Message-ID: <494929E5.8060302@kernel.org>
Date: Thu, 18 Dec 2008 01:33:41 +0900
From: Tejun Heo <tj@kernel.org>
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To: Steven Rostedt <srostedt@redhat.com>
CC: George Spelvin <linux@horizon.com>, peterz@infradead.org,
        andi@firstfloor.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC] globmatch() helper function
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Steven Rostedt wrote:
> On Thu, 2008-12-18 at 01:22 +0900, Tejun Heo wrote:
>> Hello,
>>
>> George Spelvin wrote:
>>> Do people think that would be, on balance, better?  It would be plenty
>>> good enough for the blacklist application.
>> Just pass a depth parameter and trigger WARN_ON() and return -EINVAL
>> when it exceeds ten.  It's a five minute change and should be enough
>> for kernel usages.
> 
> If this is ever expected to be used by userspace, I would not include
> the WARN_ON. If this is a generic function, then I'll include in in
> ftrace as well, and that takes userspace input. The last thing I want is
> a DoS because of printk's to the serial console because some userspace
> app is constantly writing bad patterns to this file.

Well, then, how about printk_ratelimit()?  Having one too many
asterisk will be a very rare occasion and when it happens it's
something which can easily escape attention, so I think some form of
whining is in order.

Thanks.

-- 
tejun
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