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

Alan Stern [off-list ref] writes:

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

quoted

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.)

I have just been running this in qemu.  But yes.  I suppose the easy
way would be to print a message asking the usb device to be unplugged
and then just wait for the signal.  I might try that.

quoted

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.

That probably explains why the breakage in big-endian was never noticed.
I am starting to wonder if anyone is actually doing big-endian for new
systems anymore.

Eric