linux-kernel - [PATCH 2/7] x86/vm86: Preserve orig

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Message-Id: <1437047167-5634-3-git-send-email-brgerst@gmail.com>
Date:	Thu, 16 Jul 2015 07:46:02 -0400
From:	Brian Gerst <brgerst@...il.com>
To:	x86@...nel.org, linux-kernel@...r.kernel.org
Cc:	Ingo Molnar <mingo@...nel.org>, "H. Peter Anvin" <hpa@...or.com>,
	Denys Vlasenko <dvlasenk@...hat.com>,
	Andy Lutomirski <luto@...capital.net>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [PATCH 2/7] x86/vm86: Preserve orig_ax

There is no legitimate reason for usermode to modify the orig_ax field on
entry to vm86 mode, so copy it from the 32-bit regs.

Signed-off-by: Brian Gerst <brgerst@...il.com>
---
 arch/x86/kernel/vm86_32.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 75eab83..8424290 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -294,6 +294,8 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
 	info->regs.pt.flags |= info->regs32->flags & ~SAFE_MASK;
 	info->regs.pt.flags |= X86_VM_MASK;
 
+	info->regs.pt.orig_ax = info->regs32->orig_ax;
+
 	switch (info->cpu_type) {
 	case CPU_286:
 		tsk->thread.v86mask = 0;
-- 
2.4.3

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