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| author |   Andy Lutomirski <luto@kernel.org> | 2016-01-19 13:38:58 -0800 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-01-20 11:39:14 +0100 |
| commit | 320d25b6a05f8b73c23fc21025d2906ecdd2d4fc (patch) | |
| tree | 811660369c7225b275700592f8617eb020a53d44 /arch/x86/kernel/head_32.S | |
| parent | x86/mm: Streamline and restore probe_memory_block_size() (diff) | |
| download | linux-dev-320d25b6a05f8b73c23fc21025d2906ecdd2d4fc.tar.xz linux-dev-320d25b6a05f8b73c23fc21025d2906ecdd2d4fc.zip | |
x86/mm/32: Set NX in __supported_pte_mask before enabling paging
There's a short window in which very early mappings can end up
with NX clear because they are created before we've noticed that
we have NX.
It turns out that we detect NX very early, so there's no need to
defer __supported_pte_mask setup.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2b544627345f7110160545a3f47031eb45c3ad4f.1453239349.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/head_32.S')
| -rw-r--r-- | arch/x86/kernel/head_32.S | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 6bc9ae24b6d2..57fc3f8c85fd 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -389,6 +389,12 @@ default_entry: /* Make changes effective */ wrmsr + /* + * And make sure that all the mappings we set up have NX set from + * the beginning. + */ + orl $(1 << (_PAGE_BIT_NX - 32)), pa(__supported_pte_mask + 4) + enable_paging: /* |