From: Andy Lutomirski <luto@amacapital.net>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
xen-devel <Xen-devel@lists.xen.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Borislav Petkov <bp@alien8.de>, X86 ML <x86@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
KVM list <kvm@vger.kernel.org>, Andy Lutomirski <luto@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v4 2/5] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops
Date: Mon, 14 Mar 2016 11:48:47 -0700 [thread overview]
Message-ID: <CALCETrWxSBwwFTFsRoR_9AVBoC0iJ1pdWwOq_cnFf3NHUpG4QA@mail.gmail.com> (raw)
In-Reply-To: <CA+55aFy2dNgBJwjd+fRUYQf9OxqGkkcjUEarv+o3QSFTJ6+gJQ@mail.gmail.com>
On Mon, Mar 14, 2016 at 11:40 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Mon, Mar 14, 2016 at 11:24 AM, Andy Lutomirski <luto@amacapital.net> 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.
OK, will do. I need to rewrork the early IDT code a bit so it
generates a real pt_regs layout, but that's arguably a cleanup anyway.
--Andy
next prev parent reply other threads:[~2016-03-14 18:49 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-12 18:08 [PATCH v4 0/5] [PATCH v3 0/5] Improve non-"safe" MSR access failure handling Andy Lutomirski
2016-03-12 18:08 ` [PATCH v4 1/5] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Andy Lutomirski
2016-03-14 11:57 ` Borislav Petkov
2016-03-14 17:07 ` Andy Lutomirski
2016-03-12 18:08 ` [PATCH v4 2/5] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops Andy Lutomirski
2016-03-14 12:02 ` Borislav Petkov
2016-03-14 17:05 ` Andy Lutomirski
[not found] ` <CA+55aFwhBA8yPhuP8FfHjgbfDj3dwEjR86kkTH3rymYZqikhjw@mail.gmail.com>
2016-03-14 17:17 ` Andy Lutomirski
2016-03-14 18:04 ` Linus Torvalds
2016-03-14 18:10 ` Andy Lutomirski
2016-03-14 18:15 ` Linus Torvalds
2016-03-14 18:24 ` Andy Lutomirski
2016-03-14 18:40 ` Linus Torvalds
2016-03-14 18:48 ` Andy Lutomirski [this message]
2016-03-15 10:22 ` Ingo Molnar
2016-03-15 10:26 ` Ingo Molnar
2016-03-14 20:18 ` Peter Zijlstra
2016-03-14 18:10 ` Linus Torvalds
2016-03-15 10:21 ` Ingo Molnar
2016-03-12 18:08 ` [PATCH v4 3/5] x86/paravirt: Add paravirt_{read,write}_msr Andy Lutomirski
2016-03-12 18:08 ` [PATCH v4 4/5] x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y Andy Lutomirski
2016-03-12 18:08 ` [PATCH v4 5/5] x86/msr: Set the return value to zero when native_rdmsr_safe fails Andy Lutomirski
2016-03-14 14:32 ` [Xen-devel] [PATCH v4 0/5] [PATCH v3 0/5] Improve non-"safe" MSR access failure handling Boris Ostrovsky
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