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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68252C3A5A3 for ; Fri, 30 Aug 2019 07:54:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37DA92077B for ; Fri, 30 Aug 2019 07:54:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727781AbfH3Hy4 (ORCPT ); Fri, 30 Aug 2019 03:54:56 -0400 Received: from mx2.suse.de ([195.135.220.15]:50912 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726975AbfH3Hyz (ORCPT ); Fri, 30 Aug 2019 03:54:55 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id A1977AD7F; Fri, 30 Aug 2019 07:54:53 +0000 (UTC) Date: Fri, 30 Aug 2019 09:54:51 +0200 From: Michal =?UTF-8?B?U3VjaMOhbmVr?= To: Christophe Leroy Cc: linuxppc-dev@lists.ozlabs.org, David Hildenbrand , Heiko Carstens , David Howells , Paul Mackerras , Breno Leitao , Michael Neuling , Nicolai Stange , Geert Uytterhoeven , Allison Randal , Firoz Khan , Joel Stanley , Arnd Bergmann , Nicholas Piggin , Thomas Gleixner , Christian Brauner , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, "Eric W. Biederman" , Andrew Donnellan , Hari Bathini Subject: Re: [PATCH v5 3/5] powerpc/64: make buildable without CONFIG_COMPAT Message-ID: <20190830095451.47ab750f@naga> In-Reply-To: <8a755a692fb26b04aa4f95dccc20b076ef7dcf0c.1567146181.git.christophe.leroy@c-s.fr> References: <90594004804c6a9b690b69bdf0e5c4d6c880c5f4.1567117050.git.msuchanek@suse.de> <8a755a692fb26b04aa4f95dccc20b076ef7dcf0c.1567146181.git.christophe.leroy@c-s.fr> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 30 Aug 2019 06:35:13 +0000 (UTC) Christophe Leroy wrote: > On 08/29/2019 10:28 PM, Michal Suchanek wrote: > > There are numerous references to 32bit functions in generic and 64bit > > code so ifdef them out. > > > > Signed-off-by: Michal Suchanek > > --- > > v2: > > - fix 32bit ifdef condition in signal.c > > - simplify the compat ifdef condition in vdso.c - 64bit is redundant > > - simplify the compat ifdef condition in callchain.c - 64bit is redundant > > v3: > > - use IS_ENABLED and maybe_unused where possible > > - do not ifdef declarations > > - clean up Makefile > > v4: > > - further makefile cleanup > > - simplify is_32bit_task conditions > > - avoid ifdef in condition by using return > > v5: > > - avoid unreachable code on 32bit > > - make is_current_64bit constant on !COMPAT > > - add stub perf_callchain_user_32 to avoid some ifdefs > > --- > > arch/powerpc/include/asm/thread_info.h | 4 ++-- > > arch/powerpc/kernel/Makefile | 7 +++---- > > arch/powerpc/kernel/entry_64.S | 2 ++ > > arch/powerpc/kernel/signal.c | 3 +-- > > arch/powerpc/kernel/syscall_64.c | 6 ++---- > > arch/powerpc/kernel/vdso.c | 5 ++--- > > arch/powerpc/perf/callchain.c | 13 +++++++++++-- > > 7 files changed, 23 insertions(+), 17 deletions(-) > > > [...] > > > diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c > > index c84bbd4298a0..881be5c4e9bb 100644 > > --- a/arch/powerpc/perf/callchain.c > > +++ b/arch/powerpc/perf/callchain.c > > @@ -15,7 +15,7 @@ > > #include > > #include > > #include > > -#ifdef CONFIG_PPC64 > > +#ifdef CONFIG_COMPAT > > #include "../kernel/ppc32.h" > > #endif > > #include > > @@ -291,7 +291,8 @@ static inline int current_is_64bit(void) > > * interrupt stack, and the thread flags don't get copied over > > * from the thread_info on the main stack to the interrupt stack. > > */ > > - return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT); > > + return !IS_ENABLED(CONFIG_COMPAT) || > > + !test_ti_thread_flag(task_thread_info(current), TIF_32BIT); > > } > > > > #else /* CONFIG_PPC64 */ > > @@ -341,6 +342,7 @@ static inline int valid_user_sp(unsigned long sp, int