Messages in this thread | | | From | Thomas Garnier <> | Date | Tue, 4 Sep 2018 10:57:42 -0700 | Subject | Re: [PATCH 1/2] x86/mm/KASLR: Fix the wrong calculation of kalsr region initial size |
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Thanks Baoquan!
Reviewed-by: Thomas Garnier <thgarnie@google.com>
On Wed, Aug 29, 2018 at 4:49 AM Kirill A. Shutemov <kirill@shutemov.name> wrote: > > On Wed, Aug 29, 2018 at 10:17:53AM +0800, Baoquan He wrote: > > In memory KASLR, __PHYSICAL_MASK_SHIFT is taken to calculate the > > initial size of the direct mapping region. This is right in the > > old code where __PHYSICAL_MASK_SHIFT was equal to MAX_PHYSMEM_BITS, > > 46bit, and only 4-level mode was supported. > > > > Later, in commit: > > b83ce5ee91471d ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52"), > > __PHYSICAL_MASK_SHIFT was changed to be 52 always, no matter it's > > 5-level or 4-level. This is wrong for 4-level paging. Then when > > adapt phyiscal memory region size based on available memory, it > > will overflow if the amount of system RAM and the padding is bigger > > than 64TB. > > > > In fact, here MAX_PHYSMEM_BITS should be used instead. Fix it by > > by replacing __PHYSICAL_MASK_SHIFT with MAX_PHYSMEM_BITS. > > > > Signed-off-by: Baoquan He <bhe@redhat.com> > > Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > -- > Kirill A. Shutemov
-- Thomas
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