Messages in this thread Patch in this message | | | From | "Kirill A. Shutemov" <> | Subject | [PATCH] x86/mm: Do not use paravirtualized calls in native_set_p4d() | Date | Mon, 5 Mar 2018 11:16:41 +0300 |
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In 4-level paging mode, native_set_p4d() updates entry in the top-level page table. With PTI, update to top-level kernel page table requires update to userspace copy of the table using pti_set_user_pgd().
native_set_p4d() uses p4d_val() and pgd_val() to convert types between p4d_t and pgd_t.
p4d_val() and pgd_val() are paravirtualized and we must not use them in native helpers. They cause boot failure in paravirtualized environments.
Replace p4d_val() and pgd_val() with native_p4d_val() and native_pgd_val() in native_set_p4d().
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Fixes: 91f606a8fa68 ("x86/mm: Replace compile-time checks for 5-level paging with runtime-time checks") --- arch/x86/include/asm/pgtable_64.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index af0cb0d2b7d2..877bc27718ae 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -225,9 +225,9 @@ static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d) return; } - pgd = native_make_pgd(p4d_val(p4d)); + pgd = native_make_pgd(native_p4d_val(p4d)); pgd = pti_set_user_pgd((pgd_t *)p4dp, pgd); - *p4dp = native_make_p4d(pgd_val(pgd)); + *p4dp = native_make_p4d(native_pgd_val(pgd)); } static inline void native_p4d_clear(p4d_t *p4d) -- 2.16.1
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