[PATCH v4 8/11] x86/mm: Fix gup_huge_p?d() to handle large PAT bit
From: Toshi Kani <hidden>
Date: 2015-08-25 21:57:40
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
gup_huge_pud() and gup_huge_pmd() cast *pud and *pmd to *pte, and use pte_xxx() interfaces to obtain the flags and PFN. However, the pte_xxx() interface does not handle the large PAT bit properly for PUD/PMD. Fix gup_huge_pud() and gup_huge_pmd() to use pud_xxx() and pmd_xxx() interfaces according to their type. Signed-off-by: Toshi Kani <redacted> Cc: Juergen Gross <jgross@suse.com> Cc: Thomas Gleixner <redacted> 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/gup.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index 81bf3d2..ae9a37b 100644
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c@@ -118,21 +118,20 @@ static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { unsigned long mask; - pte_t pte = *(pte_t *)&pmd; struct page *head, *page; int refs; mask = _PAGE_PRESENT|_PAGE_USER; if (write) mask |= _PAGE_RW; - if ((pte_flags(pte) & mask) != mask) + if ((pmd_flags(pmd) & mask) != mask) return 0; /* hugepages are never "special" */ - VM_BUG_ON(pte_flags(pte) & _PAGE_SPECIAL); - VM_BUG_ON(!pfn_valid(pte_pfn(pte))); + VM_BUG_ON(pmd_flags(pmd) & _PAGE_SPECIAL); + VM_BUG_ON(!pfn_valid(pmd_pfn(pmd))); refs = 0; - head = pte_page(pte); + head = pmd_page(pmd); page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT); do { VM_BUG_ON_PAGE(compound_head(page) != head, page);
@@ -195,21 +194,20 @@ static noinline int gup_huge_pud(pud_t pud, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { unsigned long mask; - pte_t pte = *(pte_t *)&pud; struct page *head, *page; int refs; mask = _PAGE_PRESENT|_PAGE_USER; if (write) mask |= _PAGE_RW; - if ((pte_flags(pte) & mask) != mask) + if ((pud_flags(pud) & mask) != mask) return 0; /* hugepages are never "special" */ - VM_BUG_ON(pte_flags(pte) & _PAGE_SPECIAL); - VM_BUG_ON(!pfn_valid(pte_pfn(pte))); + VM_BUG_ON(pud_flags(pud) & _PAGE_SPECIAL); + VM_BUG_ON(!pfn_valid(pud_pfn(pud))); refs = 0; - head = pte_page(pte); + head = pud_page(pud); page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT); do { VM_BUG_ON_PAGE(compound_head(page) != head, page); --
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