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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2017-03-13 17:33:08 +0300
committerIngo Molnar <mingo@kernel.org>2017-03-14 08:45:08 +0100
commitb50858ce3e2a25a7f4638464e857853fbfc81823 (patch)
tree072faad8f646fe3a5c85308509b471e14910dc3e /arch/x86/mm/fault.c
parentea3b5e60ce804403ca019039d6331368521348de (diff)
x86/mm/vmalloc: Add 5-level paging support
Modify vmalloc_fault() to handle additional page table level. With 4-level paging, copying happens on p4d level, as we have pgd_none() always false if p4d_t is folded. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170313143309.16020-6-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/fault.c')
-rw-r--r--arch/x86/mm/fault.c27
1 files changed, 24 insertions, 3 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 605fd5e8e048..8ad91a01cbc8 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -435,6 +435,7 @@ 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;
@@ -458,17 +459,37 @@ static noinline int vmalloc_fault(unsigned long address)
if (pgd_none(*pgd)) {
set_pgd(pgd, *pgd_ref);
arch_flush_lazy_mmu_mode();
- } else {
+ } else if (CONFIG_PGTABLE_LEVELS > 4) {
+ /*
+ * With folded p4d, pgd_none() is always false, so the pgd may
+ * point to an empty page table entry and pgd_page_vaddr()
+ * will return garbage.
+ *
+ * We will do the correct sanity check on the p4d level.
+ */
BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
}
+ /* With 4-level paging, copying happens on the 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;