From: Thomas Pedersen <thomas@adapt-ip.com>
To: Nick Owens <mischief@offblast.org>
Cc: linux-wireless@vger.kernel.org, Yan-Hsuan Chuang <yhchuang@realtek.com>
Subject: Re: [PATCH] rtw88: fix skb_under_panic in tx path
Date: Thu, 25 Jun 2020 17:10:51 -0700 [thread overview]
Message-ID: <3d8546b66a4f2027a7fab1de291ec40f@adapt-ip.com> (raw)
In-Reply-To: <20200625201857.almm27xgzburyxxu@wololo.home.arpa>
On 2020-06-25 13:18, Nick Owens wrote:
> hello :)
Hi Nick :)
> this change fixes a reliable crash on my thinkpad A485.
>
> please note i have no prior experience doing kernel development or
> sending patches, and i'm not sure if this is a correct approach.
You probably want to submit patches with git-send-email. See
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
> From aa589182d30a0f99e1b3201ed4f3830e8af71dac Mon Sep 17 00:00:00 2001
> From: Nick Owens <mischief@offblast.org>
> Date: Thu, 25 Jun 2020 12:55:41 -0700
> Subject: [PATCH] rtw88: fix skb_under_panic in tx path
>
> fixes the following panic on my thinkpad A485
>
> Oops#1 Part3
> <0>[ 3743.881656] skbuff: skb_under_panic: text:000000005f69fd98
> len:208 put:48 head:000000009e2719e8 data:00000000bd3795e0 tail:0xc2
> end:0x2c0 dev:wlp2s0
skb->head and skb->data here are really far (0.5GB) apart. Maybe
skb->data actually got corrupted earlier?
> diff --git a/drivers/net/wireless/realtek/rtw88/pci.c
> b/drivers/net/wireless/realtek/rtw88/pci.c
> index d735f3127fe8..21b3b268cb25 100644
> --- a/drivers/net/wireless/realtek/rtw88/pci.c
> +++ b/drivers/net/wireless/realtek/rtw88/pci.c
> @@ -741,6 +741,12 @@ static int rtw_pci_tx_write_data(struct rtw_dev
> *rtwdev,
> else if (!avail_desc(ring->r.wp, ring->r.rp, ring->r.len))
> return -ENOSPC;
>
> + if (skb_headroom(skb) < chip->tx_pkt_desc_sz &&
> + pskb_expand_head(skb, chip->tx_pkt_desc_sz - skb_headroom(skb),
> 0, GFP_ATOMIC)) {
> + dev_err(rtwdev->dev, "no headroom available");
> + return -ENOMEM;
> + }
> +
If it is a headroom issue, you can actually express the needed headroom
needed by the driver in hw->extra_tx_headroom during init and avoid the
pskb_expand_head() here.
--
thomas
next prev parent reply other threads:[~2020-06-26 0:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-25 20:18 [PATCH] rtw88: fix skb_under_panic in tx path Nick Owens
2020-06-26 0:10 ` Thomas Pedersen [this message]
2020-06-29 5:20 ` Tony Chuang
2020-11-21 1:43 ` Brian Norris
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3d8546b66a4f2027a7fab1de291ec40f@adapt-ip.com \
--to=thomas@adapt-ip.com \
--cc=linux-wireless@vger.kernel.org \
--cc=mischief@offblast.org \
--cc=yhchuang@realtek.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).