1 #include "u.h" 2 #include "../port/lib.h" 3 #include "mem.h" 4 #include "dat.h" 5 #include "fns.h" 6 #include "../port/error.h" 7 #include "../port/systab.h" 8 9 #include <tos.h> 10 #include "ureg.h" 11 12 #include "arm.h" 13 14 typedef struct { 15 uintptr ip; 16 Ureg* arg0; 17 char* arg1; 18 char msg[ERRMAX]; 19 Ureg* old; 20 Ureg ureg; 21 } NFrame; 22 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"); 36 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 pprint("bad ureg in noted %#p\n", nf); 46 qunlock(&up->debug); 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, BY2SE, 0) || !okaddr(nur->sp, BY2SE, 0)){ 61 qunlock(&up->debug); 62 pprint("suicide: trap in noted\n"); 63 pexit("Suicide", 0); 64 } 65 up->ureg = nf->old; 66 qunlock(&up->debug); 67 break; 68 case NSAVE: 69 if(!okaddr(nur->pc, BY2SE, 0) || !okaddr(nur->sp, BY2SE, 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; 78 nf->arg0 = &nf->ureg; 79 nf->ip = 0; 80 cur->sp = PTR2UINT(nf); 81 break; 82 default: 83 pprint("unknown noted arg %#p\n", arg0); 84 up->lastnote.flag = NDebug; 85 /*FALLTHROUGH*/ 86 case NDFLT: 87 if(up->lastnote.flag == NDebug){ 88 qunlock(&up->debug); 89 pprint("suicide: %s\n", up->lastnote.msg); 90 } 91 else 92 qunlock(&up->debug); 93 pexit(up->lastnote.msg, up->lastnote.flag != NDebug); 94 } 95 } 96 97 /* 98 * Call user, if necessary, with note. 99 * Pass user the Ureg struct and the note on his stack. 100 */ 101 int 102 notify(Ureg* ureg) 103 { 104 int l; 105 Note *n; 106 u32int s; 107 uintptr sp; 108 NFrame *nf; 109 110 if(up->procctl) 111 procctl(up); 112 if(up->nnote == 0) 113 return 0; 114 115 fpunotify(ureg); 116 117 s = spllo(); 118 qlock(&up->debug); 119 120 up->notepending = 0; 121 n = &up->note[0]; 122 if(strncmp(n->msg, "sys:", 4) == 0){ 123 l = strlen(n->msg); 124 if(l > ERRMAX-23) /* " pc=0x0123456789abcdef\0" */ 125 l = ERRMAX-23; 126 snprint(n->msg + l, sizeof n->msg - l, " pc=%#lux", ureg->pc); 127 } 128 129 if(n->flag != NUser && (up->notified || up->notify == 0)){ 130 if(n->flag == NDebug) 131 pprint("suicide: %s\n", n->msg); 132 qunlock(&up->debug); 133 pexit(n->msg, n->flag != NDebug); 134 } 135 136 if(up->notified){ 137 qunlock(&up->debug); 138 splhi(); 139 return 0; 140 } 141 142 if(up->notify == nil){ 143 qunlock(&up->debug); 144 pexit(n->msg, n->flag != NDebug); 145 } 146 if(!okaddr(PTR2UINT(up->notify), 1, 0)){ 147 pprint("suicide: notify function address %#p\n", up->notify); 148 qunlock(&up->debug); 149 pexit("Suicide", 0); 150 } 151 152 sp = ureg->sp - sizeof(NFrame); 153 if(!okaddr(sp, sizeof(NFrame), 1)){ 154 pprint("suicide: notify stack address %#p\n", sp); 155 qunlock(&up->debug); 156 pexit("Suicide", 0); 157 } 158 159 nf = UINT2PTR(sp); 160 memmove(&nf->ureg, ureg, sizeof(Ureg)); 161 nf->old = up->ureg; 162 up->ureg = nf; 163 memmove(nf->msg, up->note[0].msg, ERRMAX); 164 nf->arg1 = nf->msg; 165 nf->arg0 = &nf->ureg; 166 nf->ip = 0; 167 168 ureg->sp = sp; 169 ureg->pc = PTR2UINT(up->notify); 170 up->notified = 1; 171 up->nnote--; 172 memmove(&up->lastnote, &up->note[0], sizeof(Note)); 173 memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note)); 174 175 qunlock(&up->debug); 176 splx(s); 177 178 return 1; 179 } 180 181 void 182 syscall(Ureg* ureg) 183 { 184 char *e; 185 u32int s; 186 ulong sp; 187 long ret; 188 int i, scallnr; 189 190 if(!userureg(ureg)) 191 panic("syscall: from kernel: pc %#lux