1siginfo.h(3HEAD) Headers siginfo.h(3HEAD)
2
6 siginfo.h, siginfo - signal generation information
7
9 #include <siginfo.h>
10
13 If a process is catching a signal, it might request information that
14 tells why the system generated that signal. See sigaction(2). If a
15 process is monitoring its children, it might receive information that
16 tells why a child changed state. See waitid(2). In either case, the
17 system returns the information in a structure of type siginfo_t, which
18 includes the following information:
19 int si_signo /* signal number */
21 int si_errno /* error number */
22 int si_code /* signal code */
23 union sigval si_value /* signal value */
24 si_signo contains the system-generated signal number. For the
28 waitid(2) function, si_signo is always SIGCHLD.
29 If si_errno is non-zero, it contains an error number associated with
32 this signal, as defined in <errno.h>.
33 si_code contains a code identifying the cause of the signal.
36 If the value of the si_code member is SI_NOINFO, only the si_signo
39 member of siginfo_t is meaningful, and the value of all other members
40 is unspecified.
41 User Signals
43 If the value of si_code is less than or equal to 0, then the signal
44 was generated by a user process (see kill(2), _lwp_kill(2),
45 sigqueue(3C), sigsend(2), abort(3C), and raise(3C)) and the siginfo
46 structure contains the following additional information:
47 pid_t si_pid /* sending process ID */
49 uid_t si_uid /* sending user ID */
50 ctid_t si_ctid /* sending contract ID */
51 zoneid_t si_zoneid /* sending zone ID */S
52 If the signal was generated by a user process, the following values are
56 defined for si_code:
57 SI_USER The implementation sets si_code to SI_USER if the signal
59 was sent by kill(2), sigsend(2), raise(3C) or abort(3C).
60 SI_LWP The signal was sent by _lwp_kill(2).
63 SI_QUEUE The signal was sent by sigqueue(3C).
66 SI_TIMER The signal was generated by the expiration of a timer
69 created by timer_settime(3C).
70 SI_ASYNCIO The signal was generated by the completion of an asyn‐
73 chronous I/O request.
74 SI_MESGQ The signal was generated by the arrival of a message on
77 an empty message queue. See mq_notify(3C).
78 si_value contains the application specified value, which is passed to
82 the application's signal-catching function at the time of the signal
83 delivery if si_code is any of SI_QUEUE, SI_TIMER, SI_ASYNCHIO, or
84 SI_MESGQ.
85 System Signals
87 Non-user generated signals can arise for a number of reasons. For all
88 of these cases, si_code contains a positive value reflecting the reason
89 why the system generated the signal:
90 Signal Code Reason
95 ──────────────────────────────────────────────────────────────────────────
96 SIGILL ILL_ILLOPC illegal opcode
97 ILL_ILLOPN illegal operand
98 ILL_ILLADR illegal addressing mode
99 ILL_ILLTRP illegal trap
100 ILL_PRVOPC privileged opcode
101 ILL_PRVREG privileged register
102 ILL_COPROC co-processor error
103 ILL_BADSTK internal stack error
104 ──────────────────────────────────────────────────────────────────────────
105 SIGFPE FPE_INTDIV integer divide by zero
106 FPE_INTOVF integer overflow
107 FPE_FLTDIV floating point divide by zero
108 FPE_FLTOVF floating point overflow
109 FPE_FLTUND floating point underflow
110 FPE_FLTRES floating point inexact result
111 FPE_FLTINV invalid floating point operation
112 FPE_FLTSUB subscript out of range
113 ──────────────────────────────────────────────────────────────────────────
114 SIGSEGV SEGV_MAPERR address not mapped to object
115 SEGV_ACCERR invalid permissions for mapped object
116 ──────────────────────────────────────────────────────────────────────────
117 SIGBUS BUS_ADRALN invalid address alignment
118 BUS_ADRERR non-existent physical address
119 BUS_OBJERR object specific hardware error
120 ──────────────────────────────────────────────────────────────────────────
121 SIGTRAP TRAP_BRKPT process breakpoint
122 TRAP_TRACE process trace trap
123 ──────────────────────────────────────────────────────────────────────────
124 SIGCHLD CLD_EXITED child has exited
125 CLD_KILLED child was killed
126 CLD_DUMPED child terminated abnormally
127 CLD_TRAPPED traced child has trapped
128 CLD_STOPPED child has stopped
129 CLD_CONTINUED stopped child had continued
130 ──────────────────────────────────────────────────────────────────────────
131 SIGPOLL POLL_IN data input available
132 POLL_OUT output buffers available
133 POLL_MSG input message available
134 POLL_ERR I/O error
136 POLL_PRI high priority input available
137 POLL_HUP device disconnected
138 Signals can also be generated from the resource control subsystem.
142 Where these signals do not already possess kernel-level siginfo codes,
143 the siginfo si_code will be filled with SI_RCTL to indicate a kernel-
144 generated signal from an established resource control value.
145 Signal Code Reason
150 ────────────────────────────────────────────────────────────────────
151 SIGXRES SI_RCTL resource-control generated signal
152 ────────────────────────────────────────────────────────────────────
153 SIGHUP
154 SIGTERM
155 The uncatchable signals SIGSTOP and SIGKILL have undefined siginfo
159 codes.
160 Signals sent with a siginfo code of SI_RCTL contain code-dependent
163 information for kernel-generated signals:
164 Code Field Value
169 ───────────────────────────────────────────────────────────────────
170 SI_RCTL hr_time si_entity process-model entity of control
171 In addition, the following signal-dependent information is available
175 for kernel-generated signals:
176 Signal Field Value
181 ────────────────────────────────────────────────────────────────────────
182 SIGILL caddr_t si_addr address of faulting instruction
183 ────────────────────────────────────────────────────────────────────────
184 SIGFPE
185 ────────────────────────────────────────────────────────────────────────
186 SIGSEGV caddr_t si_addr address of faulting memory reference
187 SIGBUS
188 ────────────────────────────────────────────────────────────────────────
189 SIGCHLD pid_t si_pid child process ID
190 int si_status exit value or signal
191 ────────────────────────────────────────────────────────────────────────
192 SIGPOLL long si_band band event for POLL_IN, POLL_OUT, or
193 POLL_MSG
194
197 _lwp_kill(2), kill(2), setrctl(2), sigaction(2), sigsend(2), waitid(2),
198 abort(3C), aio_read(3C), mq_notify(3C), raise(3C), signal.h(3HEAD),
199 sigqueue(3C), timer_create(3C), timer_settime(3C)
200
202 For SIGCHLD signals, if si_code is equal to CLD_EXITED, then
203 si_status is equal to the exit value of the process; otherwise, it is
204 equal to the signal that caused the process to change state. For some
205 implementations, the exact value of si_addr might not be available; in
206 that case, si_addr is guaranteed to be on the same page as the faulting
207 instruction or memory reference.
208SunOS 5.11 5 Feb 2008 siginfo.h(3HEAD)