From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: klassert@kernel.org, davem@davemloft.net,
anna-maria@linutronix.de, bigeasy@linutronix.de,
nhorman@tuxdriver.com, keescook@chromium.org
Cc: netdev@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [REPORT] net: 3com: 3c59x: Possible data races
Date: Wed, 3 Oct 2018 21:52:14 +0800 [thread overview]
Message-ID: <412162cd-8fab-104b-ce73-6f70f108218f@gmail.com> (raw)
****** Possible race0 ******
CPU0:
vortex_boomerang_interrupt
line 2510: spin_lock_irqsave()
_boomerang_interrupt
line 2432: vp->tx_skbuff[entry] [READ]
line 2433: vp->tx_skbuff[entry] [READ]
line 2453: vp->tx_skbuff[entry] = NULL [WRITE]
CPU1:
boomerang_start_xmit
line 2145: vp->tx_skbuff[entry] = skb [WRITE]
As for vp->tx_skbuff[entry], the WRITE and READ operations in CPU0
are performed with holding a spinlock, but the WRITE operation in CPU1
is performed without holding this spinlock, so there may exist data races.
****** Possible race1 ******
CPU0:
vortex_boomerang_interrupt
line 2510: spin_lock_irqsave()
_boomerang_interrupt
line 2421: vp->dirty_tx = dirty_tx [WRITE]
CPU1:
boomerang_start_xmit
line 2137: vp->dirty_tx [READ]
As for vp->dirty_tx, the WRITE operation in CPU0 is performed
with holding a spinlock, but the READ operation in CPU1 is performed
without holding this spinlock, so there may exist a data race.
****** Possible race2 ******
CPU0:
vortex_boomerang_interrupt
line 2510: spin_lock_irqsave()
_boomerang_interrupt
line 2381: vp->handling_irq = 1 [WRITE]
line 2498: vp->handling_irq = 0 [WRITE]
CPU1:
boomerang_start_xmit
line 2134: vp->handling_irq [READ]
As for vp->handling_irq, the WRITE operations in CPU0 are performed
with holding a spinlock, but the READ operation in CPU1 is performed
without holding this spinlock, so there may exist data races.
****** Possible race3 ******
CPU0:
vortex_boomerang_interrupt
line 2510: spin_lock_irqsave()
_boomerang_interrupt
boomerang_rx
line 2669: skb->ip_summed = ... [WRITE]
CPU1:
boomerang_start_xmit
line 2149: skb->ip_summed [READ]
As for skb->ip_summed, the WRITE operation in CPU0 is performed
with holding a spinlock, but the READ operation in CPU1 is performed
without holding this spinlock, so there may exist data races.
These possible races are detected by a runtime testing.
A possible fix of these races is protecting the code in
boomerang_start_xmit()
using the spinlock in vortex_boomerang_interrupt().
But I am not sure whether this fix is correct, so I only report these races.
Best wishes,
Jia-Ju Bai
next reply other threads:[~2018-10-03 13:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-03 13:52 Jia-Ju Bai [this message]
2018-10-05 15:04 ` Sebastian Andrzej Siewior
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=412162cd-8fab-104b-ce73-6f70f108218f@gmail.com \
--to=baijiaju1990@gmail.com \
--cc=anna-maria@linutronix.de \
--cc=bigeasy@linutronix.de \
--cc=davem@davemloft.net \
--cc=keescook@chromium.org \
--cc=klassert@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=nhorman@tuxdriver.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
all inboxes | Powered by JetHome®