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Date: Fri, 17 Feb 2017 17:13:07 +0300 From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com> To: Linus Torvalds <torvalds@...ux-foundation.org>, Andrew Morton <akpm@...ux-foundation.org>, x86@...nel.org, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Arnd Bergmann <arnd@...db.de>, "H. Peter Anvin" <hpa@...or.com> Cc: Andi Kleen <ak@...ux.intel.com>, Dave Hansen <dave.hansen@...el.com>, Andy Lutomirski <luto@...capital.net>, linux-arch@...r.kernel.org, linux-mm@...ck.org, linux-kernel@...r.kernel.org, "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com> Subject: [PATCHv3 12/33] x86/mm: add support of p4d_t in vmalloc_fault() With 4-level paging copying happens on p4d level, as we have pgd_none() always false when p4d_t folded. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com> --- arch/x86/mm/fault.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 59104b78e8a7..b4bcf2dac4a9 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -434,6 +434,7 @@ void vmalloc_sync_all(void) static noinline int vmalloc_fault(unsigned long address) { pgd_t *pgd, *pgd_ref; + p4d_t *p4d, *p4d_ref; pud_t *pud, *pud_ref; pmd_t *pmd, *pmd_ref; pte_t *pte, *pte_ref; @@ -461,13 +462,26 @@ static noinline int vmalloc_fault(unsigned long address) BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); } + /* With 4-level paging copying happens on p4d level. */ + p4d = p4d_offset(pgd, address); + p4d_ref = p4d_offset(pgd_ref, address); + if (p4d_none(*p4d_ref)) + return -1; + + if (p4d_none(*p4d)) { + set_p4d(p4d, *p4d_ref); + arch_flush_lazy_mmu_mode(); + } else { + BUG_ON(p4d_pfn(*p4d) != p4d_pfn(*p4d_ref)); + } + /* * Below here mismatches are bugs because these lower tables * are shared: */ - pud = pud_offset(pgd, address); - pud_ref = pud_offset(pgd_ref, address); + pud = pud_offset(p4d, address); + pud_ref = pud_offset(p4d_ref, address); if (pud_none(*pud_ref)) return -1; -- 2.11.0
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