Commit | Line | Data |
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f644bb55 DF |
1 | /* |
2 | * Copyright (c) 1980 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | */ | |
fa1f8751 | 6 | |
f644bb55 DF |
7 | #ifndef lint |
8 | static char sccsid[] = "@(#)ptrace.c 5.1 (Berkeley) %G%"; | |
9 | #endif not lint | |
7838db54 ML |
10 | |
11 | /* | |
12 | * routines for tracing the execution of a process | |
13 | * | |
14 | * The system call "ptrace" does all the work, these | |
15 | * routines just try to interface easily to it. | |
16 | */ | |
17 | ||
18 | #include "defs.h" | |
19 | #include <signal.h> | |
20 | #include <sys/param.h> | |
f3338386 | 21 | #include <machine/reg.h> |
7838db54 ML |
22 | #include "process.h" |
23 | #include "object.h" | |
24 | #include "process.rep" | |
25 | ||
f9e6f1f3 ML |
26 | # if (isvaxpx) |
27 | # include "pxinfo.h" | |
28 | # endif | |
7838db54 | 29 | |
fa1f8751 ML |
30 | #ifndef vax |
31 | # define U_PAGE 0x2400 | |
32 | # define U_AR0 (14*sizeof(int)) | |
33 | LOCAL int ar0val = -1; | |
34 | #endif | |
35 | ||
7838db54 ML |
36 | /* |
37 | * This magic macro enables us to look at the process' registers | |
38 | * in its user structure. Very gross. | |
39 | */ | |
40 | ||
fa1f8751 ML |
41 | #ifdef vax |
42 | # define regloc(reg) (ctob(UPAGES) + ( sizeof(int) * (reg) )) | |
43 | #else | |
44 | # define regloc(reg) (ar0val + ( sizeof(int) * (reg) )) | |
45 | #endif | |
7838db54 | 46 | |
f9e6f1f3 ML |
47 | #define WMASK (~(sizeof(WORD) - 1)) |
48 | #define cachehash(addr) ((unsigned) ((addr >> 2) % CSIZE)) | |
7838db54 | 49 | |
f9e6f1f3 ML |
50 | #define FIRSTSIG SIGINT |
51 | #define LASTSIG SIGQUIT | |
52 | #define ischild(pid) ((pid) == 0) | |
53 | #define traceme() ptrace(0, 0, 0, 0) | |
54 | #define setrep(n) (1 << ((n)-1)) | |
55 | #define istraced(p) (p->sigset&setrep(p->signo)) | |
7838db54 ML |
56 | |
57 | /* | |
58 | * ptrace options (specified in first argument) | |
59 | */ | |
60 | ||
f9e6f1f3 ML |
61 | #define UREAD 3 /* read from process's user structure */ |
62 | #define UWRITE 6 /* write to process's user structure */ | |
63 | #define IREAD 1 /* read from process's instruction space */ | |
64 | #define IWRITE 4 /* write to process's instruction space */ | |
65 | #define DREAD 2 /* read from process's data space */ | |
66 | #define DWRITE 5 /* write to process's data space */ | |
67 | #define CONT 7 /* continue stopped process */ | |
68 | #define SSTEP 9 /* continue for approximately one instruction */ | |
69 | #define PKILL 8 /* terminate the process */ | |
7838db54 ML |
70 | |
71 | /* | |
72 | * Start up a new process by forking and exec-ing the | |
73 | * given argument list, returning when the process is loaded | |
74 | * and ready to execute. The PROCESS information (pointed to | |
75 | * by the first argument) is appropriately filled. | |
76 | * | |
77 | * If the given PROCESS structure is associated with an already running | |
78 | * process, we terminate it. | |
79 | */ | |
80 | ||
81 | /* VARARGS2 */ | |
33ece7d5 | 82 | pstart(p, cmd, argv, infile, outfile) |
7838db54 | 83 | PROCESS *p; |
33ece7d5 | 84 | char *cmd; |
7838db54 ML |
85 | char **argv; |
86 | char *infile; | |
87 | char *outfile; | |
88 | { | |
f9e6f1f3 ML |
89 | int status; |
