On 23/11/24(Sat) 21:45, Kirill A. Korinsky wrote:
> I had dig a bit future and setup a breakpoint at usbd_ref_decr.
>
> It was called from uvideo_vs_start_bulk_thread, but still it crahses:
Could you check if uvideo_vs_close() is called multiple times?
>
> Breakpoint at usbd_ref_decr: endbr64
> ddb{0}> bt
> usbd_ref_decr(ffff800002177400) at usbd_ref_decr
> uvideo_vs_start_bulk_thread(ffff80000021bf000) at
> uvideo_vs_start_bulk_thread+0xc2
> end trace frame: 0x0, count: -1
> ddb{0}> c
> uvm_fault(0xfffffffff027c89c8, 0x3f, 0, 2) -> e
> kernel: page fault trap, code=2
> Stopped at usbd_close_pipe+0x91: movq %rcx,0x40(%rax)
> TID PID UID PRFLAGS PFLAGS CPU COMMAND
> 121458 83085 1000 0x100002 0 2 xconsole
> 210971 28938 0 0x14000 0x200 3 reaper
> *468258 76766 0 0x14000 0x200 0K usbtask
> 512899 87028 0 0x14000 0x40000200 1 sensors
> usbd_close_pipe(ffff800001e54000) at usbd_close_pipe+0x91
> uvideo_close(ffff80000021bf000) at uvideo_close+0x57
> videoclose(2c01,4,2000,ffff80003ab096e0) at videoclose+0x63
> spec_close(ffff80003ab8f6c8) at spec_close+0x2b2
> VOP_CLOSE(fffffdb23c0922c8,4,ffffffffffffff,ffff80003ab096e0) at
> VOP_CLOSE+0x59
> vclean(fffffdb23c0922c8,0,ffff80003ab096e0) at vclean+0x147
> vgonel(fffffdb23c0922c8,ffff80003ab096e0) at vgonel+0x67
> vop_generic_revoke(ffff80003ab8f7f8) at vop_generic_revoke+0x1a2
> VOP_REVOKE(fffffdb23c0922c8,1) at VOP_REVOKE+0x3b
> vdevgone(2c,1,1,4) at vdevgone+0xd5
> videodetach(ffff800001fe4400,1) at videodetach+0x67
> config_detach(ffff800001fe4400,1) at config_detach+0x166
> uvideo_detach(ffff80000021bf000,1) at uvideo_detach+0x4a
> config_detach(ffff80000021bf000,1) at config_detach+0x166
> end trace frame: 0xffff80003ab8fa20, count: 0
> https://www.openbsd.org/ddb.html describes the minimum info required
> in bug
> reports. Insufficient info makes it difficult to find and fix bugs.
> ddb{0}>
>
> and here the photo which I've captured with this stacktrace:
> https://kirill.korins.ky/pub/openbsd-webcam-deattach-crash.jpg
>
> --
> wbr, Kirill
>
