Signal system calls
Signals are software interrupts that provide a mechanism for handling asynchronous events. These events can originate from outside the system - such as when the user generates the interrupt character (usually via Ctrl-C) - or from activities within the program or kernel, such as when the process executes code that divides by zero. As a primitive form of interprocess communication (IPC), one process can also send a signal to another process.
Contents
Tip: For detailed information about each system call please read: Linux man pages
Standard signals
| Syscall | Number | Description |
|---|---|---|
| KILL | 62 | Send signal to a process |
| TKILL | 200 | Send a signal to a thread |
| TGKILL | 234 | Send a signal to a thread |
| PAUSE | 34 | Wait for a signal |
Real-time signals
| Syscall | Number | Description |
|---|---|---|
| RT_SIGACTION | 13 | Examine and change a signal action |
| RT_SIGPROCMASK | 14 | Examine and change blocked signals |
| RT_SIGPENDING | 127 | Examine pending signals |
| RT_SIGQUEUEINFO | 129 | Queue a signal and data |
| RT_TGSIGQUEUEINFO | 297 | Queue a signal and data |
| RT_SIGTIMEDWAIT | 128 | Synchronously wait for queued signals |
| RT_SIGSUSPEND | 130 | Wait for a signal |
| RT_SIGRETURN | 15 | Return from signal handler and cleanup stack frame |
| SIGALTSTACK | 131 | Set and/or get signal stack context |
File descriptor based signals
| Syscall | Number | Description |
|---|---|---|
| SIGNALFD | 282 | Create a file descriptor for accepting signals |
| SIGNALFD4 | 289 | Create a file descriptor for accepting signals |
| EVENTFD | 284 | Create a file descriptor for event notification |
| EVENTFD2 | 290 | Create a file descriptor for event notification |
Miscellaneous
| Syscall | Number | Description |
|---|---|---|
| RESTART_SYSCALL | 219 | Restart a system call after interruption by a stop signal |