From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B4CF9CF318B for ; Wed, 2 Oct 2024 01:01:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:Mime-Version:References:In-Reply-To:Message-Id:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Q+cg4pWJe4FDUIFzcFMmIf8DMtuJOytlWYHZxI+uc/Q=; b=uxPWmw939WErotLxmof7tcKdZl ea+1bUAsBWjPLrrjYWK2qGXCtR4s7ceTptPB9AZh9/1goaobKEwteJTYfvhzCKngn+b7fygYUt7jG Evhhxb+450Z48vHqDu60MPXj8jRU1psED8zTp0vEvbs7jSZQbtthCGZTMm0mLeCFvnTuGs/Jl2h1D L8moRjqQ3XqgK0teBdLOjESw6sAOz6jzOaZYtg2R+SoPqsCjYsehBpeZHudC2sUfPIcrX0/Ce6XRh ItUkQkx1gm6OvuG/UDicHaEgMhAE5DM4tQO6KtgTwShh6HnyW9cwGyUu1BL/ID1dYk+6GT3Wgsb+B R8H9SWig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1svnkN-00000004Uks-3fsm; Wed, 02 Oct 2024 01:01:43 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1svmG6-00000004MXt-41MM for linux-arm-kernel@lists.infradead.org; Tue, 01 Oct 2024 23:26:24 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 392B95C5564; Tue, 1 Oct 2024 23:26:18 +0000 (UTC) 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) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241001_162623_119960_FD75FF10 X-CRM114-Status: GOOD ( 27.47 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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)