90 | FILE *in, *out; | |
91 | ||
92 | if (p->pid != 0) { /* child already running? */ | |
93 | ptrace(PKILL, p->pid, 0, 0); /* ... kill it! */ | |
94 | } | |
95 | psigtrace(p, SIGTRAP, TRUE); | |
96 | if ((p->pid = fork()) == -1) { | |
97 | panic("can't fork"); | |
98 | } | |
99 | if (ischild(p->pid)) { | |
100 | traceme(); | |
101 | if (infile != NIL) { | |
102 | if ((in = fopen(infile, "r")) == NIL) { | |
103 | printf("can't read %s\n", infile); | |
104 | exit(1); | |
105 | } | |
106 | fswap(0, fileno(in)); | |
7838db54 | 107 | } |
f9e6f1f3 ML |
108 | if (outfile != NIL) { |
109 | if ((out = fopen(outfile, "w")) == NIL) { | |
110 | printf("can't write %s\n", outfile); | |
111 | exit(1); | |
112 | } | |
113 | fswap(1, fileno(out)); | |
7838db54 | 114 | } |
f9e6f1f3 ML |
115 | execvp(cmd, argv); |
116 | panic("can't exec %s", argv[0]); | |
117 | } | |
118 | pwait(p->pid, &status); | |
119 | getinfo(p, status); | |
7838db54 ML |
120 | } |
121 | ||
122 | /* | |
123 | * Continue a stopped process. The argument points to a PROCESS structure. | |
124 | * Before the process is restarted it's user area is modified according to | |
125 | * the values in the structure. When this routine finishes, | |
126 | * the structure has the new values from the process's user area. | |
127 | * | |
128 | * Pcont terminates when the process stops with a signal pending that | |
129 | * is being traced (via psigtrace), or when the process terminates. | |
130 | */ | |
131 | ||
132 | pcont(p) | |
133 | PROCESS *p; | |
134 | { | |
f9e6f1f3 | 135 | int status; |
7838db54 | 136 | |
f9e6f1f3 ML |
137 | if (p->pid == 0) { |
138 | error("program not active"); | |
139 | } | |
140 | do { | |
141 | setinfo(p); | |
142 | sigs_off(); | |
143 | if (ptrace(CONT, p->pid, p->pc, p->signo) < 0) { | |
144 | panic("can't continue process"); | |
7838db54 | 145 | } |
f9e6f1f3 ML |
146 | pwait(p->pid, &status); |
147 | sigs_on(); | |
148 | getinfo(p, status); | |
149 | } while (p->status == STOPPED && !istraced(p)); | |
7838db54 ML |
150 | } |
151 | ||
152 | /* | |
153 | * single step as best ptrace can | |
154 | */ | |
155 | ||
156 | pstep(p) | |
157 | PROCESS *p; | |
158 | { | |
f9e6f1f3 ML |
159 | int status; |
160 | ||
161 | setinfo(p); | |
162 | sigs_off(); | |
163 | ptrace(SSTEP, p->pid, p->pc, p->signo); | |
164 | pwait(p->pid, &status); | |
165 | sigs_on(); | |
166 | getinfo(p, status); | |
7838db54 ML |
167 | } |
168 | ||
169 | /* | |
170 | * Return from execution when the given signal is pending. | |
171 | */ | |
172 | ||
173 | psigtrace(p, sig, sw) | |
174 | PROCESS *p; | |
175 | int sig; | |
176 | int sw; | |
177 | { | |
f9e6f1f3 ML |
178 | if (sw) { |
179 | p->sigset |= setrep(sig); | |
180 | } else { | |
181 | p->sigset &= ~setrep(sig); | |
182 | } | |
7838db54 ML |
183 | } |
184 | ||
185 | /* | |
186 | * Don't catch any signals. | |
187 | * Particularly useful when letting a process finish uninhibited (i.e. px). | |
188 | */ | |
189 | ||
190 | unsetsigtraces(p) | |
191 | PROCESS *p; | |
192 | { | |
f9e6f1f3 | 193 | p->sigset = 0; |
7838db54 ML |
194 | } |
195 | ||
196 | /* | |
197 | * turn off attention to signals not being caught | |
198 | */ | |
199 | ||
200 | typedef int INTFUNC(); | |
201 | ||
202 | LOCAL INTFUNC *sigfunc[NSIG]; | |
