From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752457AbeAESWj (ORCPT + 1 other); Fri, 5 Jan 2018 13:22:39 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:48322 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750739AbeAESWi (ORCPT ); Fri, 5 Jan 2018 13:22:38 -0500 Date: Fri, 5 Jan 2018 18:22:29 +0000 From: Catalin Marinas To: Ard Biesheuvel Cc: linux-mips , Benjamin Herrenschmidt , Will Deacon , Paul Mackerras , "H. Peter Anvin" , sparclinux@vger.kernel.org, linux-s390 , Nicolas Pitre , Michael Ellerman , the arch/x86 maintainers , Russell King , Ingo Molnar , "Serge E. Hallyn" , Petr Mladek , Kees Cook , Arnd Bergmann , Heiko Carstens , Steven Rostedt , James Morris , Josh Poimboeuf , Bjorn Helgaas , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Linus Torvalds , Linux Kernel Mailing List , Ralf Baechle , "David S. Miller" , Sergey Senozhatsky , Jessica Yu , Martin Schwidefsky , Andrew Morton , linuxppc-dev , Thomas Garnier Subject: Re: [PATCH v7 07/10] kernel/jump_label: abstract jump_entry member accessors Message-ID: <20180105182229.pjnlq3l5hzfac4na@armageddon.cambridge.arm.com> References: <20180102200549.22984-1-ard.biesheuvel@linaro.org> <20180102200549.22984-8-ard.biesheuvel@linaro.org> <20180105175834.vqgpsme7itsdg54u@armageddon.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Fri, Jan 05, 2018 at 06:01:33PM +0000, Ard Biesheuvel wrote: > On 5 January 2018 at 17:58, Catalin Marinas wrote: > > On Tue, Jan 02, 2018 at 08:05:46PM +0000, Ard Biesheuvel wrote: > >> diff --git a/arch/arm/include/asm/jump_label.h b/arch/arm/include/asm/jump_label.h > >> index e12d7d096fc0..7b05b404063a 100644 > >> --- a/arch/arm/include/asm/jump_label.h > >> +++ b/arch/arm/include/asm/jump_label.h > >> @@ -45,5 +45,32 @@ struct jump_entry { > >> jump_label_t key; > >> }; > >> > >> +static inline jump_label_t jump_entry_code(const struct jump_entry *entry) > >> +{ > >> + return entry->code; > >> +} > >> + > >> +static inline struct static_key *jump_entry_key(const struct jump_entry *entry) > >> +{ > >> + return (struct static_key *)((unsigned long)entry->key & ~1UL); > >> +} > >> + > >> +static inline bool jump_entry_is_branch(const struct jump_entry *entry) > >> +{ > >> + return (unsigned long)entry->key & 1UL; > >> +} > >> + > >> +static inline bool jump_entry_is_module_init(const struct jump_entry *entry) > >> +{ > >> + return entry->code == 0; > >> +} > >> + > >> +static inline void jump_entry_set_module_init(struct jump_entry *entry) > >> +{ > >> + entry->code = 0; > >> +} > >> + > >> +#define jump_label_swap NULL > > > > Is there any difference between these functions on any of the > > architectures touched? Even with the relative offset, arm64 and x86 > > looked the same to me (well, I may have missed some detail). > > No, the latter two are identical everywhere, and the others are the > same modulo absolute vs relative. > > The issue is that the struct definition is per-arch so the accessors > should be as well. Up to this patch, even the jump_entry structure is the same on all architectures (the jump_label_t type differs). With relative offset, can you not just define jump_label_t to s32? At a quick grep in mainline, it doesn't seem to be used outside the structure definition. > Perhaps I should introduce two variants two asm-generic, similar to > how we have different flavors of unaligned accessors. You could as well define them directly in kernel/jump_label.h or, if used outside this file, include/linux/jump_label.h. -- Catalin