes: Remove kretprobe hash") Cc: Peter Zijlstra Cc: Ingo Molnar Cc: bpf Cc: Kernel Team Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) Acked-by: Jiri Olsa Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_kprobe.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 93507330462c..a245ea673715 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1718,8 +1718,17 @@ static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) { struct kretprobe *rp =3D get_kretprobe(ri); - struct trace_kprobe *tk =3D container_of(rp, struct trace_kprobe, rp); + struct trace_kprobe *tk; + + /* + * There is a small chance that get_kretprobe(ri) returns NULL when + * the kretprobe is unregister on another CPU between kretprobe's + * trampoline_handler and this function. + */ + if (unlikely(!rp)) + return 0; =20 + tk =3D container_of(rp, struct trace_kprobe, rp); raw_cpu_inc(*tk->nhit); =20 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) --=20 2.35.1 From nobody Sun Apr 26 08:21:08 2026 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 22300C43334 for ; Mon, 20 Jun 2022 21:32:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244561AbiFTVc3 (ORCPT ); Mon, 20 Jun 2022 17:32:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241653AbiFTVcZ (ORCPT ); Mon, 20 Jun 2022 17:32:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6338E13D24 for ; Mon, 20 Jun 2022 14:32:24 -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 F0DF760FBD for ; Mon, 20 Jun 2022 21:32:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A3A1C341C4; Mon, 20 Jun 2022 21:32:23 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1o3P0Q-003o1n-AX; Mon, 20 Jun 2022 17:32:22 -0400 Message-ID: <20220620213222.161743834@goodmis.org> User-Agent: quilt/0.66 Date: Mon, 20 Jun 2022 17:32:00 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , sunliming Subject: [for-linus][PATCH 2/4] tracing: Simplify conditional compilation code in tracing_set_tracer() References: <20220620213158.468216113@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: sunliming Two conditional compilation directives "#ifdef CONFIG_TRACER_MAX_TRACE" are used consecutively, and no other code in between. Simplify conditional the compilation code and only use one "#ifdef CONFIG_TRACER_MAX_TRACE". Link: https://lkml.kernel.org/r/20220602140613.545069-1-sunliming@kylinos.cn Signed-off-by: sunliming Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2c95992e2c71..a8cfac0611bc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6424,9 +6424,7 @@ int tracing_set_tracer(struct trace_array *tr, const = char *buf) synchronize_rcu(); free_snapshot(tr); } -#endif =20 -#ifdef CONFIG_TRACER_MAX_TRACE if (t->use_max_tr && !had_max_tr) { ret =3D tracing_alloc_snapshot_instance(tr); if (ret < 0) --=20 2.35.1 From nobody Sun Apr 26 08:21:08 2026 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 BEFFCC433EF for ; Mon, 20 Jun 2022 21:32:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245324AbiFTVcb (ORCPT ); Mon, 20 Jun 2022 17:32:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243278AbiFTVc0 (ORCPT ); Mon, 20 Jun 2022 17:32:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DEF2C12D32 for ; Mon, 20 Jun 2022 14:32:25 -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 ams.source.kernel.org (Postfix) with ESMTPS id A2F56B811EC for ; Mon, 20 Jun 2022 21:32:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 704E8C341CB; Mon, 20 Jun 2022 21:32:23 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1o3P0Q-003o2N-GK; Mon, 20 Jun 2022 17:32:22 -0400 Message-ID: <20220620213222.344762745@goodmis.org> User-Agent: quilt/0.66 Date: Mon, 20 Jun 2022 17:32:01 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Xiang wangx Subject: [for-linus][PATCH 3/4] tracefs: Fix syntax errors in comments References: <20220620213158.468216113@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Xiang wangx Delete the redundant word 'to'. Link: https://lkml.kernel.org/r/20220605092729.13010-1-wangxiang@cdjrlc.com Signed-off-by: Xiang wangx Signed-off-by: Steven Rostedt (Google) --- fs/tracefs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index de7252715b12..81d26abf486f 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -553,7 +553,7 @@ struct dentry *tracefs_create_dir(const char *name, str= uct dentry *parent) * * Only one instances directory is allowed. * - * The instances directory is special as it allows for mkdir and rmdir to + * The instances directory is special as it allows for mkdir and rmdir * to be done by userspace. When a mkdir or rmdir is performed, the inode * locks are released and the methods passed in (@mkdir and @rmdir) are * called without locks and with the name of the directory being created --=20 2.35.1 From nobody Sun Apr 26 08:21:08 2026 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 444B9C43334 for ; Mon, 20 Jun 2022 21:32:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242592AbiFTVce (ORCPT ); Mon, 20 Jun 2022 17:32:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243528AbiFTVc0 (ORCPT ); Mon, 20 Jun 2022 17:32:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FC9813CFE for ; Mon, 20 Jun 2022 14:32:26 -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 ams.source.kernel.org (Postfix) with ESMTPS id E8519B81645 for ; Mon, 20 Jun 2022 21:32:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CC4EC341CD; Mon, 20 Jun 2022 21:32:23 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1o3P0Q-003o2v-M3; Mon, 20 Jun 2022 17:32:22 -0400 Message-ID: <20220620213222.521941315@goodmis.org> User-Agent: quilt/0.66 Date: Mon, 20 Jun 2022 17:32:02 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Gautam Menghani Subject: [for-linus][PATCH 4/4] tracing/uprobes: Remove unwanted initialization in __trace_uprobe_create() References: <20220620213158.468216113@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Gautam Menghani Remove the unwanted initialization of variable 'ret'. This fixes the clang scan warning: Value stored to 'ret' is never read [deadcode.DeadStores] Link: https://lkml.kernel.org/r/20220612144232.145209-1-gautammenghani201@g= mail.com Signed-off-by: Gautam Menghani Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_uprobe.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 9711589273cd..c3dc4f859a6b 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -546,7 +546,6 @@ static int __trace_uprobe_create(int argc, const char *= *argv) bool is_return =3D false; int i, ret; =20 - ret =3D 0; ref_ctr_offset =3D 0; =20 switch (argv[0][0]) { --=20 2.35.1