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 A51FE1D9324; Mon, 28 Oct 2024 15:25:22 +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=1730129122; cv=none; b=E+xGvwCaSirv1ZIA2dF6a1FUmFdpgrRxYldD6Tq5hPaXbY5KD+nJCZ4WQ5GPaAipg4iV4FvaGVHWRoBxVkIJZQGJqEWglOoP9T0nBddHF7HqsWu1vwlP3tUOWTvoCoT+MuCTVV45Aoq8TSW6YpeckjOKx0QeR8ZXf99I9H8V0Jc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730129122; c=relaxed/simple; bh=JoX429j4Zj7g7EFQnQUQiXELq1ar7frfVq2eJPtKDUk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ie5Xl90rMDkdbsUmk1Eb8m8V8DQq6HgUqpkZN1GAQPwlllpfF20oO873LzVZz7/afO4456Asp4Nvn+fRzkMWT3H6UQFSU89cG/5HWm4qQVfSmzzp+X/0Nvq3A4dvFDyyE0EW5QEucd/iJeyDT0u38oC4ufOH7TL+48YNiXQXA1U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OnCDUrlv; 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="OnCDUrlv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11844C4CEC3; Mon, 28 Oct 2024 15:25:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730129122; bh=JoX429j4Zj7g7EFQnQUQiXELq1ar7frfVq2eJPtKDUk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OnCDUrlvKWOl4ui5qkrNelEEk6CP5hbi5EReMeY/fQBWS7hxQY6sjMmRtdyjeMXSG 7o3ZV2QyQ0dRQ4AO6h+zs2QOXnNtsMdMnbI1pGiZDNZgcv4MN9/BMflRiAa7QdgWaj qzKxzGWGFv/KXOnjMKrO4KN+Q06FOQOjHZTiyHtfCQDNq+86O2RdRaQifs+BrE9Pti MnBBrjav/s1BKmwXFqmjq9tVcfYwxoemSoKyYKQFhdZ87gXvD5yoBJyefQZFPDB4wb +GUN8q16XfVYH2gpv+8cpeEhlk40VUeNiSS92NH3zfaon9ZyO/SQBWWErWRt/qNRz9 oAhmNGbC4uMJA== Date: Mon, 28 Oct 2024 15:25:13 +0000 From: Will Deacon To: "Masami Hiramatsu (Google)" Cc: Alexei Starovoitov , Steven Rostedt , Florent Revest , linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Alexei Starovoitov , Jiri Olsa , Alan Maguire , Mark Rutland , linux-arch@vger.kernel.org, Catalin Marinas , Huacai Chen , WANG Xuerui , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Paul Walmsley , Palmer Dabbelt , Albert Ou , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Mathieu Desnoyers Subject: Re: [PATCH v18 01/17] fgraph: Pass ftrace_regs to entryfunc Message-ID: <20241028152512.GB2484@willie-the-truck> References: <172991731968.443985.4558065903004844780.stgit@devnote2> <172991733069.443985.15154246733356205391.stgit@devnote2> 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: <172991733069.443985.15154246733356205391.stgit@devnote2> User-Agent: Mutt/1.10.1 (2018-07-13) On Sat, Oct 26, 2024 at 01:35:30PM +0900, Masami Hiramatsu (Google) wrote: > From: Masami Hiramatsu (Google) > > Pass ftrace_regs to the fgraph_ops::entryfunc(). If ftrace_regs is not > available, it passes a NULL instead. User callback function can access > some registers (including return address) via this ftrace_regs. > > Note that the ftrace_regs can be NULL when the arch does NOT define: > HAVE_DYNAMIC_FTRACE_WITH_ARGS or HAVE_DYNAMIC_FTRACE_WITH_REGS. > More specifically, if HAVE_DYNAMIC_FTRACE_WITH_REGS is defined but > not the HAVE_DYNAMIC_FTRACE_WITH_ARGS, and the ftrace ops used to > register the function callback does not set FTRACE_OPS_FL_SAVE_REGS. > In this case, ftrace_regs can be NULL in user callback. > > Signed-off-by: Masami Hiramatsu (Google) > Cc: Steven Rostedt > Cc: Mark Rutland > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Huacai Chen > Cc: WANG Xuerui > Cc: Michael Ellerman > Cc: Nicholas Piggin > Cc: Christophe Leroy > Cc: Naveen N Rao > Cc: Madhavan Srinivasan > Cc: Paul Walmsley > Cc: Palmer Dabbelt > Cc: Albert Ou > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: Dave Hansen > Cc: x86@kernel.org > Cc: "H. Peter Anvin" > Cc: Mathieu Desnoyers > > --- > Changes in v18: > - Remove unclear comment about `regs->fp` access on arm64. > Changes in v16: > - Add a note when the ftrace_regs can be NULL. > - Update against for the latest kernel. > Changes in v11: > - Update for the latest for-next branch. > Changes in v8: > - Just pass ftrace_regs to the handler instead of adding a new > entryregfunc. > - Update riscv ftrace_graph_func(). > Changes in v3: > - Update for new multiple fgraph. > --- > arch/arm64/kernel/ftrace.c | 15 ++++++++- For the arm64 bits: Acked-by: Will Deacon Will