lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 18 Jan 2007 11:48:21 -0500
From:	Jeff Garzik <>
To:	Chris Lalancette <>
CC:	Francois Romieu <>,,
	Herbert Xu <>,
	Ingo Molnar <>,
Subject: Re: [PATCH 2.6.20-rc3]: 8139cp: Don't blindly enable interrupts

Chris Lalancette wrote:
> Francois Romieu wrote:
>> Chris Lalancette <> :
>> [...]
>>>     Thanks for the comments.  While the patch you sent will help, there are
>>> still other places that will have problems.  For example, in netpoll_send_skb,
>>> we call local_irq_save(flags), then call dev->hard_start_xmit(), and then call
>>> local_irq_restore(flags).  This is a similar situation to what I described
>>> above; we will re-enable interrupts in cp_start_xmit(), when netpoll_send_skb
>>> doesn't expect that, and will probably run into issues.
>>>     Is there a problem with changing cp_start_xmit to use the
>>> spin_lock_irqsave(), besides the extra instructions it needs?
>> No. Given the history of locking in netpoll and the content of
>> Documentation/networking/netdevices.txt, asking Herbert which rule(s)
>> the code is supposed to follow seemed safer to me.
>> You can forget my patch.
>> Please resend your patch inlined to Jeff as described in
> Francois,
>      Great.  Resending mail, shortening subject to < 65 characters and
> inlining the patch.
> Thanks,
> Chris Lalancette
> Similar to this commit:
> It's not safe in cp_start_xmit to blindly call spin_lock_irq and then
> spin_unlock_irq, since it may very well be the case that cp_start_xmit
> was called with interrupts already disabled (I came across this bug in
> the context of netdump in RedHat kernels, but the same issue holds, for
> example, in netconsole). Therefore, replace all instances of
> spin_lock_irq and spin_unlock_irq with spin_lock_irqsave and
> spin_unlock_irqrestore, respectively, in cp_start_xmit(). I tested this
> against a fully-virtualized Xen guest using netdump, which happens to
> use the 8139cp driver to talk to the emulated hardware. I don't have a
> real piece of 8139cp hardware to test on, so someone else will have to
> do that.
> Signed-off-by: Chris Lalancette <>


In the future, please remove the quoted emails stuff, and anything else 
that does not belong in the kernel changelog.  It must be hand-edited 
out, before using git-am to merge your patch into the kernel tree.


To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists