Path: csiph.com!au2pb.net!feeder.erje.net!us.feeder.erje.net!news2.arglkargh.de!news.ecp.fr!aioe.org!bofh.it!news.nic.it!robomod From: Toshi Kani Newsgroups: linux.kernel Subject: [PATCH v3 7/10] x86/mm: Fix gup_huge_p?d() to handle large PAT bit Date: Wed, 05 Aug 2015 23:50:02 +0200 Message-ID: References: X-Original-To: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com X-Mailer: git-send-email 2.4.3 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 80 Organization: linux.* mail to news gateway X-Original-Cc: akpm@linux-foundation.org, bp@alien8.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, jgross@suse.com, konrad.wilk@oracle.com, elliott@hp.com, Toshi Kani X-Original-Date: Wed, 5 Aug 2015 15:43:30 -0600 X-Original-Message-ID: <1438811013-30983-8-git-send-email-toshi.kani@hp.com> X-Original-References: <1438811013-30983-1-git-send-email-toshi.kani@hp.com> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1201167 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 Cc: Juergen Gross Cc: Thomas Gleixner Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Borislav Petkov Cc: Andrew Morton --- 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/