From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794583234; b=yZNltHz+HtKe+Yaw6d3XbIe5YXV6yZGEGXMOY3EootkhaDqzO0jbz/D5ZWrKaOr41LCv WTyS3/e7Jw2WnQj6fh//muK4x6ulD605xFqUvWCmmj8PW068ys/wekoPFLoGZwWQuIFi9 kbtJGaAWBdSsRWPfFuh7W4uGz8Zad27Ilr36JYoreL0e+11Vug8MI6I3iPaHF8RXaVoMj oKkfbsfVSddC33DnnPFk1Mw9B0EKBm8Qie1p6S/BF0mTI5fQawzPatlvG86dmgV6fVayH dVUX1H7izKzqkOkBJsOOzsRtDhQyGEdkwYc35i79UBPrPXNK+cUrZT6RN62NUhdpVdw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794583234; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=S1pLWYbamOi5rXtFLm0Gwq6ZibslKhk1ncxUfDLldzs=; b=rzElB9iQcl04VAXXVzd4gFiR/pvJGx6lpkXvz5YGYxfSz90R7hwOolGCt4w24pNnDb7H 3qQUUxoowK9s76KSmkRaqSS5R6x6LFGhE62DBmkR8CojePFFPhpq2tiv7WcmL9BqygIRQ ohwsETL5Cp1SdAOyl0lStIHE7tlmFSBIxm0Cvb1iL0KO7XN+ehlZEeMMwh11qA/Pk9aHB S+09FjOEJOGfSAhmVu109RodXQ3rh7CGU1vF3Tto8LNTrRc+KPj5S/lrPnSdFoU716F6s 95uFBYdwE1wlV9hj9AXxXveX5C5cgnM1bORlDBs8j+0XGpZzQwM+mX+Lt2ZS6BfYgpQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DCBUVnEh; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5623F606A33B; Fri, 13 Nov 2026 15:20:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DCBUVnEh Received: by smtp.kernel.org (Postfix) with ESMTPSA id B129E1F000C4; Fri, 13 Nov 2026 15:20:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794583234; bh=S1pLWYbamOi5rXtFLm0Gwq6ZibslKhk1ncxUfDLldzs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=DCBUVnEhluFN2HEDgsBMW1F2A4ZRslNIsw4PxHM20KWA7pF4wrjZTq6/lk+gnp52P HZVM3+UOtffwp/3M2GVGCDEcwncEZiLTpvuhaqVKLrcNanY6S6AZMv6yRt3rCIgwv3 zMZzW2++Wqsa+492i/zlv2/E9JQPc61d2SKBUf+HUOSY2WKpD5xfco8cVZmgnwChr9 idrCMM2Y2Oe1aCHu9DRUmWnbtooL3ULIvh/Pt11xb3KFaokbo02XDbF+c2M229JNrt 6eTSo1KnEOlev7K91W2zAWj7Mbs8X5H+syMKZQotm/ISNNEPVVGy9Yid6yzDpJT54V ayB6PxHII7QhA== Date: Fri, 13 Nov 2026 12:20:31 -0300 From: Arnaldo Carvalho de Melo To: Leo Yan Cc: Namhyung Kim , Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Mike Leach , Robert Walker , Suzuki K Poulose , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v1 09/12] perf cs-etm: Fall back to the recorded instruction size on a failed read Message-ID: References: <20261113150555.1163049-1-acme@kernel.org> <20261113150555.1163049-10-acme@kernel.org> <20261113151549.GR9176@e132581.arm.com> X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261113151549.GR9176@e132581.arm.com> On Fri, Nov 13, 2026 at 03:15:49PM +0000, Leo Yan wrote: > Hi Arnaldo, > > On Fri, Nov 13, 2026 at 12:05:50PM -0300, Arnaldo Carvalho de Melo wrote: > > From: Arnaldo Carvalho de Melo > > > > cs_etm__t32_instr_size() reads the instruction bytes from the traced > > program's memory to tell a 16-bit from a 32-bit T32 instruction, but it > > ignores cs_etm__frontend_mem_access() failing, which happens when the > > DSO or its debug data is missing, and then reads the uninitialized > > buffer. GCC 16 warns about it and build-test fails with -Werror. > > > > Use the instruction size recorded by the decoder, as the A32/A64 path > > already does, when the read doesn't return the full two bytes. > > This patch is duplicate with: > > https://lore.kernel.org/linux-perf-users/20261113-perf_fix_gcc15_failure-v1-0-eae592c5ff64@arm.com/T/#m5f610e381705bc587a9ce3d31be4e1e0ed595506 > > I prefer that one, it handle cs_etm__frontend_mem_access() failure > throughly. Ok, I'll replace it with yours, - Arnaldo