Messages in this thread Patch in this message | | | Date | Tue, 22 Sep 2015 12:45:58 -0700 | From | tip-bot for Toshi Kani <> | Subject | [tip:x86/mm] x86/mm: Fix no-change case in try_preserve_large_page() |
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Commit-ID: 55696b1f664e52b3036f21631f9c2247b667f587 Gitweb: http://git.kernel.org/tip/55696b1f664e52b3036f21631f9c2247b667f587 Author: Toshi Kani <toshi.kani@hpe.com> AuthorDate: Thu, 17 Sep 2015 12:24:24 -0600 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 22 Sep 2015 21:27:33 +0200
x86/mm: Fix no-change case in try_preserve_large_page()
try_preserve_large_page() checks if new_prot is the same as old_prot. If so, it simply sets do_split to 0, and returns with no-operation. However, old_prot is set as a 4KB pgprot value while new_prot is a large page pgprot value.
Now that old_prot is initially set from p?d_pgprot() as a large page pgprot value, fix it by not overwriting old_prot with a 4KB pgprot value.
Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Robert Elliot <elliott@hpe.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1442514264-12475-12-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/mm/pageattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index ab9465b..e2621a8 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -518,7 +518,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, * up accordingly. */ old_pte = *kpte; - old_prot = req_prot = pgprot_large_2_4k(old_prot); + req_prot = pgprot_large_2_4k(old_prot); pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr); pgprot_val(req_prot) |= pgprot_val(cpa->mask_set);
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