From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CWXP265CU009.outbound.protection.outlook.com (mail-ukwestazon11021079.outbound.protection.outlook.com [52.101.100.79]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 001E14AD7F4; Tue, 6 Oct 2026 23:28:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.100.79 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791329313; cv=fail; b=QuMPIvguTALRA/jbkofQHpK9rvgwhk58LEAazwrKZLPY1niaoF5MZ+TzNKcx896ehcBakCp1W3QYNA07R6wDK3RmbK2qXdC6O772EnDoDj5DQcARNJRwa/3Z0JboCfWcpz9FBqyC5MoF9mDiO8z8tBc0g22ZhaWXjJAJ6PScOR4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791329313; c=relaxed/simple; bh=nFGDiVpJco1EwoHKOizC0/QO0dS6c34d1cNGFhy+EiQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=TON1rQJjxre3EybrkQW098G4+OixcaytcgZB71qcryb+VOJk0nkWB5cxpVO6cXHXDaRrNLQ4/9Z88eU4wMSH1VoHlXllwbdu5GWGbyLpw0Z3736cpBh+m2+BGOpsZG5jAewwRfyJCWmZhuwQ5BgFHyXCOV1T6/bl6ApHHXljUZM= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=atomlin.com; spf=pass smtp.mailfrom=atomlin.com; arc=fail smtp.client-ip=52.101.100.79 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=atomlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=atomlin.com ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=NnJ/UmL1fqxomsQ+8C0/6yJD3KZWl5f23EXrJkTVSEfuXETmJ9MTU7bAsWqBj70ljuDZRqwOXDv8e1+eml5xseioOmGzGs354+Q7bNhG3UzYdkrLarBEjxdnMspVwJCBmfAUlXnzLb6czaksqk+wuxu5zr6s7fBODyXEx2hVM92prVWtQtp2eDlnhHX6lGUcKClFzWkq8mb5J8LE2fENuzCmvov8s2/pBmQyr7djFtzUnoZ1vtdkzPwqVMSB2GRiCjVgSCkWwRlpDBeIuAuKYn55Fm56MxCJiCVaOQCNF/SWVKI/1CVrWvQbaAMPZldBYcVo+f4orsYd8lgVTM7/Ew== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:MIME-Version; bh=1hekU8W/NBDwMM/ly75JO+B9cJxIOy8xInDG9kYYFlE=; b=X5GT0fBwTWkWLip2i9dNNUX79rB8Nj3bS2MyX1MLYgnX+GeYr1cx0ZyHd2VJrfcgu0CYGnDRq9TITz8gZpO79BwW0i6Hc2trMpytkD5FvwciIIeSTly57UGAbSXQlqT4STH+jH9RRmKYeylh9fL/t96YfvOHbqRyTmm+fAlEEXHtXjDocvruQ8usCgWtqGKhFisHPCmiUNgQcqAdM6qP5TvJhEekwgvJLA1L3UnB95+yR6fA4zWMP5jv7/dxdgi/ffkDjKz9S1D0TGep9d5rTiYVGkbBNEthINknS+5B1349i65thnawh3C6yMCUl1sH3Y7CJgWb37/JUEsqYCkLkA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=atomlin.com; dmarc=pass action=none header.from=atomlin.com; dkim=pass header.d=atomlin.com; arc=none Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=atomlin.com; Received: from CWLP123MB6607.GBRP123.PROD.OUTLOOK.COM (2603:10a6:400:183::5) by CWLP123MB4004.GBRP123.PROD.OUTLOOK.COM (2603:10a6:400:d1::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.496.16; Tue, 6 Oct 2026 23:28:03 +0000 Received: from CWLP123MB6607.GBRP123.PROD.OUTLOOK.COM ([fe80::cec4:77ab:262e:d230]) by CWLP123MB6607.GBRP123.PROD.OUTLOOK.COM ([fe80::cec4:77ab:262e:d230%4]) with mapi id 15.21.0496.010; Tue, 6 Oct 2026 23:28:03 +0000 From: Aaron Tomlin To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org Cc: mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, atomlin@atomlin.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH perf-tools-next v2 2/4] perf ftrace: Support filtering return address comments Date: Tue, 6 Oct 2026 19:27:54 -0400 Message-ID: <20261006232756.65620-3-atomlin@atomlin.