203 | ||
204 | LOCAL sigs_off() | |
205 | { | |
f9e6f1f3 | 206 | register int i; |
7838db54 | 207 | |
f9e6f1f3 ML |
208 | for (i = FIRSTSIG; i < LASTSIG; i++) { |
209 | if (i != SIGKILL) { | |
210 | sigfunc[i] = signal(i, SIG_IGN); | |
7838db54 | 211 | } |
f9e6f1f3 | 212 | } |
7838db54 ML |
213 | } |
214 | ||
215 | /* | |
216 | * turn back on attention to signals | |
217 | */ | |
218 | ||
219 | LOCAL sigs_on() | |
220 | { | |
f9e6f1f3 | 221 | register int i; |
7838db54 | 222 | |
f9e6f1f3 ML |
223 | for (i = FIRSTSIG; i < LASTSIG; i++) { |
224 | if (i != SIGKILL) { | |
225 | signal(i, sigfunc[i]); | |
7838db54 | 226 | } |
f9e6f1f3 | 227 | } |
7838db54 ML |
228 | } |
229 | ||
230 | /* | |
231 | * get PROCESS information from process's user area | |
232 | */ | |
233 | ||
fa1f8751 ML |
234 | #if vax |
235 | LOCAL int rloc[] ={ | |
236 | R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, | |
237 | }; | |
238 | #else | |
239 | LOCAL int rloc[] ={ | |
240 | R0, R1, R2, R3, R4, R5, R6, R7, AR0, AR1, AR2, AR3, AR4, AR5, | |
241 | }; | |
242 | #endif | |
7838db54 ML |
243 | |
244 | LOCAL getinfo(p, status) | |
245 | register PROCESS *p; | |
246 | register int status; | |
247 | { | |
f9e6f1f3 ML |
248 | register int i; |
249 | ||
250 | p->signo = (status&0177); | |
251 | p->exitval = ((status >> 8)&0377); | |
252 | if (p->signo == STOPPED) { | |
253 | p->status = p->signo; | |
254 | p->signo = p->exitval; | |
255 | p->exitval = 0; | |
256 | } else { | |
257 | p->status = FINISHED; | |
258 | return; | |
259 | } | |
fa1f8751 ML |
260 | #ifndef vax |
261 | if (ar0val < 0){ | |
262 | ar0val = ptrace(UREAD, p->pid, U_AR0, 0); | |
263 | ar0val -= U_PAGE; | |
264 | } | |
265 | #endif | |
f9e6f1f3 ML |
266 | for (i = 0; i < NREG; i++) { |
267 | p->reg[i] = ptrace(UREAD, p->pid, regloc(rloc[i]), 0); | |
268 | p->oreg[i] = p->reg[i]; | |
269 | } | |
fa1f8751 | 270 | #ifdef vax |
f9e6f1f3 ML |
271 | p->fp = p->ofp = ptrace(UREAD, p->pid, regloc(FP), 0); |
272 | p->ap = p->oap = ptrace(UREAD, p->pid, regloc(AP), 0); | |
273 | p->sp = p->osp = ptrace(UREAD, p->pid, regloc(SP), 0); | |
274 | p->pc = p->opc = ptrace(UREAD, p->pid, regloc(PC), 0); | |
fa1f8751 ML |
275 | #else |
276 | p->fp = p->ofp = ptrace(UREAD, p->pid, regloc(AR6), 0); | |
277 | p->ap = p->oap = p->fp; | |
278 | p->sp = p->osp = ptrace(UREAD, p->pid, regloc(SP), 0); | |
279 | p->pc = p->opc = ptrace(UREAD, p->pid, regloc(PC), 0); | |
280 | #endif | |
7838db54 ML |
281 | } |
282 | ||
283 | /* | |
284 | * set process's user area information from given PROCESS structure | |
285 | */ | |
286 | ||
287 | LOCAL setinfo(p) | |
288 | register PROCESS *p; | |
289 | { | |
f9e6f1f3 ML |
290 | register int i; |
291 | register int r; | |
292 | ||
293 | if (istraced(p)) { | |
294 | p->signo = 0; | |
295 | } | |
296 | for (i = 0; i < NREG; i++) { | |
297 | if ((r = p->reg[i]) != p->oreg[i]) { | |
298 | ptrace(UWRITE, p->pid, regloc(rloc[i]), r); | |
7838db54 | 299 | } |
f9e6f1f3 | 300 | } |
fa1f8751 | 301 | #if vax |
f9e6f1f3 ML |
302 | if ((r = p->fp) != p->ofp) { |
303 | ptrace(UWRITE, p->pid, regloc(FP), r); | |
304 | } | |
305 | if ((r = p->sp) != p->osp) { | |
306 | ptrace(UWRITE, p->pid, regloc(SP), r); | |
307 | } | |
308 | if ((r = p->ap) != p->oap) { | |
