Messages in this thread | | | Date | Fri, 20 Mar 2020 14:47:41 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH] x86/mm: Make pud_present() check _PAGE_PROTNONE and _PAGE_PSE as well |
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On Fri, Mar 20, 2020 at 08:53:16AM +0530, Anshuman Khandual wrote: > > > On 03/18/2020 10:31 AM, Anshuman Khandual wrote: > > pud_present() should also check _PAGE_PROTNONE and _PAGE_PSE bits like in > > case pmd_present(). This makes a PUD entry test positive for pud_present() > > after getting invalidated with pud_mknotpresent(), hence standardizing the > > semantics with PMD helpers. > > > > Cc: Thomas Gleixner <tglx@linutronix.de> > > Cc: Ingo Molnar <mingo@redhat.com> > > Cc: Borislav Petkov <bp@alien8.de> > > Cc: "H. Peter Anvin" <hpa@zytor.com> > > Cc: Dave Hansen <dave.hansen@intel.com> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: x86@kernel.org > > Cc: linux-mm@kvack.org > > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > > --- > > Even though pud_mknotpresent() is not used any where currently, there is > > a discrepancy between PMD and PUD. > > > > WARN_ON(!pud_present(pud_mknotpresent(pud_mkhuge(pud)))) -> Fail > > WARN_ON(!pmd_present(pmd_mknotpresent(pmd_mkhuge(pmd)))) -> Pass > > > > Though pud_mknotpresent() currently clears _PAGE_PROTNONE, pud_present() > > does not check it. This change fixes both inconsistencies. > > > > This has been build and boot tested on x86. > > Adding Kirill and Dan. > > +Cc: Kirill A. Shutemov <kirill@shutemov.name> > +Cc: Dan Williams <dan.j.williams@intel.com>
Or we can just drop the pud_mknotpresent(). There's no users AFAICS and only x86 provides it.
-- Kirill A. Shutemov
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