diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 21:25:34 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-16 10:48:46 +0100 |
| commit | 4c2b4058ab32581931c2caf760b689fd4b019a87 (patch) | |
| tree | 002a98036eebe725c27045731d51b24179aa57db /arch/x86/boot | |
| parent | 09e61a779e7f171c50325e6d7108a593afb2e5d4 (diff) | |
x86/mm: Initialize 'pgtable_l5_enabled' at boot-time
'pgtable_l5_enabled' indicates which paging mode we are using. We need to
initialize it at boot-time according to machine capability.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180214182542.69302-2-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index b18e8f9512de..d02a838c0ce4 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -47,7 +47,7 @@ #include <linux/decompress/mm.h> #ifdef CONFIG_X86_5LEVEL -unsigned int pgtable_l5_enabled __ro_after_init = 1; +unsigned int pgtable_l5_enabled __ro_after_init; unsigned int pgdir_shift __ro_after_init = 48; unsigned int ptrs_per_p4d __ro_after_init = 512; #endif @@ -729,6 +729,12 @@ void choose_random_location(unsigned long input, return; } +#ifdef CONFIG_X86_5LEVEL + if (__read_cr4() & X86_CR4_LA57) { + pgtable_l5_enabled = 1; + } +#endif + boot_params->hdr.loadflags |= KASLR_FLAG; /* Prepare to add new identity pagetables on demand. */ |