Movatterモバイル変換

If a process is catching a signal, it might request informationthat tells why the system generated that signal. Seesigaction(2). Ifa process is monitoring its children, it might receive information that tells whya child changed state. Seewaitid(2). In either case, the systemreturns the information in a structure of typesiginfo_t, which includes thefollowing 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 thewaitid(2) function,si_signo is alwaysSIGCHLD.

Ifsi_errno is non-zero, it contains an error number associated withthis signal, as defined in<errno.h>.

si_code contains a code identifying the cause of the signal.

If the value of thesi_code member isSI_NOINFO, onlythesi_signo member ofsiginfo_t is meaningful, and the value ofall other members is unspecified.

User Signals

If the value ofsi_code is less than or equal to0, then the signal was generated by a user process (seekill(2),_lwp_kill(2),sigqueue(3C),sigsend(2),abort(3C), andraise(3C)) and thesiginfo structurecontains 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 valuesare defined forsi_code:

SI_USER: The implementation setssi_code toSI_USER if the signal was sent bykill(2),sigsend(2),raise(3C) orabort(3C).
SI_LWP: The signal was sent by_lwp_kill(2).
SI_QUEUE: The signal was sent bysigqueue(3C).
SI_TIMER: The signal was generated by the expiration of a timer created bytimer_settime(3C).
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. Seemq_notify(3C).

si_value contains the application specified value, which is passed to the application'ssignal-catching function at the time of the signal delivery ifsi_codeis any ofSI_QUEUE,SI_TIMER,SI_ASYNCHIO, orSI_MESGQ.

System Signals

Non-user generated signals can arise for a number of reasons. For allof these cases,si_code contains a positive value reflecting the reason whythe 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-processorerror
	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 pointoverflow
	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	addressnot mapped to object
	SEGV_ACCERR	invalid permissions for mapped object
SIGBUS	BUS_ADRALN	invalid address alignment
	BUS_ADRERR	non-existent physical address
	BUS_OBJERR	objectspecific 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	tracedchild 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	inputmessage 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 thesesignals do not already possess kernel-levelsiginfo codes, thesiginfosi_code willbe filled withSI_RCTL to indicate a kernel-generated signal from an established resourcecontrol value.

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

The uncatchable signalsSIGSTOP andSIGKILL have undefinedsiginfo codes.

Signals sent with asiginfo code ofSI_RCTL contain code-dependent information forkernel-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	addressof faulting instruction
SIGFPE
SIGSEGV	caddr_t si_addr	address of faulting memory reference
SIGBUS
SIGCHLD	pid_t si_pid	child process ID
	intsi_status	exit value or signal
SIGPOLL	long si_band	band event for`POLL_IN`,`POLL_OUT`, or`POLL_MSG`

Notes

ForSIGCHLD signals, ifsi_code is equal toCLD_EXITED,thensi_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 ofsi_addr might notbe available; in that case,si_addr is guaranteed to be on thesame page as the faulting instruction or memory reference.

Skip Navigation Links
Exit Print View
	man pages section 3: Library Interfaces and Headers Oracle Solaris 11 Information Library

Movatterモバイル変換

siginfo.h

, siginfo

Synopsis

Description

User Signals

System Signals

See Also

Notes