Messages in this thread | | | Date | Sun, 16 Nov 2014 19:52:05 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH v2] x86, mm: set NX across entire PMD at boot |
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On Fri, 14 Nov 2014, Yinghai Lu wrote:
> On Fri, Nov 14, 2014 at 6:46 PM, Kees Cook <keescook@chromium.org> wrote: > > On Fri, Nov 14, 2014 at 6:29 PM, Yinghai Lu <yinghai@kernel.org> wrote: > > >> should use attached one instead. > >> > >> 1. should use _brk_end instead of &end, as we only use partial of > >> brk. > >> 2. [_brk_end, pm_end) page range is already converted. aka > >> is not wasted. > > > > Are you sure? For me, _brk_end isn't far enough: > > > > [ 1.475572] all_end: 0xffffffff82df5000 > > [ 1.476736] _brk_end: 0xffffffff82dd6000 > > Yes. _brk_end should be small then &_end.
Wrong. _brk_end can move up to _end, i.e. to __brk_limit.
But it's safe to use _brk_end when mark_rodata_ro() is called because extend_brk() is gone already at that point.
Thanks,
tglx
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