On Wed, Oct 24, 2012 at 10:29 PM, Ping Cheng <pingli...@gmail.com> wrote: > On Wednesday, October 24, 2012, Jason Gerecke wrote: >> >> On Wed, Oct 24, 2012 at 12:20 AM, Peter Hutterer >> <peter.hutte...@who-t.net> wrote: >> > An xorg.conf InputDevice section that does not have Option Type set is >> > invalid. Skip the type assignment and return, triggering an error about >> > an >> > invalid type lateron. > > > I think the above comments reflect a valid reaction of the driver to an > invalid xorg.conf section. The part that I miss is how to link it to the > description below. > >> > >> > Fixes crash triggered as of xf86-input-wacom-0.17.0-8-g0debde6 by having >> > an >> > InputDevice section like this: >> > >> > Section "InputDevice" >> > Identifier "--device--" >> > Driver "wacom" >> > Option "CorePointer" "on" >> > EndSection >> > >> > This would lead to the device being assigned a type and assumed to be >> > for >> > hotplugging. Later, when the device attributes are duplicated during >> > QueueHotplug, asprintf() tries to duplicate attr->product, which is >> > always >> > NULL for xorg.conf devices. >> > >> > Signed-off-by: Peter Hutterer <peter.hutte...@who-t.net> >> > --- >> > Full config for the lazy :) >> > >> > Section "ServerLayout" >> > Identifier "Dummy layout" >> > Option "AutoAddDevices" "off" >> > Screen 0 "dummy screen" 0 0 >> > InputDevice "--device--" >> > EndSection >> > >> > Section "ServerFlags" >> > Option "Log" "flush" >> > EndSection >> > >> > Section "Device" >> > Identifier "dummy" >> > Driver "dummy" >> > EndSection >> > >> > Section "Screen" >> > Identifier "dummy screen" >> > Device "dummy" >> > EndSection >> > >> > Section "InputDevice" >> > Identifier "--device--" >> > Driver "wacom" >> > Option "CorePointer" "on" >> > EndSection >> > >> > Running 9f896f4800593c7fa232e40fd934b7f51d0dde6d (0.17.99.1) with that >> > config >> > file below crashes the server immediately. git bisect pointed to >> > xf86-input-wacom-0.17.0-8-g0debde6, but that seems to just trigger the >> > bug, >> > it's not the direct cause of it. >> > >> > src/wcmValidateDevice.c | 3 +++ >> > 1 file changed, 3 insertions(+) >> > >> > diff --git a/src/wcmValidateDevice.c b/src/wcmValidateDevice.c >> > index 658092b..bc5ad44 100644 >> > --- a/src/wcmValidateDevice.c >> > +++ b/src/wcmValidateDevice.c >> > @@ -578,6 +578,9 @@ int wcmNeedAutoHotplug(InputInfoPtr pInfo, const >> > char **type) >> > if (*type) /* type specified, don't hotplug */ >> > return 0; >> > >> > + if (!source) /* xorg.conf device, don't auto-pick type */ >> > + return 0; >> > + > > > I am too lazy to read the whole routine/code. I guess this dummy --device-- > will be ignored and some message indicating invalid xorg.conf options will > be posted. Then, a solution to make the device usable for the dummy user > would be to add it through hot plugging. > > Or, maybe we do not want to make the dummy feel good :)?
I wondered the same thing initially too. After the function returns zero to wcmConfig.c:wcmPreInit(), the next line calls wcmIsAValidType, which fails because NULL isn't a valid type. The error message is printed, and the "if" statement the call is embedded in is satisfied since we have a statically-defined device with a bad type. This whisks us off to SetupProc_fail to keep us from bombing out later on. Jason --- When you're rife with devastation / There's a simple explanation: You're a toymaker's creation / Trapped inside a crystal ball. And whichever way he tilts it / Know that we must be resilient We won't let them break our spirits / As we sing our silly song. > > Ping > >> >> > if (source && strcmp(source, "server/hal") && strcmp(source, >> > "server/udev")) >> > return 0; >> >L >> > -- >> > 1.7.11.7 >> > ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_sfd2d_oct _______________________________________________ Linuxwacom-devel mailing list Linuxwacom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
