linux-kernel - Re: [PATCH 2/3] introduce probe_slab

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

Message-ID: <1414559432.8574.15.camel@tkhai>
Date:	Wed, 29 Oct 2014 08:10:32 +0300
From:	Kirill Tkhai <ktkhai@...allels.com>
To:	Oleg Nesterov <oleg@...hat.com>
CC:	Kirill Tkhai <tkhai@...dex.ru>,
	Peter Zijlstra <peterz@...radead.org>,
	<linux-kernel@...r.kernel.org>, Ingo Molnar <mingo@...hat.com>,
	"Vladimir Davydov" <vdavydov@...allels.com>,
	Christoph Lameter <cl@...ux.com>
Subject: Re: [PATCH 2/3] introduce probe_slab_address()

В Вт, 28/10/2014 в 21:12 +0100, Oleg Nesterov пишет:
> On 10/28, Oleg Nesterov wrote:
> >
> > On 10/28, Kirill Tkhai wrote:
> > >
> > > Yes, probe_kernel_read() is in [1/3], but it's not the same as
> > > __probe_kernel_read() for blackfin, for example.
> > >
> > > It's defined as
> > >
> > > long __weak probe_kernel_read(void *dst, const void *src, size_t size)
> > >     __attribute__((alias("__probe_kernel_read")));
> > >
> > > But blackfin's probe_kernel_read() redefines this __weak function,
> > > isn't it? Didn't get_freepointer_safe() use to call architecture's
> > > probe_kernel_read() before?
> >
> > I _think_ that __probe_kernel_read(slab_ddr) should be fine.
> >
> > Yes, an architecture may want to reimplement probe_kernel_read() to
> > allow to safely access the special areas, or special addresses.
> >
> > But again, in this case we know that this address points to the
> > "normal" kernel memory, __copy_from_user_inatomic() should work fine.
> 
> OTOH, perhaps probe_kernel_address() should use probe_kernel_read(), not
> __probe_kernel_read(). But currently it just calls __copy_inatomic() so
> 1/3 follows this logic.

Ok, thanks for the explanation, Oleg.

--
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/