1 files changed, 13 insertions, 15 deletions

diff --git a/sys/compat/linuxkpi/common/include/linux/fs.h b/sys/compat/linuxkpi/common/include/linux/fs.h
index f1568ad6282d..40e1b396fe86 100644
--- a/sys/compat/linuxkpi/common/include/linux/fs.h
+++ b/sys/compat/linuxkpi/common/include/linux/fs.h
@@ -364,8 +364,9 @@ static inline ssize_t
 simple_read_from_buffer(void __user *dest, size_t read_size, loff_t *ppos,
     void *orig, size_t buf_size)
 {
-	void *p, *read_pos = ((char *) orig) + *ppos;
+	void *read_pos = ((char *) orig) + *ppos;
 	size_t buf_remain = buf_size - *ppos;
+	ssize_t num_read;
 
 	if (buf_remain < 0 || buf_remain > buf_size)
 		return -EINVAL;
@@ -373,18 +374,13 @@ simple_read_from_buffer(void __user *dest, size_t read_size, loff_t *ppos,
 	if (read_size > buf_remain)
 		read_size = buf_remain;
 
-	/*
-	 * XXX At time of commit only debugfs consumers could be
-	 * identified.  If others will use this function we may
-	 * have to revise this: normally we would call copy_to_user()
-	 * here but lindebugfs will return the result and the
-	 * copyout is done elsewhere for us.
-	 */
-	p = memcpy(dest, read_pos, read_size);
-	if (p != NULL)
-		*ppos += read_size;
+	/* copy_to_user returns number of bytes NOT read */
+	num_read = read_size - copy_to_user(dest, read_pos, read_size);
+	if (num_read == 0)
+		return -EFAULT;
+	*ppos += num_read;
 
-	return (read_size);
+	return (num_read);
 }
 
 MALLOC_DECLARE(M_LSATTR);
@@ -415,11 +411,13 @@ int simple_attr_open(struct inode *inode, struct file *filp,
 
 int simple_attr_release(struct inode *inode, struct file *filp);
 
-ssize_t simple_attr_read(struct file *filp, char *buf, size_t read_size, loff_t *ppos);
+ssize_t simple_attr_read(struct file *filp, char __user *buf, size_t read_size,
+    loff_t *ppos);
 
-ssize_t simple_attr_write(struct file *filp, const char *buf, size_t write_size, loff_t *ppos);
+ssize_t simple_attr_write(struct file *filp, const char __user *buf,
+    size_t write_size, loff_t *ppos);
 
-ssize_t simple_attr_write_signed(struct file *filp, const char *buf,
+ssize_t simple_attr_write_signed(struct file *filp, const char __user *buf,
 	    size_t write_size, loff_t *ppos);
 
 #endif /* _LINUXKPI_LINUX_FS_H_ */