linux-kernel - Re: [PATCH] bnx2: Use dev_kfree_skb_any() in bnx2_tx

lists.openwall.net		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 linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20131031.002602.2030884257299947291.davem@davemloft.net>
Date:	Thu, 31 Oct 2013 00:26:02 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	xiyou.wangcong@...il.com
Cc:	tdmackey@...leanhaiku.com, mchan@...adcom.com,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] bnx2: Use dev_kfree_skb_any() in bnx2_tx_int()

From: Cong Wang <xiyou.wangcong@...il.com>
Date: Wed, 30 Oct 2013 15:01:12 -0700

> On Wed, Oct 30, 2013 at 2:32 PM, David Miller <davem@...emloft.net> wrote:
>>
>> Explain to me then why other ethernet drivers implemented identically,
>> such as tg3, can use plain dev_kfree_skb() just fine?
> 
> I don't think they are fine, I just don't see bug reports
> for them. At very least, I saw a same bug report for be2net too.
> 
> To reproduce this bug, we need to find some one calling printk()
> within IRQ handler, which seems rare? It seems there are few
> people using hpsa driver together with netconsole.

We've had this conversation before I believe, and I absolutely do not
want to have to add IRQ safety to every ->poll() implementation.

We have to provide a softint compatible environment for this callback
to run in else everything is completely broken.

All these drivers can safely assume softirq safe locking is
sufficient, you're suggesting we need to take this hardirq safety and
I'm really not willing to allow things to go that far.  A lot of
effort has been expended precisely to avoid that kind of overhead and
cost.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/