Commit-ID: cbe0317bf10acf1f41811108ed0f9a316103c0f3 Gitweb: http://git.kernel.org/tip/cbe0317bf10acf1f41811108ed0f9a316103c0f3 Author: Kirill A. Shutemov <kirill.shute...@linux.intel.com> AuthorDate: Tue, 6 Jun 2017 14:31:21 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 13 Jun 2017 08:56:51 +0200
x86/asm: Fix comment in return_from_SYSCALL_64() On x86-64 __VIRTUAL_MASK_SHIFT depends on paging mode now. Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Hansen <dave.han...@intel.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: linux-a...@vger.kernel.org Cc: linux...@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-3-kirill.shute...@linux.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/entry/entry_64.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 4a4c083..a9a8027 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -265,7 +265,8 @@ return_from_SYSCALL_64: * If width of "canonical tail" ever becomes variable, this will need * to be updated to remain correct on both old and new CPUs. * - * Change top 16 bits to be the sign-extension of 47th bit + * Change top bits to match most significant bit (47th or 56th bit + * depending on paging mode) in the address. */ shl $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx sar $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx