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-rw-r--r--include/linux/uio.h14
-rw-r--r--lib/iov_iter.c57
2 files changed, 71 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 71880299ed48..1f4a37f1f025 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -139,4 +139,18 @@ static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
+int import_iovec(int type, const struct iovec __user * uvector,
+ unsigned nr_segs, unsigned fast_segs,
+ struct iovec **iov, struct iov_iter *i);
+
+#ifdef CONFIG_COMPAT
+struct compat_iovec;
+int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
+ unsigned nr_segs, unsigned fast_segs,
+ struct iovec **iov, struct iov_iter *i);
+#endif
+
+int import_single_range(int type, void __user *buf, size_t len,
+ struct iovec *iov, struct iov_iter *i);
+
#endif
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 9d96e283520c..fc6e33f6b7f3 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -766,3 +766,60 @@ const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags)
flags);
}
EXPORT_SYMBOL(dup_iter);
+
+int import_iovec(int type, const struct iovec __user * uvector,
+ unsigned nr_segs, unsigned fast_segs,
+ struct iovec **iov, struct iov_iter *i)
+{
+ ssize_t n;
+ struct iovec *p;
+ n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs,
+ *iov, &p);
+ if (n < 0) {
+ if (p != *iov)
+ kfree(p);
+ *iov = NULL;
+ return n;
+ }
+ iov_iter_init(i, type, p, nr_segs, n);
+ *iov = p == *iov ? NULL : p;
+ return 0;
+}
+EXPORT_SYMBOL(import_iovec);
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+
+int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
+ unsigned nr_segs, unsigned fast_segs,
+ struct iovec **iov, struct iov_iter *i)
+{
+ ssize_t n;
+ struct iovec *p;
+ n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs,
+ *iov, &p);
+ if (n < 0) {
+ if (p != *iov)
+ kfree(p);
+ *iov = NULL;
+ return n;
+ }
+ iov_iter_init(i, type, p, nr_segs, n);
+ *iov = p == *iov ? NULL : p;
+ return 0;
+}
+#endif
+
+int import_single_range(int rw, void __user *buf, size_t len,
+ struct iovec *iov, struct iov_iter *i)
+{
+ if (len > MAX_RW_COUNT)
+ len = MAX_RW_COUNT;
+ if (unlikely(!access_ok(!rw, buf, len)))
+ return -EFAULT;
+
+ iov->iov_base = buf;
+ iov->iov_len = len;
+ iov_iter_init(i, rw, iov, 1, len);
+ return 0;
+}