Messages in this thread | | | Date | Mon, 21 Apr 2008 17:34:19 +0100 | From | "Jan Beulich" <> | Subject | Re: [PATCH] x86: prevent unconditional writes to DebugCtl MSR |
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>>> Ingo Molnar <mingo@elte.hu> 21.04.08 17:55 >>> > >* Roland McGrath <roland@redhat.com> wrote: > >> If TIF_DEBUGCTLMSR is ever set on a machine without the support, that >> is a bug we should diagnose earlier. If you want some paranoia, then >> keep update_debugctlmsr but make it do: >> >> BUG_ON(boot_cpu_data.x86 < 6); >> >> instead. > >agreed. Jan, wanna send a fix for this?
Hmm, without knowing the context here I'd say the way it's done in .25 is quite reasonable; a BUG_ON() here would seem quite rude to me. I thought it really should be the call sites ensuring this doesn't get called, and the silent ignoring is just to prevent bringing the system down. A WARN_ON() (or perhaps even WARN_ON_ONCE()) would be the most I'd be inclined to add there.
Jan
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