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@mortenpi
Last active March 2, 2023 01:41
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Recover gracefully from a segmentation fault (SIGSEGV) in C due to invalid pointer.
/*
Credits to:
- https://linux.die.net/man/2/setcontext
- https://stackoverflow.com/questions/8456085/why-cant-i-ignore-sigsegv-signal
*/
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <signal.h>
#include <setjmp.h>
bool debug_catch_sigsegv_mode = false;
static jmp_buf jbuf;
void debug_signal_handler(int signo)
{
if(debug_catch_sigsegv_mode) {
//printf("\nsignal_handler: received %d\n", signo);
siglongjmp(jbuf, 1);
} else {
SIG_DFL(signo);
}
}
void debug_enable_sigsev_handler() {
if(signal(SIGSEGV, debug_signal_handler) == SIG_ERR) {
printf("enable_sigsev_handler: ERROR, can't catch SIGSEGV\n");
}
}
void debug_print_pointer(const void* ptr)
{
long ptr_deref;
printf("debug_print_pointer(%p) = ", ptr);
debug_catch_sigsegv_mode = true;
if(ptr != NULL && sigsetjmp(jbuf, !0) == 0) {
ptr_deref = *(long*)ptr;
printf("[%016lx]", ptr_deref);
} else {
printf("<segmentation fault>");
}
debug_catch_sigsegv_mode = false;
printf("\n");
}
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