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#include "u.h"
2
#include "../port/lib.h"
3
#include "mem.h"
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#include "dat.h"
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#include "fns.h"
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#include "../port/error.h"
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#include "../port/systab.h"
8
 
9
#include <tos.h>
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#include "ureg.h"
11
 
12
#include "arm.h"
13
 
14
typedef struct {
15
	uintptr	ip;
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	Ureg*	arg0;
17
	char*	arg1;
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	char	msg[ERRMAX];
19
	Ureg*	old;
20
	Ureg	ureg;
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} NFrame;
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23
/*
24
 *   Return user to state before notify()
25
 */
26
static void
27
noted(Ureg* cur, uintptr arg0)
28
{
29
	NFrame *nf;
30
	Ureg *nur;
31
 
32
	qlock(&up->debug);
33
	if(arg0 != NRSTR && !up->notified){
34
		qunlock(&up->debug);
35
		pprint("call to noted() when not notified\n");
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		pexit("Suicide", 0);
37
	}
38
	up->notified = 0;
39
	fpunoted();
40
 
41
	nf = up->ureg;
42
 
43
	/* sanity clause */
44
	if(!okaddr(PTR2UINT(nf), sizeof(NFrame), 0)){
45
		qunlock(&up->debug);
46
		pprint("bad ureg in noted %#p\n", nf);
47
		pexit("Suicide", 0);
48
	}
49
 
50
	/* don't let user change system flags */
51
	nur = &nf->ureg;
52
	nur->psr &= PsrMask|PsrDfiq|PsrDirq;
53
	nur->psr |= (cur->psr & ~(PsrMask|PsrDfiq|PsrDirq));
54
 
55
	memmove(cur, nur, sizeof(Ureg));
56
 
57
	switch((int)arg0){
58
	case NCONT:
59
	case NRSTR:
60
		if(!okaddr(nur->pc, BY2WD, 0) || !okaddr(nur->sp, BY2WD, 0)){
61
			qunlock(&up->debug);
62
			pprint("suicide: trap in noted\n");
63
			pexit("Suicide", 0);
64
		}
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		up->ureg = nf->old;
66
		qunlock(&up->debug);
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		break;
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	case NSAVE:
69
		if(!okaddr(nur->pc, BY2WD, 0) || !okaddr(nur->sp, BY2WD, 0)){
70
			qunlock(&up->debug);
71
			pprint("suicide: trap in noted\n");
72
			pexit("Suicide", 0);
73
		}
74
		qunlock(&up->debug);
75
 
76
		splhi();
77
		nf->arg1 = nf->msg;
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		nf->arg0 = &nf->ureg;
79
		nf->ip = 0;
80
		cur->sp = PTR2UINT(nf);
81
		cur->r0 = PTR2UINT(nf->arg0);
82
		break;
83
	default:
84
		pprint("unknown noted arg %#p\n", arg0);
85
		up->lastnote.flag = NDebug;
86
		/*FALLTHROUGH*/
87
	case NDFLT:
88
		if(up->lastnote.flag == NDebug){ 
89
			qunlock(&up->debug);
90
			pprint("suicide: %s\n", up->lastnote.msg);
91
		}
92
		else
93
			qunlock(&up->debug);
94
		pexit(up->lastnote.msg, up->lastnote.flag != NDebug);
95
	}
96
}
97
 
98
/*
99
 *  Call user, if necessary, with note.
100
 *  Pass user the Ureg struct and the note on his stack.
101
 */
102
int
103
notify(Ureg* ureg)
104
{
105
	int l;
106
	Note *n;
107
	u32int s;
108
	uintptr sp;
109
	NFrame *nf;
110
 
111
	if(up->procctl)
112
		procctl(up);
113
	if(up->nnote == 0)
114
		return 0;
115
 
