Messages in this thread | | | Subject | Re: [PATCH 1/2] x86: mm: ptdump: Calculate effective permissions correctly | From | Steven Price <> | Date | Wed, 27 May 2020 16:55:26 +0100 |
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On 27/05/2020 16:15, Jan Beulich wrote: > On 21.05.2020 17:23, Steven Price wrote: >> By switching the x86 page table dump code to use the generic code the >> effective permissions are no longer calculated correctly because the >> note_page() function is only called for *leaf* entries. To calculate the >> actual effective permissions it is necessary to observe the full >> hierarchy of the page tree. >> >> Introduce a new callback for ptdump which is called for every entry and >> can therefore update the prot_levels array correctly. note_page() can >> then simply access the appropriate element in the array. >> >> Reported-by: Jan Beulich <jbeulich@suse.com> >> Fixes: 2ae27137b2db ("x86: mm: convert dump_pagetables to use walk_page_range") >> Signed-off-by: Steven Price <steven.price@arm.com> > > This (with the later correction) and the 2nd patch > Tested-by: Jan Beulich <jbeulich@suse.com> > > It allowed me to go and finally find why under Xen there was still > a single W+X mapping left - another bug, another patch. > > Thanks, Jan >
Thanks for testing (and sorry for breaking it in the first place)!
Steve
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