2 a84cbb2a 2004-04-19 devnull * process interface for Linux.
4 a84cbb2a 2004-04-19 devnull * Uses ptrace for registers and data,
5 a84cbb2a 2004-04-19 devnull * /proc for some process status.
6 a84cbb2a 2004-04-19 devnull * There's not much point to worrying about
7 a84cbb2a 2004-04-19 devnull * byte order here -- using ptrace means
8 a84cbb2a 2004-04-19 devnull * we're running on the architecture we're debugging,
9 a84cbb2a 2004-04-19 devnull * unless truly weird stuff is going on.
11 a84cbb2a 2004-04-19 devnull * It is tempting to use /proc/%d/mem along with
12 a84cbb2a 2004-04-19 devnull * the sp and pc in the stat file to get a stack trace
13 a84cbb2a 2004-04-19 devnull * without attaching to the program, but unfortunately
14 a84cbb2a 2004-04-19 devnull * you can't read the mem file unless you've attached.
17 a84cbb2a 2004-04-19 devnull #include <u.h>
18 a84cbb2a 2004-04-19 devnull #include <sys/ptrace.h>
19 a84cbb2a 2004-04-19 devnull #include <sys/types.h>
20 a84cbb2a 2004-04-19 devnull #include <sys/wait.h>
21 1cc215aa 2004-12-25 devnull #include <sys/procfs.h>
22 a84cbb2a 2004-04-19 devnull #include <signal.h>
23 a84cbb2a 2004-04-19 devnull #include <errno.h>
24 a84cbb2a 2004-04-19 devnull #include <libc.h>
25 a84cbb2a 2004-04-19 devnull #include <mach.h>
26 1cc215aa 2004-12-25 devnull #include <elf.h>
27 a84cbb2a 2004-04-19 devnull #include "ureg386.h"
29 a84cbb2a 2004-04-19 devnull Mach *machcpu = &mach386;
31 a84cbb2a 2004-04-19 devnull typedef struct PtraceRegs PtraceRegs;
33 a84cbb2a 2004-04-19 devnull struct PtraceRegs
39 1cc215aa 2004-12-25 devnull static int ptracesegrw(Map*, Seg*, ulong, void*, uint, int);
40 4f0073fe 2004-06-11 devnull static int ptraceregrw(Regs*, char*, ulong*, int);
42 2e965b33 2004-05-05 devnull static int attachedpids[1000];
43 2e965b33 2004-05-05 devnull static int nattached;
45 39dbe6e7 2005-01-07 devnull static int
46 1cc215aa 2004-12-25 devnull ptraceattach(int pid)
51 2e965b33 2004-05-05 devnull if(nattached==1 && attachedpids[0] == pid)
52 2e965b33 2004-05-05 devnull goto already;
53 2e965b33 2004-05-05 devnull if(nattached)
54 2e965b33 2004-05-05 devnull detachproc(attachedpids[0]);
57 2e965b33 2004-05-05 devnull for(i=0; i<nattached; i++)
58 2e965b33 2004-05-05 devnull if(attachedpids[i]==pid)
59 1cc215aa 2004-12-25 devnull return 0;
60 2e965b33 2004-05-05 devnull if(nattached == nelem(attachedpids)){
61 2e965b33 2004-05-05 devnull werrstr("attached to too many processes");
62 2e965b33 2004-05-05 devnull return -1;
65 a84cbb2a 2004-04-19 devnull if(ptrace(PTRACE_ATTACH, pid, 0, 0) < 0){
66 a84cbb2a 2004-04-19 devnull werrstr("ptrace attach %d: %r", pid);
67 a84cbb2a 2004-04-19 devnull return -1;
70 a84cbb2a 2004-04-19 devnull if(ctlproc(pid, "waitstop") < 0){
71 2e965b33 2004-05-05 devnull fprint(2, "waitstop: %r");
72 a84cbb2a 2004-04-19 devnull ptrace(PTRACE_DETACH, pid, 0, 0);
73 a84cbb2a 2004-04-19 devnull return -1;
75 2e965b33 2004-05-05 devnull attachedpids[nattached++] = pid;
76 1cc215aa 2004-12-25 devnull return 0;
80 1cc215aa 2004-12-25 devnull unmapproc(Map *map)
84 1cc215aa 2004-12-25 devnull if(map == nil)
86 1cc215aa 2004-12-25 devnull for(i=0; i<map->nseg; i++)
87 1cc215aa 2004-12-25 devnull while(i<map->nseg && map->seg[i].pid){
88 1cc215aa 2004-12-25 devnull map->nseg--;
89 1cc215aa 2004-12-25 devnull memmove(&map->seg[i], &map->seg[i+1],
90 1cc215aa 2004-12-25 devnull (map->nseg-i)*sizeof(map->seg[0]));
95 1cc215aa 2004-12-25 devnull mapproc(int pid, Map *map, Regs **rp)
98 1cc215aa 2004-12-25 devnull PtraceRegs *r;
100 1cc215aa 2004-12-25 devnull if(ptraceattach(pid) < 0)
101 1cc215aa 2004-12-25 devnull return -1;
103 a84cbb2a 2004-04-19 devnull memset(&s, 0, sizeof s);
104 a84cbb2a 2004-04-19 devnull s.base = 0;
105 a84cbb2a 2004-04-19 devnull s.size = 0xFFFFFFFF;
106 a84cbb2a 2004-04-19 devnull s.offset = 0;
107 a84cbb2a 2004-04-19 devnull s.name = "data";
108 a84cbb2a 2004-04-19 devnull s.file = nil;
109 1cc215aa 2004-12-25 devnull s.rw = ptracesegrw;
110 a84cbb2a 2004-04-19 devnull s.pid = pid;
111 2e965b33 2004-05-05 devnull if(addseg(map, s) < 0){
112 2e965b33 2004-05-05 devnull fprint(2, "addseg: %r\n");
113 a84cbb2a 2004-04-19 devnull return -1;
116 2e965b33 2004-05-05 devnull if((r = mallocz(sizeof(PtraceRegs), 1)) == nil){
117 2e965b33 2004-05-05 devnull fprint(2, "mallocz: %r\n");
118 a84cbb2a 2004-04-19 devnull return -1;
120 a84cbb2a 2004-04-19 devnull r->r.rw = ptraceregrw;
121 a84cbb2a 2004-04-19 devnull r->pid = pid;
122 a84cbb2a 2004-04-19 devnull *rp = (Regs*)r;
123 a84cbb2a 2004-04-19 devnull return 0;
127 a84cbb2a 2004-04-19 devnull detachproc(int pid)
131 2e965b33 2004-05-05 devnull for(i=0; i<nattached; i++){
132 2e965b33 2004-05-05 devnull if(attachedpids[i] == pid){
133 2e965b33 2004-05-05 devnull attachedpids[i] = attachedpids[--nattached];
137 a84cbb2a 2004-04-19 devnull return ptrace(PTRACE_DETACH, pid, 0, 0);
140 a84cbb2a 2004-04-19 devnull static int
141 1cc215aa 2004-12-25 devnull ptracerw(int type, int xtype, int isr, int pid, ulong addr, void *v, uint n)
144 a84cbb2a 2004-04-19 devnull u32int u;
145 a84cbb2a 2004-04-19 devnull uchar buf[4];
147 a84cbb2a 2004-04-19 devnull for(i=0; i<n; i+=4){
148 a84cbb2a 2004-04-19 devnull if(isr){
149 a84cbb2a 2004-04-19 devnull errno = 0;
150 1cc215aa 2004-12-25 devnull u = ptrace(type, pid, addr+i, 0);
151 a84cbb2a 2004-04-19 devnull if(errno)
152 a84cbb2a 2004-04-19 devnull goto ptraceerr;
153 a84cbb2a 2004-04-19 devnull if(n-i >= 4)
154 a84cbb2a 2004-04-19 devnull *(u32int*)((char*)v+i) = u;
156 a84cbb2a 2004-04-19 devnull *(u32int*)buf = u;
157 a84cbb2a 2004-04-19 devnull memmove((char*)v+i, buf, n-i);
160 a84cbb2a 2004-04-19 devnull if(n-i >= 4)
161 a84cbb2a 2004-04-19 devnull u = *(u32int*)((char*)v+i);
163 a84cbb2a 2004-04-19 devnull errno = 0;
164 1cc215aa 2004-12-25 devnull u = ptrace(xtype, pid, addr+i, 0);
165 a84cbb2a 2004-04-19 devnull if(errno)
166 a84cbb2a 2004-04-19 devnull return -1;
167 a84cbb2a 2004-04-19 devnull *(u32int*)buf = u;
168 a84cbb2a 2004-04-19 devnull memmove(buf, (char*)v+i, n-i);
169 a84cbb2a 2004-04-19 devnull u = *(u32int*)buf;
171 dd944ec7 2005-01-23 devnull if(ptrace(type, pid, addr+i, u) < 0)
172 a84cbb2a 2004-04-19 devnull goto ptraceerr;
175 a84cbb2a 2004-04-19 devnull return 0;
177 a84cbb2a 2004-04-19 devnull ptraceerr:
178 a84cbb2a 2004-04-19 devnull werrstr("ptrace: %r");
179 a84cbb2a 2004-04-19 devnull return -1;
182 1cc215aa 2004-12-25 devnull static int
183 1cc215aa 2004-12-25 devnull ptracesegrw(Map *map, Seg *seg, ulong addr, void *v, uint n, int isr)
185 1cc215aa 2004-12-25 devnull addr += seg->base;
186 1cc215aa 2004-12-25 devnull return ptracerw(isr ? PTRACE_PEEKDATA : PTRACE_POKEDATA, PTRACE_PEEKDATA,
187 1cc215aa 2004-12-25 devnull isr, seg->pid, addr, v, n);
190 a84cbb2a 2004-04-19 devnull static char* linuxregs[] = {
205 a84cbb2a 2004-04-19 devnull "EFLAGS",
210 a84cbb2a 2004-04-19 devnull static ulong
211 a84cbb2a 2004-04-19 devnull reg2linux(char *reg)
215 a84cbb2a 2004-04-19 devnull for(i=0; i<nelem(linuxregs); i++)
216 a84cbb2a 2004-04-19 devnull if(strcmp(linuxregs[i], reg) == 0)
217 a84cbb2a 2004-04-19 devnull return 4*i;
218 a84cbb2a 2004-04-19 devnull return ~(ulong)0;
221 a84cbb2a 2004-04-19 devnull static int
222 4f0073fe 2004-06-11 devnull ptraceregrw(Regs *regs, char *name, ulong *val, int isr)
224 a84cbb2a 2004-04-19 devnull int pid;
225 a84cbb2a 2004-04-19 devnull ulong addr;
226 a84cbb2a 2004-04-19 devnull u32int u;
228 a84cbb2a 2004-04-19 devnull pid = ((PtraceRegs*)regs)->pid;
229 a84cbb2a 2004-04-19 devnull addr = reg2linux(name);
230 a84cbb2a 2004-04-19 devnull if(~addr == 0){
231 a84cbb2a 2004-04-19 devnull if(isr){
232 4f0073fe 2004-06-11 devnull *val = ~(ulong)0;
233 a84cbb2a 2004-04-19 devnull return 0;
235 a84cbb2a 2004-04-19 devnull werrstr("register not available");
236 a84cbb2a 2004-04-19 devnull return -1;
238 a84cbb2a 2004-04-19 devnull if(isr){
239 a84cbb2a 2004-04-19 devnull errno = 0;
240 a84cbb2a 2004-04-19 devnull u = ptrace(PTRACE_PEEKUSER, pid, addr, 0);
241 a84cbb2a 2004-04-19 devnull if(errno)
242 a84cbb2a 2004-04-19 devnull goto ptraceerr;
243 a84cbb2a 2004-04-19 devnull *val = u;
245 a84cbb2a 2004-04-19 devnull u = *val;
246 a84cbb2a 2004-04-19 devnull if(ptrace(PTRACE_POKEUSER, pid, addr, &u) < 0)
247 a84cbb2a 2004-04-19 devnull goto ptraceerr;
249 a84cbb2a 2004-04-19 devnull return 0;
251 a84cbb2a 2004-04-19 devnull ptraceerr:
252 a84cbb2a 2004-04-19 devnull werrstr("ptrace: %r");
253 a84cbb2a 2004-04-19 devnull return -1;
256 a84cbb2a 2004-04-19 devnull static int
257 a84cbb2a 2004-04-19 devnull isstopped(int pid)
259 a84cbb2a 2004-04-19 devnull char buf[1024];
260 a84cbb2a 2004-04-19 devnull int fd, n;
261 a84cbb2a 2004-04-19 devnull char *p;
263 a84cbb2a 2004-04-19 devnull snprint(buf, sizeof buf, "/proc/%d/stat", pid);
264 a84cbb2a 2004-04-19 devnull if((fd = open(buf, OREAD)) < 0)
265 a84cbb2a 2004-04-19 devnull return 0;
266 a84cbb2a 2004-04-19 devnull n = read(fd, buf, sizeof buf-1);
267 a84cbb2a 2004-04-19 devnull close(fd);
268 a84cbb2a 2004-04-19 devnull if(n <= 0)
269 a84cbb2a 2004-04-19 devnull return 0;
270 a84cbb2a 2004-04-19 devnull buf[n] = 0;
272 a84cbb2a 2004-04-19 devnull /* command name is in parens, no parens afterward */
273 a84cbb2a 2004-04-19 devnull p = strrchr(buf, ')');
274 a84cbb2a 2004-04-19 devnull if(p == nil || *++p != ' ')
275 a84cbb2a 2004-04-19 devnull return 0;
278 a84cbb2a 2004-04-19 devnull /* next is state - T is stopped for tracing */
279 a84cbb2a 2004-04-19 devnull return *p == 'T';
282 a84cbb2a 2004-04-19 devnull /* /proc/pid/stat contains
284 a84cbb2a 2004-04-19 devnull command in parens
285 a84cbb2a 2004-04-19 devnull 0. state
288 a84cbb2a 2004-04-19 devnull 3. session
289 a84cbb2a 2004-04-19 devnull 4. tty_nr
290 a84cbb2a 2004-04-19 devnull 5. tpgid
291 a84cbb2a 2004-04-19 devnull 6. flags (math=4, traced=10)
292 a84cbb2a 2004-04-19 devnull 7. minflt
293 a84cbb2a 2004-04-19 devnull 8. cminflt
294 a84cbb2a 2004-04-19 devnull 9. majflt
295 a84cbb2a 2004-04-19 devnull 10. cmajflt
296 a84cbb2a 2004-04-19 devnull 11. utime
297 a84cbb2a 2004-04-19 devnull 12. stime
298 a84cbb2a 2004-04-19 devnull 13. cutime
299 a84cbb2a 2004-04-19 devnull 14. cstime
300 a84cbb2a 2004-04-19 devnull 15. priority
301 a84cbb2a 2004-04-19 devnull 16. nice
303 a84cbb2a 2004-04-19 devnull 18. itrealvalue
304 a84cbb2a 2004-04-19 devnull 19. starttime
305 a84cbb2a 2004-04-19 devnull 20. vsize
307 a84cbb2a 2004-04-19 devnull 22. rlim
308 a84cbb2a 2004-04-19 devnull 23. startcode
309 a84cbb2a 2004-04-19 devnull 24. endcode
310 a84cbb2a 2004-04-19 devnull 25. startstack
311 a84cbb2a 2004-04-19 devnull 26. kstkesp
312 a84cbb2a 2004-04-19 devnull 27. kstkeip
313 a84cbb2a 2004-04-19 devnull 28. pending signal bitmap
314 a84cbb2a 2004-04-19 devnull 29. blocked signal bitmap
315 a84cbb2a 2004-04-19 devnull 30. ignored signal bitmap
