Commit a129a7c8 authored Nov 19, 2010 by Andi Kleen Committed by Tony Luck May 23, 2012

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 <ak@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

parent 8571723a

arch/x86/kernel/cpu/mcheck/mce.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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)