kdb: virt_to_phys is broken

[voidus]

Using virt_to_phys in the kernel debugger causes kernel pagefaults in userland and assertion errors

[jkehne]

I finally got around to looking into this, but I couldn't reproduce it. Could you explain how you triggered this bug?

[voidus]

I think it triggered every time I tried to use the debugger function to resolve a virtual address to a physical address. (I think it was the i-key, but I'm not sure.)

I am pretty sure though that it was triggered unconditionally

[jkehne]

I did the same thing, but didn't experience any crashes. I also used the same lab environment you did. Very strange.

[voidus]

If I remember correctly, I submitted a pull request that fixed a problem back then. Not sure if it was this one, but it might have been.

[jkehne]

You mean #7, but that's in mapctrl, which is only called while modifying mappings, but not for resolving. I'll test it anyway to make sure.

[voidus]

Yeah, doesn't look like it. If that's not it, I have no idea.