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authorMeizu OpenSource <patchwork@meizu.com>2016-08-15 10:19:42 +0800
committerMeizu OpenSource <patchwork@meizu.com>2016-08-15 10:19:42 +0800
commitd2e1446d81725c351dc73a03b397ce043fb18452 (patch)
tree4dbc616b7f92aea39cd697a9084205ddb805e344 /include/linux/uio.h
first commit
Diffstat (limited to 'include/linux/uio.h')
-rw-r--r--include/linux/uio.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h
new file mode 100644
index 000000000..c55ce243c
--- /dev/null
+++ b/include/linux/uio.h
@@ -0,0 +1,41 @@
+/*
+ * Berkeley style UIO structures - Alan Cox 1994.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef __LINUX_UIO_H
+#define __LINUX_UIO_H
+
+#include <uapi/linux/uio.h>
+
+
+struct kvec {
+ void *iov_base; /* and that should *never* hold a userland pointer */
+ size_t iov_len;
+};
+
+/*
+ * Total number of bytes covered by an iovec.
+ *
+ * NOTE that it is not safe to use this function until all the iovec's
+ * segment lengths have been validated. Because the individual lengths can
+ * overflow a size_t when added together.
+ */
+static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
+{
+ unsigned long seg;
+ size_t ret = 0;
+
+ for (seg = 0; seg < nr_segs; seg++)
+ ret += iov[seg].iov_len;
+ return ret;
+}
+
+unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
+
+int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
+int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len);
+#endif