116
	fpunotify(ureg);
117
 
118
	s = spllo();
119
	qlock(&up->debug);
120
 
121
	up->notepending = 0;
122
	n = &up->note[0];
123
	if(strncmp(n->msg, "sys:", 4) == 0){
124
		l = strlen(n->msg);
125
		if(l > ERRMAX-23)	/* " pc=0x0123456789abcdef\0" */
126
			l = ERRMAX-23;
127
		snprint(n->msg + l, sizeof n->msg - l, " pc=%#lux", ureg->pc);
128
	}
129
 
130
	if(n->flag != NUser && (up->notified || up->notify == 0)){
131
		if(n->flag == NDebug)
132
			pprint("suicide: %s\n", n->msg);
133
		qunlock(&up->debug);
134
		pexit(n->msg, n->flag != NDebug);
135
	}
136
 
137
	if(up->notified){
138
		qunlock(&up->debug);
139
		splhi();
140
		return 0;
141
	}
142
 
143
	if(up->notify == nil){
144
		qunlock(&up->debug);
145
		pexit(n->msg, n->flag != NDebug);
146
	}
147
	if(!okaddr(PTR2UINT(up->notify), 1, 0)){
148
		pprint("suicide: notify function address %#p\n", up->notify);
149
		qunlock(&up->debug);
150
		pexit("Suicide", 0);
151
	}
152
 
153
	sp = ureg->sp - sizeof(NFrame);
154
	if(!okaddr(sp, sizeof(NFrame), 1)){
155
		qunlock(&up->debug);
156
		pprint("suicide: notify stack address %#p\n", sp);
157
		pexit("Suicide", 0);
158
	}
159
 
160
	nf = UINT2PTR(sp);
161
	memmove(&nf->ureg, ureg, sizeof(Ureg));
162
	nf->old = up->ureg;
163
	up->ureg = nf;
164
	memmove(nf->msg, up->note[0].msg, ERRMAX);
165
	nf->arg1 = nf->msg;
166
	nf->arg0 = &nf->ureg;
167
	ureg->r0 = PTR2UINT(nf->arg0);
168
	nf->ip = 0;
169
 
170
	ureg->sp = sp;
171
	ureg->pc = PTR2UINT(up->notify);
172
	up->notified = 1;
173
	up->nnote--;
174
	memmove(&up->lastnote, &up->note[0], sizeof(Note));
175
	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));
176
 
177
	qunlock(&up->debug);
178
	splx(s);
179
 
180
	return 1;
181
}
182
 
183
void
184
syscall(Ureg* ureg)
185
{
186
	char *e;
187
	u32int s;
188
	ulong sp;
189
	long ret;
190
	int i, scallnr;
191
 
192
	if(!userureg(ureg))
193
		panic("syscall: from kernel: pc %#lux r14 %#lux psr %#lux",
194
			ureg->pc, ureg->r14, ureg->psr);
195
 
196
	cycles(&up->kentry);
197
 
198
	m->syscall++;
199
	up->insyscall = 1;
200
	up->pc = ureg->pc;
201
	up->dbgreg = ureg;
202
 
203
	if(up->procctl == Proc_tracesyscall){
204
		up->procctl = Proc_stopme;
205
		procctl(up);
206
	}
207
 
208
	scallnr = ureg->r0;
209
	up->scallnr = scallnr;
210
	if(scallnr == RFORK)
211
		fpusysrfork(ureg);
212
	spllo();
213
 
214
	sp = ureg->sp;
215
	up->nerrlab = 0;
216
	ret = -1;
217
	if(!waserror()){
218
		if(scallnr >= nsyscall){
219
			pprint("bad sys call number %d pc %#lux\n",
220
				scallnr, ureg->pc);
221
			postnote(up, 1, "sys: bad sys call", NDebug);
222
			error(Ebadarg);
223
		}
224
 
225
		if(sp < (USTKTOP-BY2PG) || sp > (USTKTOP-sizeof(Sargs)-BY2WD))
226
			validaddr(sp, sizeof(Sargs)+BY2WD, 0);
227
 
