From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 28 Jun 2017 14:09:45 +0000 (-0600)
Subject: fs/fcntl: use copy_to/from_user() for u64 types
X-Git-Tag: v4.13-rc1~212^2~30
X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=commitdiff_plain;h=5657cb0797c4ab303f5782442095319bd971257b

fs/fcntl: use copy_to/from_user() for u64 types

Some architectures (at least PPC) doesn't like get/put_user with
64-bit types on a 32-bit system. Use the variably sized copy
to/from user variants instead.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: c75b1d9421f8 ("fs: add fcntl() interface for setting/getting write life time hints")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 67bdc6e8ccad..ed051f825bad 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -264,15 +264,18 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
 	struct inode *inode = file_inode(file);
 	u64 *argp = (u64 __user *)arg;
 	enum rw_hint hint;
+	u64 h;
 
 	switch (cmd) {
 	case F_GET_FILE_RW_HINT:
-		if (put_user(file_write_hint(file), argp))
+		h = file_write_hint(file);
+		if (copy_to_user(argp, &h, sizeof(*argp)))
 			return -EFAULT;
 		return 0;
 	case F_SET_FILE_RW_HINT:
-		if (get_user(hint, argp))
+		if (copy_from_user(&h, argp, sizeof(h)))
 			return -EFAULT;
+		hint = (enum rw_hint) h;
 		if (!rw_hint_valid(hint))
 			return -EINVAL;
 
@@ -281,12 +284,14 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
 		spin_unlock(&file->f_lock);
 		return 0;
 	case F_GET_RW_HINT:
-		if (put_user(inode->i_write_hint, argp))
+		h = inode->i_write_hint;
+		if (copy_to_user(argp, &h, sizeof(*argp)))
 			return -EFAULT;
 		return 0;
 	case F_SET_RW_HINT:
-		if (get_user(hint, argp))
+		if (copy_from_user(&h, argp, sizeof(h)))
 			return -EFAULT;
+		hint = (enum rw_hint) h;
 		if (!rw_hint_valid(hint))
 			return -EINVAL;