Re: [RFC PATCH v2] x86/arch_prctl: Add ARCH_SET_XCR0 to set XCR0 per-thread

[Keno Fischer]

> Would it make matters easier if tasks with nonstandard XCR0 were not
> allowed to use ptrace() at all?  And if ARCH_SET_XCR0 were disallowed
> if the caller is tracing anyone?

That would be fine by me (as long as you're still allowed to ptrace them of
course). I do think that using the kernel XCR0 is the best choice, but since
I don't really have a use case for it, I'm happy to disallow that and
let anybody who does have a use case come back here and
argue for it one way or the other.