// https://syzkaller.appspot.com/bug?id=84eb6336ee2426ddc34156f2cabba8c7e22c84d1
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <string.h>
#include <errno.h>

#define MAX_FILES 256
#define NUM_THREADS 8
#define ITERATIONS 10000

char target_files[MAX_FILES][256];
int num_files = 0;

void *read_status(void *arg)
{
    char buf[64];
    for (int i = 0; i < ITERATIONS; i++) {
        for (int j = 0; j < num_files; j++) {
            int fd = open(target_files[j], O_RDONLY);
            if (fd >= 0) {
                if (read(fd, buf, sizeof(buf)) < 0) {
                    /* Ignore read errors as we just want to trigger ACPI methods */
                }
                close(fd);
            }
        }
    }
    return NULL;
}

int main(void)
{
    DIR *dir = opendir("/sys/bus/acpi/devices");
    if (!dir) {
        printf("[-] Failed to opendir /sys/bus/acpi/devices: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] opendir /sys/bus/acpi/devices successful.\n");
    
    struct dirent *ent;
    while ((ent = readdir(dir)) != NULL && num_files < MAX_FILES) {
        if (ent->d_name[0] == '.') 
            continue;
            
        snprintf(target_files[num_files], sizeof(target_files[num_files]), 
                 "/sys/bus/acpi/devices/%s/status", ent->d_name);
                 
        if (access(target_files[num_files], R_OK) == 0) {
            num_files++;
        }
    }
    closedir(dir);

    if (num_files == 0) {
        printf("[-] No readable ACPI status files found.\n");
        exit(1);
    }
    printf("[+] Found %d readable ACPI status files.\n", num_files);

    pthread_t threads[NUM_THREADS];
    for (int i = 0; i < NUM_THREADS; i++) {
        int res = pthread_create(&threads[i], NULL, read_status, NULL);
        if (res != 0) {
            printf("[-] Failed to pthread_create: %s\n", strerror(res));
            exit(1);
        }
    }
    printf("[+] pthread_create successful.\n");

    for (int i = 0; i < NUM_THREADS; i++) {
        int res = pthread_join(threads[i], NULL);
        if (res != 0) {
            printf("[-] Failed to pthread_join: %s\n", strerror(res));
            exit(1);
        }
    }
    printf("[+] pthread_join successful.\n");

    return 0;
}