From: Logan Gunthorpe <logang@xxxxxxxxxxxx> [ Upstream commit 912e12813dd03c602e4922fc34709ec4d4380cf0 ] 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@xxxxxxxxxxxx> Acked-by: Allen Hubbe <allenbh@xxxxxxxxx> Tested-by: Alexander Fomichev <fomichev.ru@xxxxxxxxx> Signed-off-by: Jon Mason <jdmason@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 9eaeb221d9802..b7bf3f863d79b 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); - -- 2.25.1