[MIR] SDL_Init() crashes on the bq Aquaris E4.5 phone

[Sturm Flut]

Device: bq Aquaris E4.5 Ubuntu Edition
Environment: Ubuntu 14.10 (r21)

libSDL2 has been ported to Mir and the Mir backend should therefore work on the phone too. libSDL2 is not shipped with the device's system image, so I built libSDL2 manually on the device, copied the resulting files over and shipped the shared object as part of the Click package. The desktop file references a shell script which sets the needed LD_LIBRARY_PATH and then calls the actual binary. So far, so good.

The binary kept crashing with a segmentation fault in its call to SDL_Init(SDL_INIT_VIDEO). For some reason I managed to get it working a single time (see the attached screenshot) after trying enough times, in all other cases it would crash. I managed to get a GDB trace and it points to line 304 in SDL2-2.0.2/src/video/SDL_egl.c , but I don't have enough knowledge about video APIs to find out what's happening:

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) bt
#0 0x00000000 in ?? ()
#1 0xb6fa4baa in SDL_EGL_ChooseConfig (_this=_this@entry=0x28660) at /home/phablet/SDL2-2.0.2/src/video/SDL_egl.c:304
#2 0xb6faf658 in MIR_GL_LoadLibrary (_this=0x28660, path=0x0) at /home/phablet/SDL2-2.0.2/src/video/mir/SDL_miropengl.c:71
#3 0xb6fadc88 in SDL_GL_LoadLibrary_REAL (path=0x0) at /home/phablet/SDL2-2.0.2/src/video/SDL_video.c:2398
#4 SDL_CreateWindow_REAL (title=0xb6fbd198 "OpenGL test", x=x@entry=-32, y=y@entry=-32, w=w@entry=32, h=h@entry=32,
    flags=flags@entry=10) at /home/phablet/SDL2-2.0.2/src/video/SDL_video.c:1237
#5 0xb6fad916 in ShouldUseTextureFramebuffer () at /home/phablet/SDL2-2.0.2/src/video/SDL_video.c:189
#6 SDL_VideoInit_REAL (driver_name=<optimized out>) at /home/phablet/SDL2-2.0.2/src/video/SDL_video.c:503
#7 0xb6f3215c in SDL_InitSubSystem_REAL (flags=16416) at /home/phablet/SDL2-2.0.2/src/SDL.c:173
#8 SDL_Init_REAL (flags=<optimized out>) at /home/phablet/SDL2-2.0.2/src/SDL.c:244
#9 0x00010be8 in main ()

I configured the library as follows:

./configure --disable-rpath --enable-sdl-dlopen --disable-loadso --disable-nas --disable-esd --disable-arts --disable-alsa-shared --disable-pulseaudio-shared --disable-video-x11 --disable-x11-shared --disable-video-directfb --enable-video-opengles --disable-mir-shared --enable-video-mir

The configure summary was the following:

SDL2 Configure Summary:
Building Shared Libraries
Building Static Libraries
Enabled modules : atomic audio video render events joystick haptic power filesystem threads timers file cpuinfo assembly
Assembly Math :
Audio drivers : disk dummy oss
Video drivers : dummy mir opengl opengl_es2
Input drivers : linuxev linuxkd
Using libudev : YES
Using dbus : YES

[Neil McPhail (njmcphail)]

SDL works! Disabling mir-shared seems to be the fix.

https://raw.githubusercontent.com/mcphail/ubuntu-touch-sdl-template/master/lib/src/how_to_build_sdl_for_ubuntu_phone.txt

Can this bug be closed?

[Gianfranco Costamagna (costamagnagianfranco)]

we do not disable mir shared in 2.0.4, is this an issue?