From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9C32B2594BD; Sat, 12 Sep 2026 10:19:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208360; cv=none; b=mnibsmaocHx7c0yVnRDy9EXYFTwABYllNk87UVGf2n9KV5A8D9WhlGqYI+6AtOF1pPTFarI3TGel54c8qZQ6AfjGvL1AiNeNV/9xc6CchzkgfBooJahhxbvBaeJlAva+Gf8J/iP8ERxZacDIFKHIlGBYupUHiGxl2Aw1nFVYZzo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208360; c=relaxed/simple; bh=oW81/SY8it3/vQLJfykQlgBWtIQjlSUwdxE+BUnWbuA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SLpAWvGqi6pIuQBywlePSLMyfSmHX8ustKLu3+1zgrwCZRKel+o4Z3HCBhcSOUoQas49RP9bGnOkZiFm60uoTyFOiVfsuIXQ0EaO9Ep7FGyct3NbpfE0csyI2xlf+R7m8tQr+7wWQ2d40fNhdvh2uEdF8iP+hp4ymzUYJmBarjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Y243xisK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Y243xisK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31B481F000FF; Sat, 12 Sep 2026 10:19:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789208358; bh=ju9VNXRGYpbzgm3XypsqyuGD2albIpKdUwOa2C10Xjw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Y243xisKXtn9B9EUVbmBZHa8bfPhvZz8WNMXR7fC5hKKAZZQr5QzkjnogHrtxHCg7 RvmCModVeRD6/kLPcTKak2JXwWPdcTyaNa/OBC3Epzg2R41+yef9p7V/8Dq8Yn4fCB 2VbmooAkUGZy27h4VmuG+LElo8gNwFTppdWf8hD4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Suyash Mahar , Leo Yan , James Clark , Namhyung Kim , Sasha Levin Subject: [PATCH 6.18 0557/1518] perf cs-etm: Avoid truncating AUX buffer sizes to int Date: Sat, 12 Sep 2026 08:45:26 +0200 Message-ID: <20260912065636.037707929@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Leo Yan [ Upstream commit ec99be8a31db999a4f866be74ea7db61dbb19f24 ] cs_etm__get_trace() returns an int, but it used to return etmq->buf_len on success. That value comes from auxtrace_buffer::size, which is a size_t. For a large AUX trace block, returning the byte count through an int can overflow and make a valid buffer look like a negative error. The callers do not need the actual byte count from cs_etm__get_trace(). The buffer length is already stored in the etmq->buf_len. The callers only need to distinguish three states: < 0: error = 0: no more AUX buffers > 0: data is available Make cs_etm__get_trace() return 0 for all non-error cases and use etmq->buf_len to indicate whether a new buffer was found. Then make cs_etm__get_data_block() return 1 whenever data is available, instead of returning the buffer length. Also refactor cs_etm__get_data_block() to make its return value semantics clearer. Reported-by: Suyash Mahar Fixes: 8224531cf5a1 ("perf cs-etm: Modularize auxtrace_buffer fetch function") Signed-off-by: Leo Yan Reviewed-by: James Clark Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin --- tools/perf/util/cs-etm.c | 46 +++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 20 deletions(-) diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 215414a8f61f1..15f99c2c2775a 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -1509,8 +1509,7 @@ cs_etm__get_trace(struct cs_etm_queue *etmq) etmq->buf_used = 0; etmq->buf_len = aux_buffer->size; etmq->buf = aux_buffer->data; - - return etmq->buf_len; + return 0; } /* @@ -2116,26 +2115,33 @@ static int cs_etm__get_data_block(struct cs_etm_queue *etmq) { int ret; - if (!etmq->buf_len) { - ret = cs_etm__get_trace(etmq); - if (ret <= 0) - return ret; - /* - * We cannot assume consecutive blocks in the data file - * are contiguous, reset the decoder to force re-sync. - */ - ret = cs_etm_decoder__reset(etmq->decoder); - if (ret) - return ret; + /* The current block is not finished */ + if (etmq->buf_len) + return 1; - /* - * Since the decoder is reset, this causes a global trace - * discontinuity. Flush all thread stacks. - */ - cs_etm__flush_all_stack(etmq); - } + ret = cs_etm__get_trace(etmq); + if (ret < 0) + return ret; + + /* No more buffer to read */ + if (!etmq->buf_len) + return 0; + + /* + * We cannot assume consecutive blocks in the data file + * are contiguous, reset the decoder to force re-sync. + */ + ret = cs_etm_decoder__reset(etmq->decoder); + if (ret) + return ret; + + /* + * Since the decoder is reset, this causes a global trace + * discontinuity. Flush all thread stacks. + */ + cs_etm__flush_all_stack(etmq); - return etmq->buf_len; + return 1; } static bool cs_etm__is_svc_instr(struct cs_etm_queue *etmq, -- 2.53.0