Bug#954004: Info received (Bug#954004: systemd-udevd: do_page_fault() type=15 address=0x00000005)

[John David Anglin]

The attached file provides debug info regarding the page fault generated by systemd-udevd.  The
fault appears to occur in builtin_net_setup_link.  The faulting instruction comes from line 64 in
../src/basic/string-util.h.

As noted, version 244.3-1 does not fault.  Later versions do.

Hope this helps.

Regards,
Dave Anglin

-- 
John David Anglin  dave.anglin at bell.net

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Page fault occurs in page 0.

Apr 16 21:24:30 atlas kernel: do_page_fault() command='systemd-udevd' type=15 address=0x00000005 in systemd-udevd[4109c000+9f000]
Apr 16 21:24:30 atlas kernel: trap #15: Data TLB miss fault
Apr 16 21:24:30 atlas kernel: CPU: 1 PID: 1152 Comm: systemd-udevd Not tainted 4.14.176+ #1
Apr 16 21:24:30 atlas kernel: Hardware name: 9000/785/C8000
Apr 16 21:24:30 atlas kernel: task: 000000412e148ac0 task.stack: 000000412e1b4000
Apr 16 21:24:30 atlas kernel:
Apr 16 21:24:30 atlas kernel:     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
Apr 16 21:24:30 atlas kernel: PSW: 00000000000001001111111000001111 Not tainted
Apr 16 21:24:30 atlas kernel: r00-03  000000ff0004fe0f 0000000f00000000 00000000410f9093 00000000411c9368
Apr 16 21:24:30 atlas kernel: r04-07  000000004114b000 0000000000000000 0000000000000000 00000000f8f1740c
Apr 16 21:24:30 atlas kernel: r08-11  00000000411a19a8 0000000041153840 00000000411541b0 00000000f8f1742c
Apr 16 21:24:30 atlas kernel: r12-15  000000004115a980 00000000f8f17448 00000000f8f17440 00000000f8f1754c
Apr 16 21:24:30 atlas kernel: r16-19  00000000f8f17348 0000000041134a30 00000000f8f17444 000000004114b000
Apr 16 21:24:30 atlas kernel: r20-23  0000000000000000 0000000000000056 00000000f8b0f1ba 000000000000001b
Apr 16 21:24:30 atlas kernel: r24-27  0000000041131648 000000000000001e 0000000000000005 000000004114b000
Apr 16 21:24:30 atlas kernel: r28-31  fffffffffffffffe 000000000000000f 00000000f8f17580 00000000410c9223
Apr 16 21:24:30 atlas kernel: sr00-03  000000000007b800 0000000000000000 0000000000000000 000000000007b800
Apr 16 21:24:30 atlas kernel: sr04-07  000000000007b800 000000000007b800 000000000007b800 000000000007b800
Apr 16 21:24:30 atlas kernel:
Apr 16 21:24:30 atlas kernel:      VZOUICununcqcqcqcqcqcrmunTDVZOUI
Apr 16 21:24:30 atlas kernel: FPSR: 00000000000000000000000000000000
Apr 16 21:24:30 atlas kernel: FPER1: 00000000
Apr 16 21:24:30 atlas kernel: fr00-03  0000000000000000 0000000000000000 0000000000000000 0000000000000000
Apr 16 21:24:30 atlas kernel: fr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000
Apr 16 21:24:30 atlas kernel: fr08-11  0000000000000000 0000000000000000 0000000000000000 0000000000000000
Apr 16 21:24:30 atlas kernel: fr12-15  0000000000000000 0000000000000000 0000000000000000 0000000000000000
Apr 16 21:24:30 atlas kernel: fr16-19  0000000000000000 0000000000000000 0000000000000000 0000000000000000
Apr 16 21:24:30 atlas kernel: fr20-23  0000000000000000 0000000000000000 00000000000000e0 00000000000001e0
Apr 16 21:24:30 atlas kernel: fr24-27  0000000000000000 0000000000000000 0000000000000000 0000000000000000
Apr 16 21:24:30 atlas kernel: fr28-31  0000000000000000 0000000000000000 0000000000000000 0000000000000000
Apr 16 21:24:30 atlas kernel:
Apr 16 21:24:30 atlas kernel: IASQ: 000000000007b800 000000000007b800 IAOQ: 00000000410f8dc3 00000000410f8dc7
Apr 16 21:24:30 atlas kernel: IIR: 0f40101c    ISR: 000000000007b800  IOR: 0000000000000005
Apr 16 21:24:30 atlas kernel: CPU:        1   CR30: 000000412e1b4000 CR31: 17fcfcfa83419f83
Apr 16 21:24:30 atlas kernel: ORIG_R28: 0000000000000000
Apr 16 21:24:30 atlas kernel: IAOQ[0]: 00000000410f8dc3
Apr 16 21:24:30 atlas kernel: IAOQ[1]: 00000000410f8dc7
Apr 16 21:24:30 atlas kernel: RP(r2): 00000000410f9093

Instruction at IAOQ[0] matches fault instruction in IIR.  Register r26 contains page fault address 5.

(gdb) disass 0x410f8dc0-16,0x410f8dc0+16
Dump of assembler code from 0x410f8db0 to 0x410f8dd0:
   0x410f8db0 <builtin_net_setup_link+7744>:    copy r3,r26
   0x410f8db4 <builtin_net_setup_link+7748>:    copy r4,r19
   0x410f8db8 <builtin_net_setup_link+7752>:    ldw 0(r7),r26
   0x410f8dbc <builtin_net_setup_link+7756>:    cmpib,=,n 0,r26,0x410f8df0 <bui>
   0x410f8dc0 <builtin_net_setup_link+7760>:    ldb 0(r26),ret0
   0x410f8dc4 <builtin_net_setup_link+7764>:    cmpiclr,<> 0,ret0,r0
   0x410f8dc8 <builtin_net_setup_link+7768>:    b,l,n 0x410f8df0 <builtin_net_s0
   0x410f8dcc <builtin_net_setup_link+7772>:    b,l 0x410f3808,rp
End of assembler dump.

  20:   0f 40 10 1c     ldb 0(r26),ret0
  24:   93 80 30 00     cmpiclr,<> 0,ret0,r0

(gdb) break *0x410f8dc0
Breakpoint 1 at 0x410f8dc0: file ../src/basic/string-util.h, line 64.