From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 2/3] compat: add a compat_need_64bit_alignment_fixup() helper Date: Fri, 31 Jul 2020 14:22:01 +0200 Message-ID: <20200731122202.213333-3-hch@lst.de> References: <20200731122202.213333-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200731122202.213333-1-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org To: x86@kernel.org, Jan Kara Cc: linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org List-Id: linux-arch.vger.kernel.org Add a helper to check if the calling syscall needs a fixup for non-natural 64-bit type alignment in the compat ABI. This will only return true for i386 syscalls on x86_64. Signed-off-by: Christoph Hellwig --- arch/x86/include/asm/compat.h | 1 + include/linux/compat.h | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index bf547701f41f87..0e327a01f50fbb 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -209,6 +209,7 @@ static inline bool in_compat_syscall(void) return in_32bit_syscall(); } #define in_compat_syscall in_compat_syscall /* override the generic impl */ +#define compat_need_64bit_alignment_fixup in_ia32_syscall #endif struct compat_siginfo; diff --git a/include/linux/compat.h b/include/linux/compat.h index e90100c0de72e4..a195f90f156cf6 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -937,6 +937,15 @@ static inline bool in_compat_syscall(void) { return false; } #endif /* CONFIG_COMPAT */ +/* + * Some legacy ABIs like the i386 one use less than natural alignment for 64-bit + * types, and will need special compat treatment for that. Most architectures + * don't need that special handling even for compat syscalls. + */ +#ifndef compat_need_64bit_alignment_fixup +#define compat_need_64bit_alignment_fixup() false +#endif + /* * A pointer passed in from user mode. This should not * be used for syscall parameters, just declare them -- 2.27.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733285AbgGaMWM (ORCPT ); Fri, 31 Jul 2020 08:22:12 -0400 From: Christoph Hellwig Subject: [PATCH 2/3] compat: add a compat_need_64bit_alignment_fixup() helper Date: Fri, 31 Jul 2020 14:22:01 +0200 Message-ID: <20200731122202.213333-3-hch@lst.de> In-Reply-To: <20200731122202.213333-1-hch@lst.de> References: <20200731122202.213333-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: x86@kernel.org, Jan Kara Cc: linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org Message-ID: <20200731122201.wSIAW3YaKqXBavMcRklDWJFi_KFZ2PBMw8NcD3hGBOQ@z> Add a helper to check if the calling syscall needs a fixup for non-natural 64-bit type alignment in the compat ABI. This will only return true for i386 syscalls on x86_64. Signed-off-by: Christoph Hellwig --- arch/x86/include/asm/compat.h | 1 + include/linux/compat.h | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index bf547701f41f87..0e327a01f50fbb 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -209,6 +209,7 @@ static inline bool in_compat_syscall(void) return in_32bit_syscall(); } #define in_compat_syscall in_compat_syscall /* override the generic impl */ +#define compat_need_64bit_alignment_fixup in_ia32_syscall #endif struct compat_siginfo; diff --git a/include/linux/compat.h b/include/linux/compat.h index e90100c0de72e4..a195f90f156cf6 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -937,6 +937,15 @@ static inline bool in_compat_syscall(void) { return false; } #endif /* CONFIG_COMPAT */ +/* + * Some legacy ABIs like the i386 one use less than natural alignment for 64-bit + * types, and will need special compat treatment for that. Most architectures + * don't need that special handling even for compat syscalls. + */ +#ifndef compat_need_64bit_alignment_fixup +#define compat_need_64bit_alignment_fixup() false +#endif + /* * A pointer passed in from user mode. This should not * be used for syscall parameters, just declare them -- 2.27.0