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[dragonfly.git] / sys / emulation / linux / i386 / linux_ptrace.c
blob71d70f2531f8ec2905afd43dabb8fa55d4fb82cb
1 /*
2 * Copyright (c) 2001 Alexander Kabaev
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: src/sys/i386/linux/linux_ptrace.c,v 1.7.4.3 2003/01/03 17:13:23 kan Exp $
29 * $DragonFly: src/sys/emulation/linux/i386/linux_ptrace.c,v 1.15 2007/02/19 01:14:23 corecode Exp $
30 */
31
32 #include "opt_cpu.h"
33
34 #include <sys/param.h>
35 #include <sys/lock.h>
36 #include <sys/proc.h>
37 #include <sys/ptrace.h>
38 #include <sys/systm.h>
39
40 #include <vm/vm.h>
41 #include <vm/pmap.h>
42 #include <vm/vm_map.h>
43 #include <sys/user.h>
44 #include <sys/reg.h>
45
46 #include <machine/md_var.h>
47 #include <machine/pcb.h>
48
49 #include "linux.h"
50 #include "linux_proto.h"
51
52 /*
53 * Linux ptrace requests numbers. Mostly identical to FreeBSD,
54 * except for MD ones and PT_ATTACH/PT_DETACH.
55 */
56 #define PTRACE_TRACEME 0
57 #define PTRACE_PEEKTEXT 1
58 #define PTRACE_PEEKDATA 2
59 #define PTRACE_PEEKUSR 3
60 #define PTRACE_POKETEXT 4
61 #define PTRACE_POKEDATA 5
62 #define PTRACE_POKEUSR 6
63 #define PTRACE_CONT 7
64 #define PTRACE_KILL 8
65 #define PTRACE_SINGLESTEP 9
66
67 #define PTRACE_ATTACH 16
68 #define PTRACE_DETACH 17
69
70 #define PTRACE_SYSCALL 24
71
72 #define PTRACE_GETREGS 12
73 #define PTRACE_SETREGS 13
74 #define PTRACE_GETFPREGS 14
75 #define PTRACE_SETFPREGS 15
76 #define PTRACE_GETFPXREGS 18
77 #define PTRACE_SETFPXREGS 19
78
79 #define PTRACE_SETOPTIONS 21
80
81 /*
82 * Linux keeps debug registers at the following
83 * offset in the user struct
84 */
85 #define LINUX_DBREG_OFFSET 252
86 #define LINUX_DBREG_SIZE (8*sizeof(l_int))
87
88 static __inline__ int
89 map_signum(int signum)
90 {
91
92 if (signum > 0 && signum <= LINUX_SIGTBLSZ)
93 signum = linux_to_bsd_signal[_SIG_IDX(signum)];
94 return ((signum == SIGSTOP)? 0 : signum);
95 }
96
97 struct linux_pt_reg {
98 l_long ebx;
99 l_long ecx;
100 l_long edx;
101 l_long esi;
102 l_long edi;
103 l_long ebp;
104 l_long eax;
105 l_int xds;
106 l_int xes;
107 l_int xfs;
108 l_int xgs;
109 l_long orig_eax;
110 l_long eip;
111 l_int xcs;
112 l_long eflags;
113 l_long esp;
114 l_int xss;
115 };
116
117 /*
118 * Translate i386 ptrace registers between Linux and FreeBSD formats.
119 * The translation is pretty straighforward, for all registers, but
120 * orig_eax on Linux side and r_trapno and r_err in FreeBSD
121 */
122 static void
123 map_regs_to_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
124 {
125 linux_r->ebx = bsd_r->r_ebx;
126 linux_r->ecx = bsd_r->r_ecx;
127 linux_r->edx = bsd_r->r_edx;
128 linux_r->esi = bsd_r->r_esi;
129 linux_r->edi = bsd_r->r_edi;
130 linux_r->ebp = bsd_r->r_ebp;
131 linux_r->eax = bsd_r->r_eax;
132 linux_r->xds = bsd_r->r_ds;
133 linux_r->xes = bsd_r->r_es;
134 linux_r->xfs = bsd_r->r_fs;
135 linux_r->xgs = bsd_r->r_gs;
136 linux_r->orig_eax = bsd_r->r_eax;
137 linux_r->eip = bsd_r->r_eip;
138 linux_r->xcs = bsd_r->r_cs;
139 linux_r->eflags = bsd_r->r_eflags;
140 linux_r->esp = bsd_r->r_esp;
141 linux_r->xss = bsd_r->r_ss;
142 }
143
144 static void
145 map_regs_from_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
146 {
147 bsd_r->r_ebx = linux_r->ebx;
148 bsd_r->r_ecx = linux_r->ecx;
149 bsd_r->r_edx = linux_r->edx;
150 bsd_r->r_esi = linux_r->esi;
151 bsd_r->r_edi = linux_r->edi;
152 bsd_r->r_ebp = linux_r->ebp;
153 bsd_r->r_eax = linux_r->eax;
154 bsd_r->r_ds = linux_r->xds;
155 bsd_r->r_es = linux_r->xes;
156 bsd_r->r_fs = linux_r->xfs;
157 bsd_r->r_gs = linux_r->xgs;
158 bsd_r->r_eip = linux_r->eip;
159 bsd_r->r_cs = linux_r->xcs;
160 bsd_r->r_eflags = linux_r->eflags;
161 bsd_r->r_esp = linux_r->esp;
162 bsd_r->r_ss = linux_r->xss;
163 }
164
165 struct linux_pt_fpreg {
166 l_long cwd;
167 l_long swd;
168 l_long twd;
169 l_long fip;
170 l_long fcs;
171 l_long foo;
172 l_long fos;
173 l_long st_space[2*10];
174 };
175
