| Updated: October 28, 2024 |
Information about a signal
#include <sys/siginfo.h>
typedef struct {
int si_signo;
int si_code;
int si_errno;
union {
int __pad[7];
struct {
pid_t __pid;
union {
struct {
uid_t __uid;
union sigval __value;
} __kill; /* si_code <= 0 SI_FROMUSER */
struct {
clock_t __utime;
int __status; /* CLD_EXITED status, else signo */
clock_t __stime;
} __chld; /* si_signo=SIGCHLD si_code=CLD_* */
} __pdata;
} __proc;
struct {
int __fltno;
void *__fltip;
void *__addr;
int __bdslot;
} __fault; /* si_signo=SIGSEGV,ILL,FPE,TRAP,BUS */
} __data;
} siginfo_t;
#define si_pid __data.__proc.__pid
#define si_value __data.__proc.__pdata.__kill.__value
#define si_uid __data.__proc.__pdata.__kill.__uid
#define si_status __data.__proc.__pdata.__chld.__status
#define si_utime __data.__proc.__pdata.__chld.__utime
#define si_stime __data.__proc.__pdata.__chld.__stime
#define si_fltno __data.__fault.__fltno
#define si_trapno si_fltno
#define si_addr __data.__fault.__addr
#define si_fltip __data.__fault.__fltip
#define si_bdslot __data.__fault.__bdslot
The siginfo_t structure is used to hold information about a signal. It's defined in <sys/siginfo.h>, which <signal.h> includes. This structure includes the following:
| Value | Description |
|---|---|
| -128 <= si_code <= 0 | User values; you can provide this when you call SignalKill() or SignalKillSigval() |
| 0 < si_code <= 127 | System values generated by the kernel |
QNX Neutrino defines SI_FROMUSER() and SI_FROMKERNEL() macros that determine whether or not an si_code value falls in the above ranges.
POSIX defines the following values, not all of which QNX Neutrino uses:
| Signal | Code | Reason |
|---|---|---|
| SIGILL | ILL_ILLOPC | Illegal opcode |
| ILL_ILLOPN | Illegal operand (not currently used) | |
| ILL_ILLADR | Illegal addressing mode (not currently used) | |
| ILL_ILLTRP | Illegal trap (not currently used) | |
| ILL_PRVOPC | Privileged opcode; instruction requires privileged CPU mode | |
| ILL_PRVREG | Privileged register (not currently used) | |
| ILL_COPROC | Coprocessor instruction error | |
| ILL_BADSTK | Internal stack error | |
| SIGFPE | FPE_INTDIV | Integer division 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 (not currently used) | |
| SIGSEGV | SEGV_MAPERR | Address isn't mapped to an object |
| SEGV_ACCERR | The mapping doesn't allow the attempted access | |
| SIGBUS | BUS_ADRALN | Invalid address alignment |
| BUS_ADRERR | The MMU detected a problem with page table translation | |
| BUS_OBJERR | Object-specific hardware error | |
| BUS_ENDOBJ | The mapping doesn't span the area of the memory object | |
| BUS_ENOMEM | A fault failed to allocate memory; this should only occur when using lazy mappings | |
| BUS_SRVERR | Used in conjunction with another SIGBUS code to represent an error returned by an external resource manager when faulting on a page backed by the resource manager. For example, BUS_SRVERR + BUS_EINVAL means that the resource manager replied with EINVAL to the memory manager's request to read or write a page. | |
| SIGTRAP | TRAP_BRKPT | Process breakpoint trap |
| TRAP_TRACE | Process trace trap | |
| SIGCHLD | CLD_EXITED | Child has exited |
| CLD_KILLED | Child has terminated abnormally and did not create a core file | |
| CLD_DUMPED | Child has terminated abnormally and created a core file | |
| CLD_TRAPPED | Traced child has trapped | |
| CLD_STOPPED | Child has stopped | |
| CLD_CONTINUED | Stopped child has 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 | |
| Any | SI_USER | Signal sent by kill() |
| SI_QUEUE | Signal sent by sigqueue() | |
| SI_TIMER | Signal generated by expiration of a timer set by timer_settime() | |
| SI_ASYNCIO | Signal generated by completion of an asynchronous I/O request | |
| SI_MESGQ | Signal generated by arrival of a message on an empty POSIX (not QNX) message queue |
QNX Neutrino also defines the following:
| Signal | Code | Reason |
|---|---|---|
| SIGFPE | FPE_NOFPU | No floating point hardware or software emulator present |
| FPE_NOMEM | No memory for floating point context save area | |
| SIGSEGV | SEGV_STKERR | Stack exception |
| SEGV_GPERR | General protection | |
| SEGV_IRQERR | Interrupt handler fault (not currently used) | |
| SIGTRAP | TRAP_KDBRK | Kdebug breakpoint |
| TRAP_CRASH | Crash |
As a QNX Neutrino extension, if si_code is SI_NOINFO, only si_signo is valid.
| Signal | Member | Value |
|---|---|---|
| SIGILL, SIGFPE | void *si_addr | The address of the faulting instruction |
| SIGSEGV, SIGBUS | void *si_addr | The address of the faulting memory reference |
| SIGCHLD | pid_t si_pid | The child process ID |
| int si_status | The exit value or signal | |
| uid_t si_uid | The real user ID of the process that sent the signal |
QNX Neutrino defines the following:
| Signal | Member | Value |
|---|---|---|
| SIGILL, SIGFPE, SIGSEGV, SIGBUS | int si_fltno | The fault number (see below) |
| void * si_fltip | The address of the instruction that caused the fault | |
| int si_bdslot | (QNX Neutrino 6.3.2 or later) Nonzero if the faulting instruction
is in a branch delay slot on architectures that support them
Earlier versions of procnto left this field as a random value, so you should check the procnto version number before examining this field. |
|
| SIGTRAP | int si_trapno | The trap number |
| SIGCHLD | clock_t si_utime | The user time consumed, in clock ticks |
| clock_t si_stime | The system time consumed, in clock ticks |
The fault numbers (reported in si_fltno), are defined in <sys/fault.h> and include:
Target-specific fault numbers are defined in <platform/fault.h>.
POSIX 1003.1, with QNX Neutrino extensions