Merge with Linux 2.3.22.

1 files changed, 20 insertions, 1 deletions

diff --git a/include/asm-ppc/uaccess.h b/include/asm-ppc/uaccess.h
index b8afd599b..c2a9c91e5 100644
--- a/include/asm-ppc/uaccess.h
+++ b/include/asm-ppc/uaccess.h
@@ -259,7 +259,26 @@ strncpy_from_user(char *dst, const char *src, long count)
  * Return 0 for error
  */
 
-extern long strlen_user(const char *);
+extern int __strnlen_user(const char *str, long len, unsigned long top);
+
+/*
+ * Returns the length of the string at str (including the null byte),
+ * or 0 if we hit a page we can't access,
+ * or something > len if we didn't find a null byte.
+ *
+ * The `top' parameter to __strnlen_user is to make sure that
+ * we can never overflow from the user area into kernel space.
+ */
+extern __inline__ int strnlen_user(const char *str, long len)
+{
+	unsigned long top = __kernel_ok? ~0UL: TASK_SIZE - 1;
+
+	if ((unsigned long)str > top)
+		return 0;
+	return __strnlen_user(str, len, top);
+}
+
+#define strlen_user(str)	strnlen_user((str), 0x7ffffffe)
 
 #endif  /* __ASSEMBLY__ */