Re: umip: AMD Ryzen 3900X, pagefault after emulate SLDT/SIDT instruction

From: andi
Date: Fri May 22 2020 - 22:21:49 EST


On 11:56 19.05.20, Brendan Shanks wrote:
> The problem is that the kernel does not emulate/spoof the SLDT instruction, only SGDT, SIDT, and SMSW.
> SLDT and STR weren't thought to be commonly used, so emulation/spoofing wasnât added.
> In the last few months I have seen reports of one or two (32-bit) Windows games that use SLDT though.
> Can you share more information about the application youâre running?

This is basically the "minimal" reproducer for the issue I've been
observed (as by the previously linked article):

https://gist.githubusercontent.com/andir/071981717460242a1df2e0fc20836fdc/raw/0c31877aa7ee59146596fe68934f9cecb5c998ae/test.c