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| author | Sai Praneeth <sai.praneeth.prakhya@intel.com> | 2016-02-17 12:36:04 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-22 08:26:28 +0100 |
| commit | 15f003d20782a4079e078d16df57081ebd1fc150 (patch) | |
| tree | c606c64f7f1123cbbbbca830ffa37e07ef7c4af3 /arch/x86/mm/pageattr.c | |
| parent | b9d6769b5678dbd6cb328d20716561d35b2b1510 (diff) | |
| download | linux-15f003d20782a4079e078d16df57081ebd1fc150.tar.bz2 | |
x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd()
As part of the preparation for the EFI_MEMORY_RO flag added in the UEFI
2.5 specification, we need the ability to map pages in kernel page
tables without _PAGE_RW being set.
Modify kernel_map_pages_in_pgd() to require its callers to pass _PAGE_RW
if the pages need to be mapped read/write. Otherwise, we'll map the
pages as read-only.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1455712566-16727-12-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/pageattr.c')
| -rw-r--r-- | arch/x86/mm/pageattr.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index bf312da41a6d..14c38ae80409 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1971,6 +1971,9 @@ int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, if (!(page_flags & _PAGE_NX)) cpa.mask_clr = __pgprot(_PAGE_NX); + if (!(page_flags & _PAGE_RW)) + cpa.mask_clr = __pgprot(_PAGE_RW); + cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags); retval = __change_page_attr_set_clr(&cpa, 0); |