experiments.old.c

#include <sched.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
 
void *copy_stack(void *dst) {
    pid_t tid = gettid();
    char buff[256];
    snprintf(buff, sizeof(buff), "/proc/self/task/%d/maps", tid);
    FILE *file = fopen(buff, "r");
    if (!file) file = fopen("/proc/self/maps", "r");
    if (!file) return nullptr;
 
    uintptr_t stack_start = 0, stack_end = 0;
 
    while (fgets(buff, sizeof(buff), file)) {
        if (strstr(buff, "[stack]")) {
            char *end;
            stack_start = strtoul(buff, &end, 16);
            stack_end = strtoul(end + 1, &end, 16);
            break;
        }
    }
 
    fclose(file);
 
    memcpy(dst, (void*)stack_start, stack_end - stack_start);
    return (void*)stack_end;
}