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 06A0C16130B; Wed, 23 Oct 2024 08:58:00 +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=1729673881; cv=none; b=oInmV/zSfwJxGLusnETdVSGs56dcsgfmuboDpk7UkKKd0v1sPWfn7XlJa5J12v3WgBa10IskqL1Lq1gN3SlT90SzwRdYSFrcLx2Lx0SN7XVIoFRewARtvYpUrgH8szZVmDAP5+ZB6YfmC5vDXxgTRPQgLnbye1zHN1cm15DBN/I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729673881; c=relaxed/simple; bh=VXUL0OcM4+MvIg0hKX2tHVp6D78yAed1n0F8G8f0kVM=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=T/YmL8AxJzH9L47Uddkb83tjIbS3pMBOnIaVcOX3lcoDRqCVCKrcDCf6z4Mr5uPPnRK5sy67TWGcX59xNzriLaAbBlMzWjmU2KPKW4EKGWVXNiwzBhG/i5aEP4tylvVow6f3Q0COG7hGjw9MSaBtWK5Z0b/wvcTzofPqV+w0qLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lp1KvIgv; 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="lp1KvIgv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BAE4C4CEE7; Wed, 23 Oct 2024 08:57:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729673880; bh=VXUL0OcM4+MvIg0hKX2tHVp6D78yAed1n0F8G8f0kVM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lp1KvIgv+7tN1FxJbtK7i0ZSIUA2XcKaVtNO/BmohJaZnUQFcL2d9YslaGbpHtVYn XqW8UiQkA53mkDL1mwVcU5B0RTrmVRbqOFspUmgKo/C3BaZeY2itBnvL3Dk+mIv+tJ eguh734eX+gqKslZLUCqH8rjE/AdkpFEnD1rfASCWr6VocAaI6Uz0c3sWonRGjuUf/ TUeLZeA95Xox5QH/VVHCrkytBc9W+hvXA22wGCJSwPfasQc92QB54edb8hbrOF3mzS AsZjGzN2BSioUXkbZjC6LdgJYwsDJubVUfCaozWYlTR4cBHI7H/loR6wE2iSvHRiWN c5QxzmirSOzXw== Date: Wed, 23 Oct 2024 17:57:56 +0900 From: Masami Hiramatsu (Google) To: Will Deacon 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 , Paul Walmsley , Palmer Dabbelt , Albert Ou Subject: Re: [PATCH v17 06/16] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Message-Id: <20241023175756.eb42bcec858f6ac1c852de0c@kernel.org> In-Reply-To: <20241021164619.GA26073@willie-the-truck> References: <172904026427.36809.516716204730117800.stgit@devnote2> <172904034052.36809.10990962223606196850.stgit@devnote2> <20241021164619.GA26073@willie-the-truck> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit On Mon, 21 Oct 2024 17:46:19 +0100 Will Deacon wrote: > On Wed, Oct 16, 2024 at 09:59:00AM +0900, Masami Hiramatsu (Google) wrote: > > From: Masami Hiramatsu (Google) > > > > Add ftrace_partial_regs() which converts the ftrace_regs to pt_regs. > > This is for the eBPF which needs this to keep the same pt_regs interface > > to access registers. > > Thus when replacing the pt_regs with ftrace_regs in fprobes (which is > > used by kprobe_multi eBPF event), this will be used. > > > > If the architecture defines its own ftrace_regs, this copies partial > > registers to pt_regs and returns it. If not, ftrace_regs is the same as > > pt_regs and ftrace_partial_regs() will return ftrace_regs::regs. > > > > Signed-off-by: Masami Hiramatsu (Google) > > Acked-by: Florent Revest > > Cc: Steven Rostedt > > Cc: Mark Rutland > > Cc: Catalin Marinas > > Cc: Will Deacon > > Cc: Paul Walmsley > > Cc: Palmer Dabbelt > > Cc: Albert Ou > > > > --- > > Changes in v14: > > - Add riscv change. > > Changes in v8: > > - Add the reason why this required in changelog. > > Changes from previous series: NOTHING, just forward ported. > > --- > > arch/arm64/include/asm/ftrace.h | 11 +++++++++++ > > arch/riscv/include/asm/ftrace.h | 14 ++++++++++++++ > > include/linux/ftrace.h | 17 +++++++++++++++++ > > 3 files changed, 42 insertions(+) > > > > diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h > > index b5fa57b61378..d344c69eb01e 100644 > > --- a/arch/arm64/include/asm/ftrace.h > > +++ b/arch/arm64/include/asm/ftrace.h > > @@ -135,6 +135,17 @@ ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs) > > return arch_ftrace_regs(fregs)->fp; > > } > > > > +static __always_inline struct pt_regs * > > +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) > > +{ > > + memcpy(regs->regs, arch_ftrace_regs(fregs)->regs, sizeof(u64) * 9); > > Since ftrace_regs::regs is an 'unsigned long regs[9]' can we just use > sizeof() on that instead of hard-coding the length of the array here? Good catch! I will update it. Thank you! > > Will -- Masami Hiramatsu (Google)