From 260bee9451b4f0f5f9845c5b3024f0bfb8de8f22 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Mon, 13 Jul 2015 08:07:11 -0400 Subject: [PATCH] NTB: Fix oops in debugfs when transport is half-up When the remote side is not up, we do not have all the context for the transport, and that causes NULL ptr access. Have the debugfs reads check to see if transport is up before we make access. Signed-off-by: Dave Jiang Signed-off-by: Jon Mason --- drivers/ntb/ntb_transport.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 25e973ff64cf..a049f96fab8d 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -439,13 +439,17 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count, char *buf; ssize_t ret, out_offset, out_count; + qp = filp->private_data; + + if (!qp || !qp->link_is_up) + return 0; + out_count = 1000; buf = kmalloc(out_count, GFP_KERNEL); if (!buf) return -ENOMEM; - qp = filp->private_data; out_offset = 0; out_offset += snprintf(buf + out_offset, out_count - out_offset, "NTB QP stats\n");