Introduction
If you are a developer, you might have come across the error message 'error: protect(): protection stack overflow.' This error message is usually displayed when there is an issue with the stack size or stack overflow protection.
In this guide, we will provide you with valuable information on how to troubleshoot this error efficiently. We will also provide you with a step-by-step solution to fix the issue.
Understanding the Error Message
The error message 'error: protect(): protection stack overflow' usually occurs when there is an issue with the stack overflow protection. The stack overflow protection is a mechanism that prevents the stack from overflowing.
The stack is a data structure that is used by the program to store variables and function calls. When a function is called, the program pushes the current state of the program onto the stack. When the function returns, the program pops the state from the stack.
If the stack overflows, it can cause the program to crash or behave unexpectedly. The stack overflow protection is a mechanism that prevents this from happening.
Troubleshooting the Error
To troubleshoot the error, you need to check the stack size and stack overflow protection. Here are the steps to follow:
- Check the stack size: You need to check the stack size of your program. You can do this by adding the following code to your program:
#include <stdio.h>
#include <stdlib.h>
int main()
{
printf("Stack size: %d\n", (int)(&stack) - (int)(&main));
return 0;
}
This code calculates the size of the stack. If the stack size is too small, you can increase it by adding the following code to your program:
#include <sys/resource.h>
int main()
{
const rlim_t kStackSize = 64L * 1024L * 1024L; // min stack size = 64 Mb
struct rlimit rl;
int result;
result = getrlimit(RLIMIT_STACK, &rl);
if (result == 0)
{
if (rl.rlim_cur < kStackSize)
{
rl.rlim_cur = kStackSize;
result = setrlimit(RLIMIT_STACK, &rl);
if (result != 0)
{
fprintf(stderr, "setrlimit returned result = %d\n", result);
}
}
}
printf("Stack size: %d\n", (int)(&stack) - (int)(&main));
return 0;
}
This code increases the stack size to 64MB. You can adjust the stack size as per your requirement.
- Check the stack overflow protection: You need to check the stack overflow protection of your program. You can do this by adding the following code to your program:
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
void handler(int sig)
{
fprintf(stderr, "Error: signal %d\n", sig);
exit(EXIT_FAILURE);
}
int main()
{
struct sigaction sa;
sa.sa_handler = handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_ONSTACK;
if (sigaltstack(NULL, &sa.sa_restorer) == -1)
{
perror("sigaltstack");
exit(EXIT_FAILURE);
}
sa.sa_restorer = NULL;
if (sigaction(SIGSEGV, &sa, NULL) == -1)
{
perror("sigaction");
exit(EXIT_FAILURE);
}
// Your program code here
return 0;
}
This code sets up the stack overflow protection. If the stack overflows, it will generate a SIGSEGV signal, which will be caught by the handler function.
FAQ
Q1. What causes the 'error: protect(): protection stack overflow' error message?
The 'error: protect(): protection stack overflow' error message is usually caused by an issue with the stack size or stack overflow protection.
Q2. How can I increase the stack size of my program?
You can increase the stack size of your program by adding the following code to your program:
#include <sys/resource.h>
int main()
{
const rlim_t kStackSize = 64L * 1024L * 1024L; // min stack size = 64 Mb
struct rlimit rl;
int result;
result = getrlimit(RLIMIT_STACK, &rl);
if (result == 0)
{
if (rl.rlim_cur < kStackSize)
{
rl.rlim_cur = kStackSize;
result = setrlimit(RLIMIT_STACK, &rl);
if (result != 0)
{
fprintf(stderr, "setrlimit returned result = %d\n", result);
}
}
}
printf("Stack size: %d\n", (int)(&stack) - (int)(&main));
return 0;
}
This code increases the stack size to 64MB. You can adjust the stack size as per your requirement.
Q3. How can I check the stack size of my program?
You can check the stack size of your program by adding the following code to your program:
#include <stdio.h>
#include <stdlib.h>
int main()
{
printf("Stack size: %d\n", (int)(&stack) - (int)(&main));
return 0;
}
This code calculates the size of the stack.
Q4. What is the stack overflow protection?
The stack overflow protection is a mechanism that prevents the stack from overflowing. If the stack overflows, it can cause the program to crash or behave unexpectedly.
Q5. How can I set up the stack overflow protection?
You can set up the stack overflow protection by adding the following code to your program:
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
void handler(int sig)
{
fprintf(stderr, "Error: signal %d\n", sig);
exit(EXIT_FAILURE);
}
int main()
{
struct sigaction sa;
sa.sa_handler = handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_ONSTACK;
if (sigaltstack(NULL, &sa.sa_restorer) == -1)
{
perror("sigaltstack");
exit(EXIT_FAILURE);
}
sa.sa_restorer = NULL;
if (sigaction(SIGSEGV, &sa, NULL) == -1)
{
perror("sigaction");
exit(EXIT_FAILURE);
}
// Your program code here
return 0;
}
This code sets up the stack overflow protection. If the stack overflows, it will generate a SIGSEGV signal, which will be caught by the handler function.