Messages in this thread Patch in this message | | | Date | Tue, 13 Jun 2017 03:05:08 -0700 | From | "tip-bot for Kirill A. Shutemov" <> | Subject | [tip:x86/mm] x86/asm: Fix comment in return_from_SYSCALL_64() |
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Commit-ID: cbe0317bf10acf1f41811108ed0f9a316103c0f3 Gitweb: http://git.kernel.org/tip/cbe0317bf10acf1f41811108ed0f9a316103c0f3 Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> AuthorDate: Tue, 6 Jun 2017 14:31:21 +0300 Committer: Ingo Molnar <mingo@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.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> 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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@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
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