linux-kernel - [PATCH 2/2] xen: don't use sysret for sysexit32

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Date:	Mon, 21 Jul 2008 16:49:58 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Mark McLoughlin <markmc@...hat.com>,
	Eduardo Habkost <ehabkost@...hat.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH 2/2] xen: don't use sysret for sysexit32

When implementing sysexit32, don't let Xen use sysret to return to
userspace.  That results in usermode register state being trashed.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>
---
 arch/x86/xen/xen-asm_64.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

===================================================================
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -173,7 +173,7 @@
 	pushq $__USER32_CS
 	pushq %rdx
 
-	pushq $VGCF_in_syscall
+	pushq $0
 1:	jmp hypercall_iret
 ENDPATCH(xen_sysexit)
 RELOC(xen_sysexit, 1b+1)


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