309 | ptrace(UWRITE, p->pid, regloc(AP), r); | |
310 | } | |
fa1f8751 ML |
311 | #else |
312 | if ((r = p->fp) != p->ofp) { | |
313 | ptrace(UWRITE, p->pid, regloc(AR6), r); | |
314 | } | |
315 | if ((r = p->sp) != p->osp) { | |
316 | ptrace(UWRITE, p->pid, regloc(SP), r); | |
317 | } | |
318 | #endif | |
f9e6f1f3 ML |
319 | if ((r = p->pc) != p->opc) { |
320 | ptrace(UWRITE, p->pid, regloc(PC), r); | |
321 | } | |
7838db54 ML |
322 | } |
323 | ||
324 | /* | |
325 | * Structure for reading and writing by words, but dealing with bytes. | |
326 | */ | |
327 | ||
328 | typedef union { | |
f9e6f1f3 ML |
329 | WORD pword; |
330 | BYTE pbyte[sizeof(WORD)]; | |
7838db54 ML |
331 | } PWORD; |
332 | ||
333 | /* | |
334 | * Read (write) from (to) the process' address space. | |
335 | * We must deal with ptrace's inability to look anywhere other | |
336 | * than at a word boundary. | |
337 | */ | |
338 | ||
339 | LOCAL WORD fetch(); | |
340 | LOCAL store(); | |
341 | ||
342 | pio(p, op, seg, buff, addr, nbytes) | |
343 | PROCESS *p; | |
344 | PIO_OP op; | |
345 | PIO_SEG seg; | |
346 | char *buff; | |
347 | ADDRESS addr; | |
348 | int nbytes; | |
349 | { | |
f9e6f1f3 ML |
350 | register int i; |
351 | register ADDRESS newaddr; | |
352 | register char *cp; | |
353 | char *bufend; | |
354 | PWORD w; | |
355 | ADDRESS wordaddr; | |
356 | int byteoff; | |
357 | ||
358 | if (p->status != STOPPED) { | |
359 | error("program is not active"); | |
360 | } | |
361 | cp = buff; | |
362 | newaddr = addr; | |
363 | wordaddr = (newaddr&WMASK); | |
364 | if (wordaddr != newaddr) { | |
365 | w.pword = fetch(p, seg, wordaddr); | |
366 | for (i = newaddr - wordaddr; i<sizeof(WORD) && nbytes>0; i++) { | |
367 | if (op == PREAD) { | |
368 | *cp++ = w.pbyte[i]; | |
369 | } else { | |
370 | w.pbyte[i] = *cp++; | |
371 | } | |
372 | nbytes--; | |
7838db54 | 373 | } |
f9e6f1f3 ML |
374 | if (op == PWRITE) { |
375 | store(p, seg, wordaddr, w.pword); | |
7838db54 | 376 | } |
f9e6f1f3 ML |
377 | newaddr = wordaddr + sizeof(WORD); |
378 | } | |
379 | byteoff = (nbytes&(~WMASK)); | |
380 | nbytes -= byteoff; | |
381 | bufend = cp + nbytes; | |
382 | while (cp < bufend) { | |
383 | if (op == PREAD) { | |
384 | *((WORD *) cp) = fetch(p, seg, newaddr); | |
385 | } else { | |
386 | store(p, seg, newaddr, *((WORD *) cp)); | |
7838db54 | 387 | } |
f9e6f1f3 ML |
388 | cp += sizeof(WORD); |
389 | newaddr += sizeof(WORD); | |
390 | } | |
391 | if (byteoff > 0) { | |
392 | w.pword = fetch(p, seg, newaddr); | |
393 | for (i = 0; i < byteoff; i++) { | |
394 | if (op == PREAD) { | |
395 | *cp++ = w.pbyte[i]; | |
396 | } else { | |
397 | w.pbyte[i] = *cp++; | |
398 | } | |
7838db54 | 399 | } |
f9e6f1f3 ML |
400 | if (op == PWRITE) { |
401 | store(p, seg, newaddr, w.pword); | |
402 | } | |
403 | } | |
7838db54 ML |
404 | } |
405 | ||
406 | /* | |
407 | * Get a word from a process at the given address. | |
408 | * The address is assumed to be on a word boundary. | |
409 | * | |
410 | * We use a simple cache scheme to avoid redundant references to | |
411 | * the instruction space (which is assumed to be pure). In the | |
412 | * case of px, the "instruction" space lies between ENDOFF and | |
413 | * ENDOFF + objsize. | |
414 | * | |
