Regular kernel exceptions with java playing sound

Dear Sir or Madam I’m getting regular exceptions with java midi or wav plaing as below

@apalis-imx6:~/home/xxx$ [ 4530.103912] pgd = e3964000
[ 4530.106658] [76f53000] *pgd=6f13d831, *pte=767f7e9f, *ppte=00000000
[ 4530.113049] CPU: 2 PID: 2363 Comm: java Tainted: G           O    4.9.87-2.8.3+g07d40f6f #1
[ 4530.121453] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[ 4530.128019] task: e2e19600 task.stack: e3f7c000
[ 4530.132562] PC is at 0x741a4010
[ 4530.135709] LR is at 0x741a84c8
[ 4530.138890] pc : [<741a4010>]    lr : [<741a84c8>]    psr: 800d0010
[ 4530.138890] sp : 629fe850  ip : 76f53000  fp : 629fe9b0
[ 4530.150405] r10: 62c71000  r9 : 0000012c  r8 : 63dd0e28
[ 4530.155641] r7 : 64154858  r6 : 64154398  r5 : 64154858  r4 : 64154398
[ 4530.162202] r3 : 64080240  r2 : 64154858  r1 : 00000001  r0 : 0000012c
[ 4530.168769] Flags: Nzcv  IRQs on  FIQs on  Mode USER_32  ISA ARM  Segment user
[ 4530.175999] Control: 10c5387d  Table: 7396404a  DAC: 00000055
[ 4530.181791] CPU: 2 PID: 2363 Comm: java Tainted: G           O    4.9.87-2.8.3+g07d40f6f #1
[ 4530.190154] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[ 4530.196687] Backtrace:
[ 4530.199175] [<8010ba5c>] (dump_backtrace) from [<8010bd34>] (show_stack+0x18/0x1c)
[ 4530.206754]  r7:00000017 r6:600d0113 r5:00000000 r4:80c1ab30
[ 4530.212430] [<8010bd1c>] (show_stack) from [<803f9204>] (dump_stack+0x90/0xa4)
[ 4530.219663] [<803f9174>] (dump_stack) from [<80108ad8>] (show_regs+0x14/0x18)
[ 4530.226806]  r7:00000017 r6:76f53000 r5:0000000b r4:e2e19600
[ 4530.232475] [<80108ac4>] (show_regs) from [<8011531c>] (__do_user_fault+0xc4/0xc8)
[ 4530.240053] [<80115258>] (__do_user_fault) from [<8011552c>] (do_page_fault+0x20c/0x3a4)
[ 4530.248151]  r8:76f53000 r7:00000017 r6:e2f17c00 r5:e2e19600 r4:e3f7dfb0
[ 4530.254863] [<80115320>] (do_page_fault) from [<8010134c>] (do_DataAbort+0x44/0xc0)
[ 4530.262528]  r10:62c71000 r9:0000012c r8:e3f7dfb0 r7:76f53000 r6:80115320 r5:00000017
[ 4530.270363]  r4:80c0809c
[ 4530.272906] [<80101308>] (do_DataAbort) from [<8010cbe0>] (__dabt_usr+0x40/0x60)
[ 4530.280305] Exception stack(0xe3f7dfb0 to 0xe3f7dff8)
[ 4530.285365] dfa0:                                     0000012c 00000001 64154858 64080240
[ 4530.293550] dfc0: 64154398 64154858 64154398 64154858 63dd0e28 0000012c 62c71000 629fe9b0
[ 4530.301733] dfe0: 76f53000 629fe850 741a84c8 741a4010 800d0010 ffffffff
[ 4530.308359]  r8:10c5387d r7:10c5387d r6:ffffffff r5:800d0010 r4:741a4010

To reproduce this error I have made the following steps:

  1. Downloaded and installed Apalis-iMX6_LXDE-Image 2.8b3.111 20180626

  2. downloaded java for arm 32 from web page: java oracle

  3. unpacked java with command tar -vxzf downloaded java

  4. compiled java program with command: java_unpack_folder/bin/javac Midi.java

  5. run few times program with command java_unpack_folder/bin/java Midi

Java source code program: Midi.java

We have CONFIG_DEBUG_USER option enabled in kernel. What you’re seeing are crashes in java binaries, you can try moving from oracle to OpenJDK.