Commit-ID: 397630150632639b3ca5b4414accd5011c45e276 Gitweb: http://git.kernel.org/tip/397630150632639b3ca5b4414accd5011c45e276 Author: Sai Praneeth <[email protected]> AuthorDate: Wed, 17 Feb 2016 12:35:56 +0000 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 22 Feb 2016 08:26:26 +0100
x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Since EFI page tables can be treated as kernel page tables they should be global. All the other page mapping functions in pageattr.c set the _PAGE_GLOBAL bit and we want to avoid inconsistencies when we map a page in the EFI code paths, for example when that page is split in __split_large_page(), etc. It also makes it easier to validate that the EFI region mappings have the correct attributes because there are fewer differences compared with regular kernel mappings. Signed-off-by: Sai Praneeth Prakhya <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Luis R. Rodriguez <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Shankar <[email protected]> Cc: Ricardo Neri <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Toshi Kani <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/mm/pageattr.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 632d34d..bf312da 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -909,6 +909,20 @@ static void populate_pte(struct cpa_data *cpa, pte = pte_offset_kernel(pmd, start); + /* + * Set the GLOBAL flags only if the PRESENT flag is + * set otherwise pte_present will return true even on + * a non present pte. The canon_pgprot will clear + * _PAGE_GLOBAL for the ancient hardware that doesn't + * support it. + */ + if (pgprot_val(pgprot) & _PAGE_PRESENT) + pgprot_val(pgprot) |= _PAGE_GLOBAL; + else + pgprot_val(pgprot) &= ~_PAGE_GLOBAL; + + pgprot = canon_pgprot(pgprot); + while (num_pages-- && start < end) { set_pte(pte, pfn_pte(cpa->pfn, pgprot));
