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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id u18sm29724557pfk.14.2022.02.03.09.33.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Feb 2022 09:33:08 -0800 (PST) From: Kees Cook To: Kees Cook Cc: Miguel Ojeda , Nick Desaulniers , Nathan Chancellor , llvm@lists.linux.dev, George Burgess IV , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v6 2/4] Compiler Attributes: Add __overloadable for Clang Date: Thu, 3 Feb 2022 09:33:05 -0800 Message-Id: <20220203173307.1033257-3-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220203173307.1033257-1-keescook@chromium.org> References: <20220203173307.1033257-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1446; h=from:subject; bh=KMIyemBEeogv0prZ4PjXHBrE0psPPqx5j7gZUW7T9OQ=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBh/BHSjKRmsjxgw96UF0ULSGoSRDajl4PKbrjZ5H1m qvM6GwuJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYfwR0gAKCRCJcvTf3G3AJvp+EA CHifGQYlU/vyOgRTFiBUh2o2UcOBRzjmfvCANd+VySak7rvfpyLFYaD2b/KZR+bvpMIwxmKKRMVMgA bcOzv588jJFGqgeabG/ez2ppSc31+DZYscdVT16K5tdTMd56FsbYQWsIauZGy25an5pOe1vdX7qUdU 96CRYKYktuZCj8rLFsN/2ptyObfY0ZDMWx+oY+uT+eQJsk7QICGaycui8n7ZDF+umQ9bXi34Vmm5a0 iq48nXsnOXqWLSFXEfl23DrXjOWRxhf5IMrwX+7pHvxfE1IXC6oTk+t5Y/LqAirc5OqBEUY2kxS94Z 9nblGXGO3EDSh3DAFhTGUqNO/LdU3HuyFeVau3TSCgD2MFV/kePGim0QGn7NTrvbpclEcBDeV+T1cL uqNDvQsvJ2O6c25GtWehSZWPsb3Q5Sn7oW541ZBfAIUZtAz8tT+8AhYQY6rMcJr10BYH7euQgiYSeH j+rdQCt2ux5XL93GfgjCOaeXaEOT2dPN1hm+mcMJksEY1pG2ZoKsDvrZ2Fl+w0tofWJhPpsN6tbmrj 3yojOjQnE0K+C3p0otFZulTm2JsRe9FUxfV/c3Z0FAKDpaea3BE7TjonpuMsJ4HyockIjz+Fv8dJl5 0PPfQL56Ph+nm9i3dFsl0YbJgHJdaKyCmsevhv8YZEyzCZ8lSXCy6HO38Rxg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org In order for FORTIFY_SOURCE to use __pass_object_size on an "inline extern" function, as all the fortified string functions are, the functions must be marked as being overloadable (i.e. different prototypes). This allows the __pass_object_size versions to take precedence. Cc: Miguel Ojeda Cc: Nick Desaulniers Cc: Nathan Chancellor Cc: llvm@lists.linux.dev Signed-off-by: Kees Cook Reviewed-by: Nick Desaulniers --- include/linux/compiler_attributes.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 4ce370094e3a..dc3bf2a6e1c9 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -257,6 +257,18 @@ */ #define __noreturn __attribute__((__noreturn__)) +/* + * Optional: not supported by gcc. + * Optional: not supported by icc. + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#overloadable + */ +#if __has_attribute(__overloadable__) +# define __overloadable __attribute__((__overloadable__)) +#else +# define __overloadable +#endif + /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-packed-type-attribute * clang: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-packed-variable-attribute