From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Subject: Re: [RFC PATCH 6/6] x86/alternatives: remove text_poke() return value Date: Wed, 29 Aug 2018 18:52:22 +0900 Message-ID: <20180829185222.e85026ff22638002a1df70e0@kernel.org> References: <20180829081147.184610-1-namit@vmware.com> <20180829081147.184610-7-namit@vmware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180829081147.184610-7-namit@vmware.com> Sender: linux-kernel-owner@vger.kernel.org To: Nadav Amit Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , x86@kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Andy Lutomirski , Masami Hiramatsu , Kees Cook , Peter Zijlstra List-Id: linux-arch.vger.kernel.org On Wed, 29 Aug 2018 01:11:47 -0700 Nadav Amit wrote: > The return value of text_poke() is meaningless - it is one of the > function inputs. One day someone may allow the callers to deal with > text_poke() failures, if those actually happen. > > In the meanwhile, remove the return value. > > Cc: Andy Lutomirski > Cc: Masami Hiramatsu > Cc: Kees Cook > Cc: Peter Zijlstra > Signed-off-by: Nadav Amit > --- > arch/x86/include/asm/text-patching.h | 2 +- > arch/x86/kernel/alternative.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h > index ffe7902cc326..1f73f71b4de2 100644 > --- a/arch/x86/include/asm/text-patching.h > +++ b/arch/x86/include/asm/text-patching.h > @@ -34,7 +34,7 @@ extern void *text_poke_early(void *addr, const void *opcode, size_t len); > * On the local CPU you need to be protected again NMI or MCE handlers seeing an > * inconsistent instruction while you patch. > */ > -extern void *text_poke(void *addr, const void *opcode, size_t len); > +extern void text_poke(void *addr, const void *opcode, size_t len); > extern int poke_int3_handler(struct pt_regs *regs); > extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler); > extern int after_bootmem; > diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c > index 0feac3dfabe9..45b7fdeaed90 100644 > --- a/arch/x86/kernel/alternative.c > +++ b/arch/x86/kernel/alternative.c > @@ -795,7 +795,7 @@ static void text_poke_safe(void *addr, const void *opcode, size_t len, > * > * Note: Must be called under text_mutex. > */ > -void *text_poke(void *addr, const void *opcode, size_t len) > +void text_poke(void *addr, const void *opcode, size_t len) > { > bool cross_page_boundary = offset_in_page(addr) + len > PAGE_SIZE; > struct page *pages[2] = {0}; Could you also remove "return addr;" in this patch ? Thank you, > -- > 2.17.1 > -- Masami Hiramatsu From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:47808 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727099AbeH2Nsa (ORCPT ); Wed, 29 Aug 2018 09:48:30 -0400 Date: Wed, 29 Aug 2018 18:52:22 +0900 From: Masami Hiramatsu Subject: Re: [RFC PATCH 6/6] x86/alternatives: remove text_poke() return value Message-ID: <20180829185222.e85026ff22638002a1df70e0@kernel.org> In-Reply-To: <20180829081147.184610-7-namit@vmware.com> References: <20180829081147.184610-1-namit@vmware.com> <20180829081147.184610-7-namit@vmware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Nadav Amit Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , x86@kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Andy Lutomirski , Masami Hiramatsu , Kees Cook , Peter Zijlstra Message-ID: <20180829095222.aNzSV35LoWbedRuMah1Uy9Ygz1JDRSpBN9-hu5CNdZc@z> On Wed, 29 Aug 2018 01:11:47 -0700 Nadav Amit wrote: > The return value of text_poke() is meaningless - it is one of the > function inputs. One day someone may allow the callers to deal with > text_poke() failures, if those actually happen. > > In the meanwhile, remove the return value. > > Cc: Andy Lutomirski > Cc: Masami Hiramatsu > Cc: Kees Cook > Cc: Peter Zijlstra > Signed-off-by: Nadav Amit > --- > arch/x86/include/asm/text-patching.h | 2 +- > arch/x86/kernel/alternative.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h > index ffe7902cc326..1f73f71b4de2 100644 > --- a/arch/x86/include/asm/text-patching.h > +++ b/arch/x86/include/asm/text-patching.h > @@ -34,7 +34,7 @@ extern void *text_poke_early(void *addr, const void *opcode, size_t len); > * On the local CPU you need to be protected again NMI or MCE handlers seeing an > * inconsistent instruction while you patch. > */ > -extern void *text_poke(void *addr, const void *opcode, size_t len); > +extern void text_poke(void *addr, const void *opcode, size_t len); > extern int poke_int3_handler(struct pt_regs *regs); > extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler); > extern int after_bootmem; > diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c > index 0feac3dfabe9..45b7fdeaed90 100644 > --- a/arch/x86/kernel/alternative.c > +++ b/arch/x86/kernel/alternative.c > @@ -795,7 +795,7 @@ static void text_poke_safe(void *addr, const void *opcode, size_t len, > * > * Note: Must be called under text_mutex. > */ > -void *text_poke(void *addr, const void *opcode, size_t len) > +void text_poke(void *addr, const void *opcode, size_t len) > { > bool cross_page_boundary = offset_in_page(addr) + len > PAGE_SIZE; > struct page *pages[2] = {0}; Could you also remove "return addr;" in this patch ? Thank you, > -- > 2.17.1 > -- Masami Hiramatsu