1 files changed, 32 insertions, 11 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index 61b58c7b6531..a2b9a47235c5 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -413,7 +413,20 @@ ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
 	else
 		return -EINVAL;
 }
-EXPORT_SYMBOL(__vfs_read);
+
+ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
+{
+	mm_segment_t old_fs;
+	ssize_t result;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	result = vfs_read(file, (void __user *)buf, count, pos);
+	set_fs(old_fs);
+	return result;
+}
+EXPORT_SYMBOL(kernel_read);
 
 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 {
@@ -441,8 +454,6 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 	return ret;
 }
 
-EXPORT_SYMBOL(vfs_read);
-
 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
 {
 	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
@@ -471,9 +482,8 @@ ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
 	else
 		return -EINVAL;
 }
-EXPORT_SYMBOL(__vfs_write);
 
-ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
+ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
 {
 	mm_segment_t old_fs;
 	const char __user *p;
@@ -496,9 +506,24 @@ ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t
 	inc_syscw(current);
 	return ret;
 }
-
 EXPORT_SYMBOL(__kernel_write);
 
+ssize_t kernel_write(struct file *file, const void *buf, size_t count,
+			    loff_t *pos)
+{
+	mm_segment_t old_fs;
+	ssize_t res;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	res = vfs_write(file, (__force const char __user *)buf, count, pos);
+	set_fs(old_fs);
+
+	return res;
+}
+EXPORT_SYMBOL(kernel_write);
+
 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
 {
 	ssize_t ret;
@@ -527,8 +552,6 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
 	return ret;
 }
 
-EXPORT_SYMBOL(vfs_write);
-
 static inline loff_t file_pos_read(struct file *file)
 {
 	return file->f_pos;
@@ -959,9 +982,8 @@ ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
 
 	return ret;
 }
-EXPORT_SYMBOL(vfs_readv);
 
-ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
+static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 		   unsigned long vlen, loff_t *pos, rwf_t flags)
 {
 	struct iovec iovstack[UIO_FASTIOV];
@@ -978,7 +1000,6 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 	}
 	return ret;
 }
-EXPORT_SYMBOL(vfs_writev);
 
 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
 			unsigned long vlen, rwf_t flags)