[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Xen-devel] [PATCH v4 2/5] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops
- To: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
- From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
- Date: Mon, 14 Mar 2016 11:40:58 -0700
- Cc: KVM list <kvm@xxxxxxxxxxxxxxx>, Peter Zijlstra <peterz@xxxxxxxxxxxxx>, X86 ML <x86@xxxxxxxxxx>, "linux-kernel@xxxxxxxxxxxxxxx" <linux-kernel@xxxxxxxxxxxxxxx>, xen-devel <Xen-devel@xxxxxxxxxxxxx>, Borislav Petkov <bp@xxxxxxxxx>, Andy Lutomirski <luto@xxxxxxxxxx>, Paolo Bonzini <pbonzini@xxxxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
- Delivery-date: Mon, 14 Mar 2016 18:41:34 +0000
- List-id: Xen developer discussion <xen-devel.lists.xen.org>
On Mon, Mar 14, 2016 at 11:24 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>
> The code in my queue is, literally:
>
> bool ex_handler_rdmsr_unsafe(const struct exception_table_entry *fixup,
> struct pt_regs *regs, int trapnr)
> {
> WARN_ONCE(1, "unchecked MSR access error: RDMSR from 0x%x",
> (unsigned int)regs->cx);
>
> /* Pretend that the read succeeded and returned 0. */
> regs->ip = ex_fixup_addr(fixup);
> regs->ax = 0;
> regs->dx = 0;
> return true;
> }
> EXPORT_SYMBOL(ex_handler_rdmsr_unsafe);
I guess I can live with this, as long as we also extend the
early-fault handling to work with the special exception handlers.
And as long as people start understanding that killing the machine is
a bad bad bad thing. It's a debugging nightmare.
Linus
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
|
