From nobody Fri Apr 3 05:19:03 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 DE0FFC6FA8A for ; Thu, 15 Sep 2022 14:16:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229986AbiIOOQo (ORCPT ); Thu, 15 Sep 2022 10:16:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229940AbiIOOQm (ORCPT ); Thu, 15 Sep 2022 10:16:42 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9AB95A3FB; Thu, 15 Sep 2022 07:16:40 -0700 (PDT) Date: Thu, 15 Sep 2022 14:16:38 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1663251399; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ccBMjjEeCKeUdwVrOFsmFb8BeKecH/ZVqdBTIwVLElM=; b=RJpovITKExtVTmuAHptPBNR9PtznBpCM6Suuk5yWYGc5WB/PnCQEfARwivICTanaLsJ9B8 spiyLa0X9TeqClHZz+oV+YqmBO6PHDywQ3jlJpmO566D4VtzLGmvdPTmcWPgl86jB449KL 4EOOmuTc59qfy4JeivVfI4B9CctZj0/GJBEH22hURxsXl/uWgxMVRnzxiTwUXU5FjNjMOl Fk8MzsmAiU32oNeEoDT4QwSLZSlfZGTaAIuZI2oVx/ssjvYhSExOQlS/oRD+DPI3bp948U iwDk2XT56HWv97n7FEwVNzJfaaSovB8S4cvEI3gHIsKTHXPss1TatApchuMQaw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1663251399; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ccBMjjEeCKeUdwVrOFsmFb8BeKecH/ZVqdBTIwVLElM=; b=CkbA7pmMzY+xzbHVpcP05CCYUfVjtWjytJDbKfrAw0q04VqagaEUxQ06dT0oNcyIa30btE Rqo1OHcWfD0tT4Aw== From: "tip-bot2 for Namhyung Kim" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf/bpf: Always use perf callchains if exist Cc: Namhyung Kim , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220908214104.3851807-2-namhyung@kernel.org> References: <20220908214104.3851807-2-namhyung@kernel.org> MIME-Version: 1.0 Message-ID: <166325139832.401.13098591458028743653.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the perf/core branch of tip: Commit-ID: 16817ad7e8b31728b44ff9f17d8d894ed8a450d0 Gitweb: https://git.kernel.org/tip/16817ad7e8b31728b44ff9f17d8d894ed= 8a450d0 Author: Namhyung Kim AuthorDate: Thu, 08 Sep 2022 14:41:03 -07:00 Committer: Peter Zijlstra CommitterDate: Tue, 13 Sep 2022 15:03:22 +02:00 perf/bpf: Always use perf callchains if exist If the perf_event has PERF_SAMPLE_CALLCHAIN, BPF can use it for stack trace. The problematic cases like PEBS and IBS already handled in the PMU driver a= nd they filled the callchain info in the sample data. For others, we can call perf_callchain() before the BPF handler. Signed-off-by: Namhyung Kim Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220908214104.3851807-2-namhyung@kernel.org --- kernel/bpf/stackmap.c | 4 ++-- kernel/events/core.c | 12 ++++++++++-- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 1adbe67..aecea74 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -338,7 +338,7 @@ BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_da= ta_kern *, ctx, int ret; =20 /* perf_sample_data doesn't have callchain, use bpf_get_stackid */ - if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY)) + if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)) return bpf_get_stackid((unsigned long)(ctx->regs), (unsigned long) map, flags, 0, 0); =20 @@ -506,7 +506,7 @@ BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data= _kern *, ctx, int err =3D -EINVAL; __u64 nr_kernel; =20 - if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY)) + if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)) return __bpf_get_stack(regs, NULL, NULL, buf, size, flags); =20 if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | diff --git a/kernel/events/core.c b/kernel/events/core.c index c98ecf3..7da5515 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10000,8 +10000,16 @@ static void bpf_overflow_handler(struct perf_event= *event, goto out; rcu_read_lock(); prog =3D READ_ONCE(event->prog); - if (prog) + if (prog) { + if (prog->call_get_stack && + (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) && + !(data->sample_flags & PERF_SAMPLE_CALLCHAIN)) { + data->callchain =3D perf_callchain(event, regs); + data->sample_flags |=3D PERF_SAMPLE_CALLCHAIN; + } + ret =3D bpf_prog_run(prog, &ctx); + } rcu_read_unlock(); out: __this_cpu_dec(bpf_prog_active); @@ -10027,7 +10035,7 @@ static int perf_event_set_bpf_handler(struct perf_e= vent *event, =20 if (event->attr.precise_ip && prog->call_get_stack && - (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY) || + (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) || event->attr.exclude_callchain_kernel || event->attr.exclude_callchain_user)) { /*