Messages in this thread | | | Date | Tue, 9 Feb 2016 15:30:05 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH v2] x86/mm: avoid premature success when changing page attributes |
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* Jan Beulich <JBeulich@suse.com> wrote:
> >>> On 28.01.16 at 09:42, <mingo@kernel.org> wrote: > > Could we try a v3? > > Okay, I withdraw the patch: Upon further consideration it is note really clear > what the intended behavior of set_memory_*() on address ranges with mapping > holes is supposed to be. The original issue was with set_memory_nx() (called > from mark_rodata_ro()) stumbling across an unmapped region (resulting from an > out of tree change completely unmapping the kernel mappings of address ranges > passed to free_init_pages()). [...]
So it still looks like a legitimate fix to me, even though your testcase was in an out of tree context:
> [...] I simply don't have the time to check whether the unmapping done with > CONFIG_DEBUG_PAGEALLOC would have a similar effect. The net result in any event > were pages (past the hole) reported as problematic when CONFIG_DEBUG_WX is > enabled.
Adding all the above information to the changelog addresses most of my complaints about it. You can also rephrase the DEBUG_PAGEALLOC bit to something like:
I'm not completely sure about whether the unmapping done with CONFIG_DEBUG_PAGEALLOC would have a similar effect.
as it's perfectly fine to submit fixes you couldn't fully test.
Thanks,
Ingo
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