Null pointer exception

[vinothkumars]

Hi All,

How to resolve this issue. Is there any any problem with ram or secondary cpu's ?

[ 9.215124] Unable to handle kernel NULL pointer dereference at virtual address 00000008
[ 9.215183] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 9.215193] Unable to handle kernel NULL pointer dereference at virtual address 00000048
[ 9.215195] Mem abort info:
[ 9.215197] Exception class = DABT (current EL), IL = 32 bits
[ 9.215199] SET = 0, FnV = 0
[ 9.215201] EA = 0, S1PTW = 0
[ 9.215202] Data abort info:
[ 9.215203] ISV = 0, ISS = 0x00000004
[ 9.215205] CM = 0, WnR = 0
[ 9.215208] user pgtable: 4k pages, 48-bit VAs, pgd = ffff80082d190000
[ 9.215210] [0000000000000048] *pgd=0000000000000000
[ 9.215216] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 9.215218] Modules linked in:
[ 9.215225] CPU: 4 PID: 1651 Comm: kworker/4:2 Not tainted 4.14.98-dirty #1
[ 9.215226] Hardware name: Freescale i.MX8QM MEK (DT)
[ 9.215240] Workqueue: events free_work
[ 9.215244] task: ffff80083a4acb00 task.stack: ffff000018548000
[ 9.215247] PC is at __vunmap+0x28/0xd8
[ 9.215249] LR is at __vunmap+0x28/0xd8
[ 9.215252] pc : [<ffff000008206b54>] lr : [<ffff000008206b54>] pstate: a0000145
[ 9.215253] sp : ffff00001854bd60
[ 9.215255] x29: ffff00001854bd60 x28: 0000000000000000
[ 9.215259] x27: ffff00000934bcd8 x26: ffff80083ff3a200
[ 9.215263] x25: 0000000000000000 x24: ffff80083ff37520
[ 9.215267] x23: 0000000000000000 x22: ffff80083ff3e100
[ 9.215270] x21: 0000000000000001 x20: ffff80083ff37518
[ 9.215274] x19: ffff00001acf0000 x18: 000000000000000e
[ 9.215277] x17: 0000000000000001 x16: 0000000000000019
[ 9.215281] x15: 0000000000000033 x14: 000000000000004c
[ 9.215284] x13: 0000000000000068 x12: ffff00001acf3b58
[ 9.215287] x11: 0000000000000008 x10: 00000000000008c0
[ 9.215291] x9 : ffff00001854bd40 x8 : ffff80083a4ad420
[ 9.215294] x7 : 0000000000000000 x6 : 0000000000000000
[ 9.215298] x5 : 0000000000000000 x4 : ffff000011cf0000
[ 9.215301] x3 : 0000000000000000 x2 : ffff8008318fbb00
[ 9.215304] x1 : ffff80083a4acb00 x0 : 0000000000000000
[ 9.215309]
[ 9.215309] X1: 0xffff80083a4aca80:
[ 9.215311] ca80 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215324] caa0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215336] cac0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215349] cae0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215361] cb00 00000020 00000000 ffffffff ffffffff 00000001 00000000 00000000 00000000
[ 9.215374] cb20 18548000 ffff0000 00000002 04208060 00000000 00000000 00000000 00000000
[ 9.215387] cb40 00000001 00000004 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215399] cb60 00000004 00000001 00000078 00000078 00000078 00000000 08a09630 ffff0000
[ 9.215413]
[ 9.215413] X2: 0xffff8008318fba80:
[ 9.215414] ba80 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215426] baa0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215439] bac0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215451] bae0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215463] bb00 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215475] bb20 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215488] bb40 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215500] bb60 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215513]
[ 9.215513] X8: 0xffff80083a4ad3a0:
[ 9.215514] d3a0 00000000 00000000 2d059d80 ffff8008 00000001 00000000 00000000 00000000
[ 9.215527] d3c0 3a113200 ffff8008 3a4acb00 ffff8008 3a4acb00 ffff8008 08e23000 ffff0000
[ 9.215539] d3e0 3bfb4700 ffff8008 00000000 00000000 3a4ad0a0 ffff8008 08fe9000 ffff0000
[ 9.215552] d400 089f3acc ffff0000 08a094f0 ffff0000 1854bd40 ffff0000 1854bd40 ffff0000
[ 9.215564] d420 0808606c ffff0000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215577] d440 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215589] d460 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215601] d480 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215616]
[ 9.215616] X20: 0xffff80083ff37498:
[ 9.215617] 7498 3a0b4400 ffff8008 00000004 00000000 00000000 00000000 00000000 00000000
[ 9.215629] 74b8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215642] 74d8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215654] 74f8 00000000 00000000 3ff37500 ffff8008 3ff37500 ffff8008 00000000 00000000
[ 9.215666] 7518 00000100 00000000 3ff37520 ffff8008 3ff37520 ffff8008 08206c04 ffff0000
[ 9.215679] 7538 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215691] 7558 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215704] 7578 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215717]
