Messages in this thread Patch in this message | | | Subject | [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask | From | Dave Hansen <> | Date | Thu, 22 Feb 2018 12:36:58 -0800 |
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From: Dave Hansen <dave.hansen@linux.intel.com>
In creating its page tables, the espfix code masks its PGTABLE_PROT value with the supported mask: __supported_pte_mask. This ensures that unsupported bits are not set in the final PTE. But, it also sets _PAGE_GLOBAL which we do not want for PTE. Use __default_kernel_pte_mask instead which clears _PAGE_GLOBAL for PTI.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Juergen Gross <jgross@suse.com> Cc: x86@kernel.org Cc: Nadav Amit <namit@vmware.com> ---
b/arch/x86/kernel/espfix_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN arch/x86/kernel/espfix_64.c~espfix-use-kern-defaults-not-supported arch/x86/kernel/espfix_64.c --- a/arch/x86/kernel/espfix_64.c~espfix-use-kern-defaults-not-supported 2018-02-22 12:36:19.217036552 -0800 +++ b/arch/x86/kernel/espfix_64.c 2018-02-22 12:36:19.221036552 -0800 @@ -167,7 +167,7 @@ void init_espfix_ap(int cpu) goto unlock_done; node = cpu_to_node(cpu); - ptemask = __supported_pte_mask; + ptemask = __default_kernel_pte_mask; pud_p = &espfix_pud_page[pud_index(addr)]; pud = *pud_p; _
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