qsort segfault в C

Я пытаюсь использовать qsort в соответствии с справочной страницей, но независимо от того, что я пытаюсь, я продолжаю получать segfault

Вот часть кода, которая имеет значение

int compare_dirent(const void *a, const void *b)
{
    const struct dirent *first = (const struct dirent *) a;
    const struct dirent *second = (const struct dirent *) b;

    return first->d_ino - second->d_ino;
}


int process(FILE* output,const char *dirname, int flags)
{
    struct dirent *entries = NULL;
    struct dirent *table[256];
    int entry_num = 0;
    DIR *directory = NULL;
    char cwd[1024];

    getcwd(cwd,1024);
    bzero(table,256);

    directory = opendir(dirname);
    while((entries = readdir(directory))!=NULL)
    {
        if(entries->d_type == DT_REG)
        {
            fprintf(output,"%s\t\n",entries->d_name);
            table[entry_num] = entries;
            entry_num++;
        }
    }
    fprintf(stderr,"last entry: %s\n", table[entry_num-1]->d_name);

    /* RIGHT HERE */
    qsort(table, entry_num, sizeof(struct dirent), &compare_dirent);

    return entry_num;
}

При запуске gdb я вижу список файлов в каталоге по fprintf в цикле while и вижу последнюю запись. Я поставил точку останова в сравнении, которая выполняется N раз, где N — количество файлов, а затем я сразу же получаю SEGFAULT от _qsort.

При N-м вызове compare_dirent из qsort происходит сбой.

Вот вывод gdb

Starting program: /Users/luke/Documents/Dev/code/cs647/prog2/bin/prog2 ./
Reading symbols for shared libraries +........................ done
.main.c.swp 
get_pdf.sh  
main.c  
main.o  
Makefile    
program2.pdf    
test.txt    
last entry: test.txt

Breakpoint 1, compare_dirent (a=0x7fff5fbff018, b=0x7fff5fbfec00) at main.c:88
88      const struct dirent *first = (const struct dirent *) a;
(gdb) n
89      const struct dirent *second = (const struct dirent *) b;
(gdb) n
91      return first->d_ino - second->d_ino;
(gdb) c
Continuing.

Breakpoint 1, compare_dirent (a=0x7fff5fbff430, b=0x7fff5fbfec00) at main.c:88
88      const struct dirent *first = (const struct dirent *) a;
(gdb) c
Continuing.

Breakpoint 1, compare_dirent (a=0x7fff5fbff848, b=0x7fff5fbfec00) at main.c:88
88      const struct dirent *first = (const struct dirent *) a;
(gdb) c
Continuing.

Breakpoint 1, compare_dirent (a=0x7fff5fbffc60, b=0x7fff5fbfec00) at main.c:88
88      const struct dirent *first = (const struct dirent *) a;
(gdb) c
Continuing.

Breakpoint 1, compare_dirent (a=0x7fff5fc00078, b=0x7fff5fbfec00) at main.c:88
88      const struct dirent *first = (const struct dirent *) a;
(gdb) c
Continuing.

Breakpoint 1, compare_dirent (a=0x7fff5fc00490, b=0x7fff5fbfec00) at main.c:88
88      const struct dirent *first = (const struct dirent *) a;
(gdb) c
Continuing.

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00007fff5fc00490
0x00007fff8e238540 in _qsort ()

Решение (полное) было немного обоих ответов

int compare_dirent(const void *a, const void *b)
{
    const struct dirent *first = (const struct dirent *) a;
    const struct dirent *second = (const struct dirent *) b;

    return first->d_ino - second->d_ino;
}


int process(FILE* output,const char *dirname, int flags)
{
    struct dirent *entries = NULL;
    struct dirent table[256];
    int entry_num = 0;
    DIR *directory = NULL;
    char cwd[1024];

    getcwd(cwd,1024);
    bzero(table,256);

    directory = opendir(dirname);
    while((entries = readdir(directory))!=NULL)
    {
        if(entries->d_type == DT_REG)
        {
            fprintf(output,"%s\t\n",entries->d_name);
            memcpy(table+entry_num, entries, sizeof(struct dirent));
            entry_num++;
        }
    }
    fprintf(stderr,"size: %lu\n", sizeof(struct dirent));
    qsort(table, entry_num, sizeof(struct dirent) , compare_dirent);

    fprintf(output,"\n\n");
    for(int i=0;i<entry_num;i++)
    {
        fprintf(output,"%s\n", table[i].d_name);
    }

    return entry_num;
}