Re: [PATCH] cx23885/vb2 regression: please test this patch

[Hans Verkuil <hverkuil@xs4all.nl>]

On 01/18/2015 09:54 AM, Jurgen Kramer wrote:
> I have been running the original code (because of issues with the patch)
> for a while with some added printks. This morning I found this NULL
> pointer derefence:

That's what my patch fixes, so that's no surprise that you get this.

I don't understand why you have issues with the patch, very weird.

Regards,

	Hans

> 
> [47772.121968] DEBUG: vb2_thread_stop entered
> [47772.122014] BUG: unable to handle kernel NULL pointer dereference at
> (null)
> [47772.122042] vb2: counters for queue ffff880407ee9828: UNBALANCED!
> [47772.122043] vb2:     setup: 1 start_streaming: 1 stop_streaming: 1
> [47772.122043] vb2:     wait_prepare: 249333 wait_finish: 249334
> [47772.122083] IP: [<ffffffffa057b65c>] cx23885_buf_prepare+0x6c/0xd0
> [cx23885]
> [47772.122102] PGD 0 
> [47772.122107] Oops: 0000 [#1] SMP 
> [47772.122116] Modules linked in: cfg80211 rfkill
> nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_rpfilter ip6t_REJECT
> xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter
> ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6
> ip6table_mangle ip6table_security ip6table_raw ip6table_filter
> ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4
> nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw sp2(OE)
> si2157(OE) si2168(OE) i2c_mux cx25840(OE) cx23885(OE) altera_ci(OE)
> tda18271(OE) altera_stapl(OE) videobuf2_dvb(OE) videobuf2_core(OE)
> videobuf2_dma_sg(OE) videobuf2_memops(OE) snd_seq snd_seq_device snd_pcm
> snd_timer snd soundcore tveeprom(OE) cx2341x(OE) dvb_core(OE)
> rc_core(OE) v4l2_common(OE) videodev(OE) raid456 async_raid6_recov
> async_memcpy
> [47772.122321]  async_pq async_xor xor async_tx raid6_pq media(OE)
> mxm_wmi intel_rapl x86_pkg_temp_thermal coretemp kvm_intel kvm serio_raw
> shpchp mei_me mei i2c_i801 crct10dif_pclmul crc32_pclmul crc32c_intel
> ghash_clmulni_intel microcode dw_dmac wmi dw_dmac_core tpm_tis tpm
> i2c_hid i2c_designware_platform i2c_designware_core acpi_pad nfsd
> auth_rpcgss nfs_acl lockd sunrpc e1000e i915 ptp pps_core i2c_algo_bit
> drm_kms_helper drm sdhci_acpi sdhci mmc_core video
> [47772.122472] CPU: 0 PID: 6151 Comm: vb2-cx23885[2] Tainted: G
> OE  3.17.8-200.fc20.x86_64 #1
> [47772.122492] Hardware name: To Be Filled By O.E.M. To Be Filled By
> O.E.M./Z97 Extreme4, BIOS P1.50 12/17/2014
> [47772.122523] task: ffff8803dcfc9d70 ti: ffff8803652a8000 task.ti:
> ffff8803652a8000
> [47772.122549] RIP: 0010:[<ffffffffa057b65c>]  [<ffffffffa057b65c>]
> cx23885_buf_prepare+0x6c/0xd0 [cx23885]
> [47772.122573] RSP: 0018:ffff8803652abdc8  EFLAGS: 00010246
> [47772.122585] RAX: 0000000000005e00 RBX: ffff880036a6d600 RCX:
> 00000000000002f0
> [47772.122609] RDX: 0000000000005e00 RSI: ffff88040608a3b8 RDI:
> ffff8804091f3000
> [47772.122624] RBP: ffff8803652abdf0 R08: 0000000000000020 R09:
> 0000000000000000
> [47772.122649] R10: ffff880407ee9828 R11: ffff880407ee9828 R12:
> ffff88040608a000
> [47772.122663] R13: 0000000000005e00 R14: ffff880036a6c000 R15:
> 0000000000000000
> [47772.122677] FS:  0000000000000000(0000) GS:ffff88041fa00000(0000)
> knlGS:0000000000000000
> [47772.122693] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [47772.122705] CR2: 0000000000000000 CR3: 0000000001c14000 CR4:
> 00000000001407f0
> [47772.122720] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000
> [47772.123643] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
> 0000000000000400
> [47772.124605] Stack:
> [47772.125468]  ffff88040608a000 ffff88040608c458 ffff88040608a000
> 0000000000000000
> [47772.126350]  ffff880407ee9828 ffff8803652abe00 ffffffffa057cd69
> ffff8803652abe30
> [47772.127230]  ffffffffa04f183e 0000000000005e00 ffff880407ee9828
> ffff88040608c458
> [47772.128129] Call Trace:
> [47772.129002]  [<ffffffffa057cd69>] buffer_prepare+0x19/0x20 [cx23885]
> [47772.129916]  [<ffffffffa04f183e>] __buf_prepare+0x27e/0x390
> [videobuf2_core]
> [47772.130838]  [<ffffffffa04f301b>] vb2_internal_qbuf+0x6b/0x210
> [videobuf2_core]
> [47772.131722]  [<ffffffffa04f32f6>] vb2_thread+0x136/0x4d0
> [videobuf2_core]
> [47772.132642]  [<ffffffffa04f31c0>] ? vb2_internal_qbuf+0x210/0x210
> [videobuf2_core]
> [47772.133527]  [<ffffffff810b04b8>] kthread+0xd8/0xf0
> [47772.134400]  [<ffffffff810b03e0>] ? kthread_create_on_node
> +0x190/0x190
> [47772.135268]  [<ffffffff8173057c>] ret_from_fork+0x7c/0xb0
> [47772.136134]  [<ffffffff810b03e0>] ? kthread_create_on_node
> +0x190/0x190
> [47772.137058] Code: 24 60 02 00 00 85 c0 75 3e 45 85 ed 75 4d 90 8b 8b
> f0 00 00 00 49 8b be 20 01 00 00 49 8d b4 24 b8 03 00 00 44 8b 83 f4 00
> 00 00 <49> 8b 17 45 31 c9 e8 c9 f0 ff ff 31 c0 5b 41 5c 41 5d 41 5e 41 
> [47772.138917] RIP  [<ffffffffa057b65c>] cx23885_buf_prepare+0x6c/0xd0
> [cx23885]
> [47772.139841]  RSP <ffff8803652abdc8>
> [47772.140776] CR2: 0000000000000000
> [47772.146080] ---[ end trace 2c986045fea9fe0a ]---
> [47772.146236] DEBUG: vb2_thread_stop quit
> 
> This happened only once normally it just prints:
> [47179.170117] DEBUG: vb2_thread
> [47400.670021] DEBUG: vb2_thread_stop entered
> [47400.670105] DEBUG: vb2_thread_stop quit
> [47401.012711] DEBUG: vb2_thread
> [47456.200792] DEBUG: vb2_thread_stop entered
> [47456.200908] DEBUG: vb2_thread_stop quit
> [47456.544154] DEBUG: vb2_thread
> [47480.938606] DEBUG: vb2_thread_stop entered
> [47480.938711] DEBUG: vb2_thread_stop quit
> [47481.024019] DEBUG: vb2_thread
> [47708.823051] DEBUG: vb2_thread_stop entered
> [47708.823184] DEBUG: vb2_thread_stop quit
> [47709.166499] DEBUG: vb2_thread
> 
> Regards,
> Jurgen
>