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Message-ID: <20160615182332.GI30309@pd.tnic>
Date: Wed, 15 Jun 2016 20:23:32 +0200
From: Borislav Petkov <bp@...en8.de>
To: Andy Lutomirski <luto@...capital.net>
Cc: Paolo Bonzini <pbonzini@...hat.com>, wfg@...ux.intel.com,
LKP <lkp@...org>, lkml <linux-kernel@...r.kernel.org>,
Fengguang Wu <fengguang.wu@...el.com>,
Eduardo Habkost <ehabkost@...hat.com>,
Josh Poimboeuf <jpoimboe@...hat.com>
Subject: Re: [x86] 5ac0c41bf3: WARNING: CPU: 0 PID: 0 at
arch/x86/mm/extable.c:50 ex_handler_rdmsr_unsafe
On Wed, Jun 15, 2016 at 11:12:37AM -0700, Andy Lutomirski wrote:
> I want to see actual_problem in the log.
So the optimal thing to do for that is to return an error to the calling
site which says "exception got handled" and then the *calling* site can
dump_stack().
And the old code did that:
static inline unsigned long long native_read_msr_safe(unsigned int msr,
int *err)
{
DECLARE_ARGS(val, low, high);
asm volatile("2: rdmsr ; xor %[err],%[err]\n"
"1:\n\t"
".section .fixup,\"ax\"\n\t"
"3: mov %[fault],%[err] ; jmp 1b\n\t"
".previous\n\t"
_ASM_EXTABLE(2b, 3b)
: [err] "=r" (*err), EAX_EDX_RET(val, low, high)
: "c" (msr), [fault] "i" (-EIO));
^^^^
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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