From: Ingo Molnar <mingo@kernel.org>
To: Borislav Petkov <bp@alien8.de>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>,
linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Alexander Viro <viro@zeniv.linux.org.uk>,
Jan-Simon <dl9pf@gmx.de>,
linux-fsdevel@vger.kernel.org, kees Cook <keescook@chromium.org>,
Ismael Ripoll <iripoll@disca.upv.es>
Subject: Re: [PATCH] mm/x86: AMD Bulldozer ASLR fix
Date: Tue, 31 Mar 2015 09:59:50 +0200 [thread overview]
Message-ID: <20150331075949.GA11795@gmail.com> (raw)
In-Reply-To: <20150329095334.GA4973@pd.tnic>
* Borislav Petkov <bp@alien8.de> wrote:
> On Sun, Mar 29, 2015 at 10:51:22AM +0200, Ingo Molnar wrote:
> > s/reduces the mmapped file's entropy by 3 bits
> >
> > Which does:
> >
> > - a grammar fix
> >
> > - measure it in bits, as later on we are talking about randomness in
> > bits as well.
>
> Fixed.
>
> > Btw., does this limitation affect both executable and non-executable
> > mmap()s?
>
> Only executable mappings.
>
> > Because data mmap()s don't need this I$ related workaround, right? So
> > we could relax it for data-mmap()s?
>
> Well, AFAIR, we wanted to keep this as less intrusive as possble. If
> we're going to relax this, one way to solve it would be to pass down
> @prot from do_mmap_pgoff() and friends to get_unmapped_area() which
> would need to touch other arches.
>
> I'm not sure it is worth it...
Well, we could define arch_get_unmapped_area_exec(), and if an arch
defines it, the mm code would call into it.
But yeah, it would add a function pointer to mm_struct, which I'm not
sure is worth it.
Thanks,
Ingo
prev parent reply other threads:[~2015-03-31 7:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-24 18:00 [PATCH] mm/x86: AMD Bulldozer ASLR fix Hector Marco-Gisbert
2015-03-24 19:15 ` Borislav Petkov
2015-03-25 18:29 ` Hector Marco
2015-03-25 18:36 ` Hector Marco-Gisbert
2015-03-26 19:08 ` Borislav Petkov
2015-03-27 11:38 ` Hector Marco-Gisbert
2015-03-27 12:14 ` Ingo Molnar
2015-03-27 12:35 ` Borislav Petkov
2015-03-27 14:44 ` Borislav Petkov
2015-03-27 15:06 ` Hector Marco-Gisbert
2015-03-28 13:10 ` Kees Cook
2015-03-29 8:51 ` Ingo Molnar
2015-03-29 9:53 ` Borislav Petkov
2015-03-31 7:59 ` Ingo Molnar [this message]
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