Messages in this thread | | | Date | Wed, 21 May 2014 23:25:51 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: [RFC] x86_64: A real proposal for iret-less return to kernel |
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On Wed, 21 May 2014, Borislav Petkov wrote:
> > ISTM the do_machine_check code ought to consider any kill-worthy MCE > > from kernel space to be non-recoverable, but I want to keep the scope > > of these patches under control. > > MCA has a bit called RIPV which, if set, signals that RIP is valid and > it is safe to return provided we've taken proper care of handling even > non-correctable errors (memory poisoning, etc).
Yeah, but it tries to send SIGBUS from MCE context. And if MCE triggered at the time the CPU was already holding sighand->siglock for that particular task, it'll deadlock against itself.
-- Jiri Kosina SUSE Labs
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