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IV56154: PPP ON POWER7 WITH AIX7 CRASH IN IPINTR_NOQUEUE_POST_FW() APPLIES TO AIX 6100-09

A fix is available

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APAR status

  • Closed as program error.

Error description

  • PPP crashed in ipintr_noqueue_post_fw() due to SKEY
    violation. Only on Power7/AIX7 combo
    
    Stack:
     netinet:ipintr_noqueue_post_fw+000B84
     netinet:ipintr_noqueue+000120
     Netintr+0002FC
     netisr_thread+000020
     threadentry+000088
    
      (0)> status
    CPU INTR      TID  TSLOT     PID  PSLOT  PROC_NAME
      0         230047     35  140028     20  gil     <<<<
    
    (0)> vmlog
    Most recent VMM errorlog entry
    Error id               =  DSI_PROC
    Exception DSISR/ISISR  =  0000000000200000
    Exception srval        =  0000000082031510
    Exception virt addr    =  F1000A0310150018
    Exception value        =  0000010E  EXCEPT_SKEY <<<<
    
    In this case PPP interface received packets are processed
    by the AIX gil thread.
    

Local fix

  • Work around is to ensure that the ppp ip address does not
    hash to ANY ethernet ip address/broadcast address.
    EX:
    This would expose the problem.
    10.71.4.255 =  0x0A4704FF   (enX broadcast addr)
    >  print (unsigned int)0x0A4704FF % 229(0xE5);
    unsigned int  = 29(0x0000001d)
    
    192.168.254.135 = 0xC0A8FE87 (pp0 assigned addr)
    > print (unsigned int)0xC0A8FE87 % 229 (0xE5);
    unsigned int  = 29(0x0000001d)
    
    In this case the workaround is to change pp0 address by
    one to 192.168.254.136
    

Problem summary

  • When processing ppp(point to point protocol) packet, AIX
    machine can crash with storage key exception, with the
    following stack trace:
    
    netinet:ipintr_noqueue_post_fw+000B84
    netinet:ipintr_noqueue+000120
    Netintr+0002FC
    netisr_thread+000020
    threadentry+000088
    

Problem conclusion

  • Modified code to add the required storage keys which avoids the
    crash.
    

Temporary fix

Comments

  • 6100-07 - use AIX APAR IV58201
    6100-08 - use AIX APAR IV57783
    6100-09 - use AIX APAR IV56154
    6100-09 - use AIX APAR IV56154
    6100-09 - use AIX APAR IV56154
    7100-01 - use AIX APAR IV57485
    7100-02 - use AIX APAR IV53819
    7100-03 - use AIX APAR IV56143
    7100-04 - use AIX APAR IV56172
    

APAR Information

  • APAR number

    IV56154

  • Reported component name

    AIX 610 STD EDI

  • Reported component ID

    5765G6200

  • Reported release

    610

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2014-03-03

  • Closed date

    2014-03-03

  • Last modified date

    2016-05-10

  • APAR is sysrouted FROM one or more of the following:

    IV53819

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    AIX 610 STD EDI

  • Fixed component ID

    5765G6200

Applicable component levels

  • R610 PSY U859304

       UP14/05/21 I 1000

PTF to Fileset Mapping



Document information

More support for: AIX Standard Edition

Software version: 610

Operating system(s): AIX

Reference #: IV56154

Modified date: 10 May 2016