From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v2 14/29] vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA Date: Thu, 10 Oct 2019 17:05:54 -0700 Message-ID: <20191011000609.29728-15-keescook@chromium.org> References: <20191011000609.29728-1-keescook@chromium.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=O8SEsfE9Vx0Hoh9SzPjKsL9yL1yAPo1QWRZUpqQZ5BE=; b=Gv7TLEhljmk67n05hXgtlXOGcw9tGWMBrimWEdgAzAJXSYD424xsVS93uPgKCKbOtA KpknhwokmtlZdLNepzxzaEOUq/9kMlkIhbFFmT4rtodx7TYV09GcbgOeE2Tx2zJJHzL4 OqaceGT7qpam5Y2W3jNCRpS/l3/Ec0FSl0z+s= In-Reply-To: <20191011000609.29728-1-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Borislav Petkov Cc: Kees Cook , Rick Edgecombe , 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 , linux-parisc@vger.kernel.org, linux-xtensa@linux-xtensa.org, x86@kernel.org, linux-kernel@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