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 80036F9CB; Thu, 10 Oct 2024 01:12:54 +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=1728522774; cv=none; b=W10ktxwfSdtXAMskqm2b+79mmuqUgHoTAkcyIPwHfIwpcMNjOpWjxuKFS3W0CUtPQQXxTbBRFGrhNeQOEQK90mE9QUsgPstMGjbY+LK2Xdv0Mk7ZK5ulPvI5hj3t/Nz4XBrQsQZVGo5DTD0ENNmGv7VuQWks+Co2irn8vMh+7LI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728522774; c=relaxed/simple; bh=P+IBwA3DyX2CWGogUkSF7cmDoIFQ90YAqvQcabiWl8U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=W9e/QG/HM/nQAcLmsgBWBmp+ESMnb0UWz2/SuALg3Wdbz69AY+vSZI7Z6nkRx22qxWqVVkzML853cUWSfGQOwZepcsMbUa4/IP5ALzJxS3K430sxTmkpz2y11jqO6poFvtwnD9YohE44ZTxZrqRaFgN3fnporNHTeVwicAA+3Io= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i3hZ/bbk; 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="i3hZ/bbk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85311C4CEC3; Thu, 10 Oct 2024 01:12:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728522774; bh=P+IBwA3DyX2CWGogUkSF7cmDoIFQ90YAqvQcabiWl8U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i3hZ/bbknDvLNasdunyHCfM87m7KM5od3fO2hLEWdOCyA/KR1xvUV5cszN7rj1Nt/ PDuKYodMHxE63SVnuAixpZevTnZWnlhJBSnZRmcLWE2z6LfdTrrqXJ5wxKYRcH2iI/ Yf1KOB2ouj6QWr29Xmnwkq6WZXsb6+i79GxUy9GjoH9/98vTGS++ViARAd2MYWYSg6 ImmFYrCPl+fkANUSGVK4SkEdZgIRpym629XSxntaINch+PzflcD9aW+cGgxhTyOl1T ygu8bv7pa+/WUc3N1Chi15ooGqL1cFJao4E0r5utVZHsHv1Y3mrEpynwPgTBARpntr Tb1s0SKFyESUQ== Date: Wed, 9 Oct 2024 18:12:52 -0700 From: Namhyung Kim To: Leo Yan , Masami Hiramatsu Cc: Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Dima Kogan , james.clark@linaro.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 0/3] perf probe: Support long symbol Message-ID: References: <20241007141116.882450-1-leo.yan@arm.com> 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: <20241007141116.882450-1-leo.yan@arm.com> Hello Leo, On Mon, Oct 07, 2024 at 03:11:13PM +0100, Leo Yan wrote: > Currently, a probe supports event name maximum to a 64-byte length. The > event name comes from the probed symbol name, otherwise, user can > specify an event name. > > In the case when user tries to inject a probe for a long symbol, e.g. > mangled symbol name in a C++ program, the kernel buffer cannot > accommodate it if the symbol name is longer than 64 bytes. > > On the other hand, this series relies on the perf tool to resolve the > issue. When the tool detects user doesn't specify event name and the > probed symbol is longer than 64 bytes, it will generate a hashed event > name with 64-byte length to avoid failure. Please CC Masami for probe related changes in the future. Thanks, Namhyung > > > Leo Yan (3): > perf: Dynamically allocate buffer for event string > perf probe: Check group string length > perf probe: Generate hash event for long symbol > > tools/perf/util/probe-event.c | 71 ++++++++++++++++++++++++++++++++--- > 1 file changed, 65 insertions(+), 6 deletions(-) > > -- > 2.34.1 >