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261006232756.65620-1-atomlin@atomlin.com> References: <20261006232756.65620-1-atomlin@atomlin.com> Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: VIUP296CA0101.AUTP296.PROD.OUTLOOK.COM (2603:10a6:800:351::15) To CWLP123MB6607.GBRP123.PROD.OUTLOOK.COM (2603:10a6:400:183::5) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CWLP123MB6607:EE_|CWLP123MB4004:EE_ X-MS-Office365-Filtering-Correlation-Id: a1c9ad37-30a8-4218-e7eb-08df240177b8 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|23010399003|376014|7416014|1800799024|56012099006|10067099003|18002099003|22082099003|6133799003|3023799007; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CWLP123MB6607.GBRP123.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230040)(366016)(23010399003)(376014)(7416014)(1800799024)(56012099006)(10067099003)(18002099003)(22082099003)(6133799003)(3023799007);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Prh8fqdJ6w3PMio1incdbhWDb8p3cacf0hWFatpP8BDhZDGWe3rJij9LeogH?= =?us-ascii?Q?mF2I+jRqBJn9EPZaLi98dYajfp5izqgUt2nT3/wrt2sTKB5odxTNG6VJYvFK?= =?us-ascii?Q?U/XbFZK8UBemqaRtn2Vd8ObBc7LGTFgMcyfvS/yS8Vk5R+nzfZeokHyLmg60?= =?us-ascii?Q?6mTPbGJJL/ex8ia/V/tUrpjMjnMysoHbDw8lZTnAhrYh6Ma7cSiu7xlub2Ph?= =?us-ascii?Q?kVyhun2e4YFeCPrgyjMu6lcKYDrwxdqmcViGObhzERaxAjrdy9YanHtl4qtQ?= =?us-ascii?Q?3aPPBslNSMXPgLdSqQ6BvxBqcRUEOAPFzFM558LNdFAsuyVoD715tc/FUOB0?= =?us-ascii?Q?MgAO71Er/dkkxivuejYb4bHQFQRPKfD/XeWpM6I+tMO8GcttCwi+ZgOaFKiG?= =?us-ascii?Q?T9UtxVGcl8/UCjgXDKIe+ysoPNOmd19YRxKKRdWbzeej1dWjXSf/BQ8PUSYx?= =?us-ascii?Q?CrHds9xAbjOTmSk4jpVvHROkXN3ymx9Wa4nNE7IB8C6VTpobdB+Y8Ce3wgy/?= =?us-ascii?Q?tU/zShHlJLvHTkkGCAsPTkyOg9gzs/CnN7g6ViOJaVK+iiBmi2n/7/LMe01+?= =?us-ascii?Q?Fauo9vNAd57J1yfbR+yq2jSo8nGtFa6OqoFYN4fcX6AqYYiPzC9LuQd6ehmk?= =?us-ascii?Q?uhyRBE3UnsMJNb6rpcEuDqUHzOMT7cfMW0qApvcxPpb2B6sDELz3fLGMbXWA?= =?us-ascii?Q?xUzi9nWA2RdcKxIgRuInvt0OeVi95Q4kWia40O7lRkdYBzE/HeNEe2/wEANy?= =?us-ascii?Q?NfenGbLxjx6nZUSFj0F3bmu31UTXcwvdBXlgJzgHabe+dEv9xGPGxJhgWcST?= =?us-ascii?Q?hucYhzO1lMO4t5RCTkvbhUmaqjqbwZM/pWRledmNVHqpgRcj9BMdxNbRd2pd?= =?us-ascii?Q?rEqaI1VfO1eUCadGChdC4fL6AadRZ4mFRRG5u8TKsINXkZPPnx6yReIk+iLv?= =?us-ascii?Q?8nBz2I6tzndFgbncyuVJdfeMSwgA+MYJtPHpL56l45w72czk1+y0N1PvbwVS?= =?us-ascii?Q?9Lv5kTagMm6OjLTI/ypZLVWFKwNAS5HTdAWPRAng3ZpROF210PHFa9wdTe+E?= =?us-ascii?Q?cDULSJ6J6FThcyOSTA99QKF2o3Gd1+1vktWJqXvTEmmuZtnkGvQpiNskneD1?= =?us-ascii?Q?CvWnKYZ68xZyeE426bvZWe/vslYrx4rpsF3qc4v1DzPxE4Lqcg+39S5H8siw?= =?us-ascii?Q?0BMe7MRtqEbxHADYBXe4AqnOFg1xE47O7Mh0Jjyy8zswFKEtxy1t/Ib7i0s9?= =?us-ascii?Q?TwXba0fv2U/RZkSM9OhaA0FqswAdNQs6IknfnVgIZII6CBHP7zlu8IDi9Drb?= =?us-ascii?Q?hv9LSVDVYOJ0kyt47bcpUQtsYJCPMgcjI5j5tLUOqPbbF1iDlvoFZarGgkUX?= =?us-ascii?Q?QLv+zkr5TVi+G3heZ+eTcvkXQvprzKz2j4W6hWbvsD+oGcrpXrxTrhdh9OCi?= =?us-ascii?Q?vc0pGonamjvH94TKvNhmBdQDYvtTBPycSt2EoSm9Z5ickzGc1K0667glb0Ah?= =?us-ascii?Q?8IfZTYZZJJAOkvsrw72cK8vFJs+vns/s5+Fe7AKGVdWXERNuv3amq+R8ctKR?= =?us-ascii?Q?aSBkmy+FdAH3CJUPJ7zdbI3ORthBD0sy50KnhR/qK8s0Wn1iMKP1g2lqmuJA?