CODEWITHSUNDEEP
cmemorysegmentation-fault
t14njin
t14njin

Reputation: 45

How to detect memory addresses that cause Address Boundary Error when writing data on it

I have this C program:

void main(){
    *(unsigned int*)0x100000 = 0xdeadbeef;
}

When running this C Program, it obviously causes an address boundary error when running. Is there a way to detect potential address boundary errors on certain memory addresses?

Upvotes: 1

Views: 100

Answers (1)

kzsnyk
kzsnyk

Reputation: 2211

Here is a way to recover from a SIGSEGV signal by using a signal handler and performing a non local goto :

#include <stdio.h>
#include <signal.h>
#include <setjmp.h>

static volatile sig_atomic_t jump = 0;
static sigjmp_buf env;

static void handler(int sig)
{
    if (!jump)
        return;

    siglongjmp(env, 1);
}

int main()
{
    /* install the signal handler */
    struct sigaction sa;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;
    sa.sa_handler = handler;

    if (sigaction(SIGSEGV, &sa, NULL) == -1) {

        perror("sigaction");
        return 1;
    }

    if (sigsetjmp(env, 1) == 0) {

        jump = 1;
        /* will trigger SIGSEGV */
        *(unsigned int *)0x100000 = 0xdeadbeef;

    } else {
        /* after siglongjmp */
        puts("SIGSEGV detected");
        return 0;
    }

    return 1;
}

It is POSIX specific but at least it can gives a clue on how it can be done on Linux for example. Hope this helps.

Upvotes: 1

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