---
breadcrumbs:
- - /chromium-os/developer-library/reference
  - Chromium OS > Developer Library > Reference
page_name: signals
title: Linux Signal Table
---

These are the signal numbers and their corresponding symbolic names.

While some architectures/ABIs have different number<->symbol mappings, they're
equivalent on x86 (32-bit & 64-bit) and arm (32-bit & 64-bit).

For more details on signals in general, see the [signal(7)] man page.

## Real-time Signals

The `SIGRTMIN` & `SIGRTMAX` values listed below are technically dynamic.
Implementations (e.g. glibc) are allowed to reserve things internally from the
user's program.
The constants listed below reflect the most common scenarios people see,
especially since real-time signal usage is not that common.
Keep this in mind if you see signal usage in that range.

For more in-depth details, see the Real-time signals chapter in the [signal(7)]
man page.

[pthreads(7)]: https://man7.org/linux/man-pages/man7/pthreads.7.html
[signal(7)]: https://man7.org/linux/man-pages/man7/signal.7.html

## Table

<!--
Note: This table is generated by the signals.py helper script.  Do not hand edit.
-->

| number | hex | symbol | description |
|:------:|:---:|--------|-------------|
| 1 | 0x01 | SIGHUP | Hangup |
| 2 | 0x02 | SIGINT | Interrupt |
| 3 | 0x03 | SIGQUIT | Quit |
| 4 | 0x04 | SIGILL | Illegal instruction |
| 5 | 0x05 | SIGTRAP | Trace/breakpoint trap |
| 6 | 0x06 | SIGABRT | Aborted |
| 6 | 0x06 | SIGIOT | *(Same value as SIGABRT)* Aborted |
| 7 | 0x07 | SIGBUS | Bus error |
| 8 | 0x08 | SIGFPE | Floating point exception |
| 9 | 0x09 | SIGKILL | Killed |
| 10 | 0x0a | SIGUSR1 | User defined signal 1 |
| 11 | 0x0b | SIGSEGV | Segmentation fault |
| 12 | 0x0c | SIGUSR2 | User defined signal 2 |
| 13 | 0x0d | SIGPIPE | Broken pipe |
| 14 | 0x0e | SIGALRM | Alarm clock |
| 15 | 0x0f | SIGTERM | Terminated |
| 16 | 0x10 | SIGSTKFLT | Stack fault |
| 17 | 0x11 | SIGCHLD | Child exited |
| 17 | 0x11 | SIGCLD | *(Same value as SIGCHLD)* Child exited |
| 18 | 0x12 | SIGCONT | Continued |
| 19 | 0x13 | SIGSTOP | Stopped (signal) |
| 20 | 0x14 | SIGTSTP | Stopped |
| 21 | 0x15 | SIGTTIN | Stopped (tty input) |
| 22 | 0x16 | SIGTTOU | Stopped (tty output) |
| 23 | 0x17 | SIGURG | Urgent I/O condition |
| 24 | 0x18 | SIGXCPU | CPU time limit exceeded |
| 25 | 0x19 | SIGXFSZ | File size limit exceeded |
| 26 | 0x1a | SIGVTALRM | Virtual timer expired |
| 27 | 0x1b | SIGPROF | Profiling timer expired |
| 28 | 0x1c | SIGWINCH | Window changed |
| 29 | 0x1d | SIGPOLL | I/O possible |
| 29 | 0x1d | SIGIO | *(Same value as SIGPOLL)* I/O possible |
| 30 | 0x1e | SIGPWR | Power failure |
| 31 | 0x1f | SIGSYS | Bad system call |
| 32 | 0x20 | SIGRTMIN-2 | Real-time signal reserved by the C library for [NPTL][pthreads(7)]; see [signal(7)] |
| 33 | 0x21 | SIGRTMIN-1 | Real-time signal reserved by the C library for [NPTL][pthreads(7)]; see [signal(7)] |
| 34 | 0x22 | SIGRTMIN | Real-time signal 0 |
| 35 | 0x23 | SIGRTMIN+1 | Real-time signal 1 |
| 36 | 0x24 | SIGRTMIN+2 | Real-time signal 2 |
| 37 | 0x25 | SIGRTMIN+3 | Real-time signal 3 |
| 38 | 0x26 | SIGRTMIN+4 | Real-time signal 4 |
| 39 | 0x27 | SIGRTMIN+5 | Real-time signal 5 |
| 40 | 0x28 | SIGRTMIN+6 | Real-time signal 6 |
| 41 | 0x29 | SIGRTMIN+7 | Real-time signal 7 |
| 42 | 0x2a | SIGRTMIN+8 | Real-time signal 8 |
| 43 | 0x2b | SIGRTMIN+9 | Real-time signal 9 |
| 44 | 0x2c | SIGRTMIN+10 | Real-time signal 10 |
| 45 | 0x2d | SIGRTMIN+11 | Real-time signal 11 |
| 46 | 0x2e | SIGRTMIN+12 | Real-time signal 12 |
| 47 | 0x2f | SIGRTMIN+13 | Real-time signal 13 |
| 48 | 0x30 | SIGRTMIN+14 | Real-time signal 14 |
| 49 | 0x31 | SIGRTMIN+15 | Real-time signal 15 |
| 50 | 0x32 | SIGRTMAX-14 | Real-time signal 16 |
| 51 | 0x33 | SIGRTMAX-13 | Real-time signal 17 |
| 52 | 0x34 | SIGRTMAX-12 | Real-time signal 18 |
| 53 | 0x35 | SIGRTMAX-11 | Real-time signal 19 |
| 54 | 0x36 | SIGRTMAX-10 | Real-time signal 20 |
| 55 | 0x37 | SIGRTMAX-9 | Real-time signal 21 |
| 56 | 0x38 | SIGRTMAX-8 | Real-time signal 22 |
| 57 | 0x39 | SIGRTMAX-7 | Real-time signal 23 |
| 58 | 0x3a | SIGRTMAX-6 | Real-time signal 24 |
| 59 | 0x3b | SIGRTMAX-5 | Real-time signal 25 |
| 60 | 0x3c | SIGRTMAX-4 | Real-time signal 26 |
| 61 | 0x3d | SIGRTMAX-3 | Real-time signal 27 |
| 62 | 0x3e | SIGRTMAX-2 | Real-time signal 28 |
| 63 | 0x3f | SIGRTMAX-1 | Real-time signal 29 |
| 64 | 0x40 | SIGRTMAX | Real-time signal 30 |
