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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id k5sm24652213pfc.85.2022.02.01.16.30.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Feb 2022 16:30:35 -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, linux-security-module@vger.kernel.org Subject: [PATCH 3/4] Compiler Attributes: Add __diagnose_as Date: Tue, 1 Feb 2022 16:30:32 -0800 Message-Id: <20220202003033.704951-4-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220202003033.704951-1-keescook@chromium.org> References: <20220202003033.704951-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1423; h=from:subject; bh=i1fpN36antLyVBs1U1U1fSS2CEHxT+df0ZNPiHFG1jw=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBh+dCo/jbG9rFQBg8OANce/4aahaOqHs+lh9B2zqU8 116jf4uJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYfnQqAAKCRCJcvTf3G3AJvOwD/ sFAXq9aIInuKt669oChD+K7YlLbmjc+0Ev4yHmb/YOCrz7QXAyfTMQZpJqikdYEH3RFaxKnJDgwmzE mqc8G2OHkuxL5GyPhpv/O9LhhEfYBf63VDTQb8dWhG/SvsBPXM0q89OlkSDr/noi4du4zL9s+3534O kx6nfw288C24GCljYJLELUhi5IazVnMu90Eah73vJwhPj5ePPPV4W1YFVTws466TcQP232pmUTM+SN 0UGDJm7eowDUNz98idxmkAyF61U/Coi5a+Wd45R7Ieei11bgWmk972riSp9DRlY521GiRGRQ20zHp9 CAJP6EdVJc9VKK2h1idH4Lb6xwQOfbRRdUXJ1ePh2MMrt2hxWqRLwWpdpoM8hpGljgl70mtNxFSPDa q7FCYP3R+2xCQGjbWBftyNcQcsBlEqMLDJFzPfZ3UI/hMCkaW3ettYkIyEtQBwLy8Wq2YOoopQgGFw R/UZuVg8I2E6mTDYZU0ucXXYHn/6UkMntLq/F7dJfEqQKL3VPOsiDkdRFxsOpkyAsOS3fQxTmZIhb5 6GPjfb5mrzyRHCAGhWn+QNb1SQMuBdiSFQueS9KSs8nr9ApRKv6Hh9nnhWC29V7ki4CeKoInqseiEX j6AjgVKUE++SxwpcKHyfyy7/tCO16ohvH91YXRrutSLXYc7TxlBPaLRnu7nw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Clang will perform various compile-time diagnostics on uses of various functions (e.g. simple bounds-checking on strcpy(), etc). These diagnostics can be assigned to other functions (for example, new implementations of the string functions under CONFIG_FORTIFY_SOURCE) using the "diagnose_as_builtin" attribute. This allows those functions to retain their compile-time diagnostic warnings. Cc: Miguel Ojeda Cc: Nick Desaulniers Cc: Nathan Chancellor Cc: llvm@lists.linux.dev Signed-off-by: Kees Cook --- include/linux/compiler_attributes.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 51e063347fd6..b4ae0d771302 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -100,6 +100,15 @@ # define __copy(symbol) #endif +/* + * clang: https://clang.llvm.org/docs/AttributeReference.html#diagnose_as_builtin + */ +#if __has_attribute(__diagnose_as_builtin__) +# define __diagnose_as(builtin...) __attribute__((__diagnose_as_builtin__(builtin))) +#else +# define __diagnose_as(builtin...) +#endif + /* * Don't. Just don't. See commit 771c035372a0 ("deprecate the '__deprecated' * attribute warnings entirely and for good") for more information.