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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8B9DC07E9D for ; Tue, 27 Sep 2022 20:41:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233018AbiI0Ul3 (ORCPT ); Tue, 27 Sep 2022 16:41:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233090AbiI0UlW (ORCPT ); Tue, 27 Sep 2022 16:41:22 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64A2C100AA7; Tue, 27 Sep 2022 13:41:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664311278; x=1695847278; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=DtZi3Sm9jkfhyr6ST6vhbGoeIvsdEwtVMuB6wMEC3Wo=; b=GCmxp7u4W/aLLYbZI3Wwmc+XsronW8zMl5cVbAQRIxp9sTOF18KtAgyf yn047EhxrWk4Ha19qAXmxyhZrkqzJeus1qgOcLabzrIDfgcAXSdXbTHDN /E+es42Y2PBRhgAgSLcYRDnJ0PfWWy5lq/LIOY5FFihTx2SDZ88I+fMCH VRcj/qTWHXsYAfPD2dpPmN3cCwvbShy1gpIeIxyFQC27Neg6n5IP5r+ew WC8ENCYCYJSL6Uo1Jn+dr68teSKkJLcRlzwb/0RUa/6BvFKkkswzJXiDR T0FHGPn1Y+lpirijTVq674Mn17P2iH7uDGsic5uC72r/wboAxwyHcJGgb g==; X-IronPort-AV: E=McAfee;i="6500,9779,10483"; a="301404897" X-IronPort-AV: E=Sophos;i="5.93,350,1654585200"; d="scan'208";a="301404897" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Sep 2022 13:41:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10483"; a="616962254" X-IronPort-AV: E=Sophos;i="5.93,350,1654585200"; d="scan'208";a="616962254" Received: from linux.intel.com ([10.54.29.200]) by orsmga007.jf.intel.com with ESMTP; 27 Sep 2022 13:41:04 -0700 Received: from [10.252.215.51] (kliang2-mobl1.ccr.corp.intel.com [10.252.215.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id 8C3C4580BE9; Tue, 27 Sep 2022 13:41:03 -0700 (PDT) Message-ID: <8af9bdd8-47d0-b9cd-57b4-0f92c8b2889a@linux.intel.com> Date: Tue, 27 Sep 2022 16:41:02 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.3.0 Subject: Re: [PATCH -tip] bpf: Check flags for branch stack in bpf_read_branch_records helper To: Jiri Olsa , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Cc: lkml , Ingo Molnar , Alexander Shishkin , Mark Rutland , Namhyung Kim , bpf@vger.kernel.org, Song Liu , Daniel Xu References: <20220927203259.590950-1-jolsa@kernel.org> Content-Language: en-US From: "Liang, Kan" In-Reply-To: <20220927203259.590950-1-jolsa@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-09-27 4:32 p.m., Jiri Olsa wrote: > Recent commit [1] changed branch stack data indication from > br_stack pointer to sample_flags in perf_sample_data struct. > > We need to check sample_flags for PERF_SAMPLE_BRANCH_STACK > bit for valid branch stack data. > > [1] a9a931e26668 ("perf: Use sample_flags for branch stack") > > Cc: Kan Liang > Fixes: a9a931e26668 ("perf: Use sample_flags for branch stack") > Signed-off-by: Jiri Olsa Thanks for the fix. Reviewed-by: Kan Liang Thanks, Kan > --- > NOTE sending on top of tip/master because [1] is not > merged in bpf-next/master yet > > kernel/trace/bpf_trace.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 68e5cdd24cef..1fcd1234607e 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -1507,6 +1507,9 @@ BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, > if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) > return -EINVAL; > > + if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) > + return -ENOENT; > + > if (unlikely(!br_stack)) > return -ENOENT; >