IV96905: SIGSEGV IN _MUTEX_LOCK WHILE DOING BLOCKING SOCKET OPERATION

APAR status

• Closed as program error.

Error description

• Error Message: A SIGSEGV is received when user attempts blocking
  socket operations like read, connect, accept ...
  .
  Stack Trace: _mutex_lock(??, ??, ??) at 0x9000000008da714
  
  endOp(fd = 570, self = 0x000000012057eb38), line 274 in
  "linux_close.c"
  NET_Read(s = 570, buf = 0x000000012057ebf0, len = 32767), line
  407 in "linux_close.c"
  Java_java_net_SocketInputStream_socketRead0(env =
  0x0000000031ea9000, this = 0x000000011e4de500, fdObj =
  0x000000011e4de4c0, data = 0x000000011e4de4f8, off = 0, len =
  32767, timeout = 0), line 113 in "SocketInputStream.c"
  .
  .
  .
  .
  Problem occurs very intermittently.
  

Local fix

Problem summary

• The crash occurred due to a narrow timing window between two
  threads when the fd table is expanded dynamically.
  

Problem conclusion

• The JDK has been updated to allocate the maximum fd table during
   initialization and thereby avoiding the need to expand the
  fdtable dynamically.
  

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:

• Fixed component name

  JAVA CLASS LIBS

• Fixed component ID

  620700130

Applicable component levels

• R600 PSY

     UP

• R700 PSY

     UP

• R800 PSY

     UP