Re: [PATCH v2 4/7] fs/proc/task_mmu.c: shift mm_access() from m_start() to proc_maps_open()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 12/03, Kirill A. Shutemov wrote:
>
> On Tue, Aug 05, 2014 at 09:46:55PM +0200, Oleg Nesterov wrote:
> > A simple test-case from Kirill Shutemov
> >
> > 	cat /proc/self/maps >/dev/null
> > 	chmod +x /proc/self/net/packet
> > 	exec /proc/self/net/packet
> >
> > makes lockdep unhappy, cat/exec take seq_file->lock + cred_guard_mutex in
> > the opposite order.
>
> Oleg, I see it again with almost the same test-case:
>
> 	cat /proc/self/stack >/dev/null
> 	chmod +x /proc/self/net/packet
> 	exec /proc/self/net/packet

Yes, there are more lock_trace/mm_access (ab)users. Fortunately, they
are much simpler than proc/pid/maps (which also asked for other cleanups
and fixes).

I'll try to take a look, thanks for reminding.

And I agree with Eric, chmod+x probably makes no sense. Still I think
this code deserves some cleanups regardless. To the point I think that
lock_trace() should probably die.

Thanks!

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux