[uaccess] Add memcmp_user()

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/src/include/ipxe/uaccess.h b/src/include/ipxe/uaccess.h
index 95e943675..055bb2ca7 100644
--- a/src/include/ipxe/uaccess.h
+++ b/src/include/ipxe/uaccess.h
@@ -127,6 +127,23 @@ trivial_memmove_user ( userptr_t dest, off_t dest_off,
 }
 
 /**
+ * Compare data between user buffers
+ *
+ * @v first		First buffer
+ * @v first_off		First buffer offset
+ * @v second		Second buffer
+ * @v second_off	Second buffer offset
+ * @v len		Length
+ * @ret diff		Difference
+ */
+static inline __always_inline int
+trivial_memcmp_user ( userptr_t first, off_t first_off,
+		      userptr_t second, off_t second_off, size_t len ) {
+	return memcmp ( ( ( void * ) first + first_off ),
+			( ( void * ) second + second_off ), len );
+}
+
+/**
  * Fill user buffer with a constant byte
  *
  * @v buffer		User buffer
@@ -334,6 +351,19 @@ void memmove_user ( userptr_t dest, off_t dest_off,
 		    userptr_t src, off_t src_off, size_t len );
 
 /**
+ * Compare data between user buffers
+ *
+ * @v first		First buffer
+ * @v first_off		First buffer offset
+ * @v second		Second buffer
+ * @v second_off	Second buffer offset
+ * @v len		Length
+ * @ret diff		Difference
+ */
+int memcmp_user ( userptr_t first, off_t first_off,
+		  userptr_t second, off_t second_off, size_t len );
+
+/**
  * Fill user buffer with a constant byte
  *
  * @v userptr		User buffer