Messages in this thread | | | From | Dmitry Vyukov <> | Date | Wed, 27 Feb 2019 16:40:28 +0100 | Subject | Re: [PATCH 5/6] objtool: Add UACCESS validation |
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On Wed, Feb 27, 2019 at 3:33 PM Peter Zijlstra <peterz@infradead.org> wrote: > > On Wed, Feb 27, 2019 at 03:26:23PM +0100, Peter Zijlstra wrote: > > On Wed, Feb 27, 2019 at 05:17:58PM +0300, Andrey Ryabinin wrote: > > > > > > > > > On 2/27/19 5:08 PM, Peter Zijlstra wrote: > > > > > > I can't actually find any definitions of those functions, so I can't > > > > very well mark the safe, even if we wanted to. > > > > > > > > > > They are macro-generated. Use 'git grep DEFINE_ASAN' > > > > Ah, indeed! I'll go have a look. > > Urgh, kasan_report() is definitely unsafe. Now, admitedly we should > 'never' hit that, but it does leave us up a creek without a paddle. > > Not sure what to do here; best I can come up with atm. is kill SMAP on > KASAN builds.
If SMAP detects additional bugs, then it would be pity to disable it with KASAN (detect bugs in production but not during testing).
You mentioned that exception save/restore the UACCESS state. Is it possible to do the same in kasan_report? At the very least we need to survive report printing, what happens after that does not matter much (we've corrupted memory by now anyway).
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