Created attachment 141909 [details] gdb bt full Description: Downstream report of a crash after resuming from suspend. Steps to reproduce: 1. suspend the laptop while docked and connected to two external displays 2. undock the laptop 3. resume the laptop Additional data: Xwayland crashes in xwl_present_sync_callback(): (gdb) bt #0 0x00007fa32bfb353f in raise () from /lib64/libc.so.6 #1 0x00007fa32bf9d895 in abort () from /lib64/libc.so.6 #2 0x00000000005943f0 in OsAbort () at utils.c:1350 #3 0x0000000000599689 in AbortServer () at log.c:877 #4 0x000000000059a4fd in FatalError (f=f@entry=0x5c0770 "Caught signal %d (%s). Server aborting\n") at log.c:1015 #5 0x00000000005916f5 in OsSigHandler (signo=11, sip=<optimized out>, unused=<optimized out>) at osinit.c:156 #6 <signal handler called> #7 dixGetPrivate (key=<optimized out>, privates=0xf000000000404) at ../include/privates.h:122 #8 dixLookupPrivate (key=<optimized out>, privates=0xf000000000404) at ../include/privates.h:166 #9 present_screen_priv (screen=0xf000000000034) at present_priv.h:198 #10 present_wnmd_flip (damage=0xf4eee0, sync_flip=0, pixmap=0xf507a0, target_msc=268904, event_id=1985548, crtc=0xaa85b0, window=0xf4ee90) at present_wnmd.c:358 #11 present_wnmd_execute (vblank=0x5e3f1a0, ust=15397860691, crtc_msc=268904) at present_wnmd.c:466 #12 0x00000000004f8ac8 in present_wnmd_re_execute (vblank=0x5e3f1a0) at present_wnmd.c:80 #13 0x00000000004392a7 in xwl_present_sync_callback (data=0x134e860, callback=<optimized out>, time=<optimized out>) at xwayland-present.c:287 #14 0x00007fa32bebcace in ffi_call_unix64 () from /lib64/libffi.so.6 #15 0x00007fa32bebc48f in ffi_call () from /lib64/libffi.so.6 #16 0x00007fa32c6b47ad in wl_closure_invoke (closure=closure@entry=0xaa8ff0, flags=flags@entry=1, target=<optimized out>, target@entry=0x5e10480, opcode=opcode@entry=0, data=<optimized out>) at src/connection.c:1006 #17 0x00007fa32c6b0f09 in dispatch_event (display=display@entry=0xaa1a10, queue=<optimized out>) at src/wayland-client.c:1427 #18 0x00007fa32c6b241c in dispatch_queue (queue=0xaa1ad8, display=0xaa1a10) at src/wayland-client.c:1573 #19 wl_display_dispatch_queue_pending (display=0xaa1a10, queue=0xaa1ad8) at src/wayland-client.c:1815 #20 0x00007fa32c6b2480 in wl_display_dispatch_pending (display=<optimized out>) at src/wayland-client.c:1878 #21 0x000000000042ee1b in xwl_read_events (xwl_screen=0xa95d10) at xwayland.c:814 #22 0x00000000005920e1 in ospoll_wait (ospoll=0xa8b6b0, timeout=<optimized out>) at ospoll.c:651 #23 0x000000000058b9b3 in WaitForSomething (are_ready=0) at WaitFor.c:208 #24 0x000000000055b540 in Dispatch () at ../include/list.h:220 #25 0x000000000055f7d6 in dix_main (argc=12, argv=0x7ffee130c658, envp=<optimized out>) at main.c:276 #26 0x00007fa32bf9f413 in __libc_start_main () from /lib64/libc.so.6 #27 0x000000000042e33e in _start () (gdb) f 9 #9 present_screen_priv (screen=0xf000000000034) at present_priv.h:198 198 return (present_screen_priv_ptr)dixLookupPrivate(&(screen)->devPrivates, &present_screen_private_key); (gdb) p *screen Cannot access memory at address 0xf000000000034
So, looking further into the backtrace, we see that: (gdb) f 10 #10 present_wnmd_flip (damage=0xf4eee0, sync_flip=0, pixmap=0xf507a0, target_msc=268904, event_id=1985548, crtc=0xaa85b0, window=0xf4ee90) at present_wnmd.c:358 358 present_screen_priv_ptr screen_priv = present_screen_priv(screen); (gdb) p screen $2 = (ScreenPtr) 0xf000000000034 (that's a bogus value ^^^) That's coming from: 353 PixmapPtr pixmap, 354 Bool sync_flip, 355 RegionPtr damage) 356 { 357 ScreenPtr screen = crtc->pScreen; 358 present_screen_priv_ptr screen_priv = present_screen_priv(screen); 359 And so is the RRCrtcPtr: (gdb) p *crtc $5 = {id = 0, pScreen = 0xf000000000034, mode = 0x63736e552f6b6447, x = 1684368481, y = 4804676, ... So my guess is that the undock removes outputs, on resume Xwayland gets all the events at once, the xwl_present_sync_callback() occurs after the xwl_output_remove() has destroyed the xwl_output->randr_crtc so we're pointeing at freed memory here.
Maybe https://patchwork.freedesktop.org/series/50696/
Patches have landed. https://gitlab.freedesktop.org/xorg/xserver/merge_requests/45
*** Bug 108556 has been marked as a duplicate of this bug. ***
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