From: Arjan van de Ven <arjan@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Andy Lutomirski <luto@amacapital.net>,
Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
KVM list <kvm@vger.kernel.org>,
xen-devel <Xen-devel@lists.xen.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Andrew Morton <akpm@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 0/3] x86/paravirt: Fix baremetal paravirt MSR ops
Date: Thu, 17 Sep 2015 08:31:09 -0700 [thread overview]
Message-ID: <55FADCBD.4070804@linux.intel.com> (raw)
In-Reply-To: <55FADC3D.70202@redhat.com>
On 9/17/2015 8:29 AM, Paolo Bonzini wrote:
>
>
> On 17/09/2015 17:27, Arjan van de Ven wrote:
>>>
>>>> ( We should double check that rdmsr()/wrmsr() results are never left
>>>> uninitialized, but are set to zero or so, for cases where the
>>>> return code is not
>>>> checked. )
>>>
>>> It sure looks like native_read_msr_safe doesn't clear the output if
>>> the rdmsr fails.
>>
>> I'd suggest to return some poison not just 0...
>
> What about 0 + WARN?
why 0?
0xdeadbeef or any other pattern (even 0x3636363636) makes more sense (of course also WARN... but most folks don't read dmesg for WARNs)
(it's the same thing we do for list or slab poison stuff)
next prev parent reply other threads:[~2015-09-17 15:31 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-16 23:33 [PATCH 0/3] x86/paravirt: Fix baremetal paravirt MSR ops Andy Lutomirski
2015-09-16 23:33 ` [PATCH 1/3] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Andy Lutomirski
2015-09-16 23:33 ` [PATCH 2/3] x86/paravirt: Add paravirt_{read,write}_msr Andy Lutomirski
2015-09-16 23:33 ` [PATCH 3/3] x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y Andy Lutomirski
2015-09-17 7:19 ` [PATCH 0/3] x86/paravirt: Fix baremetal paravirt MSR ops Ingo Molnar
2015-09-17 9:31 ` Borislav Petkov
2015-09-17 11:22 ` H. Peter Anvin
2015-09-17 11:39 ` Paolo Bonzini
2015-09-17 15:27 ` Borislav Petkov
2015-09-17 15:32 ` [Xen-devel] " Andrew Cooper
2015-09-17 15:37 ` Borislav Petkov
2015-09-17 15:23 ` Andy Lutomirski
2015-09-17 15:27 ` Arjan van de Ven
2015-09-17 15:29 ` Paolo Bonzini
2015-09-17 15:31 ` Arjan van de Ven [this message]
2015-09-17 15:33 ` Paolo Bonzini
2015-09-17 17:30 ` Ingo Molnar
2015-09-17 18:51 ` Andy Lutomirski
2015-09-17 8:58 ` Peter Zijlstra
2015-09-17 11:40 ` Paolo Bonzini
2015-09-17 12:27 ` Peter Zijlstra
2015-09-17 15:17 ` Andy Lutomirski
2015-09-17 15:17 ` Peter Zijlstra
2015-09-17 15:26 ` Andy Lutomirski
2015-09-17 15:29 ` Paolo Bonzini
2015-09-17 9:10 ` [Xen-devel] " Andrew Cooper
2015-09-17 15:11 ` Boris Ostrovsky
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