IZ83295: XLATE_UNPIN RETURNS EINVAL CAUSING SYSTEM CRASH IN UNPIN_BUF APPLIES TO AIX 6100-06

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• In some situations xlate_unpin can return EINVAL which
  causes unpin_buf to assert.
  The stack trace in such a case will be
  
  (6)> f
  pvthread+810300 STACK:
  [001C7158]unpin_buf+00002C (0000000000000016,
  0000000000000016 [??])
  [001C7064]uphyswait+0001F0 (??, ??, ??, ??)
  [00472BEC]uphysio+000474 (??, ??, ??, ??, ??, ??, ??)
  [04057520]scsidisk_rdwr+0000DC (??, ??, ??, ??, ??)
  [04057778]scsidisk_read+000080 (??, ??, ??, ??)
  [003F077C]rdevread+0000A8 (??, ??, ??, ??)
  [005267C8]cdev_rdwr+0000C8 (??, ??, ??, ??, ??, ??, ??)
  [004C5D04]spec_rdwr+00010C (??, ??, ??, ??, ??, ??, ??,
  ??)
  [00404528]vnop_rdwr+00019C (??, ??, ??, ??, ??, ??, ??,
  ??)
  [00447DAC]vno_rw+00006C (??, ??, ??, ??)
  [003D5024]fp_rwuio+0000B4 (??, ??, ??, ??)
  [0456CCE0]rw_request+00016C (??, ??)
  [0456C96C]process_request+000090 (??, ??)
  [0456CB1C]process_queue+000048 (??)
  [0456CF10]do_requests+000038 (??)
  [0456D13C]server_main+000158 (??, ??, ??)
  [0016E350]procentry+000010 (??, ??, ??, ??)
  

Local fix

• There is no fix. System will reboot.
  

Problem summary

• When a XMEM descriptor spans multiple segments with different
  page sizes, with the first segment having the largest page
  size, and the size of the XMEM buffer is a multiple of
  the smallest page size, and the buffer does not start on the
  smallest page size's boundary, the number of physical pages
  spanned recorded in the XMEM descriptor during pinning is
  incorrect.
  

Problem conclusion

• Correctly calculate the number of pages spanned by the buffer.
  

Temporary fix

Comments

• 5300-09 - use AIX APAR IZ82778
  5300-10 - use AIX APAR IZ82639
  5300-11 - use AIX APAR IZ82751
  5300-12 - use AIX APAR IZ82454
  6100-03 - use AIX APAR IZ87711
  6100-04 - use AIX APAR IZ87678
  6100-05 - use AIX APAR IZ87603
  6100-06 - use AIX APAR IZ83295
  7100-00 - use AIX APAR IZ84272
  

APAR Information

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

  IZ78029

• 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 U833973

     UP11/05/13 I 1000

PTF to Fileset Mapping

• U833973 bos.mp64 6.1.6.15