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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-27 10:57:53 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-27 10:57:53 +0900
commit8095e4e81b4bc38eef7e0be99f9ecc744eaa1683 (patch)
treed3b5100db11784093e78513f3429022569b4bf7b /lib/iovec.c
parent6b5f146535fe6969aeded9f00b0bc42b3783f7fd (diff)
parente4aa937ec75df0eea0bee03bffa3303ad36c986b (diff)
downloadlwn-8095e4e81b4bc38eef7e0be99f9ecc744eaa1683.tar.gz
lwn-8095e4e81b4bc38eef7e0be99f9ecc744eaa1683.zip
Merge 3.10-rc3 into tty-next
We want these fixes. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/iovec.c')
-rw-r--r--lib/iovec.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/lib/iovec.c b/lib/iovec.c
new file mode 100644
index 000000000000..454baa88bf27
--- /dev/null
+++ b/lib/iovec.c
@@ -0,0 +1,53 @@
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/uio.h>
+
+/*
+ * Copy iovec to kernel. Returns -EFAULT on error.
+ *
+ * Note: this modifies the original iovec.
+ */
+
+int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
+{
+ while (len > 0) {
+ if (iov->iov_len) {
+ int copy = min_t(unsigned int, len, iov->iov_len);
+ if (copy_from_user(kdata, iov->iov_base, copy))
+ return -EFAULT;
+ len -= copy;
+ kdata += copy;
+ iov->iov_base += copy;
+ iov->iov_len -= copy;
+ }
+ iov++;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(memcpy_fromiovec);
+
+/*
+ * Copy kernel to iovec. Returns -EFAULT on error.
+ *
+ * Note: this modifies the original iovec.
+ */
+
+int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
+{
+ while (len > 0) {
+ if (iov->iov_len) {
+ int copy = min_t(unsigned int, iov->iov_len, len);
+ if (copy_to_user(iov->iov_base, kdata, copy))
+ return -EFAULT;
+ kdata += copy;
+ len -= copy;
+ iov->iov_len -= copy;
+ iov->iov_base += copy;
+ }
+ iov++;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(memcpy_toiovec);