Merge tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull FORTIFY_SOURCE updates from Kees Cook:
 "This series consists of two halves:

   - strict compile-time buffer size checking under FORTIFY_SOURCE for
     the memcpy()-family of functions (for extensive details and
     rationale, see the first commit)

   - enabling FORTIFY_SOURCE for Clang, which has had many overlapping
     bugs that we've finally worked past"

* tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  fortify: Add Clang support
  fortify: Make sure strlen() may still be used as a constant expression
  fortify: Use __diagnose_as() for better diagnostic coverage
  fortify: Make pointer arguments const
  Compiler Attributes: Add __diagnose_as for Clang
  Compiler Attributes: Add __overloadable for Clang
  Compiler Attributes: Add __pass_object_size for Clang
  fortify: Replace open-coded __gnu_inline attribute
  fortify: Update compile-time tests for Clang 14
  fortify: Detect struct member overflows in memset() at compile-time
  fortify: Detect struct member overflows in memmove() at compile-time
  fortify: Detect struct member overflows in memcpy() at compile-time

1 files changed, 39 insertions, 0 deletions

diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
index 37e260020221..445e80517cab 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -101,6 +101,19 @@
 #endif
 
 /*
+ * Optional: not supported by gcc
+ * Optional: only supported since clang >= 14.0
+ * Optional: not supported by icc
+ *
+ * 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.
  *
@@ -258,12 +271,38 @@
 #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
  */
 #define __packed                        __attribute__((__packed__))
 
 /*
+ * Note: the "type" argument should match any __builtin_object_size(p, type) usage.
+ *
+ * Optional: not supported by gcc.
+ * Optional: not supported by icc.
+ *
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#pass-object-size-pass-dynamic-object-size
+ */
+#if __has_attribute(__pass_object_size__)
+# define __pass_object_size(type)	__attribute__((__pass_object_size__(type)))
+#else
+# define __pass_object_size(type)
+#endif
+
+/*
  *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-pure-function-attribute
  */
 #define __pure                          __attribute__((__pure__))