415 | * It is necessary to use a write-through scheme so that | |
416 | * breakpoints right next to each other don't interfere. | |
417 | */ | |
418 | ||
419 | LOCAL WORD fetch(p, seg, addr) | |
420 | PROCESS *p; | |
421 | PIO_SEG seg; | |
422 | register int addr; | |
423 | { | |
f9e6f1f3 ML |
424 | register CACHEWORD *wp; |
425 | register WORD w; | |
426 | ||
427 | switch (seg) { | |
428 | case TEXTSEG: | |
429 | # if (isvaxpx) | |
430 | panic("tried to fetch from px i-space"); | |
431 | /* NOTREACHED */ | |
432 | # else | |
433 | wp = &p->word[cachehash(addr)]; | |
434 | if (addr == 0 || wp->addr != addr) { | |
435 | w = ptrace(IREAD, p->pid, addr, 0); | |
436 | wp->addr = addr; | |
437 | wp->val = w; | |
438 | } else { | |
439 | w = wp->val; | |
440 | } | |
441 | break; | |
442 | # endif | |
443 | ||
444 | case DATASEG: | |
445 | # if (isvaxpx) | |
446 | if (addr >= ENDOFF && addr < ENDOFF + objsize) { | |
447 | wp = &p->word[cachehash(addr)]; | |
448 | if (addr == 0 || wp->addr != addr) { | |
449 | w = ptrace(DREAD, p->pid, addr, 0); | |
450 | wp->addr = addr; | |
451 | wp->val = w; | |
452 | } else { | |
453 | w = wp->val; | |
454 | } | |
455 | } else { | |
456 | w = ptrace(DREAD, p->pid, addr, 0); | |
457 | } | |
458 | # else | |
459 | w = ptrace(DREAD, p->pid, addr, 0); | |
460 | # endif | |
461 | break; | |
462 | ||
463 | default: | |
464 | panic("fetch: bad seg %d", seg); | |
465 | /* NOTREACHED */ | |
466 | } | |
467 | return(w); | |
7838db54 ML |
468 | } |
469 | ||
470 | /* | |
471 | * Put a word into the process' address space at the given address. | |
472 | * The address is assumed to be on a word boundary. | |
473 | */ | |
474 | ||
475 | LOCAL store(p, seg, addr, data) | |
476 | PROCESS *p; | |
477 | PIO_SEG seg; | |
478 | int addr; | |
479 | WORD data; | |
480 | { | |
f9e6f1f3 ML |
481 | register CACHEWORD *wp; |
482 | ||
483 | switch (seg) { | |
484 | case TEXTSEG: | |
485 | wp = &p->word[cachehash(addr)]; | |
486 | wp->addr = addr; | |
487 | wp->val = data; | |
488 | ptrace(IWRITE, p->pid, addr, data); | |
489 | break; | |
490 | ||
491 | case DATASEG: | |
492 | # if (isvaxpx) | |
493 | if (addr >= ENDOFF && addr < ENDOFF + objsize) { | |
494 | wp = &p->word[cachehash(addr)]; | |
495 | wp->addr = addr; | |
496 | wp->val = data; | |
497 | } | |
498 | # endif | |
499 | ptrace(DWRITE, p->pid, addr, data); | |
500 | break; | |
501 | ||
502 | default: | |
503 | panic("store: bad seg %d", seg); | |
504 | /*NOTREACHED*/ | |
505 | } | |
506 | } | |
7838db54 | 507 | |
f9e6f1f3 ML |
508 | /* |
509 | * Initialize the instruction cache for a process. | |
510 | * This is particularly necessary after the program has been remade. | |
511 | */ | |
512 | ||
513 | initcache(process) | |
514 | PROCESS *process; | |
515 | { | |
516 | register int i; | |
517 | ||
518 | for (i = 0; i < CSIZE; i++) { | |
519 | process->word[i].addr = 0; | |
520 | } | |
7838db54 ML |
521 | } |
522 | ||
523 | /* | |
524 | * Swap file numbers so as to redirect standard input and output. | |
525 | */ | |
526 | ||
527 | LOCAL fswap(oldfd, newfd) | |
528 | int oldfd; | |
529 | int newfd; | |
530 | { | |
f9e6f1f3 ML |
531 | if (oldfd != newfd) { |
532 | close(oldfd); | |
533 | dup(newfd); | |
534 | close(newfd); | |
535 | } | |
7838db54 | 536 | } |