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 1A2CF1D5170; Wed, 26 Nov 2025 18:57:15 +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=1764183436; cv=none; b=eC4kCynLfNCs7Q7Fw2i2Ju0QVKaHQidmBzEWJf26sKLV8vQzXfbYClxfFPaLIcdpLA/kSn+z4trGF1o6DP2PnV44gjkK5qLIQvdnHHF8FZYBXkSxTvCfBe5pXrJ5Oq4xM+wW54sC2Zhlr3XEpRMaRWYfq4EJQzilcOhbq/iHEcc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764183436; c=relaxed/simple; bh=vpDzDn4Wi+CKs6uJl+BfvYWGOn9752VZ+OV59Q9ein8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fSnYzapqkxFHkfBAcIc4fRoWbyEtBPPx221Cml1ttRb3HgRVNKoBWRPHjC1Odg98mPryKxdwyL5xBRwKmmgf7ajh70/u4FvUqlIojeV3V/vXyK9wlv+fbYQH/lXrglHahl4v44CXJyO8bgPstHaAoip5/06btvV0VvrvFubJu1o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vEB3RrxE; 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="vEB3RrxE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 560A6C4CEF7; Wed, 26 Nov 2025 18:57:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764183435; bh=vpDzDn4Wi+CKs6uJl+BfvYWGOn9752VZ+OV59Q9ein8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vEB3RrxEQKJl3GoSmyhVuJqpl07ba5wkXbhnmu+yMQYtoeDUXgbZqD5TmRlOvYfzV c2Oj0ELd4PYWeOalgt83KBN5DaGnmX9m4M6W/E3Gd+aNKvsqPZ51tOj5GdZeCkQp8S s2dKAsqEB4E6TSoxOCDLHlEPgsDAljxX8SkWfPPR0Nh9WwiEnQiyBRfi3JK0RHcn5D VOKXiMztS5T2cT+kafXIJZWYI1dNXsyPZ0VZ9xp3Eur19L/Z45sP2GYE3bsN9JFAbz tbgWH3oP3+k9v3UGIzMn9D1As4oR3eIQN43zRiIizCDeZF+mv6PoRZiAF+HSZ/osuQ Y1bY6zMTEms2A== Date: Wed, 26 Nov 2025 10:57:12 -0800 From: Namhyung Kim To: Steven Rostedt Cc: acme@kernel.org, Thomas Richter , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-perf-users@vger.kernel.org, agordeev@linux.ibm.com, gor@linux.ibm.com, sumanthk@linux.ibm.com, hca@linux.ibm.com, japo@linux.ibm.com Subject: Re: [PATCH Linux-next] perf test: Fix test case perf trace BTF general tests Message-ID: References: <20251118132451.29a35127@gandalf.local.home> <20251119125903.417f595e@gandalf.local.home> <20251126102401.37af98bb@gandalf.local.home> <20251126121229.0638407b@gandalf.local.home> 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: <20251126121229.0638407b@gandalf.local.home> On Wed, Nov 26, 2025 at 12:12:29PM -0500, Steven Rostedt wrote: > > Arnaldo, > > How can I make perf trace not confused by the extra fields in the system > call trace events? > > Ftrace can now show the contents of the system call user space buffers, but > it appears that this breaks perf!!! > > system: syscalls > name: sys_enter_write > ID: 791 > format: > field:unsigned short common_type; offset:0; size:2; signed:0; > field:unsigned char common_flags; offset:2; size:1; signed:0; > field:unsigned char common_preempt_count; offset:3; size:1; signed:0; > field:int common_pid; offset:4; size:4; signed:1; > > field:int __syscall_nr; offset:8; size:4; signed:1; > field:unsigned int fd; offset:16; size:8; signed:0; > field:const char * buf; offset:24; size:8; signed:0; > field:size_t count; offset:32; size:8; signed:0; > field:__data_loc char[] __buf_val; offset:40; size:4; signed:0; > > That new __buf_val appears to confuse perf, but I'm having a hell of a time > trying to figure out where it reads it! I've discussed with Steven and concluded that we should change perf to ignore fields with "__data_loc char[]" type in syscalls. Let me take a look. Thanks, Namhyung