Messages in this thread | | | From | "Li, Xin3" <> | Subject | RE: [PATCH v5 20/34] x86/fred: add a machine check entry stub for FRED | Date | Tue, 21 Mar 2023 00:04:47 +0000 |
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> > Unlike IDT, no need to save/restore dr7 in FRED machine check handler. > > Given how fragile MCE is, the question should be, do we ever want hw > breakpoints to happen while it is running?
HW breakpoints still work if they are properly configured.
> If the hw-breakpoint handler trips on the same memory fail that got us into the > mce the first time, we're dead.
Right.
Unless the MCIP bit is turned off any subsequent #MC goes to shutdown ("machine is screwed").
It's the kernel debugger's responsibility to decide how to proceed in such cases. But if the kernel debugger itself is in a screwed memory region, we are soooooo dead.
Thanks! Xin
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