diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/iovec.c | 53 |
2 files changed, 54 insertions, 1 deletions
diff --git a/lib/Makefile b/lib/Makefile index e9c52e1b853..23772116503 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -9,7 +9,7 @@ endif lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o timerqueue.o\ - idr.o int_sqrt.o extable.o \ + idr.o int_sqrt.o extable.o iovec.o \ sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \ 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 00000000000..454baa88bf2 --- /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); |