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 #define USEVALGRIND 0
7 #ifdef USEVALGRIND
8 #include <valgrind/memcheck.h>
9 #endif
10 
11 static void
12 launcher386(void (*f)(void *arg), void *arg)
13 {
14 	Proc *p;
15 	Thread *t;
16 
17 	p = _threadgetproc();
18 	t = p->thread;
19 	_threadstacklimit(t->stk);
20 
21 	(*f)(arg);
22 	threadexits(nil);
23 }
24 
25 void
26 _threadinitstack(Thread *t, void (*f)(void*), void *arg)
27 {
28 	ulong *tos;
29 
30 	tos = (ulong*)&t->stk[t->stksize&~7];
31 	*--tos = (ulong)arg;
32 	*--tos = (ulong)f;
33 	t->sched.pc = (ulong)launcher386;
34 	t->sched.sp = (ulong)tos - 8;		/* old PC and new PC */
35 }
36 
37 void
38 _threadinswitch(int enter)
39 {
40 	USED(enter);
41 #ifdef USEVALGRIND
42 	if(enter)
43 		VALGRIND_SET_STACK_LIMIT(0, 0, 1);
44 	else
45 		VALGRIND_SET_STACK_LIMIT(0, 0, 0);
46 #endif
47 }
48 
49 void
50 _threadstacklimit(void *addr)
51 {
52 	USED(addr);
53 
54 #ifdef USEVALGRIND
55 	VALGRIND_SET_STACK_LIMIT(1, addr, 0);
56 #endif
57 }