move compat_rw_copy_check_uvector() over to fs/read_write.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 75 insertions, 76 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 3e94559c452e..ca2f3ca5dacd 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -54,82 +54,6 @@
 #include <asm/ioctls.h>
 #include "internal.h"
 
-/* A write operation does a read from user space and vice versa */
-#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
-
-ssize_t compat_rw_copy_check_uvector(int type,
-                const struct compat_iovec __user *uvector, unsigned long nr_segs,
-                unsigned long fast_segs, struct iovec *fast_pointer,
-                struct iovec **ret_pointer)
-{
-        compat_ssize_t tot_len;
-        struct iovec *iov = *ret_pointer = fast_pointer;
-        ssize_t ret = 0;
-        int seg;
-
-        /*
-         * SuS says "The readv() function *may* fail if the iovcnt argument
-         * was less than or equal to 0, or greater than {IOV_MAX}.  Linux has
-         * traditionally returned zero for zero segments, so...
-         */
-        if (nr_segs == 0)
-                goto out;
-
-        ret = -EINVAL;
-        if (nr_segs > UIO_MAXIOV)
-                goto out;
-        if (nr_segs > fast_segs) {
-                ret = -ENOMEM;
-                iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
-                if (iov == NULL)
-                        goto out;
-        }
-        *ret_pointer = iov;
-
-        ret = -EFAULT;
-        if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
-                goto out;
-
-        /*
-         * Single unix specification:
-         * We should -EINVAL if an element length is not >= 0 and fitting an
-         * ssize_t.
-         *
-         * In Linux, the total length is limited to MAX_RW_COUNT, there is
-         * no overflow possibility.
-         */
-        tot_len = 0;
-        ret = -EINVAL;
-        for (seg = 0; seg < nr_segs; seg++) {
-                compat_uptr_t buf;
-                compat_ssize_t len;
-
-                if (__get_user(len, &uvector->iov_len) ||
-                   __get_user(buf, &uvector->iov_base)) {
-                        ret = -EFAULT;
-                        goto out;
-                }
-                if (len < 0)    /* size_t not fitting in compat_ssize_t .. */
-                        goto out;
-                if (type >= 0 &&
-                    !access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
-                        ret = -EFAULT;
-                        goto out;
-                }
-                if (len > MAX_RW_COUNT - tot_len)
-                        len = MAX_RW_COUNT - tot_len;
-                tot_len += len;
-                iov->iov_base = compat_ptr(buf);
-                iov->iov_len = (compat_size_t) len;
-                uvector++;
-                iov++;
-        }
-        ret = tot_len;
-
-out:
-        return ret;
-}
-
 struct compat_ncp_mount_data {
         compat_int_t version;
         compat_uint_t ncp_fd;
diff --git a/fs/read_write.c b/fs/read_write.c
index c4f88afbc67f..47c1d4484df9 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -841,6 +841,81 @@ out:
         return ret;
 }
 
+#ifdef CONFIG_COMPAT
+ssize_t compat_rw_copy_check_uvector(int type,
+                const struct compat_iovec __user *uvector, unsigned long nr_segs,
+                unsigned long fast_segs, struct iovec *fast_pointer,
+                struct iovec **ret_pointer)
+{
+        compat_ssize_t tot_len;
+        struct iovec *iov = *ret_pointer = fast_pointer;
+        ssize_t ret = 0;
+        int seg;
+
+        /*
+         * SuS says "The readv() function *may* fail if the iovcnt argument
+         * was less than or equal to 0, or greater than {IOV_MAX}.  Linux has
+         * traditionally returned zero for zero segments, so...
+         */
+        if (nr_segs == 0)
+                goto out;
+
+        ret = -EINVAL;
+        if (nr_segs > UIO_MAXIOV)
+                goto out;
+        if (nr_segs > fast_segs) {
+                ret = -ENOMEM;
+                iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
+                if (iov == NULL)
+                        goto out;
+        }
+        *ret_pointer = iov;
+
+        ret = -EFAULT;
+        if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
+                goto out;
+
+        /*
+         * Single unix specification:
+         * We should -EINVAL if an element length is not >= 0 and fitting an
+         * ssize_t.
+         *
+         * In Linux, the total length is limited to MAX_RW_COUNT, there is
+         * no overflow possibility.
+         */
+        tot_len = 0;
+        ret = -EINVAL;
+        for (seg = 0; seg < nr_segs; seg++) {
+                compat_uptr_t buf;
+                compat_ssize_t len;
+
+                if (__get_user(len, &uvector->iov_len) ||
+                   __get_user(buf, &uvector->iov_base)) {
+                        ret = -EFAULT;
+                        goto out;
+                }
+                if (len < 0)    /* size_t not fitting in compat_ssize_t .. */
+                        goto out;
+                if (type >= 0 &&
+                    !access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
+                        ret = -EFAULT;
+                        goto out;
+                }
+                if (len > MAX_RW_COUNT - tot_len)
+                        len = MAX_RW_COUNT - tot_len;
+                tot_len += len;
+                iov->iov_base = compat_ptr(buf);
+                iov->iov_len = (compat_size_t) len;
+                uvector++;
+                iov++;
+        }
+        ret = tot_len;
+
+out:
+        return ret;
+}
+#endif
+
 static ssize_t __do_readv_writev(int type, struct file *file,
                                  struct iov_iter *iter, loff_t *pos, int flags)
 {