aboutsummaryrefslogtreecommitdiffstats
path: root/lib
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-22 10:16:49 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-22 10:16:49 -0400
commit94f1be9798c88b030256bdeb533008c3d55ec2c6 (patch)
treee73baba68b700e50cab2a22025f85c0455df5470 /lib
parent519fe2ecb755b875d9814cdda19778c2e88c6901 (diff)
parent6407d75afd08545f2252bb39806ffd3f10c7faac (diff)
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio fixes from Rusty Russell: "A build fix and a uapi exposure fix. The build fix is later than I liked, but my first version broke linux-next due to overzealous header clean." * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: virtio_console: fix uapi header Hoist memcpy_fromiovec/memcpy_toiovec into lib/
Diffstat (limited to 'lib')
-rw-r--r--lib/Makefile2
-rw-r--r--lib/iovec.c53
2 files changed, 54 insertions, 1 deletions
diff --git a/lib/Makefile b/lib/Makefile
index e9c52e1b853a..237721165035 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -9,7 +9,7 @@ endif
9 9
10lib-y := ctype.o string.o vsprintf.o cmdline.o \ 10lib-y := ctype.o string.o vsprintf.o cmdline.o \
11 rbtree.o radix-tree.o dump_stack.o timerqueue.o\ 11 rbtree.o radix-tree.o dump_stack.o timerqueue.o\
12 idr.o int_sqrt.o extable.o \ 12 idr.o int_sqrt.o extable.o iovec.o \
13 sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \ 13 sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
14 proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \ 14 proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
15 is_single_threaded.o plist.o decompress.o kobject_uevent.o \ 15 is_single_threaded.o plist.o decompress.o kobject_uevent.o \
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 @@
1#include <linux/uaccess.h>
2#include <linux/export.h>
3#include <linux/uio.h>
4
5/*
6 * Copy iovec to kernel. Returns -EFAULT on error.
7 *
8 * Note: this modifies the original iovec.
9 */
10
11int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
12{
13 while (len > 0) {
14 if (iov->iov_len) {
15 int copy = min_t(unsigned int, len, iov->iov_len);
16 if (copy_from_user(kdata, iov->iov_base, copy))
17 return -EFAULT;
18 len -= copy;
19 kdata += copy;
20 iov->iov_base += copy;
21 iov->iov_len -= copy;
22 }
23 iov++;
24 }
25
26 return 0;
27}
28EXPORT_SYMBOL(memcpy_fromiovec);
29
30/*
31 * Copy kernel to iovec. Returns -EFAULT on error.
32 *
33 * Note: this modifies the original iovec.
34 */
35
36int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
37{
38 while (len > 0) {
39 if (iov->iov_len) {
40 int copy = min_t(unsigned int, iov->iov_len, len);
41 if (copy_to_user(iov->iov_base, kdata, copy))
42 return -EFAULT;
43 kdata += copy;
44 len -= copy;
45 iov->iov_len -= copy;
46 iov->iov_base += copy;
47 }
48 iov++;
49 }
50
51 return 0;
52}
53EXPORT_SYMBOL(memcpy_toiovec);