Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH v8 31/33] x86/fred: BUG() when ERETU with %rsp not equal to that when the ring 3 event was just delivered | Date | Mon, 05 Jun 2023 16:15:18 +0200 |
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On Mon, Apr 10 2023 at 01:14, Xin Li wrote: > A FRED stack frame generated by a ring 3 event should never be messed up, and > the first thing we must make sure is that at the time an ERETU instruction is > executed, %rsp must have the same address as that when the user level event > was just delivered. > > However we don't want to bother the normal code path of ERETU because it's on > the hotest code path, a good choice is to do this check when ERETU > faults.
Which might be not catching bugs where the wrong frame makes ERETU not fault.
We have CONFIG_DEBUG_ENTRY for catching this at the proper place.
Thanks,
tglx
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