Messages in this thread | | | Date | Tue, 20 Aug 2019 15:39:34 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86/mm/pti: in pti_clone_pgtable() don't increase addr by PUD_SIZE |
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On Tue, 20 Aug 2019, Song Liu wrote: > > On Aug 20, 2019, at 4:16 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > > > > On Tue, 20 Aug 2019, Peter Zijlstra wrote: > >> What that code wants to do is skip to the end of the pud, a pmd_size > >> increase will not do that. And right below this, there's a second > >> instance of this exact pattern. > >> > >> Did I get the below right? > >> > >> --- > >> diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c > >> index b196524759ec..32b20b3cb227 100644 > >> --- a/arch/x86/mm/pti.c > >> +++ b/arch/x86/mm/pti.c > >> @@ -330,12 +330,14 @@ pti_clone_pgtable(unsigned long start, unsigned long end, > >> > >> pud = pud_offset(p4d, addr); > >> if (pud_none(*pud)) { > >> + addr &= PUD_MASK; > >> addr += PUD_SIZE; > > > > round_up(addr, PUD_SIZE); > > I guess we need "round_up(addr + PMD_SIZE, PUD_SIZE)".
Right you are.
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