228
		up->s = *((Sargs*)(sp+BY2WD));
229
		up->psstate = sysctab[scallnr];
230
 
231
	/*	iprint("%s: syscall %s\n", up->text, sysctab[scallnr]?sysctab[scallnr]:"huh?"); */
232
 
233
		ret = systab[scallnr](up->s.args);
234
		poperror();
235
	}else{
236
		/* failure: save the error buffer for errstr */
237
		e = up->syserrstr;
238
		up->syserrstr = up->errstr;
239
		up->errstr = e;
240
	}
241
	if(up->nerrlab){
242
		print("bad errstack [%d]: %d extra\n", scallnr, up->nerrlab);
243
		for(i = 0; i < NERR; i++)
244
			print("sp=%#p pc=%#p\n",
245
				up->errlab[i].sp, up->errlab[i].pc);
246
		panic("error stack");
247
	}
248
 
249
	/*
250
	 *  Put return value in frame.  On the x86 the syscall is
251
	 *  just another trap and the return value from syscall is
252
	 *  ignored.  On other machines the return value is put into
253
	 *  the results register by caller of syscall.
254
	 */
255
	ureg->r0 = ret;
256
 
257
	if(up->procctl == Proc_tracesyscall){
258
		up->procctl = Proc_stopme;
259
		s = splhi();
260
		procctl(up);
261
		splx(s);
262
	}
263
 
264
	up->insyscall = 0;
265
	up->psstate = 0;
266
 
267
	if(scallnr == NOTED)
268
		noted(ureg, *(ulong*)(sp+BY2WD));
269
 
270
	splhi();
271
	if(scallnr != RFORK && (up->procctl || up->nnote))
272
		notify(ureg);
273
 
274
	/* if we delayed sched because we held a lock, sched now */
275
	if(up->delaysched){
276
		sched();
277
		splhi();
278
	}
279
	kexit(ureg);
280
}
281
 
282
long	/* void* */
283
execregs(ulong entry, ulong ssize, ulong nargs)
284
{
285
	ulong *sp;
286
	Ureg *ureg;
287
 
288
	sp = (ulong*)(USTKTOP - ssize);
289
	*--sp = nargs;
290
 
291
	ureg = up->dbgreg;
292
//	memset(ureg, 0, 15*sizeof(ulong));
293
	ureg->r13 = (ulong)sp;
294
	ureg->pc = entry;
295
//print("%lud: EXECREGS pc %#ux sp %#ux nargs %ld\n", up->pid, ureg->pc, ureg->r13, nargs);
296
 
297
	/*
298
	 * return the address of kernel/user shared data
299
	 * (e.g. clock stuff)
300
	 */
301
	return USTKTOP-sizeof(Tos);
302
}
303
 
304
void
305
sysprocsetup(Proc* p)
306
{
307
	fpusysprocsetup(p);
308
}
309
 
310
/* 
311
 *  Craft a return frame which will cause the child to pop out of
312
 *  the scheduler in user mode with the return register zero.  Set
313
 *  pc to point to a l.s return function.
314
 */
315
void
316
forkchild(Proc *p, Ureg *ureg)
317
{
318
	Ureg *cureg;
319
 
320
//print("%lud setting up for forking child %lud\n", up->pid, p->pid);
321
	p->sched.sp = (ulong)p->kstack+KSTACK-sizeof(Ureg);
322
	p->sched.pc = (ulong)forkret;
323
 
324
	cureg = (Ureg*)(p->sched.sp);
325
	memmove(cureg, ureg, sizeof(Ureg));
326
 
327
	/* syscall returns 0 for child */
328
	cureg->r0 = 0;
329
 
330
	/* Things from bottom of syscall which were never executed */
331
	p->psstate = 0;
332
	p->insyscall = 0;
333
 
334
	fpusysrforkchild(p, cureg, up);
335
}