From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v3 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Date: Tue, 29 Oct 2019 14:13:36 -0700 Message-ID: <20191029211351.13243-15-keescook@chromium.org> References: <20191029211351.13243-1-keescook@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20191029211351.13243-1-keescook@chromium.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Borislav Petkov Cc: linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Michal Simek , linux-ia64@vger.kernel.org, Kees Cook , Arnd Bergmann , Michael Ellerman , Dave Hansen , Segher Boessenkool , linuxppc-dev@lists.ozlabs.org, Heiko Carstens , Yoshinori Sato , Andy Lutomirski , linux-alpha@vger.kernel.org, Rick Edgecombe , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org List-Id: linux-arch.vger.kernel.org Many architectures have an EXCEPTION_TABLE that only needs to be readable. As such, it should live in RO_DATA. Create a macro to identify this case for the architectures that can move EXCEPTION_TABLE into RO_DATA. Signed-off-by: Kees Cook Acked-by: Will Deacon --- include/asm-generic/vmlinux.lds.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 356078e50a5c..9867d8e41eed 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -69,6 +69,17 @@ #define NOTES_HEADERS_RESTORE #endif +/* + * Some architectures have non-executable read-only exception tables. + * They can be added to the RO_DATA segment by specifying their desired + * alignment. + */ +#ifdef RO_EXCEPTION_TABLE_ALIGN +#define RO_EXCEPTION_TABLE EXCEPTION_TABLE(RO_EXCEPTION_TABLE_ALIGN) +#else +#define RO_EXCEPTION_TABLE +#endif + /* Align . to a 8 byte boundary equals to maximum function alignment. */ #define ALIGN_FUNCTION() . = ALIGN(8) @@ -513,6 +524,7 @@ __stop___modver = .; \ } \ \ + RO_EXCEPTION_TABLE \ NOTES \ \ . = ALIGN((align)); \ -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f196.google.com ([209.85.210.196]:43543 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729601AbfJ2VOS (ORCPT ); Tue, 29 Oct 2019 17:14:18 -0400 Received: by mail-pf1-f196.google.com with SMTP id 3so10521336pfb.10 for ; Tue, 29 Oct 2019 14:14:17 -0700 (PDT) From: Kees Cook Subject: [PATCH v3 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Date: Tue, 29 Oct 2019 14:13:36 -0700 Message-ID: <20191029211351.13243-15-keescook@chromium.org> In-Reply-To: <20191029211351.13243-1-keescook@chromium.org> References: <20191029211351.13243-1-keescook@chromium.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Borislav Petkov Cc: Kees Cook , Rick Edgecombe , Segher Boessenkool , Dave Hansen , Andy Lutomirski , Arnd Bergmann , Michael Ellerman , Heiko Carstens , Will Deacon , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-c6x-dev@linux-c6x.org, Yoshinori Sato , Michal Simek Message-ID: <20191029211336.DdwTVByB5x5V7sN2T5fz04YRZA031ZGNF1lqUfEz4Ps@z> Many architectures have an EXCEPTION_TABLE that only needs to be readable. As such, it should live in RO_DATA. Create a macro to identify this case for the architectures that can move EXCEPTION_TABLE into RO_DATA. Signed-off-by: Kees Cook Acked-by: Will Deacon --- include/asm-generic/vmlinux.lds.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 356078e50a5c..9867d8e41eed 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -69,6 +69,17 @@ #define NOTES_HEADERS_RESTORE #endif +/* + * Some architectures have non-executable read-only exception tables. + * They can be added to the RO_DATA segment by specifying their desired + * alignment. + */ +#ifdef RO_EXCEPTION_TABLE_ALIGN +#define RO_EXCEPTION_TABLE EXCEPTION_TABLE(RO_EXCEPTION_TABLE_ALIGN) +#else +#define RO_EXCEPTION_TABLE +#endif + /* Align . to a 8 byte boundary equals to maximum function alignment. */ #define ALIGN_FUNCTION() . = ALIGN(8) @@ -513,6 +524,7 @@ __stop___modver = .; \ } \ \ + RO_EXCEPTION_TABLE \ NOTES \ \ . = ALIGN((align)); \ -- 2.17.1