From 912e12813dd03c602e4922fc34709ec4d4380cf0 Mon Sep 17 00:00:00 2001
From: Logan Gunthorpe <logang@deltatee.com>
Date: Wed, 9 Jan 2019 12:22:26 -0700
Subject: [PATCH] NTB: ntb_tool: reading the link file should not end in a NULL byte
Git-commit: 912e12813dd03c602e4922fc34709ec4d4380cf0
Patch-mainline: v5.8-rc1
References: git-fixes

When running ntb_test this warning is issued:

./ntb_test.sh: line 200: warning: command substitution: ignored null
byte in input

This is caused by the kernel returning one more byte than is necessary
when reading the link file.

Reduce the number of bytes read back to 2 as it was before the
commit that regressed this.

Fixes: 7f46c8b3a552 ("NTB: ntb_tool: Add full multi-port NTB API support")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Allen Hubbe <allenbh@gmail.com>
Tested-by: Alexander Fomichev <fomichev.ru@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/ntb/test/ntb_tool.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
index 9eaeb221d980..b7bf3f863d79 100644
--- a/drivers/ntb/test/ntb_tool.c
+++ b/drivers/ntb/test/ntb_tool.c
@@ -504,7 +504,7 @@ static ssize_t tool_peer_link_read(struct file *filep, char __user *ubuf,
 	buf[1] = '\n';
 	buf[2] = '\0';
 
-	return simple_read_from_buffer(ubuf, size, offp, buf, 3);
+	return simple_read_from_buffer(ubuf, size, offp, buf, 2);
 }
 
 static TOOL_FOPS_RDWR(tool_peer_link_fops,
@@ -1690,4 +1690,3 @@ static void __exit tool_exit(void)
 	debugfs_remove_recursive(tool_dbgfs_topdir);
 }
 module_exit(tool_exit);
-
-- 
2.16.4