[ 9.215717] X22: 0xffff80083ff3e080:
[ 9.215718] e080 09280000 ffff0000 00000000 00000000 51b80000 00000000 00000379 00000000
[ 9.215731] e0a0 00000000 00000000 00000000 00000000 00000000 00000000 ffffffdf 00000009
[ 9.215743] e0c0 00000000 00000000 0827e608 ffff0000 00000000 00000000 00000000 00000000
[ 9.215755] e0e0 000d0118 03050001 00000000 01e90c00 00000000 00000000 00000000 00000000
[ 9.215768] e100 3ff3a200 ffff8008 3a006600 ffff8008 00000000 ffffffff 00000002 00000001
[ 9.215781] e120 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215793] e140 00000000 00000000 00000000 00000000 00000000 00000000 00000001 00000100
[ 9.215805] e160 3ff3e160 ffff8008 3ff3e160 ffff8008 3ff28170 ffff8008 3ff54170 ffff8008
[ 9.215818]
[ 9.215818] X24: 0xffff80083ff374a0:
[ 9.215819] 74a0 00000004 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215832] 74c0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215844] 74e0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215856] 7500 3ff37500 ffff8008 3ff37500 ffff8008 00000000 00000000 00000100 00000000
[ 9.215870] 7520 3ff37520 ffff8008 3ff37520 ffff8008 08206c04 ffff0000 00000000 00000000
[ 9.215883] 7540 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215895] 7560 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215907] 7580 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215920]
[ 9.215920] X26: 0xffff80083ff3a180:
[ 9.215921] a180 00000000 00000000 00000000 00000000 00000000 00000000 088b6e10 ffff0000
[ 9.215933] a1a0 3ff3a180 ffff8008 3ff3a1a8 ffff8008 3ff3a1a8 ffff8008 00000000 00000000
[ 9.215946] a1c0 3a482680 ffff8008 00000000 00000000 00000015 00000000 3809f6c0 ffff8008
[ 9.215958] a1e0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 9.215971] a200 04ac04ac 00000004 00000000 00000008 00000000 00000000 fffee3da 00000000
[ 9.215983] a220 3ff3a220 ffff8008 3ff3a220 ffff8008 00000003 00000002 3a492300 ffff8008
[ 9.215996] a240 3a1f9000 ffff8008 00000000 00000000 3ff34878 ffff8008 00000448 00000001
[ 9.216008] a260 080c9c7c ffff0000 3ff3a200 ffff8008 40480004 00000000 00000200 dead0000
[ 9.216022]
[ 9.216024] Process kworker/4:2 (pid: 1651, stack limit = 0xffff000018548000)
[ 9.216026] Call trace:
[ 9.216029] Exception stack(0xffff00001854bc20 to 0xffff00001854bd60)
[ 9.216032] bc20: 0000000000000000 ffff80083a4acb00 ffff8008318fbb00 0000000000000000
[ 9.216034] bc40: ffff000011cf0000 0000000000000000 0000000000000000 0000000000000000
[ 9.216037] bc60: ffff80083a4ad420 ffff00001854bd40 00000000000008c0 0000000000000008
[ 9.216039] bc80: ffff00001acf3b58 0000000000000068 000000000000004c 0000000000000033
[ 9.216041] bca0: 0000000000000019 0000000000000001 000000000000000e ffff00001acf0000
[ 9.216044] bcc0: ffff80083ff37518 0000000000000001 ffff80083ff3e100 0000000000000000
[ 9.216046] bce0: ffff80083ff37520 0000000000000000 ffff80083ff3a200 ffff00000934bcd8
[ 9.216048] bd00: 0000000000000000 ffff00001854bd60 ffff000008206b54 ffff00001854bd60
[ 9.216051] bd20: ffff000008206b54 00000000a0000145 ffff00001854bd60 ffff000008206b54
[ 9.216053] bd40: ffffffffffffffff ffff80083ff37518 ffff00001854bd60 ffff000008206b54
[ 9.216056] [<ffff000008206b54>] __vunmap+0x28/0xd8
[ 9.216059] [<ffff000008206c40>] free_work+0x3c/0x50
[ 9.216064] [<ffff0000080cb990>] process_one_work+0x140/0x3f8
[ 9.216067] [<ffff0000080cbd80>] worker_thread+0x138/0x3e4
[ 9.216069] [<ffff0000080d1d68>] kthread+0x104/0x130
[ 9.216074] [<ffff000008084f14>] ret_from_fork+0x10/0x18
[ 9.216078] Code: 92402c01 aa0003f3 b50002e1 97fff640 (f9402414)
[ 9.216084] ---[ end trace 28650559095a726b ]---
[ 9.216086] Kernel panic - not syncing: Fatal exception
[ 9.216089] SMP: stopping secondary CPUs
[ 10.043619] Mem abort info:
[ 10.046413] Exception class = IABT (current EL), IL = 32 bits
[ 10.052327] SET = 0, FnV = 0
[ 10.055376] EA = 0, S1PTW = 0
[ 10.058515] user pgtable: 4k pages, 48-bit VAs, pgd = ffff80082d190000
[ 10.065037] [0000000000000000] *pgd=0000000000000000
[ 10.216094] SMP: failed to stop secondary CPUs 2,4
[ 10.220884] Kernel Offset: disabled
[ 10.224368] CPU features: 0x180200c
[ 10.227851] Memory Limit: none
[ 10.230903] trusty-log panic notifier - trusty version Built: 17:00:46 Mar 5 2019
[ 10.230908] Rebooting in 5 seconds..
[ 15.242046] SMP: stopping secondary CPUs
[ 16.245968] SMP: failed to stop secondary CPUs 2,4

[Bio_TICFSL]

Hello vinothkumars,

It means you are trying to access a NULL pointer in your code. Put NULL checks in your code to find out where.Also please note that some registers are not available for access in user mode. You need to write a driver that will access them.

Regards

[vinothkumars]

Thank you for the reply