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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 14:16:55 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-14 15:11:15 +0300 |
| commit | 09e61a779e7f171c50325e6d7108a593afb2e5d4 (patch) | |
| tree | b32c4f5ab83c696463e439910afa1d8657d61cc0 /arch/x86/entry/entry_64.S | |
| parent | 162434e7f58b21f0b6c9cc5fb02222cd7d9064cc (diff) | |
| download | linux-09e61a779e7f171c50325e6d7108a593afb2e5d4.tar.xz | |
x86/mm: Make __VIRTUAL_MASK_SHIFT dynamic
For boot-time switching between paging modes, we need to be able to
adjust virtual mask shifts.
The change doesn't affect the kernel image size much:
text data bss dec hex filename
8628892 4734340 1368064 14731296 e0c820 vmlinux.before
8628966 4734340 1368064 14731370 e0c86a vmlinux.after
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@suse.de>
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/20180214111656.88514-9-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 30c8c5344c4a..2c06348b7807 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -274,8 +274,20 @@ GLOBAL(entry_SYSCALL_64_after_hwframe) * Change top bits to match most significant bit (47th or 56th bit * depending on paging mode) in the address. */ +#ifdef CONFIG_X86_5LEVEL + testl $1, pgtable_l5_enabled(%rip) + jz 1f + shl $(64 - 57), %rcx + sar $(64 - 57), %rcx + jmp 2f +1: + shl $(64 - 48), %rcx + sar $(64 - 48), %rcx +2: +#else shl $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx sar $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx +#endif /* If this changed %rcx, it was not canonical */ cmpq %rcx, %r11 |