= =?us-ascii?Q?GAJS2uyRxFrbAYwo9Cb/mhSwH/SPaGF8n8QiYfENqgIej5vPU8aef/SOdeCL?= =?us-ascii?Q?1k9SSzhLE5mOYD7t6I69gse+H6oToYksh0mPAhpdzKYKwElLWwSz9HvOndmI?= =?us-ascii?Q?zYqGfs+K6w=3D=3D?= X-OriginatorOrg: atomlin.com X-MS-Exchange-CrossTenant-Network-Message-Id: a1c9ad37-30a8-4218-e7eb-08df240177b8 X-MS-Exchange-CrossTenant-AuthSource: CWLP123MB6607.GBRP123.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Oct 2026 23:28:03.3168 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: e6a32402-7d7b-4830-9a2b-76945bbbcb57 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: B1fEFIVxEopWIoVzeRg7PrxZ2nHY/rr+XsV/5fG0kXwcPMwuQ2xAfRogFMT29fPq8nl7B4idnvQQmBeSPkPvkg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CWLP123MB4004 When tracing with the Linux kernel's function graph tracer, enabling funcgraph-retaddr records the return address of each function entry as a comment in the trace stream (e.g. /* <-load_elf_phdrs+0x6c/0xb0 */). While valuable for tracing execution origins, these trailing comments can add considerable visual clutter to the call graph, particularly when examining deeply nested call trees or when synthesising higher-level abstractions. Introduce support for filtering out return address comments from function graph trace output. Provide both a standalone --filter-retaddr flag and a --graph-opts filter-retaddr sub-option. Key aspects of this implementation: 1. Return address parsing and filtering Implement ftrace_parse_retaddr() and ftrace_filter_retaddr() in tools/perf/util/ftrace.c to robustly match return address comments across diverse output styles (standard format, return values, and bracketed addresses) and strip them in-place with memmove(3). 2. Command-line interface Expose --filter-retaddr and --graph-opts filter-retaddr in tools/perf/builtin-ftrace.c, updating the documentation in tools/perf/Documentation/perf-ftrace.txt accordingly. 3. Automated verification Add a dedicated unit test suite ("Ftrace return address processing") in tools/perf/tests/ftrace.c to validate comment parsing and string filtering across all supported formats. Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Aaron Tomlin --- tools/perf/Documentation/perf-ftrace.txt | 5 ++ tools/perf/builtin-ftrace.c | 17 ++++- tools/perf/tests/Build | 1 + tools/perf/tests/builtin-test.c | 1 + tools/perf/tests/ftrace.c | 80 ++++++++++++++++++++++++ tools/perf/tests/tests.h | 1 + tools/perf/util/Build | 1 + tools/perf/util/ftrace.c | 68 ++++++++++++++++++++ tools/perf/util/ftrace.h | 5 ++ 9 files changed, 178 insertions(+), 1 deletion(-) create mode 100644 tools/perf/tests/ftrace.c create mode 100644 tools/perf/util/ftrace.c diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 3f3808e513fe..ee126604a8ca 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -127,6 +127,7 @@ OPTIONS for 'perf ftrace trace' - retval - Show function return value. - retval-hex - Show function return value in hexadecimal format. - retaddr - Show function return address. + - filter-retaddr - Filter out function