3 files changed, 21 insertions, 7 deletions
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index d3318a3c2577..d095beb904ea 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -369,7 +369,7 @@ struct ftrace_likely_data {
  * Optional: only supported since clang >= 18
  *
  *   gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
- * clang: https://github.com/llvm/llvm-project/pull/76348
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#counted-by-counted-by-or-null-sized-by-sized-by-or-null
  *
  * __bdos on clang < 19.1.2 can erroneously return 0:
  * https://github.com/llvm/llvm-project/pull/110497
@@ -384,6 +384,22 @@ struct ftrace_likely_data {
 #endif
 
 /*
+ * Runtime track number of objects pointed to by a pointer member for use by
+ * CONFIG_FORTIFY_SOURCE and CONFIG_UBSAN_BOUNDS.
+ *
+ * Optional: only supported since gcc >= 16
+ * Optional: only supported since clang >= 22
+ *
+ *   gcc: https://gcc.gnu.org/pipermail/gcc-patches/2025-April/681727.html
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#counted-by-counted-by-or-null-sized-by-sized-by-or-null
+ */
+#ifdef CONFIG_CC_HAS_COUNTED_BY_PTR
+#define __counted_by_ptr(member)	__attribute__((__counted_by__(member)))
+#else
+#define __counted_by_ptr(member)
+#endif
+
+/*
  * Optional: only supported since gcc >= 15
  * Optional: not supported by Clang
  *
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index b3b53f8c1b28..171982e53c9a 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -2,7 +2,6 @@
 #ifndef _LINUX_FORTIFY_STRING_H_
 #define _LINUX_FORTIFY_STRING_H_
 
-#include <linux/bitfield.h>
 #include <linux/bug.h>
 #include <linux/const.h>
 #include <linux/limits.h>
@@ -10,10 +9,9 @@
 #define __FORTIFY_INLINE extern __always_inline __gnu_inline __overloadable
 #define __RENAME(x) __asm__(#x)
 
-#define FORTIFY_REASON_DIR(r)		FIELD_GET(BIT(0), r)
-#define FORTIFY_REASON_FUNC(r)		FIELD_GET(GENMASK(7, 1), r)
-#define FORTIFY_REASON(func, write)	(FIELD_PREP(BIT(0), write) | \
-					 FIELD_PREP(GENMASK(7, 1), func))
+#define FORTIFY_REASON_DIR(r)		((r) & 1)
+#define FORTIFY_REASON_FUNC(r)		((r) >> 1)
+#define FORTIFY_REASON(func, write)	((func) << 1 | (write))
 
 /* Overridden by KUnit tests. */
 #ifndef fortify_panic
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 64e9afe7d647..296b5ee5c979 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -114,7 +114,7 @@ struct simple_xattr {
 	struct rb_node rb_node;
 	char *name;
 	size_t size;
-	char value[];
+	char value[] __counted_by(size);
 };
 
 void simple_xattrs_init(struct simple_xattrs *xattrs);