Matteo Beniamino
Pressing a trigger button on a Steam Controller causes a segmentation fault both with stable version and latest mercurial head on Linux. I'm using the recent hid_steam kernel module with lizard_mode disabled (that is no keyboard/mouse emulation). I suspect this is what's happening: the driver exposes two hats. The two hats have indices 0 and 2. Inside linux/SDL_sysjoystick.c two hats are allocated in allocate_hatdata for joystick->hwdata->hats. In HandleHat function the hat parameter (that can be 2) is directly used as the index of the array that only has two elements, causing an out of bounds access. SDL is not expecting to have "holes" between hats indices.
The index 2 is calculated in HandleInputEvents() as (ABS_HAT2X - ABS_HAT0X) / 2 where ABS_HAT2X is the value associated to the hat inside the hid_steam module.
Noam Preil
In src/joystick/linux/SDL_sysjoystick.c:
The ConfigJoystick function's axes detection starts with a for loop using an index i for Linux's axes names. When i gets to ABS_HAT0X, it's set to ABS_HAT3Y and a continue statement appears, to skip the hats. This makes sense, as SDL handles hats separately from axes.
However, in PollAllValues, *two* indices are used: a and b. Both start out the same, and remain so until the hats are reached. At that point, a becomes identical to the i from ConfigJoystick's loop, but b is equal to a - (ABS_HAT3Y - ABS_HAT0X), or a - 8.
While all the joystick->hwdata->abs_* structures in ConfigJoystick used i - which would here be a - as both the index and the ioctl argument, PollAllValues uses b for the structure index and a as the ioctl argument.
It would appear, however, that no joystick HAS such axes, and that the b index is entirely unnecessary.
I tested three separate joysticks, and while that was far from a complete listing, I was unable to find a joystick with an axis above 0x08.
maxxus
The Dualshock 3's motion sensors don't seem to be reported by the call to EVIOCGBIT but they still send EV_ABS events. Because they're not reported by EVIOCGBIT they're not assigned a proper axis ids and the default of 0 is used, which is the valid id for the left analog sticks left/right axis.
The code is now reliant on SDL_PrivateJoystickAdded() and SDL_PrivateJoystickRemoved() being called correctly when devices are added or removed on Windows
Author: James Zipperer <james.zipperer@synapse.com>
Date: Sun Aug 21 01:19:19 2016 -0700
bugfix for controller / joystick add / remove being in the event queue at the same time
This apparently has fallout: the PS4 (and maybe PS3?) controllers apparently
report some bogus axes, but it won't change the axes we currently expect, and
thus the game controller config string is still stable.
Fixes Bugzilla #2719.
--HG--
extra : rebase_source : 8c5a4d949e4706366bbf2d98d2d2df1762d040a9
It was simpler to just have the polling (actually: hotplug detection)
functions return immediately if it's not an appropriate time to poll.
Note that previously, if any joystick/controller was opened, we would poll
every time anyhow, skipping this function.
Andreas Ertelt
The problem in question is caused by changeset 7771 (http://hg.libsdl.org/SDL/rev/4434498bf4b9 / https://bugzilla.libsdl.org/show_bug.cgi?id=2121)
The redefinition of __inline__ (introduced by the addition of begin_code.h:128's "|| __STRICT_ANSI__") results in mingw's gcc throwing multiple
warning: always_inline function might not be inlinable [-Wattributes]
as well as a whole bunch of redefinitions of mingw internals which break linking of projects including the SDL2 headers.
T. Joseph Carter
As discussed (possibly to death), the Linux joystick driver does not actually report events for added or removed joysticks when you haven't got udev support.
We simply cannot know about removed joysticks without udev. But we can (and we should) report adding them. This brings the legacy case in line with pretty much the rest of SDL's joystick drivers.
This lets us change things like this...
if (Failed) {
SDL_SetError("We failed");
return -1;
}
...into this...
if (Failed) {
return SDL_SetError("We failed");
}
Fixes Bugzilla #1778.
