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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 21:25:36 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-16 10:48:47 +0100 |
| commit | 4fa5662b6b49611f11856db8be346710217473ef (patch) | |
| tree | 4866f0255ba7a62d9b427960c8341564f5d1d35b /arch/x86/mm/kaslr.c | |
| parent | b16e770bfa5344f1cd4f7b4ecd7bbae25001e120 (diff) | |
| download | linux-4fa5662b6b49611f11856db8be346710217473ef.tar.bz2 | |
x86/mm: Initialize 'page_offset_base' at boot-time
For 4- and 5-level paging we have different 'page_offset_base'.
Let's initialize it at boot-time accordingly to machine capability.
We also have to split __PAGE_OFFSET_BASE into two constants -- for 4-
and 5-level paging.
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/20180214182542.69302-4-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/kaslr.c')
| -rw-r--r-- | arch/x86/mm/kaslr.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index d079878c6cbc..7828a7ca3bba 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -34,13 +34,10 @@ #define TB_SHIFT 40 /* - * Virtual address start and end range for randomization. - * * The end address could depend on more configuration options to make the * highest amount of space for randomization available, but that's too hard * to keep straight and caused issues already. */ -static const unsigned long vaddr_start = __PAGE_OFFSET_BASE; static const unsigned long vaddr_end = CPU_ENTRY_AREA_BASE; /* @@ -76,11 +73,14 @@ static inline bool kaslr_memory_enabled(void) void __init kernel_randomize_memory(void) { size_t i; - unsigned long vaddr = vaddr_start; + unsigned long vaddr_start, vaddr; unsigned long rand, memory_tb; struct rnd_state rand_state; unsigned long remain_entropy; + vaddr_start = pgtable_l5_enabled ? __PAGE_OFFSET_BASE_L5 : __PAGE_OFFSET_BASE_L4; + vaddr = vaddr_start; + /* * These BUILD_BUG_ON checks ensure the memory layout is consistent * with the vaddr_start/vaddr_end variables. These checks are very |