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 67B991CEAD7; Tue, 1 Oct 2024 23:26:22 +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=1727825182; cv=none; b=TN2GpN714ir89rLLSVGbH0Gg+Y5GAK2Zj/qWhQVCk9QlAJg0d1VCARx+q9LTvqQT4Z9TmgjjZmizKIFpQ3Fo/c9WN1XMTAgEUBp1mSaMjTl5i/mYmLiIhZaPbs/nf1YY5FivZ2PgCjNVgDxhHq1r8EcjrXzLkHwMXtRe1zMNCfw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727825182; c=relaxed/simple; bh=YG/qa9jzP2BgsMhKT8ybaJ73W1pJe3SjqzugQP9q1BI=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=ffDcrIDq+6mCuXLcqKYQW26i8HgQQM37gIEp4AhvjG5/oYMSwsospqpi7UIC3XBJxmyMCR+/dcMnm1tL6uXicuWl3OJcLYMRBRR/V0m/lAcn8Z+wNhlKc8XEZeq9CpNv0u7BxUsDW0nla7RJsq9TSnKJeDrbo0CJDB4+YtTob/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rm5cBieP; 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="rm5cBieP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B996CC4CEC6; Tue, 1 Oct 2024 23:26:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727825181; bh=YG/qa9jzP2BgsMhKT8ybaJ73W1pJe3SjqzugQP9q1BI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rm5cBiePWcg8iYf7bE4lqRquENW9eLl4sXQipIJaPPycW/zicBqKK7djvdjFZ+aMu rERUvcSwfksEaGznesvvVNl3/ibF3sL4kOM4rfIQlqNzbb9+3kdM7rvM8C3TX/9fHO dm2NDzgidKvXlv31t6Z75N8C3b6d1UcZRCBbmsBSkW0vv8pGc1hFvLa6MOWNd+pC0e Myi9eWsSRJmD+ckUv3whYzTIebDotlmH2U3EmANzmDabAY4Iasn5UVmqKrChOhvw7Q VhR2rv+fxvV43NTkEfL1npva7Oxi3zXyCp320N9KkQKZmpzmJaAJK4GrHSNadShPVH Jj18bJHjk2uxg== Date: Wed, 2 Oct 2024 08:26:16 +0900 From: Masami Hiramatsu (Google) To: Will Deacon Cc: Steven Rostedt , 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 08/19] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Message-Id: <20241002082616.e02d3f92968291fad7533b70@kernel.org> In-Reply-To: <20240917101454.GC27384@willie-the-truck> References: <172615368656.133222.2336770908714920670.stgit@devnote2> <172615377576.133222.5911358383330497277.stgit@devnote2> <20240915052204.3dff1f75@rorschach.local.home> <20240917101454.GC27384@willie-the-truck> X-Mailer: Sylpheed 3.7.0 (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 Tue, 17 Sep 2024 11:14:54 +0100 Will Deacon wrote: > On Sun, Sep 15, 2024 at 05:22:04AM -0400, Steven Rostedt wrote: > > On Fri, 13 Sep 2024 00:09:35 +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 > > > --- > > > 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 | 12 ++++++++++++ > > > include/linux/ftrace.h | 17 +++++++++++++++++ > > > 3 files changed, 40 insertions(+) > > > > > > diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h > > > index dffaab3dd1f1..5cd587afab6d 100644 > > > --- a/arch/arm64/include/asm/ftrace.h > > > +++ b/arch/arm64/include/asm/ftrace.h > > > @@ -132,6 +132,17 @@ ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs) > > > return fregs->fp; > > > } > > > > > > +static __always_inline struct pt_regs * > > > +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) > > > +{ > > > + memcpy(regs->regs, fregs->regs, sizeof(u64) * 9); > > > + regs->sp = fregs->sp; > > > + regs->pc = fregs->pc; > > > + regs->regs[29] = fregs->fp; > > > + regs->regs[30] = fregs->lr; > > > + return regs; > > > +} > > Ah, I guess this is where we pick up the lr that was set in patch 5. Yeah, this one also copies the fregs->pc to regs->pc, mainly for bpf. > > Acked-by: Will Deacon Thank you! > > Will -- Masami Hiramatsu (Google)