IZ33123: ERROR MESSAGES WITH IOCTL CALLS USING SIOCGIFCOUNT ON LINUX

APAR status

• Closed as program error.

Error description

• Error Message: ioct132(java:3066): Unknown cmd fd(33)
  cmd(00008938){00} arg(ffffbd98)onsocket<OSB>8441<CSB>
  .
  Stack Trace: N/A
  .
  Error messages were seen in the kernel logs when trying to get
  the number of network interfaces during JVM startup.These error
  messages although not harmful to any operation of the JVM were
  seen because of the way the network interfaces were
  obtained.First,ioctl call was made with the flag SIOCGIFCOUNT as
  the argument to the call.This flag is deprecated(from kernel
  version 2.6) and hence the call used to fail and this resulted
  in the error messages in the kernel logs.When the iotcl call
  with the deprecated flag failed another ioctl call with
  SIOCGIFCONF flag was used and using this we used to get the
  network interfaced.
  

Local fix

• N/A
  

Problem summary

• Error messages were seen in the kernel logs when trying to get
  the number of network interfaces during JVM startup.These error
  messages although not harmful to any operation of the JVM were
  seen because of the way the network interfaces were
  obtained.First,ioctl call was made with the flag SIOCGIFCOUNT as
  the argument to the call.This flag is deprecated(from kernel
  version 2.6) and hence the call used to fail and this resulted
  in the error messages in the kernel logs.When the iotcl call
  with the deprecated flag failed another ioctl call with
  SIOCGIFCONF flag was used and using this we used to get the
  network interfaces.
  

Problem conclusion

• This defect will be fixed in:
  5.0.0 SR9
  .
  Did instrumention to the code in NetworkInterface.c in
  enumipv4interfaces().First, as mentioned above to get the
  network interfaces ioctl with SIOCGIFCOUNT is used and when this
  fails ioctl with SIOCGIFCONF is used which works.Since the
  SIOCGIFCOUNT flag is deprecated we have removed the code
  pertaining to the ioctl call using SIOCGIFCOUNT flag.So with
  this change network interfaces will be got directly from the
  ioctl call with SIOCGIFCONF flag.
  We have tested locally with this change and we get the proper
  result with this.Backward compatability can be seen as a slight
  concern here, but 5.0 JDKs run on from RHEL 3 which have 2.6
  kernel where SIOCGIFCOUNT flag is bound to fail.So,believe we
  can have this change of removing the ioctl call with
  SIOCGIFCOUNT flag to avoid the error messages.
  .
  To obtain the fix:
  Install build 20081107 or later
  

Temporary fix

Comments

APAR Information

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

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

Fix information

• Fixed component name

  JAVA 5 CLASS LI

• Fixed component ID

  620500130

Applicable component levels

• R500 PSN

     UP