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 F09B637B; Tue, 17 Sep 2024 09:55:44 +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=1726566945; cv=none; b=jRDOobpeGBTmjRWe2WrAafO94VDFrfsFZFPaHBU6y6H98RV+YgLK27lfEBcS8sWDwnMJpIt/NUvvHpvtV0HJQk/eKoi5mI23kypVT7ZX0v84F9Rna0cJIorfCwp29+UYob4sF5I+lS98rwGsK6/imSC5PWZdJPlcqh1D4+AYByY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726566945; c=relaxed/simple; bh=WHbeFH5Td69vGBqxgGhIT2rQhQdb5LE6FSqeOmbeESY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LxsHXU6ais6Va8Ae3l+nsaGwFmFlkCkr8YzrFkpGdHxe4kCnHKKTM3UvmbiShGKrjHESZ17Q9K6fVAQ8KQQo0D/kZBLzJNQ4GVXwVfd+463QaKIDKcWNAJmyzARy5lWka1p9IsHb3pPXfYXwgKza6jRWrICbAVnuVNIWnzF+j9A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TX1BFEAh; 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="TX1BFEAh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58103C4CEC5; Tue, 17 Sep 2024 09:55:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726566944; bh=WHbeFH5Td69vGBqxgGhIT2rQhQdb5LE6FSqeOmbeESY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TX1BFEAhm+ZWwoXKsSRcTE128mIgVCrFrDzOfnhgjbI74MPD7etlTl2Nu8f5kmEAH odnIr3Nb6UCpPq31zJbqWeyICExBSR8Mvbv/WY13KbzhuymGLsjjQKQuHgCTunB5A5 X3vBKyOMNSshGpb55BjfdNjWltv6Rfutm8Fu4pSsKl88eq1M/EeKkl56tcthmVWQ1K 9EnNGZnVmlxv9HZGdBc/18YD0i86NfCp8NlF/dFqM9H1gt0RK94joobYPXi404jC93 75fz7rFhMX0vCl8FTlcc/ow9QLYH6wssRCMkBSDAw90yZc5pYTOarC111swTX63pBi 2LoQ6evp0eDrw== Date: Tue, 17 Sep 2024 10:55:39 +0100 From: Will Deacon To: Steven Rostedt Cc: Catalin Marinas , linux-arm-kernel@lists.infradead.org, "Masami Hiramatsu (Google)" , Florent Revest , linux-trace-kernel@vger.kernel.org, LKML , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Mark Rutland Subject: Re: [PATCH v14 04/19] function_graph: Replace fgraph_ret_regs with ftrace_regs Message-ID: <20240917095538.GA27384@willie-the-truck> References: <172615368656.133222.2336770908714920670.stgit@devnote2> <172615373091.133222.1812791604518973124.stgit@devnote2> <20240915051144.445681c2@rorschach.local.home> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240915051144.445681c2@rorschach.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) On Sun, Sep 15, 2024 at 05:11:44AM -0400, Steven Rostedt wrote: > On Fri, 13 Sep 2024 00:08:51 +0900 > "Masami Hiramatsu (Google)" wrote: > > > From: Masami Hiramatsu (Google) > > > > Use ftrace_regs instead of fgraph_ret_regs for tracing return value > > on function_graph tracer because of simplifying the callback interface. > > > > The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by > > CONFIG_HAVE_FUNCTION_GRAPH_FREGS. > > > > Signed-off-by: Masami Hiramatsu (Google) > > --- > > Changes in v8: > > - Newly added. > > --- > > arch/arm64/Kconfig | 1 + > > arch/arm64/include/asm/ftrace.h | 23 ++++++----------------- > > arch/arm64/kernel/asm-offsets.c | 12 ------------ > > arch/arm64/kernel/entry-ftrace.S | 32 ++++++++++++++++++-------------- The arm64 part looks good to me, although passing a partially-populated struct out of asm feels like it's going to cause us hard-to-debug problems down the line if any of those extra fields get used. How hard would it be to poison the unpopulated members of 'ftrace_regs'? Will