1 #include "threadimpl.h"
2 /*
3  * To use this you need some patches to Valgrind that
4  * let it help out with detecting stack overflow. 
5  */
6 #ifdef USEVALGRIND
7 #include <valgrind/memcheck.h>
8 #endif
9 
10 static void
11 launcher386(void (*f)(void *arg), void *arg)
12 {
13 	Proc *p;
14 	Thread *t;
15 
16 	p = _threadgetproc();
17 	t = p->thread;
18 	_threadstacklimit(t->stk);
19 
20 	(*f)(arg);
21 	threadexits(nil);
22 }
23 
24 void
25 _threadinitstack(Thread *t, void (*f)(void*), void *arg)
26 {
27 	ulong *tos;
28 
29 	tos = (ulong*)&t->stk[t->stksize&~7];
30 	*--tos = (ulong)arg;
31 	*--tos = (ulong)f;
32 	t->sched.pc = (ulong)launcher386;
33 	t->sched.sp = (ulong)tos - 8;		/* old PC and new PC */
34 }
35 
36 void
37 _threadinswitch(int enter)
38 {
39 	USED(enter);
40 #ifdef USEVALGRIND
41 	if(enter)
42 		VALGRIND_SET_STACK_LIMIT(0, 0, 1);
43 	else
44 		VALGRIND_SET_STACK_LIMIT(0, 0, 0);
45 #endif
46 }
47 
48 void
49 _threadstacklimit(void *addr)
50 {
51 	USED(addr);
52 
53 #ifdef USEVALGRIND
54 	VALGRIND_SET_STACK_LIMIT(1, addr, 0);
55 #endif
56 }