| From | Thomas Gleixner <> | Subject | Re: [PATCH v8 26/33] x86/fred: allow single-step trap and NMI when starting a new thread | Date | Mon, 05 Jun 2023 15:50:55 +0200 |
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On Mon, Apr 10 2023 at 01:14, Xin Li wrote: > Allow single-step trap and NMI when starting a new thread, thus once > the new thread returns to ring3, single-step trap and NMI are both > enabled immediately. > > High-order 48 bits above the lowest 16 bit CS are discarded by the > legacy IRET instruction, thus can be set unconditionally, even when > FRED is not enabled.
I assume this has been validated to be true on _all_ CPU incarnations of _all_ x86 vendors.
If so, then please document it. If not, then go back to the drawing board.
Thanks,
tglx
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