is_64) > > > > #endif /* CONFIG_PPC64 */ > > > > +#if defined(CONFIG_PPC32) || defined(CONFIG_COMPAT) > > /* > > * Layout for non-RT signal frames > > */ > > @@ -482,6 +484,13 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, > > sp = next_sp; > > } > > } > > +#else /* 32bit */ > > +static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, > > + struct pt_regs *regs) > > +{ > > + (void)&read_user_stack_32; /* unused if !COMPAT */ > > That looks pretty much like a hack. > > See possible alternative below. > > > +} > > +#endif /* 32bit */ > > > > void > > perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) > > > > --- > arch/powerpc/perf/callchain.c | 62 +++++++++++++++++++------------------------ > 1 file changed, 27 insertions(+), 35 deletions(-) > > diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c > index 881be5c4e9bb..1b169b32776a 100644 > --- a/arch/powerpc/perf/callchain.c > +++ b/arch/powerpc/perf/callchain.c > @@ -165,22 +165,6 @@ static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret) > return read_user_stack_slow(ptr, ret, 8); > } > > -static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret) > -{ > - if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) || > - ((unsigned long)ptr & 3)) > - return -EFAULT; > - > - pagefault_disable(); > - if (!__get_user_inatomic(*ret, ptr)) { > - pagefault_enable(); > - return 0; > - } > - pagefault_enable(); > - > - return read_user_stack_slow(ptr, ret, 4); > -} > - > static inline int valid_user_sp(unsigned long sp, int is_64) > { > if (!sp || (sp & 7) || sp > (is_64 ? TASK_SIZE : 0x100000000UL) - 32) > @@ -296,25 +280,10 @@ static inline int current_is_64bit(void) > } > > #else /* CONFIG_PPC64 */ > -/* > - * On 32-bit we just access the address and let hash_page create a > - * HPTE if necessary, so there is no need to fall back to reading > - * the page tables. Since this is called at interrupt level, > - * do_page_fault() won't treat a DSI as a page fault. > - */ > -static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret) > -{ > - int rc; > - > - if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) || > - ((unsigned long)ptr & 3)) > - return -EFAULT; > > - pagefault_disable(); > - rc = __get_user_inatomic(*ret, ptr); > - pagefault_enable(); > - > - return rc; > +static int read_user_stack_slow(void __user *ptr, void *buf, int nb) > +{ > + return 0; > } > > static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry, > @@ -344,6 +313,30 @@ static inline int valid_user_sp(unsigned long sp, int is_64) > > #if defined(CONFIG_PPC32) || defined(CONFIG_COMPAT) > /* > + * On 32-bit we just access the address and let hash_page create a > + * HPTE if necessary, so there is no need to fall back to reading > + * the page tables. Since this is called at interrupt level, > + * do_page_fault() won't treat a DSI as a page fault. > + */ > +static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret) > +{ > + int rc; > + > + if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) || > + ((unsigned long)ptr & 3)) > + return -EFAULT; > + > + pagefault_disable(); > + rc = __get_user_inatomic(*ret, ptr); > + pagefault_enable(); > + > + if (IS_ENABLED(CONFIG_PPC32) || !rc) > + return rc; > + > + return read_user_stack_slow(ptr, ret, 4); Which is not declared here. This is not intended to be the final state, anyway. Thanks Michal > +} > + > +/* > * Layout for non-RT signal frames > */ > struct signal_frame_32 { > @@ -488,7 +481,6 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, > static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - (void)&read_user_stack_32; /* unused if !COMPAT */ > } > #endif /* 32bit */ >