[RFC, PATCHv1 16/28] x86/asm: remove __VIRTUAL_MASK_SHIFT==47 assert

From	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Newsgroups	linux.kernel
Subject	[RFC, PATCHv1 16/28] x86/asm: remove __VIRTUAL_MASK_SHIFT==47 assert
Date	2016-12-08 17:30 +0100
Message-ID	<sM9K3-8la-83@gated-at.bofh.it> (permalink)
References	<sM9K2-8la-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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We don't need it anymore. 17be0aec74fb ("x86/asm/entry/64: Implement
better check for canonical addresses") made canonical address check
generic wrt. address width.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/entry/entry_64.S | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 02fff3ebfb87..92a6753f8c85 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -267,12 +267,9 @@ 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
 	 */
-	.ifne __VIRTUAL_MASK_SHIFT - 47
-	.error "virtual address width changed -- SYSRET checks need update"
-	.endif
-
-	/* Change top 16 bits to be the sign-extension of 47th bit */
 	shl	$(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx
 	sar	$(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx
 
-- 
2.10.2

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[RFC, PATCHv1 16/28] x86/asm: remove __VIRTUAL_MASK_SHIFT==47 assert "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
  Re: [RFC, PATCHv1 16/28] x86/asm: remove __VIRTUAL_MASK_SHIFT==47 assert Andy Lutomirski <luto@amacapital.net> - 2016-12-08 19:50 +0100
    Re: [RFC, PATCHv1 16/28] x86/asm: remove __VIRTUAL_MASK_SHIFT==47  assert "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-12-08 20:30 +0100

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