commit: a129a7c84582629741e5fa6f40026efcd7a65bd4
From: Andi Kleen <a...@firstfloor.org>
Date: Fri, 19 Nov 2010 13:16:22 +0100
Subject: MCE: Fix vm86 handling for 32bit mce handler
When running on 32bit the mce handler could misinterpret
vm86 mode as ring 0. This can affect whether it does recovery
or not; it was possible to panic when recovery was actually
possible.
Fix this by always forcing vm86 to look like ring 3.
Signed-off-by: Andi Kleen <a...@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Tony Luck <tony.l...@intel.com>
---
arch/x86/kernel/cpu/mcheck/mce.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 66e1c51..5f793e6 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -437,6 +437,14 @@ static inline void mce_gather_info(struct mce *m, struct
pt_regs *regs)
if (m->mcgstatus & (MCG_STATUS_RIPV|MCG_STATUS_EIPV)) {
m->ip = regs->ip;
m->cs = regs->cs;
+
+ /*
+ * When in VM86 mode make the cs look like ring 3
+ * always. This is a lie, but it's better than passing
+ * the additional vm86 bit around everywhere.
+ */
+ if (v8086_mode(regs))
+ m->cs |= 3;
}
/* Use accurate RIP reporting if available. */
if (rip_msr)
--
1.7.3.4
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