316 a84cbb2a 2004-04-19 devnull 31. caught signal bitmap
317 a84cbb2a 2004-04-19 devnull 32. wchan
318 a84cbb2a 2004-04-19 devnull 33. nswap
319 a84cbb2a 2004-04-19 devnull 34. cnswap
320 a84cbb2a 2004-04-19 devnull 35. exit_signal
321 a84cbb2a 2004-04-19 devnull 36. processor
326 a84cbb2a 2004-04-19 devnull procnotes(int pid, char ***pnotes)
328 a84cbb2a 2004-04-19 devnull char buf[1024], *f[40];
329 a84cbb2a 2004-04-19 devnull int fd, i, n, nf;
330 a84cbb2a 2004-04-19 devnull char *p, *s, **notes;
331 a84cbb2a 2004-04-19 devnull ulong sigs;
332 a84cbb2a 2004-04-19 devnull extern char *_p9sigstr(int, char*);
334 a84cbb2a 2004-04-19 devnull *pnotes = nil;
335 a84cbb2a 2004-04-19 devnull snprint(buf, sizeof buf, "/proc/%d/stat", pid);
336 a84cbb2a 2004-04-19 devnull if((fd = open(buf, OREAD)) < 0){
337 a84cbb2a 2004-04-19 devnull fprint(2, "open %s: %r\n", buf);
338 a84cbb2a 2004-04-19 devnull return -1;
340 a84cbb2a 2004-04-19 devnull n = read(fd, buf, sizeof buf-1);
341 a84cbb2a 2004-04-19 devnull close(fd);
342 a84cbb2a 2004-04-19 devnull if(n <= 0){
343 a84cbb2a 2004-04-19 devnull fprint(2, "read %s: %r\n", buf);
344 a84cbb2a 2004-04-19 devnull return -1;
346 a84cbb2a 2004-04-19 devnull buf[n] = 0;
348 a84cbb2a 2004-04-19 devnull /* command name is in parens, no parens afterward */
349 a84cbb2a 2004-04-19 devnull p = strrchr(buf, ')');
350 a84cbb2a 2004-04-19 devnull if(p == nil || *++p != ' '){
351 a84cbb2a 2004-04-19 devnull fprint(2, "bad format in /proc/%d/stat\n", pid);
352 a84cbb2a 2004-04-19 devnull return -1;
356 a84cbb2a 2004-04-19 devnull nf = tokenize(p, f, nelem(f));
357 a84cbb2a 2004-04-19 devnull if(0) print("code 0x%lux-0x%lux stack 0x%lux kstk 0x%lux keip 0x%lux pending 0x%lux\n",
358 a84cbb2a 2004-04-19 devnull strtoul(f[23], 0, 0), strtoul(f[24], 0, 0), strtoul(f[25], 0, 0),
359 a84cbb2a 2004-04-19 devnull strtoul(f[26], 0, 0), strtoul(f[27], 0, 0), strtoul(f[28], 0, 0));
360 a84cbb2a 2004-04-19 devnull if(nf <= 28)
361 a84cbb2a 2004-04-19 devnull return -1;
363 a84cbb2a 2004-04-19 devnull sigs = strtoul(f[28], 0, 0) & ~(1<<SIGCONT);
364 a84cbb2a 2004-04-19 devnull if(sigs == 0){
365 a84cbb2a 2004-04-19 devnull *pnotes = nil;
366 a84cbb2a 2004-04-19 devnull return 0;
369 a84cbb2a 2004-04-19 devnull notes = mallocz(32*sizeof(char*), 0);
370 a84cbb2a 2004-04-19 devnull if(notes == nil)
371 a84cbb2a 2004-04-19 devnull return -1;
373 a84cbb2a 2004-04-19 devnull for(i=0; i<32; i++){
374 a84cbb2a 2004-04-19 devnull if((sigs&(1<<i)) == 0)
375 a84cbb2a 2004-04-19 devnull continue;
376 a84cbb2a 2004-04-19 devnull if((s = _p9sigstr(i, nil)) == nil)
377 a84cbb2a 2004-04-19 devnull continue;
378 a84cbb2a 2004-04-19 devnull notes[n++] = s;
380 a84cbb2a 2004-04-19 devnull *pnotes = notes;
