From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AE46036683B; Tue, 7 Apr 2026 15:30:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775575814; cv=none; b=V2LfWLTIm+ItQnuczj6LVHTL3W3MOFm8yDzvlbS4PDuXS2S5Rp4z1180mPeWVaiU4kNeaUZgrx1xUgXhphgez71gZ6p2jhBtgragFC744X2QNGltbRtm3tDr1dGn9TToDvwJECzebzxX/aRH20nbieLwzC/wW3gW8BbTRXEhkK8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775575814; c=relaxed/simple; bh=llsE4IbiFMmBlTdmurpE6AzK69uhgqzLVniQo/ehG6w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Wvn/Mvf73/xx5jr0sfg2jeG/PZ6ulcFh74Zg4z21ge/ng/+seNtlUxUnqXrXFJ7n2qN+SRd4cDYYhtCVpIJSLIr3+9MJMxYb3xSou0lCftq8aDp0cj941aONLwNfYBOqS8h/Ibntfxd3PIWeo3jGNNwxZKiuOdG+Tf/cu/Xy3vg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=jvAKs0sj; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="jvAKs0sj" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5D4B31BB2; Tue, 7 Apr 2026 08:29:57 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B34703F7D8; Tue, 7 Apr 2026 08:30:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1775575803; bh=llsE4IbiFMmBlTdmurpE6AzK69uhgqzLVniQo/ehG6w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jvAKs0sjx33rw9GsjeF3tZl/J0axWZqCY0NiNEGV10fwcOBdwG9qCQdWnT/HNw/lR wPeMIqTlifnG03XLtPKotuEaqwbyds3KKBfp8iAAkajdICvM7V1MMEJjkW9ByjaUp3 TTRhKZNJjmNirXkynXOWULgQNci7mBCJOYWzYe+c= Date: Tue, 7 Apr 2026 16:30:00 +0100 From: Leo Yan To: James Clark Cc: John Garry , Will Deacon , Mike Leach , Leo Yan , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Al Grant , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/6] perf arm_spe: Handle missing CPU IDs Message-ID: <20260407153000.GN356832@e132581.arm.com> References: <20260407-james-spe-impdef-decode-v2-0-55d3ef997c48@linaro.org> <20260407-james-spe-impdef-decode-v2-2-55d3ef997c48@linaro.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260407-james-spe-impdef-decode-v2-2-55d3ef997c48@linaro.org> On Tue, Apr 07, 2026 at 03:05:16PM +0100, James Clark wrote: > Don't call strtol() with a null pointer to avoid undefined behavior. > > I'm not sure of the exact scenario for missing CPU IDs but I don't think > it happens in practice. SPE decoding can continue without them with > reduced functionality, but print an error message anyway. > > Signed-off-by: James Clark Reviewed-by: Leo Yan > --- > tools/perf/util/arm-spe.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c > index 7447b000f9cd..fc11f32e4911 100644 > --- a/tools/perf/util/arm-spe.c > +++ b/tools/perf/util/arm-spe.c > @@ -968,16 +968,23 @@ static int arm_spe__get_midr(struct arm_spe *spe, int cpu, u64 *midr) > > pr_warning_once("Old SPE metadata, re-record to improve decode accuracy\n"); > cpuid = perf_env__cpuid(perf_session__env(spe->session)); > + if (!cpuid) > + goto err; > + > *midr = strtol(cpuid, NULL, 16); > return 0; > } > > metadata = arm_spe__get_metadata_by_cpu(spe, cpu); > if (!metadata) > - return -EINVAL; > + goto err; > > *midr = metadata[ARM_SPE_CPU_MIDR]; > return 0; > + > +err: > + pr_err("Failed to get MIDR for CPU %d\n", cpu); > + return -EINVAL; > } > > static void arm_spe__synth_ds(struct arm_spe_queue *speq, > > -- > 2.34.1 > >