Messages in this thread Patch in this message | | | From | Toshi Kani <> | Subject | [PATCH v4 RESEND 11/11] x86/mm: Fix no-change case in try_preserve_large_page() | Date | Thu, 17 Sep 2015 12:24:24 -0600 |
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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: Juergen Gross <jgross@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andrew Morton <akpm@linux-foundation.org> --- 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 b64a451..97735f4 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -536,7 +536,7 @@ 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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