copy_from_user and memset

[lttng-modules.git] / lib / ringbuffer / backend_internal.h

diff --git a/lib/ringbuffer/backend_internal.h b/lib/ringbuffer/backend_internal.h
index d92fe36c82f39326ad846054e5f1bb248f030126..442f357a4c40120aae2f06d897aee7a723f1cd56 100644 (file)
--- a/lib/ringbuffer/backend_internal.h
+++ b/lib/ringbuffer/backend_internal.h
@@ -15,6 +15,7 @@
 #include "../../wrapper/ringbuffer/backend_types.h"
 #include "../../wrapper/ringbuffer/frontend_types.h"
 #include <linux/string.h>
+#include <linux/uaccess.h>
 
 /* Ring buffer backend API presented to the frontend */
 
@@ -40,6 +41,12 @@ void lib_ring_buffer_backend_exit(void);
 extern void _lib_ring_buffer_write(struct lib_ring_buffer_backend *bufb,
                                   size_t offset, const void *src, size_t len,
                                   ssize_t pagecpy);
+extern void _lib_ring_buffer_memset(struct lib_ring_buffer_backend *bufb,
+                                   size_t offset, int c, size_t len,
+                                   ssize_t pagecpy);
+extern void _lib_ring_buffer_copy_from_user(struct lib_ring_buffer_backend *bufb,
+                                           size_t offset, const void *src,
+                                           size_t len, ssize_t pagecpy);
 
 /*
  * Subbuffer ID bits for overwrite mode. Need to fit within a single word to be
@@ -414,4 +421,29 @@ do {                                                               \
                inline_memcpy(dest, src, __len);                \
 } while (0)
 
+/*
+ * We use __copy_from_user to copy userspace data since we already
+ * did the access_ok for the whole range.
+ */
+static inline
+unsigned long lib_ring_buffer_do_copy_from_user(void *dest,
+                                               const void __user *src,
+                                               unsigned long len)
+{
+       return __copy_from_user(dest, src, len);
+}
+
+/*
+ * write len bytes to dest with c
+ */
+static inline
+void lib_ring_buffer_do_memset(char *dest, int c,
+       unsigned long len)
+{
+       unsigned long i;
+
+       for (i = 0; i < len; i++)
+               dest[i] = c;
+}
+
 #endif /* _LINUX_RING_BUFFER_BACKEND_INTERNAL_H */