Re: [libvirt] [PATCH 2/2] virpcimock: Mock __open_2()

Hold on to your hat, this is going to be a wild ride. As nearly nothing in glic, nor open() is a real function. Just look into bits/fcntl2.h and you'll see that open() is actually a thin wrapper that calls either __open_alias() or __open_2(). Now, before 801ebb5edb6 the open() done in virPCIDeviceConfigOpenInternal() had a constant oflags (we were opening the pci config with O_RDWR). And since we were not passing any mode nor O_CREAT the wrapper decided to call __open_alias() which was open() provided by our mock. So far so good. But after the referenced commit, the oflags is no longer compile time constant and therefore the wrapper calls __open_2() which we don't mock and thus the real __open_2() from glibc was called and thus we did try to open real path from host's /sys. This of course fails with variety of errors. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; ---