3 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index bd2b881c6b63..b9d5f9c373a0 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -144,3 +144,11 @@
 #else
 #define __diag_GCC_8(s)
 #endif
+
+/*
+ * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
+ * attribute) do not work, and must be disabled.
+ */
+#if GCC_VERSION < 90100
+#undef __alloc_size__
+#endif
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
index e6ec63403965..3de06a8fae73 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -34,6 +34,15 @@
 #define __aligned_largest               __attribute__((__aligned__))
 
 /*
+ * Note: do not use this directly. Instead, use __alloc_size() since it is conditionally
+ * available and includes other attributes.
+ *
+ *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alloc_005fsize-function-attribute
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#alloc-size
+ */
+#define __alloc_size__(x, ...)		__attribute__((__alloc_size__(x, ## __VA_ARGS__)))
+
+/*
  * Note: users of __always_inline currently do not write "inline" themselves,
  * which seems to be required by gcc to apply the attribute according
  * to its docs (and also "warning: always_inline function might not be
@@ -153,6 +162,7 @@
 
 /*
  *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-malloc-function-attribute
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#malloc
  */
 #define __malloc                        __attribute__((__malloc__))
 
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index b6ff83a714ca..4f2203c4a257 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -250,6 +250,18 @@ struct ftrace_likely_data {
 # define __cficanonical
 #endif
 
+/*
+ * Any place that could be marked with the "alloc_size" attribute is also
+ * a place to be marked with the "malloc" attribute. Do this as part of the
+ * __alloc_size macro to avoid redundant attributes and to avoid missing a
+ * __malloc marking.
+ */
+#ifdef __alloc_size__
+# define __alloc_size(x, ...)	__alloc_size__(x, ## __VA_ARGS__) __malloc
+#else
+# define __alloc_size(x, ...)	__malloc
+#endif
+
 #ifndef asm_volatile_goto
 #define asm_volatile_goto(x...) asm goto(x)
 #endif