Re: [CFT][PATCH] signal/usb: Replace kill_pid_info_as_cred with kill_pid_usb_asyncio

From: Alan Stern
Date: Sat May 18 2019 - 11:23:02 EST


On Fri, 17 May 2019, Eric W. Biederman wrote:

> Wow I got a little distracted but now I am back to this.
>
> Using your test program I was able to test the basics of this.
>
> I found one bug in my patch where I was missing a memset. So I have
> corrected that, and reorganized the patch a little bit.
>
> I have not figured out how to trigger a usb disconnect so I have not
> tested that.

Heh. Assuming the device file you tell the test program to use
corresponds to an actual USB device, you can trigger a disconnect by
literally unplugging the USB cable. (Add a 10-second delay to the
program to give yourself enough time.)

> The big thing I have not been able to test is running a 64bit big-endian
> kernel with a 32bit user space. My modified version of your test
> program should report "Bad" without my patch, and should report "Good"
> with it.
>
> Is there any chance you can test that configuration? I could not figure
> out how to get a 64bit big-endian system running in qemu, and I don't
> have the necessary hardware so I was not able to test that at all. As
> that is the actual bug I am still hoping someone can test it.

Unfortunately, I don't have any big-endian systems either.

Alan Stern