gstreamer v4l2 kernel Oops

[Andrea]

Hi,
I'm using gstreamer with my driver but often I get a kernel error. I managed
to go back to the source of the error and the problem seems to be the
streamon ioctl, not the code inside it (I tried also with only the return 0
and I get the error) but the call itself. Trying to call the ioctl functions
by hand I saw that the error appears in "random" mode, once they all work
(including streamon) and the next time the streamon causes the error,
calling it again it works, maybe the next call works or not and so on. I
can't understand if the error is in my driver or if it is, for example,
there is a problem during the registration (although it is successful).

Thanks, Andrea

/[  899.083253] Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000001
[  899.092044] Mem abort info:
[  899.094832]   ESR = 0x96000021
[  899.097875]   Exception class = DABT (current EL), IL = 32 bits
[  899.103787]   SET = 0, FnV = 0
[  899.106833]   EA = 0, S1PTW = 0
[  899.109967] Data abort info:
[  899.112836]   ISV = 0, ISS = 0x00000021
[  899.116661]   CM = 0, WnR = 0
[  899.119622] user pgtable: 4k pages, 39-bit VAs, pgdp = (____ptrval____)
[  899.126228] [0000000000000001] pgd=0000000000000000, pud=0000000000000000
[  899.133018] Internal error: Oops: 96000021 [#1] SMP
[  899.137881] Modules linked in: video(O) al5d(O) al5e(O) allegro(O)
xlnx_vcu_clk xlnx_vcu xilinx_hdmi_rx(O) xilinx_vphy(O) xlnx_vcu_core mali(O)
uio_pdrv_genirq [last unloaded: video]
[  899.154143] CPU: 0 PID: 2322 Comm: test Tainted: G        W  O     
4.19.0-xilinx-v2019.1 #1
[  899.162568] Hardware name: ZynqMP ZCU106 RevA (DT)
[  899.167345] pstate: a0000005 (NzCv daif -PAN -UAO)
[  899.172125] pc : __ll_sc___cmpxchg_case_acq_8+0x4/0x20
[  899.177251] lr : mutex_lock_interruptible+0x18/0x40
[  899.182118] sp : ffffff8010c73bb0
[  899.185416] x29: ffffff8010c73bb0 x28: ffffffc87af98000
[  899.190720] x27: ffffff8008769108 x26: ffffff8000c9b1f8
[  899.196024] x25: 0000007fc63db5c4 x24: 0000000000000001
[  899.201319] x23: 0000000000000000 x22: ffffff8009138648
[  899.206615] x21: 0000000000000012 x20: 0000000040045612
[  899.211910] x19: ffffffc879d60800 x18: 0000000000000000
[  899.217205] x17: 0000000000000000 x16: 0000000000000000
[  899.222501] x15: 0000000000000000 x14: 0000000000000000
[  899.227796] x13: 0000000000000000 x12: 0000000000000000
[  899.233091] x11: 0000000000000000 x10: 0000000000000000
[  899.238387] x9 : 0000000000000000 x8 : 0000000000000000
[  899.243682] x7 : 0000000000000000 x6 : ffffffc87b942080
[  899.248977] x5 : 00000000ffffffff x4 : ffffff800876cea0
[  899.254281] x3 : 0000000000000001 x2 : ffffffc87ac2f400
[  899.259577] x1 : 0000000000000000 x0 : 0000000000000001
[  899.264873] Process test (pid: 2322, stack limit = 0x(____ptrval____))
[  899.271383] Call trace:
[  899.273817]  __ll_sc___cmpxchg_case_acq_8+0x4/0x20
[  899.278600]  __video_do_ioctl+0x124/0x498
[  899.282600]  video_usercopy+0x144/0x518
[  899.286420]  video_ioctl2+0x14/0x1c
[  899.289894]  v4l2_ioctl+0x3c/0x58
[  899.293202]  do_vfs_ioctl+0xb8/0x8a0
[  899.296768]  ksys_ioctl+0x44/0x90
[  899.300067]  __arm64_sys_ioctl+0x1c/0x28
[  899.303975]  el0_svc_common+0x84/0xd8
[  899.307627]  el0_svc_handler+0x68/0x80
[  899.311360]  el0_svc+0x8/0xc
[  899.314226] Code: 35ffff91 aa1003e0 d65f03c0 f9800011 (c85ffc10)
[  899.320310] ---[ end trace da93a42a8cf31bfc ]---
Segmentation fault/



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