siginfo.h(3HEAD)						      Headers							  siginfo.h(3HEAD)

NAME

       siginfo.h, siginfo - signal generation information

SYNOPSIS

       #include <siginfo.h>

DESCRIPTION

       If  a  process is catching a signal,  it might request information that tells why the system generated that signal. See	sigaction(2). If a
       process is monitoring its children, it might receive information that tells why a child changed state. See  waitid(2). In either case,  the
       system returns the information in a structure of type  siginfo_t, which includes the following information:

       int	      si_signo	      /* signal number */
       int	      si_errno	      /* error number */
       int	      si_code	      /* signal code */
       union sigval   si_value	      /* signal value */

       si_signo contains the system-generated signal number. For the  waitid(2) function,  si_signo is always  SIGCHLD.

       If  si_errno is non-zero, it contains an error number associated with this signal, as defined in  <errno.h>.

       si_code contains a code identifying the cause of the signal.

       If the value of the  si_code member is  SI_NOINFO, only the si_signo member of  siginfo_t is meaningful, and the value of all other members
       is unspecified.

   User Signals
       If the value of	si_code is less than or equal to 0, then the  signal  was  generated  by  a  user  process  (see   kill(2),  _lwp_kill(2),
       sigqueue(3RT), sigsend(2), abort(3C), and raise(3C)) and the  siginfo structure contains the following additional information:

       pid_t	    si_pid	/* sending process ID */
       uid_t	    si_uid	/* sending user ID */
       ctid_t	    si_ctid	/* sending contract ID */
       zoneid_t     si_zoneid	/* sending zone ID */S

       If the signal was generated by a user process, the following values are defined for si_code:

       SI_USER	       The implementation sets si_code to SI_USER if the signal was sent by kill(2), sigsend(2), raise(3C) or abort(3C).

       SI_LWP	       The signal was sent by _lwp_kill(2).

       SI_QUEUE        The signal was sent by sigqueue(3RT).

       SI_TIMER        The signal was generated by the expiration of a timer created by timer_settime(3RT).

       SI_ASYNCIO      The signal was generated by the completion of an asynchronous  I/O request.

       SI_MESGQ        The signal was generated by the arrival of a message on an empty message queue. See mq_notify(3RT).

       si_value  contains the application specified value, which is passed to the application's signal-catching function at the time of the signal
       delivery if  si_code is any of SI_QUEUE, SI_TIMER, SI_ASYNCHIO, or SI_MESGQ.

   System Signals
       Non-user generated signals can arise for a number of reasons. For all of these cases, si_code contains a positive value reflecting the rea-
       son why the system generated the signal:

       Signal	      Code		   Reason
       SIGILL	      ILL_ILLOPC	   illegal opcode
		      ILL_ILLOPN	   illegal operand
		      ILL_ILLADR	   illegal addressing mode
		      ILL_ILLTRP	   illegal trap
		      ILL_PRVOPC	   privileged opcode
		      ILL_PRVREG	   privileged register
		      ILL_COPROC	   co-processor error
		      ILL_BADSTK	   internal stack error
       SIGFPE	      FPE_INTDIV	   integer divide by zero
		      FPE_INTOVF	   integer overflow
		      FPE_FLTDIV	   floating point divide by zero
		      FPE_FLTOVF	   floating point overflow
		      FPE_FLTUND	   floating point underflow
		      FPE_FLTRES	   floating point inexact result
		      FPE_FLTINV	   invalid floating point operation
		      FPE_FLTSUB	   subscript out of range
       SIGSEGV	      SEGV_MAPERR	   address not mapped to object
		      SEGV_ACCERR	   invalid  permissions  for mapped
					   object
       SIGBUS	      BUS_ADRALN	   invalid address alignment
		      BUS_ADRERR	   non-existent physical address
		      BUS_OBJERR	   object specific hardware error
       SIGTRAP	      TRAP_BRKPT	   process breakpoint
		      TRAP_TRACE	   process trace trap
       SIGCHLD	      CLD_EXITED	   child has exited
		      CLD_KILLED	   child was killed
		      CLD_DUMPED	   child terminated abnormally
		      CLD_TRAPPED	   traced child has trapped
		      CLD_STOPPED	   child has stopped
		      CLD_CONTINUED	   stopped child had continued
       SIGPOLL	      POLL_IN		   data input available
		      POLL_OUT		   output buffers available
		      POLL_MSG		   input message available
		      POLL_ERR		   I/O error
		      POLL_PRI		   high priority input available
		      POLL_HUP		   device disconnected

       Signals can also be generated from the resource control subsystem. Where these signals do not already possess kernel-level  siginfo  codes,
       the siginfo si_code will be filled with SI_RCTL to indicate a kernel-generated signal from an established resource control value.

	  Signal	    Code		   Reason
       SIGXRES	      SI_RCTL		 resource-control generated
					 signal
       SIGHUP
       SIGTERM

       The uncatchable signals SIGSTOP and SIGKILL have undefined siginfo codes.

       Signals sent with a siginfo code of SI_RCTL contain code-dependent information for kernel-generated signals:

	  Code		    Field		       Value
       SI_RCTL	      hr_time si_entity   process-model entity of control

       In addition, the following signal-dependent information is available for kernel-generated signals:

	  Signal	    Field		       Value
       SIGILL	      caddr_t si_addr	  address of faulting instruction
       SIGFPE
       SIGSEGV	      caddr_t si_addr	  address of faulting memory  ref-
					  erence
       SIGBUS
       SIGCHLD	      pid_t si_pid	  child process ID
		      int si_status	  exit value or signal
       SIGPOLL	      long si_band	  band	  event    for	  POLL_IN,
					  POLL_OUT, or POLL_MSG

SEE ALSO

       _lwp_kill(2),  kill(2),	setrctl(2),  sigaction(2),  sigsend(2),  waitid(2),  abort(3C),  aio_read(3RT),  mq_notify(3RT),  raise(3C),  sig-
       nal.h(3HEAD), sigqueue(3RT), timer_create(3RT), timer_settime(3RT)

NOTES

       For   SIGCHLD  signals,	if   si_code  is equal to  CLD_EXITED, then  si_status is equal to the exit value of the process; otherwise, it is
       equal to the signal that caused the process to  change state. For some implementations, the exact value of si_addr might not be	available;
       in that case, si_addr is guaranteed to be on the same page as the faulting instruction or memory reference.

SunOS 5.10							    19 Jul 2004 						  siginfo.h(3HEAD)