381 a84cbb2a 2004-04-19 devnull return n;
384 a84cbb2a 2004-04-19 devnull #undef waitpid
387 a84cbb2a 2004-04-19 devnull ctlproc(int pid, char *msg)
389 a84cbb2a 2004-04-19 devnull int p, status;
391 a84cbb2a 2004-04-19 devnull if(strcmp(msg, "hang") == 0){
392 a84cbb2a 2004-04-19 devnull if(pid == getpid())
393 a84cbb2a 2004-04-19 devnull return ptrace(PTRACE_TRACEME, 0, 0, 0);
394 a84cbb2a 2004-04-19 devnull werrstr("can only hang self");
395 a84cbb2a 2004-04-19 devnull return -1;
397 a84cbb2a 2004-04-19 devnull if(strcmp(msg, "kill") == 0)
398 a84cbb2a 2004-04-19 devnull return ptrace(PTRACE_KILL, pid, 0, 0);
399 a84cbb2a 2004-04-19 devnull if(strcmp(msg, "startstop") == 0){
400 a84cbb2a 2004-04-19 devnull if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
401 a84cbb2a 2004-04-19 devnull return -1;
402 a84cbb2a 2004-04-19 devnull goto waitstop;
404 a84cbb2a 2004-04-19 devnull if(strcmp(msg, "sysstop") == 0){
405 a84cbb2a 2004-04-19 devnull if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
406 a84cbb2a 2004-04-19 devnull return -1;
407 a84cbb2a 2004-04-19 devnull goto waitstop;
409 a84cbb2a 2004-04-19 devnull if(strcmp(msg, "stop") == 0){
410 a84cbb2a 2004-04-19 devnull if(kill(pid, SIGSTOP) < 0)
411 a84cbb2a 2004-04-19 devnull return -1;
412 a84cbb2a 2004-04-19 devnull goto waitstop;
414 a84cbb2a 2004-04-19 devnull if(strcmp(msg, "waitstop") == 0){
415 a84cbb2a 2004-04-19 devnull waitstop:
416 a84cbb2a 2004-04-19 devnull if(isstopped(pid))
417 a84cbb2a 2004-04-19 devnull return 0;
418 a84cbb2a 2004-04-19 devnull for(;;){
419 2e965b33 2004-05-05 devnull p = waitpid(pid, &status, WUNTRACED|__WALL);
420 2e965b33 2004-05-05 devnull if(p <= 0){
421 2e965b33 2004-05-05 devnull if(errno == ECHILD){
422 2e965b33 2004-05-05 devnull if(isstopped(pid))
423 2e965b33 2004-05-05 devnull return 0;
425 a84cbb2a 2004-04-19 devnull return -1;
427 a84cbb2a 2004-04-19 devnull if(WIFEXITED(status) || WIFSTOPPED(status))
428 a84cbb2a 2004-04-19 devnull return 0;
431 a84cbb2a 2004-04-19 devnull if(strcmp(msg, "start") == 0)
432 a84cbb2a 2004-04-19 devnull return ptrace(PTRACE_CONT, pid, 0, 0);
433 a84cbb2a 2004-04-19 devnull werrstr("unknown control message '%s'", msg);
434 a84cbb2a 2004-04-19 devnull return -1;
438 a84cbb2a 2004-04-19 devnull proctextfile(int pid)
440 a84cbb2a 2004-04-19 devnull static char buf[1024], pbuf[128];
442 a84cbb2a 2004-04-19 devnull snprint(pbuf, sizeof pbuf, "/proc/%d/exe", pid);
443 a84cbb2a 2004-04-19 devnull if(readlink(pbuf, buf, sizeof buf) >= 0)
444 a84cbb2a 2004-04-19 devnull return buf;
445 a84cbb2a 2004-04-19 devnull if(access(pbuf, AEXIST) >= 0)
446 a84cbb2a 2004-04-19 devnull return pbuf;
447 a84cbb2a 2004-04-19 devnull return nil;
