1#define _GNU_SOURCE
 2#include "pthread_impl.h"
 3#include "libc.h"
 4#include <sys/mman.h>
 5
 6int pthread_getattr_np(pthread_t t, pthread_attr_t *a)
 7{
 8	*a = (pthread_attr_t){0};
 9	a->_a_detach = t->detach_state>=DT_DETACHED;
10	a->_a_guardsize = t->guard_size;
11	if (t->stack) {
12		a->_a_stackaddr = (uintptr_t)t->stack;
13		a->_a_stacksize = t->stack_size;
14	} else {
15		char *p = (void *)libc.auxv;
16		size_t l = PAGE_SIZE;
17		p += -(uintptr_t)p & PAGE_SIZE-1;
18		a->_a_stackaddr = (uintptr_t)p;
19		while (mremap(p-l-PAGE_SIZE, PAGE_SIZE, 2*PAGE_SIZE, 0)==MAP_FAILED && errno==ENOMEM)
20			l += PAGE_SIZE;
21		a->_a_stacksize = l;
22	}
23	return 0;
24}