Loading extension GLX
(II) [KMS] Kernel modesetting enabled.
(II) [KMS] Kernel modesetting enabled.
[tcsetpgrp failed in terminal_inferior: Operazione non permessa]
[New Thread 0x7fffef261700 (LWP 2402)]
[New Thread 0x7fffedb85700 (LWP 2403)]
radeon: The kernel rejected CS, see dmesg for more information.
[Thread 0x7fffedb85700 (LWP 2403) exited]

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) t a a bt

Thread 2 (Thread 0x7fffef261700 (LWP 2402)):
#0  pthread_cond_wait@@GLIBC_2.3.2 ()
    at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007ffff1917835 in pipe_semaphore_wait (sema=0x5555559d1a90)
    at ../../../../../../../src/gallium/auxiliary/os/os_thread.h:434
#2  radeon_drm_cs_emit_ioctl (param=0x5555559d1890) at radeon_drm_winsys.c:567
#3  0x00007ffff7106e0e in start_thread (arg=0x7fffef261700)
    at pthread_create.c:311
#4  0x00007ffff5e1f93d in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 1 (Thread 0x7ffff7fdb980 (LWP 2395)):
#0  0x0000000000000000 in ?? ()
#1  0x00007ffff172c0f9 in pipe_buffer_create (size=262144, 
    usage=<optimized out>, bind=<optimized out>, screen=<optimized out>)
    at ../../../../src/gallium/auxiliary/util/u_inlines.h:253
#2  st_bufferobj_data (ctx=<optimized out>, target=<optimized out>, 
    size=262144, data=0x0, usage=<optimized out>, obj=0x555555ad6df0)
    at ../../../../src/mesa/state_tracker/st_cb_bufferobjects.c:255
#3  0x00007ffff16474e9 in _mesa_BufferData (target=34963, size=262144, 
    data=0x0, usage=35048) at ../../../../src/mesa/main/bufferobj.c:1072
#4  0x00007ffff43b51b0 in glamor_init_composite_shaders (
---Type <return> to continue, or q <return> to quit---
    screen=<optimized out>) at glamor_render.c:409
#5  0x00007ffff43a8979 in glamor_init (screen=screen@entry=0x5555559c44e0, 
    flags=flags@entry=15) at glamor.c:418
#6  0x00007ffff20eaece in radeon_glamor_init (
    screen=screen@entry=0x5555559c44e0) at ../../src/radeon_glamor.c:318
#7  0x00007ffff20aaee8 in RADEONAccelInit (
    pScreen=pScreen@entry=0x5555559c44e0) at ../../src/radeon_accel.c:186
#8  0x00007ffff20e53ea in RADEONScreenInit_KMS (
    pScreen=pScreen@entry=0x5555559c44e0, argc=argc@entry=1, 
    argv=argv@entry=0x7fffffffec78) at ../../src/radeon_kms.c:1287
#9  0x00005555555a8fa1 in AddScreen (
    pfnInit=0x7ffff20e5100 <RADEONScreenInit_KMS>, argc=argc@entry=1, 
    argv=argv@entry=0x7fffffffec78) at ../../dix/dispatch.c:3848
#10 0x00005555555e9ccf in InitOutput (
    pScreenInfo=pScreenInfo@entry=0x5555559911e0 <screenInfo>, 
    argc=argc@entry=1, argv=argv@entry=0x7fffffffec78)
    at ../../../../hw/xfree86/common/xf86Init.c:885
#11 0x00005555555ac95b in dix_main (argc=1, argv=0x7fffffffec78, 
    envp=<optimized out>) at ../../dix/main.c:200
#12 0x00007ffff5d58995 in __libc_start_main (main=0x555555598090 <main>, 
    argc=1, ubp_av=0x7fffffffec78, init=<optimized out>, fini=<optimized out>, 
    rtld_fini=<optimized out>, stack_end=0x7fffffffec68) at libc-start.c:260
#13 0x00005555555980be in _start ()
(gdb)