r14 %#lux psr %#lux", 192 ureg->pc, ureg->r14, ureg->psr); 193 194 cycles(&up->kentry); 195 196 m->syscall++; 197 up->insyscall = 1; 198 up->pc = ureg->pc; 199 up->dbgreg = ureg; 200 201 if(up->procctl == Proc_tracesyscall){ 202 up->procctl = Proc_stopme; 203 procctl(up); 204 } 205 206 scallnr = ureg->r0; 207 up->scallnr = scallnr; 208 if(scallnr == RFORK) 209 fpusysrfork(ureg); 210 spllo(); 211 212 sp = ureg->sp; 213 up->nerrlab = 0; 214 ret = -1; 215 if(!waserror()){ 216 if(scallnr >= nsyscall){ 217 pprint("bad sys call number %d pc %#lux\n", 218 scallnr, ureg->pc); 219 postnote(up, 1, "sys: bad sys call", NDebug); 220 error(Ebadarg); 221 } 222 223 if(sp < (USTKTOP-BY2PG) || sp > (USTKTOP-sizeof(Sargs)-BY2WD)) 224 validaddr(sp, sizeof(Sargs)+BY2WD, 0); 225 226 up->s = *((Sargs*)(sp+BY2WD)); 227 up->psstate = sysctab[scallnr]; 228 229 /* iprint("%s: syscall %s\n", up->text, sysctab[scallnr]?sysctab[scallnr]:"huh?"); */ 230 231 ret = systab[scallnr](up->s.args); 232 poperror(); 233 }else{ 234 /* failure: save the error buffer for errstr */ 235 e = up->syserrstr; 236 up->syserrstr = up->errstr; 237 up->errstr = e; 238 } 239 if(up->nerrlab){ 240 print("bad errstack [%d]: %d extra\n", scallnr, up->nerrlab); 241 for(i = 0; i < NERR; i++) 242 print("sp=%#p pc=%#p\n", 243 up->errlab[i].sp, up->errlab[i].pc); 244 panic("error stack"); 245 } 246 247 /* 248 * Put return value in frame. On the x86 the syscall is 249 * just another trap and the return value from syscall is 250 * ignored. On other machines the return value is put into 251 * the results register by caller of syscall. 252 */ 253 ureg->r0 = ret; 254 255 if(up->procctl == Proc_tracesyscall){ 256 up->procctl = Proc_stopme; 257 s = splhi(); 258 procctl(up); 259 splx(s); 260 } 261 262 up->insyscall = 0; 263 up->psstate = 0; 264 265 if(scallnr == NOTED) 266 noted(ureg, *(ulong*)(sp+BY2WD)); 267 268 splhi(); 269 if(scallnr != RFORK && (up->procctl || up->nnote)) 270 notify(ureg); 271 272 /* if we delayed sched because we held a lock, sched now */ 273 if(up->delaysched){ 274 sched(); 275 splhi(); 276 } 277 kexit(ureg); 278 } 279 280 long /* void* */ 281 execregs(ulong entry, ulong ssize, ulong nargs) 282 { 283 ulong *sp; 284 Ureg *ureg; 285 286 sp = (ulong*)(USTKTOP - ssize); 287 *--sp = nargs; 288 289 ureg = up->dbgreg; 290 // memset(ureg, 0, 15*sizeof(ulong)); 291 ureg->r13 = (ulong)sp; 292 ureg->pc = entry; 293 //print("%lud: EXECREGS pc %#ux sp %#ux nargs %ld\n", up->pid, ureg->pc, ureg->r13, nargs); 294 295 /* 296 * return the address of kernel/user shared data 297 * (e.g. clock stuff) 298 */ 299 return USTKTOP-sizeof(Tos); 300 } 301 302 void 303 sysprocsetup(Proc* p) 304 { 305 fpusysprocsetup(p); 306 } 307 308 /* 309 * Craft a return frame which will cause the child to pop out of 310 * the scheduler in user mode with the return register zero. Set 311 * pc to point to a l.s return function. 312 */ 313 void 314 forkchild(Proc *p, Ureg *ureg) 315 { 316 Ureg *cureg; 317 318 //print("%lud setting up for forking child %lud\n", up->pid, p->pid); 319 p->sched.sp = (ulong)p->kstack+KSTACK-sizeof(Ureg); 320 p->sched.pc = (ulong)forkret; 321 322 cureg = (Ureg*)(p->sched.sp); 323 memmove(cureg, ureg, sizeof(Ureg)); 324 325 /* syscall returns 0 for child */ 326 cureg->r0 = 0; 327 328 /* Things from bottom of syscall which were never executed */ 329 p->psstate = 0; 330 p->insyscall = 0; 331 } 332