From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B1E341FBE9C; Thu, 13 Mar 2025 07:29:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741850947; cv=none; b=FFZsBYiUN297hh410+D2Q3ODlLlbQS45rBd6pwaTt9dBm42YfOKcOxk3QOGJLr+81INlrUTDALfS8xfEtNeQGa49TgxLGnNeMFEN2e8sS/tdz4wAhotg1mvVcuVgpZQeij3Z7kSuLogg7bn7X/bcBhsHm+qWkkt3NekD/JgFfjk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741850947; c=relaxed/simple; bh=bXd5Zvd7dZCJ4R1puUhsaSnoSdsh9qOuJCYZlCWoGgg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Jti9vEUTJoKX7SJty8uZoxC3N+F/1MwYrVlTDDwTpa4vR7pU/L6y+LjzlQDSdCoMMv53OAOWb4TD/rIa8IaOjSJoo/qIF2smC73BXWWduTm1bpRt27DAwMsvmjdciKPLz/TfxD80d+WbBJZlztqY1r2riwnor/BDoL/MSo3LwHM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Dw6NfMQk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Dw6NfMQk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCDF2C4CEDD; Thu, 13 Mar 2025 07:29:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741850947; bh=bXd5Zvd7dZCJ4R1puUhsaSnoSdsh9qOuJCYZlCWoGgg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Dw6NfMQko4STR5OR0+dkKeiLiHPVnPVIwaPlVHIXrgH/3QvFEp4FDClO9lW3KPBbo XNYNgGRRu9VX2X/iw47GZ+v8N3O0jMdxo4Egj88CjCFiLkhgBaE4EeXfm0Xt8JaT3N B4dw0g90oNdwfWgHb+tD4O7PrCxnUNEyk+Xcajep5EfUMRDuyG6HPS2IC3hGmLrVAf 97+oYBs2OwbmBJU2X5xDFvUD8nqdJtSG7n3BuMf1ZPcUmSpVBNAcaJ8zz4p/gHjTia r+WZOwBAP/kdqFX1NnIFeH8q0CS6q4EkhEMD8sxpk09tAdacrLzMj0QempPAvCP+7o sK0rCcYjRT1Tg== Date: Thu, 13 Mar 2025 00:29:05 -0700 From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo Subject: Re: [PATCH 3/3] perf hist stdio: Do bounds check when printing callchains to avoid UB with new gcc versions Message-ID: References: <20250310194534.265487-1-acme@kernel.org> <20250310194534.265487-4-acme@kernel.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=utf-8 Content-Disposition: inline In-Reply-To: On Mon, Mar 10, 2025 at 02:55:52PM -0700, Namhyung Kim wrote: > On Mon, Mar 10, 2025 at 04:45:33PM -0300, Arnaldo Carvalho de Melo wrote: > > From: Arnaldo Carvalho de Melo > > > > Do a simple bounds check to avoid this on new gcc versions: > > > > 31 15.81 fedora:rawhide : FAIL gcc version 15.0.1 20250225 (Red Hat 15.0.1-0) (GCC) > > In function 'callchain__fprintf_left_margin', > > inlined from 'callchain__fprintf_graph.constprop' at ui/stdio/hist.c:246:12: > > ui/stdio/hist.c:27:39: error: iteration 2147483647 invokes undefined behavior [-Werror=aggressive-loop-optimizations] > > Hmm.. does it warn about a signed integer overflow? > > 2147483647 is 0x7fffffff in hex and it should be INT_MAX. > I'm not sure what is the problem. Maybe the aggressive loop optimization can unroll the loop more than the INT_MAX...? Anyway the fix is simple and makes sense. > > > > 27 | for (i = 0; i < left_margin; i++) > > | ~^~ > > ui/stdio/hist.c:27:23: note: within this loop > > 27 | for (i = 0; i < left_margin; i++) > > | ~~^~~~~~~~~~~~~ > > cc1: all warnings being treated as errors > > -- > > util/units.c: In function 'unit_number__scnprintf': > > util/units.c:67:24: error: initializer-string for array of 'char' is too long [-Werror=unterminated-string-initialization] > > 67 | char unit[4] = "BKMG"; > > | ^~~~~~ > > cc1: all warnings being treated as errors > > This part belongs to the previous commit. :) I'll drop this part. Thanks, Namhyung > > > > > Cc: Adrian Hunter > > Cc: Ian Rogers > > Cc: James Clark > > Cc: Jiri Olsa > > Cc: Kan Liang > > Cc: Namhyung Kim > > Signed-off-by: Arnaldo Carvalho de Melo > > --- > > tools/perf/ui/stdio/hist.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c > > index 74b2c619c56c8ba3..7ac4b98e28bca82e 100644 > > --- a/tools/perf/ui/stdio/hist.c > > +++ b/tools/perf/ui/stdio/hist.c > > @@ -1,4 +1,5 @@ > > // SPDX-License-Identifier: GPL-2.0 > > +#include > > #include > > #include > > #include > > @@ -24,6 +25,9 @@ static size_t callchain__fprintf_left_margin(FILE *fp, int left_margin) > > int i; > > int ret = fprintf(fp, " "); > > > > + if (left_margin > USHRT_MAX) > > + left_margin = USHRT_MAX; > > + > > for (i = 0; i < left_margin; i++) > > ret += fprintf(fp, " "); > > > > -- > > 2.48.1 > >