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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D16CBC77B61 for ; Fri, 28 Apr 2023 13:37:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345489AbjD1NhZ (ORCPT ); Fri, 28 Apr 2023 09:37:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229643AbjD1NhZ (ORCPT ); Fri, 28 Apr 2023 09:37:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CBD5173E; Fri, 28 Apr 2023 06:37:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1B456643D9; Fri, 28 Apr 2023 13:37:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19CF9C433D2; Fri, 28 Apr 2023 13:37:22 +0000 (UTC) Date: Fri, 28 Apr 2023 09:37:19 -0400 From: Steven Rostedt To: "Hou Wenlong" Cc: linux-kernel@vger.kernel.org, "Thomas Garnier" , "Lai Jiangshan" , "Kees Cook" , "Masami Hiramatsu" , "Mark Rutland" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , , "H. Peter Anvin" , Subject: Re: [PATCH RFC 21/43] x86/ftrace: Adapt assembly for PIE support Message-ID: <20230428093719.037081e3@gandalf.local.home> In-Reply-To: <0092ce94b325ad8eb47ff4f95e012f9af1a127de.1682673543.git.houwenlong.hwl@antgroup.com> References: <0092ce94b325ad8eb47ff4f95e012f9af1a127de.1682673543.git.houwenlong.hwl@antgroup.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Fri, 28 Apr 2023 17:51:01 +0800 "Hou Wenlong" wrote: > Change the assembly code to use only relative references of symbols for > the kernel to be PIE compatible. > > Signed-off-by: Hou Wenlong > Cc: Thomas Garnier > Cc: Lai Jiangshan > Cc: Kees Cook > --- > arch/x86/kernel/ftrace_64.S | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S > index eddb4fabc16f..411fa4148e18 100644 > --- a/arch/x86/kernel/ftrace_64.S > +++ b/arch/x86/kernel/ftrace_64.S > @@ -315,7 +315,14 @@ STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller) > SYM_FUNC_START(__fentry__) > CALL_DEPTH_ACCOUNT > > +#ifdef CONFIG_X86_PIE > + pushq %r8 > + leaq ftrace_stub(%rip), %r8 > + cmpq %r8, ftrace_trace_function(%rip) > + popq %r8 > +#else > cmpq $ftrace_stub, ftrace_trace_function > +#endif > jnz trace > RET > > @@ -329,7 +336,7 @@ trace: > * ip and parent ip are used and the list function is called when > * function tracing is enabled. > */ > - movq ftrace_trace_function, %r8 > + movq ftrace_trace_function(%rip), %r8 > CALL_NOSPEC r8 > restore_mcount_regs > I really don't want to add more updates to !DYNAMIC_FTRACE. This code only exists to make sure I don't break it for other architectures. How about diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 442eccc00960..ee4d0713139d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -37,7 +37,7 @@ config X86_64 config FORCE_DYNAMIC_FTRACE def_bool y - depends on X86_32 + depends on X86_32 || X86_PIE depends on FUNCTION_TRACER select DYNAMIC_FTRACE help ? -- Steve