From: Al Viro <viro@ZenIV.linux.org.uk>
To: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Potentially unbounded allocations in seq_read?
Date: Thu, 12 Dec 2013 13:49:56 +0000 [thread overview]
Message-ID: <20131212134956.GC10323@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1386855640.6066.73.camel@tursulin-linux.isw.intel.com>
On Thu, Dec 12, 2013 at 01:40:40PM +0000, Tvrtko Ursulin wrote:
> So this is the story... task_mmu.c:show_map_vma() calls seq_path. There
> we have a d_path call which returns -ENAMETOOLONG and keeps doing so
> even though the buffer grows to huge proportions. It is something on
> tmpfs, don't know what.
>
> But in the meantime, shouldn't seq_path be a bit more considerate on
> this particular error and not mark the state as "could not fit" forever?
> Perhaps it would make sense to limit it a bit?
>
> Or even more so, on errors _other_ than -ENAMETOOLONG it will at the
> moment mark the result as "need more space". That also sounds broken to
> me.
a) *what* errors other than -ENAMETOOLONG?
b) d_path() not fitting into 2Mb is definitely a bug. If you really have
managed to get a dentry tree 1 million levels deep, you have much worse
problems.
c) which kernel version it is?
next prev parent reply other threads:[~2013-12-12 13:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-11 17:04 Potentially unbounded allocations in seq_read? Tvrtko Ursulin
2013-12-11 17:48 ` Tvrtko Ursulin
2013-12-11 18:00 ` Al Viro
2013-12-11 17:49 ` Al Viro
2013-12-11 17:59 ` Tvrtko Ursulin
2013-12-11 18:07 ` Al Viro
2013-12-12 13:40 ` Tvrtko Ursulin
2013-12-12 13:49 ` Al Viro [this message]
2013-12-12 13:59 ` Tvrtko Ursulin
2013-12-12 14:21 ` Al Viro
2013-12-12 14:52 ` Tvrtko Ursulin
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