return address comments from output. - nosleep-time - Measure on-CPU time only for function_graph tracer. - noirqs - Ignore functions that happen inside interrupt. - verbose - Show process names, PIDs, timestamps, etc. @@ -134,6 +135,10 @@ OPTIONS for 'perf ftrace trace' - depth= - Set max depth for function graph tracer to follow. - tail - Print function name at the end. +--filter-retaddr:: + Filter out function return address comments (`/* <-caller+offset */`) + from function_graph output. + OPTIONS for 'perf ftrace latency' --------------------------------- diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 4e77a0b2513f..ddb567781125 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -827,6 +827,8 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace) break; for (int i = 0; i < n; i++) { if (buf[i] == '\n') { + if (ftrace->filter_retaddr) + ftrace_filter_retaddr(linebuf.buf); fprintf(stdout, "%s\n", linebuf.buf); strbuf_setlen(&linebuf, 0); } else { @@ -857,6 +859,8 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace) break; for (int i = 0; i < n; i++) { if (buf[i] == '\n') { + if (ftrace->filter_retaddr) + ftrace_filter_retaddr(linebuf.buf); fprintf(stdout, "%s\n", linebuf.buf); strbuf_setlen(&linebuf, 0); } else { @@ -867,6 +871,8 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace) } if (linebuf.len > 0) { + if (ftrace->filter_retaddr) + ftrace_filter_retaddr(linebuf.buf); fprintf(stdout, "%s\n", linebuf.buf); strbuf_setlen(&linebuf, 0); } @@ -1729,6 +1735,7 @@ static int parse_graph_tracer_opts(const struct option *opt, { int ret; struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value; + int filter_retaddr = -1; struct sublevel_option graph_tracer_opts[] = { { .name = "args", .value_ptr = &ftrace->graph_args }, { .name = "retval", .value_ptr = &ftrace->graph_retval }, @@ -1740,6 +1747,7 @@ static int parse_graph_tracer_opts(const struct option *opt, { .name = "thresh", .value_ptr = &ftrace->graph_thresh }, { .name = "depth", .value_ptr = &ftrace->graph_depth }, { .name = "tail", .value_ptr = &ftrace->graph_tail }, + { .name = "filter-retaddr", .value_ptr = &filter_retaddr }, { .name = NULL, } }; @@ -1750,6 +1758,11 @@ static int parse_graph_tracer_opts(const struct option *opt, if (ret) return ret; + if (filter_retaddr != -1) { + ftrace->filter_retaddr = (filter_retaddr != 0); + ftrace->filter_retaddr_set = true; + } + return 0; } @@ -1825,12 +1838,14 @@ int cmd_ftrace(int argc, const char **argv) OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func", "Set nograph filter on given functions", parse_filter_func), OPT_CALLBACK(0, "graph-opts", &ftrace, "options", - "Graph tracer options, available options: args,retval,retval-hex,retaddr,nosleep-time,noirqs,verbose,thresh=,depth=", + "Graph tracer options, available options: args,retval,retval-hex,retaddr,filter-retaddr,nosleep-time,noirqs,verbose,thresh=,depth=", parse_graph_tracer_opts), OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size", "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size), OPT_BOOLEAN(0, "inherit", &ftrace.inherit, "Trace