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=-9.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 323A6C4727E for ; Tue, 22 Sep 2020 01:25:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00BC420709 for ; Tue, 22 Sep 2020 01:25:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729753AbgIVBZr (ORCPT ); Mon, 21 Sep 2020 21:25:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:56620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729094AbgIVBYx (ORCPT ); Mon, 21 Sep 2020 21:24:53 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5AB9923A8B; Tue, 22 Sep 2020 01:24:53 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1kKX36-001sO8-E7; Mon, 21 Sep 2020 21:24:52 -0400 Message-ID: <20200922012452.322184057@goodmis.org> User-Agent: quilt/0.66 Date: Mon, 21 Sep 2020 21:24:30 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Masami Hiramatsu Subject: [for-next][PATCH 16/26] tracing/kprobes: Support perf-style return probe References: <20200922012414.115238201@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu Support perf-style return probe ("SYMBOL%return") for kprobe events. This will allow boot-time tracing user to define a return probe event. Link: https://lkml.kernel.org/r/159972813535.428528.4437029657208468954.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 2 +- kernel/trace/trace_kprobe.c | 18 +++++++++++++++++- kernel/trace/trace_probe.h | 1 + 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 55b829863127..ca6da462326d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5122,7 +5122,7 @@ static const char readme_msg[] = "\t -:[/]\n" #ifdef CONFIG_KPROBE_EVENTS "\t place: [:][+]|\n" - "place (kretprobe): [:][+]|\n" + "place (kretprobe): [:][+]%return|\n" #endif #ifdef CONFIG_UPROBE_EVENTS " place (uprobe): :[(ref_ctr_offset)]\n" diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f8e46929ceba..9d46415296eb 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -718,6 +718,9 @@ static int trace_kprobe_create(int argc, const char *argv[]) * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] * - Add kretprobe: * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] + * Or + * p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS] + * * Fetch args: * $retval : fetch return value * $stack : fetch stack address @@ -747,7 +750,6 @@ static int trace_kprobe_create(int argc, const char *argv[]) switch (argv[0][0]) { case 'r': is_return = true; - flags |= TPARG_FL_RETURN; break; case 'p': break; @@ -805,12 +807,26 @@ static int trace_kprobe_create(int argc, const char *argv[]) symbol = kstrdup(argv[1], GFP_KERNEL); if (!symbol) return -ENOMEM; + + tmp = strchr(symbol, '%'); + if (tmp) { + if (!strcmp(tmp, "%return")) { + *tmp = '\0'; + is_return = true; + } else { + trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX); + goto parse_error; + } + } + /* TODO: support .init module functions */ ret = traceprobe_split_symbol_offset(symbol, &offset); if (ret || offset < 0 || offset > UINT_MAX) { trace_probe_log_err(0, BAD_PROBE_ADDR); goto parse_error; } + if (is_return) + flags |= TPARG_FL_RETURN; if (kprobe_on_func_entry(NULL, symbol, offset)) flags |= TPARG_FL_FENTRY; if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index a22b62813f8c..04d00987da69 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -404,6 +404,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(MAXACT_TOO_BIG, "Maxactive is too big"), \ C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \ C(BAD_RETPROBE, "Retprobe address must be an function entry"), \ + C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \ C(NO_GROUP_NAME, "Group name is not specified"), \ C(GROUP_TOO_LONG, "Group name is too long"), \ C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \ -- 2.28.0