Synopsis

Call only asynchronous-safe functions within signal handlers

Enabled by default

Yes

Severity/Certainty

High/High

Full description

Program behavior is undefined if the signal handler calls any function in the standard library that is not asynchronous-safe.

Coding standards

Code examples

The following code example fails the check and will give a warning:

#include <signal.h>
#include <stdlib.h>
 
void handler(int signum) {
    int *x = malloc(sizeof(int));
}
 
void example(void) {
    signal(SIGINT, handler);
}

The following code example passes the check and will not give a warning about this issue:

#include <signal.h>

void foo(void) {
    _exit();
}

void handler(int signum) {
    foo();
}
 
void example(void) {
    signal(SIGINT, handler);
}