children processes"), + OPT_BOOLEAN_SET(0, "filter-retaddr", &ftrace.filter_retaddr, &ftrace.filter_retaddr_set, + "Filter out funcgraph return address comments"), OPT_INTEGER('D', "delay", &ftrace.target.initial_delay, "Number of milliseconds to wait before starting tracing after program start"), OPT_PARENT(common_options), diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build index 395f2866094a..136138932fcb 100644 --- a/tools/perf/tests/Build +++ b/tools/perf/tests/Build @@ -72,6 +72,7 @@ perf-test-y += hwmon_pmu.o perf-test-y += tool_pmu.o perf-test-y += subcmd-help.o perf-test-y += kallsyms-split.o +perf-test-y += ftrace.o ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 arm arm64 powerpc riscv)) perf-test-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index d2f594921e25..9663f48afb92 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -137,6 +137,7 @@ static struct test_suite *generic_tests[] = { &suite__perf_hooks, &suite__unit_number__scnprint, &suite__mem2node, + &suite__ftrace, &suite__time_utils, &suite__jit_write_elf, &suite__pfm, diff --git a/tools/perf/tests/ftrace.c b/tools/perf/tests/ftrace.c new file mode 100644 index 000000000000..596cecee844e --- /dev/null +++ b/tools/perf/tests/ftrace.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include "tests.h" +#include "debug.h" +#include "util/ftrace.h" + +static int test_parse_retaddr(void) +{ + char sym[128]; + u64 offset = 0; + + /* Standard format */ + TEST_ASSERT_VAL("parse standard retaddr", + ftrace_parse_retaddr("kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */", + sym, sizeof(sym), &offset)); + TEST_ASSERT_EQUAL("sym name", strcmp(sym, "load_elf_phdrs"), 0); + TEST_ASSERT_VAL("offset", offset == 0x6c); + + /* With return value */ + TEST_ASSERT_VAL("parse retaddr with ret", + ftrace_parse_retaddr( + "__cond_resched(); /* <-load_elf_phdrs+0x6c/0xb0 ret=0x0 */", + sym, sizeof(sym), &offset)); + TEST_ASSERT_EQUAL("sym name", strcmp(sym, "load_elf_phdrs"), 0); + TEST_ASSERT_VAL("offset", offset == 0x6c); + + /* Bracketed address */ + TEST_ASSERT_VAL("parse bracketed retaddr", + ftrace_parse_retaddr("foo() { /* <-[0xffffffff818534c8] bar+0x20/0x40 */", + sym, sizeof(sym), &offset)); + TEST_ASSERT_EQUAL("sym name", strcmp(sym, "bar"), 0); + TEST_ASSERT_VAL("offset", offset == 0x20); + + /* No return address */ + TEST_ASSERT_VAL("no retaddr", + !ftrace_parse_retaddr("do_filp_open();", sym, sizeof(sym), &offset)); + + return TEST_OK; +} + +static int test_filter_retaddr(void) +{ + char line1[] = "kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */"; + char line2[] = "__cond_resched(); /* <-load_elf_phdrs+0x6c/0xb0 ret=0x0 */"; + char line3[] = "do_filp_open();"; + + ftrace_filter_retaddr(line1); + TEST_ASSERT_EQUAL("filter standard retaddr", strcmp(line1, "kernel_read() {"), 0); + + ftrace_filter_retaddr(line2); + TEST_ASSERT_EQUAL("filter retaddr with ret", strcmp(line2, "__cond_resched();"), 0); + + ftrace_filter_retaddr(line3); + TEST_ASSERT_EQUAL("filter