[PATCH] arm: fix handling of F_OFD_... in oabi_fcntl64()

Cc: stable@vger.kernel.org # 3.15+
Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/arm/kernel/sys_oabi-compat.c

@@ -193,22 +193,14 @@ struct oabi_flock64 {
 	pid_t	l_pid;
 } __attribute__ ((packed,aligned(4)));
 
-asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
+static long do_locks(unsigned int fd, unsigned int cmd,
 				 unsigned long arg)
 {
-	struct oabi_flock64 user;
 	struct flock64 kernel;
-	mm_segment_t fs = USER_DS; /* initialized to kill a warning */
-	unsigned long local_arg = arg;
-	int ret;
+	struct oabi_flock64 user;
+	mm_segment_t fs;
+	long ret;
 
-	switch (cmd) {
-	case F_OFD_GETLK:
-	case F_OFD_SETLK:
-	case F_OFD_SETLKW:
-	case F_GETLK64:
-	case F_SETLK64:
-	case F_SETLKW64:
 	if (copy_from_user(&user, (struct oabi_flock64 __user *)arg,
 			   sizeof(user)))
 		return -EFAULT;
@@ -217,16 +209,13 @@ asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
 	kernel.l_start	= user.l_start;
 	kernel.l_len	= user.l_len;
 	kernel.l_pid	= user.l_pid;
-		local_arg = (unsigned long)&kernel;
+
 	fs = get_fs();
 	set_fs(KERNEL_DS);
-	}
-
-	ret = sys_fcntl64(fd, cmd, local_arg);
+	ret = sys_fcntl64(fd, cmd, (unsigned long)&kernel);
+	set_fs(fs);
 
-	switch (cmd) {
-	case F_GETLK64:
-		if (!ret) {
+	if (!ret && (cmd == F_GETLK64 || cmd == F_OFD_GETLK)) {
 		user.l_type	= kernel.l_type;
 		user.l_whence	= kernel.l_whence;
 		user.l_start	= kernel.l_start;
@@ -236,12 +225,24 @@ asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
 				 &user, sizeof(user)))
 			ret = -EFAULT;
 	}
+	return ret;
+}
+
+asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
+				 unsigned long arg)
+{
+	switch (cmd) {
+	case F_OFD_GETLK:
+	case F_OFD_SETLK:
+	case F_OFD_SETLKW:
+	case F_GETLK64:
 	case F_SETLK64:
 	case F_SETLKW64:
-		set_fs(fs);
-	}
+		return do_locks(fd, cmd, arg);
 
-	return ret;
+	default:
+		return sys_fcntl64(fd, cmd, arg);
+	}
 }
 
 struct oabi_epoll_event {