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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 AB94EC7EE2F for ; Thu, 1 Jun 2023 11:08:42 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4QX3KN6vqcz3f02 for ; Thu, 1 Jun 2023 21:08:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=RhP2k+/F; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:4641:c500::1; helo=dfw.source.kernel.org; envelope-from=rppt@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=RhP2k+/F; dkim-atps=neutral Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4QX3JS4dPvz3bhY for ; Thu, 1 Jun 2023 21:07:52 +1000 (AEST) 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 92D0C64340; Thu, 1 Jun 2023 11:07:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A781FC433D2; Thu, 1 Jun 2023 11:07:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685617670; bh=+Yjm8puKI4qcOhrAjHQoPXnOlN6+/fj9nQ2KMrVKq+A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RhP2k+/FQSvli7tGw2eOKlboTIMhAX1rWIMmQojkSItsf7Pbu27Voz4XKQfKsJMv+ yk64a7+GnLa0AXm5NTg7oxgCbiU/vvM5YtvO42iXWm3c1dvWeuqaT9QYECD04AjLI8 +kurm3Gcj765DCLAHDCbNzTJmkHWERuX8j+NWUQrH79TGx2XeQSd0dO1NOebia9EMt dJu6ZE7ylH9284d9jqvK6St/2YUkHNw8jD2OIGo2TbwtTLSoShdT9QABDGhevJVWTD pUczYlcvfwWLpOJgcn012xrthp2r+mfy68euX8CFvo6UC393XjO1m9JQnHYF6C6kEn C9f6ivmZ7x+Ew== Date: Thu, 1 Jun 2023 14:07:13 +0300 From: Mike Rapoport To: Peter Zijlstra Subject: Re: [PATCH 12/13] x86/jitalloc: prepare to allocate exectuatble memory as ROX Message-ID: <20230601110713.GE395338@kernel.org> References: <20230601101257.530867-1-rppt@kernel.org> <20230601101257.530867-13-rppt@kernel.org> <20230601103050.GT4253@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230601103050.GT4253@hirez.programming.kicks-ass.net> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: x86@kernel.org, Catalin Marinas , linux-mips@vger.kernel.org, Song Liu , sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, Will Deacon , linux-s390@vger.kernel.org, Helge Deller , Huacai Chen , Russell King , "Naveen N. Rao" , linux-trace-kernel@vger.kernel.org, Heiko Carstens , Steven Rostedt , loongarch@lists.linux.dev, Thomas Gleixner , Andrew Morton , linux-arm-kernel@lists.infradead.org, Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, Kent Overstreet , linux-kernel@vger.kernel.org, Dinh Nguyen , Luis Chamberlain , Palmer Dabbelt , bpf@vger.kernel.org, linuxppc-dev@lists.ozla bs.org, "David S. Miller" , linux-modules@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Jun 01, 2023 at 12:30:50PM +0200, Peter Zijlstra wrote: > On Thu, Jun 01, 2023 at 01:12:56PM +0300, Mike Rapoport wrote: > > > +static void __init_or_module do_text_poke(void *addr, const void *opcode, size_t len) > > +{ > > + if (system_state < SYSTEM_RUNNING) { > > + text_poke_early(addr, opcode, len); > > + } else { > > + mutex_lock(&text_mutex); > > + text_poke(addr, opcode, len); > > + mutex_unlock(&text_mutex); > > + } > > +} > > So I don't much like do_text_poke(); why? I believe the idea was to keep memcpy for early boot before the kernel image is protected without going and adding if (is_module_text_address()) all over the place. I think this can be used instead without updating all the call sites of text_poke_early(): diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 91057de8e6bc..f994e63e9903 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1458,7 +1458,7 @@ void __init_or_module text_poke_early(void *addr, const void *opcode, * code cannot be running and speculative code-fetches are * prevented. Just change the code. */ - memcpy(addr, opcode, len); + text_poke_copy(addr, opcode, len); } else { local_irq_save(flags); memcpy(addr, opcode, len); > > diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c > > index aa99536b824c..d50595f2c1a6 100644 > > --- a/arch/x86/kernel/ftrace.c > > +++ b/arch/x86/kernel/ftrace.c > > @@ -118,10 +118,13 @@ ftrace_modify_code_direct(unsigned long ip, const char *old_code, > > return ret; > > > > /* replace the text with the new text */ > > - if (ftrace_poke_late) > > + if (ftrace_poke_late) { > > text_poke_queue((void *)ip, new_code, MCOUNT_INSN_SIZE, NULL); > > - else > > - text_poke_early((void *)ip, new_code, MCOUNT_INSN_SIZE); > > + } else { > > + mutex_lock(&text_mutex); > > + text_poke((void *)ip, new_code, MCOUNT_INSN_SIZE); > > + mutex_unlock(&text_mutex); > > + } > > return 0; > > } > > And in the above case it's actively wrong for loosing the _queue() > thing. -- Sincerely yours, Mike.