Re: [patch] hid2hci check usb_init return value

[Marcel Holtmann <marcel@holtmann.org>]

Hi Khem,

> > > Working on a system which did not have a USB in it. I was getting a
> > > segfault with hid2hci. The problem tracked down was usb_init () was 
> > > failing and we did not check for it and carried on with execution. 
> > > As a result the next call to libusb failed because we passed in NULL for
> > > ctx because during usb_init () this should have been malloc'ed if all
> > > have gone correctly but in case of error usb_init () free's up the
> > > allocated memory and hence the segfault. 
> > > 
> > > We should check for return value of usb_init () call and exit
> > > immediately if it fails. Tested on 4.24 release. 
> > 
> > the problem is that usb_init() doesn't return any errors on the versions
> > that I have here:
> > 
> > ii  libusb-0.1-4   2:0.1.12-12    userspace USB programming library
> > ii  libusb-dev     2:0.1.12-12    userspace USB programming library
> > 
> > Applying your patch would break complication on multiple platforms.
> What you have is libusb-0.1 which has older API I suppose. There is 
> libusb-compat which can be used as a wrapper over libusb1 to give
> libusb0 like interfaces. 
> 
> Actually I was using libusb-1.0.0 API as mentioned here
> http://libusb.sourceforge.net/api-1.0/group__lib.html
> that also means that the patch I attached should have been using
> libusb_init() instead. 
> 
> Here is updated patch

this still breaks with a system that has libusb-0.1 installed like the
current Ubuntu 8.10 does. So either we switch to libusb-1.0 completely
or we leave it as it is.

Regards

Marcel