line without retaddr unchanged", + strcmp(line3, "do_filp_open();"), 0); + + return TEST_OK; +} + +static int test__ftrace(struct test_suite *test __maybe_unused, int subtest __maybe_unused) +{ + int ret; + + ret = test_parse_retaddr(); + if (ret != TEST_OK) + return ret; + + ret = test_filter_retaddr(); + if (ret != TEST_OK) + return ret; + + return TEST_OK; +} + +DEFINE_SUITE("Ftrace return address processing", ftrace); diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index 9c96f33483d1..1aec32e094c8 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -163,6 +163,7 @@ DECLARE_SUITE(perf_hooks); DECLARE_SUITE(unit_number__scnprint); DECLARE_SUITE(mem2node); DECLARE_SUITE(maps); +DECLARE_SUITE(ftrace); DECLARE_SUITE(time_utils); DECLARE_SUITE(jit_write_elf); DECLARE_SUITE(api_io); diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 2c1f880c4c47..5b082d09006d 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -169,6 +169,7 @@ perf-util-y += list_sort.o perf-util-y += mutex.o perf-util-y += sharded_mutex.o perf-util-y += intel-tpebs.o +perf-util-y += ftrace.o perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o diff --git a/tools/perf/util/ftrace.c b/tools/perf/util/ftrace.c new file mode 100644 index 000000000000..5f582cf8531f --- /dev/null +++ b/tools/perf/util/ftrace.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include "util/ftrace.h" + +bool ftrace_parse_retaddr(const char *str, char *sym_name, size_t sym_len, u64 *offset) +{ + const char *p = strstr(str, "<-"); + const char *plus; + const char *bracket; + char *endptr; + size_t name_len; + + if (!p) + return false; + + p += 2; + while (*p == ' ') + p++; + + if (*p == '[') { + bracket = strchr(p, ']'); + if (bracket) + p = bracket + 1; + while (*p == ' ') + p++; + } + + plus = strchr(p, '+'); + if (!plus) + return false; + + name_len = plus - p; + if (name_len == 0 || name_len >= sym_len) + return false; + + memcpy(sym_name, p, name_len); + sym_name[name_len] = '\0'; + + *offset = strtoull(plus + 1, &endptr, 16); + return true; +} + +void ftrace_filter_retaddr(char *str) +{ + char *start = strstr(str, "/* <-"); + char *end; + + if (!start) + return; + + end = strstr(start, "*/"); + if (!end) + return; + + end += 2; /* skip end-of-comment delimiter */ + + /* Also backtrack any spaces before comment */ + while (start > str && *(start - 1) == ' ') + start--; + + memmove(start, end, strlen(end) + 1); +} diff --git a/tools/perf/util/ftrace.h b/tools/perf/util/ftrace.h index 950f2efafad2..50216d3fef64 100644 --- a/tools/perf/util/ftrace.h +++ b/tools/perf/util/ftrace.h @@ -39,6 +39,8 @@ struct perf_ftrace { int graph_verbose; int graph_thresh; int graph_tail; + bool filter_retaddr; + bool filter_retaddr_set; }; struct filter_entry { @@ -93,4 +95,7 @@ perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused) #endif /* HAVE_BPF_SKEL */ +bool ftrace_parse_retaddr(const char *str, char *sym_name, size_t sym_len, u64 *offset); +void ftrace_filter_retaddr(char *str); + #endif /* __PERF_FTRACE_H__ */ -- 2.55.0