/*
 * Copyright 2002-2019 Intel Corporation.
 * 
 * This software is provided to you as Sample Source Code as defined in the accompanying
 * End User License Agreement for the Intel(R) Software Development Products ("Agreement")
 * section 1.L.
 * 
 * This software and the related documents are provided as is, with no express or implied
 * warranties, other than those that are expressly stated in the License.
 */

/*! @file
 * We test two aspects:
   - tls value before and after PIN_Detach()
   - creation new threads while PIN is detached from application

 */

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <unistd.h> 
#include <asm/prctl.h> 
#include <sys/prctl.h> 
#include <errno.h>
#include <string.h>
#include <sys/utsname.h>


#define NTHREADS 4

pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

unsigned int numOfThreadsReadyForDetach = 0;
unsigned long pinDetached = 0;

extern "C" void TellPinToDetach(unsigned long *updateWhenReady)
{
    return;
}

/* 
 * Compare FS_BASE values before and after detach.
 */
void * thread_func (void *arg)
{
    unsigned long thread_no = (unsigned long)arg+1;

    unsigned long fsBase = 0;
    int res = syscall(SYS_arch_prctl, ARCH_GET_FS, &fsBase);
    if (res != 0)
    {
        printf("SYS_arch_prctl failed with error: %s\n", strerror(errno));
        return 0;
    }

    pthread_mutex_lock(&mutex);
    numOfThreadsReadyForDetach++;
    pthread_mutex_unlock(&mutex);
    
    while (!pinDetached)
    {
        sched_yield();
    }
    
    unsigned long fsBaseAfterDetach = 0;
    res = syscall(SYS_arch_prctl, ARCH_GET_FS, &fsBaseAfterDetach);
    if (res != 0)
    {
        printf("SYS_arch_prctl failed with error: %s\n", strerror(errno));
        return (void*)1;
    }
    
    if (fsBase != fsBaseAfterDetach)
    {
        fprintf(stderr, "ERROR in thread %lu: FS_BASE before detach 0x%lx; after detach 0x%lx\n",
                thread_no, fsBase, fsBaseAfterDetach);
        return (void*)1;
    }
    else
    {
        fprintf(stderr, "fs base in thread %lu: 0x%lx\n", thread_no, fsBase);
    }
    return 0;
}

int main (int argc, char *argv[])
{
    pthread_t h[NTHREADS];

    unsigned long fsBase = 0;
    int res = syscall(SYS_arch_prctl, ARCH_GET_FS, &fsBase);
    if (res != 0)
    {
        printf("SYS_arch_prctl failed with error: %s\n", strerror(errno));
        return -1;
    }

    for (unsigned long i = 0; i < NTHREADS; i++)
    {
        pthread_create (&h[i], 0, thread_func, (void *)i);
    }
    
    /*
     * If the number of threads is big, some threads leave system call "clone"
     * while PIN is detached. This functionality is also tested here.
     */ 

    TellPinToDetach(&pinDetached);
    
    void * result[NTHREADS];
    for (unsigned long i = 0; i < NTHREADS; i++)
    {
        pthread_join (h[i], &(result[i]));
    }
    for (unsigned long i = 0; i < NTHREADS; i++)
    {
        if (result[i] != 0)
        {
            fprintf(stderr, "TEST FAILED\n");
            return -1;
        }
    }
    unsigned long fsBaseAfterDetach = 0;
    res = syscall(SYS_arch_prctl, ARCH_GET_FS, &fsBaseAfterDetach);
    
    if (fsBase != fsBaseAfterDetach)
    {
        fprintf(stderr, "ERROR in the main thread: FS_BASE before detach 0x%lx; after detach 0x%lx\n",
                fsBase, fsBaseAfterDetach);
        return -1;
    }
    fprintf(stderr, "TEST PASSED\n");
    return 0;
}