Date: Thu, 05 May 2005 15:06:37 -0700 From: Julian Elischer <julian@elischer.org> To: Warner Losh <imp@bsdimp.com> Cc: usbcrash@oldach.net Subject: Re: recent USB MFCs cause panics Message-ID: <427A98ED.1000704@elischer.org> In-Reply-To: <20050505.160055.78800132.imp@bsdimp.com> References: <427A8EF3.70003@elischer.org> <20050505.153302.71182158.imp@bsdimp.com> <427A9690.9080108@elischer.org> <20050505.160055.78800132.imp@bsdimp.com>
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Warner Losh wrote: >From: Julian Elischer <julian@elischer.org> >Subject: Re: recent USB MFCs cause panics >Date: Thu, 05 May 2005 14:56:32 -0700 > > > >>Warner Losh wrote: >> >> >> >>>From: Julian Elischer <julian@elischer.org> >>>Subject: Re: recent USB MFCs cause panics >>>Date: Thu, 05 May 2005 14:24:03 -0700 >>> >>> >>> >>> >>> >>>>Julian Elischer wrote: >>>> >>>>try: >>>> >>>>in usb_port.h >>>>comment out line 425 (as below) >>>> >>>>422 >>>> 423 #define config_detach(dev, flag) \ >>>> 424 do { \ >>>> 425 /* device_detach(dev); */ \ >>>> 426 free(device_get_ivars(dev), M_USB); \ >>>> 427 device_delete_child(device_get_parent(dev), dev); \ >>>> 428 } while (0); >>>> 429 >>>> >>>> >>>> >>>> >>>Commenting it out is lame... I fixed this in current in uhub.c as >>>well as here... Since 'dev' is 0 here, I'm unsure that commenting it >>>out will fix the problem because the next line frees it.... >>> >>> >>> >>> >>yes I noticed that.. >>the next line doesn't free it, it frees the ivars >>which I don't think is the same thing.. >> >> > >if dev is NULL, then freeing the ivars from dev will still result in a >NULL pointer dereference... > > > >>the problem is that the 5.0 code does the device_delete_child() (as you >>see above) >>where 4.x did it in the device_detach() >>so with this merge I get the worst of both worlds.. >> >>the answer is to make uhub.c not call it's bus_child_detached() method >>(as 5.0 doesn't) >>or to make it a null function, as it clears the subdev entry which >>causes this problem. >> >> > >Yes. I think that's the more correct fix. > > Is there a reason tio not just remove the method entry? will it default to a good default? (i.e. not an error default?) if not then I guess just stubbibg the method would work.. >Warner > >
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