176 static void
177 map_fpregs_to_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
178 {
179 linux_r->cwd = bsd_r->fpr_env[0];
180 linux_r->swd = bsd_r->fpr_env[1];
181 linux_r->twd = bsd_r->fpr_env[2];
182 linux_r->fip = bsd_r->fpr_env[3];
183 linux_r->fcs = bsd_r->fpr_env[4];
184 linux_r->foo = bsd_r->fpr_env[5];
185 linux_r->fos = bsd_r->fpr_env[6];
186 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(linux_r->st_space));
187 }
188
189 static void
190 map_fpregs_from_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
191 {
192 bsd_r->fpr_env[0] = linux_r->cwd;
193 bsd_r->fpr_env[1] = linux_r->swd;
194 bsd_r->fpr_env[2] = linux_r->twd;
195 bsd_r->fpr_env[3] = linux_r->fip;
196 bsd_r->fpr_env[4] = linux_r->fcs;
197 bsd_r->fpr_env[5] = linux_r->foo;
198 bsd_r->fpr_env[6] = linux_r->fos;
199 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(bsd_r->fpr_acc));
200 }
201
202 struct linux_pt_fpxreg {
203 l_ushort cwd;
204 l_ushort swd;
205 l_ushort twd;
206 l_ushort fop;
207 l_long fip;
208 l_long fcs;
209 l_long foo;
210 l_long fos;
211 l_long mxcsr;
212 l_long reserved;
213 l_long st_space[32];
214 l_long xmm_space[32];
215 l_long padding[56];
216 };
217
218 #ifndef CPU_DISABLE_SSE
219 static int
220 linux_proc_read_fpxregs(struct lwp *lp, struct linux_pt_fpxreg *fpxregs)
221 {
222 int error;
223
224 error = 0;
225 if (cpu_fxsr == 0)
226 error = EIO;
227 else
228 bcopy(&lp->lwp_thread->td_pcb->pcb_save.sv_xmm,
229 fpxregs, sizeof(*fpxregs));
230 return (error);
231 }
232
233 static int
234 linux_proc_write_fpxregs(struct lwp *lp, struct linux_pt_fpxreg *fpxregs)
235 {
236 int error;
237
238 error = 0;
239 if (cpu_fxsr == 0)
240 error = EIO;
241 else
242 bcopy(fpxregs, &lp->lwp_thread->td_pcb->pcb_save.sv_xmm,
243 sizeof(*fpxregs));
244 return (error);
245 }
246 #endif
247
248 /*
249 * MPALMOSTSAFE
250 */
251 int
252 sys_linux_ptrace(struct linux_ptrace_args *uap)
253 {
254 struct thread *td = curthread;
255 struct proc *curp = td->td_proc;
256 union {
257 struct linux_pt_reg reg;
258 struct linux_pt_fpreg fpreg;
259 struct linux_pt_fpxreg fpxreg;
260 } r;
261 union {
262 struct reg bsd_reg;
263 struct fpreg bsd_fpreg;
264 struct dbreg bsd_dbreg;
265 } u;
266 void *addr;
267 pid_t pid;
268 int error, req;
269 struct proc *p = NULL; /* held process */
270
271 error = 0;
272
273 /* by default, just copy data intact */
274 req = uap->req;
275 pid = (pid_t)uap->pid;
276 addr = (void *)uap->addr;
277
278 switch (req) {
279 case PTRACE_TRACEME:
280 case PTRACE_POKETEXT:
281 case PTRACE_POKEDATA:
282 case PTRACE_KILL:
283 error = kern_ptrace(curp, req, pid, addr, uap->data,
284 &uap->sysmsg_iresult);
285 break;
286 case PTRACE_PEEKTEXT:
287 case PTRACE_PEEKDATA: {
288 /* need to preserve return value, use dummy */
289 l_int rval = 0;
290 error = kern_ptrace(curp, req, pid, addr, 0, &rval);
291 if (error == 0) {
292 error = copyout(&rval, (caddr_t)uap->data, sizeof(l_int));
293 }
294 break;
295 }
296 case PTRACE_DETACH:
297 error = kern_ptrace(curp, PT_DETACH, pid, (void *)1,
298 map_signum(uap->data),
299 &uap->sysmsg_iresult);
300 break;
301 case PTRACE_SINGLESTEP:
302 case PTRACE_CONT:
303 error = kern_ptrace(curp, req, pid, (void *)1,
304 map_signum(uap->data),
305 &uap->sysmsg_iresult);
306 break;
307 case PTRACE_ATTACH:
308 error = kern_ptrace(curp, PT_ATTACH, pid, addr, uap->data,
309 &uap->sysmsg_iresult);
310 break;
311 case PTRACE_GETREGS:
312 /* Linux is using data where FreeBSD is using addr */
313 error = kern_ptrace(curp, PT_GETREGS, pid, &u.bsd_reg, 0,
314 &uap->sysmsg_iresult);
315 if (error == 0) {
316 map_regs_to_linux(&u.bsd_reg, &r.reg);
317 error = copyout(&r.reg, (void *)uap->data,
318 sizeof(r.reg));
319 }
320 break;
321 case PTRACE_SETREGS:
322 /* Linux is using data where FreeBSD is using addr */
323 error = copyin((caddr_t)uap->data, &r.reg, sizeof(r.reg));
324 if (error == 0) {
325 map_regs_from_linux(&u.bsd_reg, &r.reg);
326 error = kern_ptrace(curp, PT_SETREGS, pid, &u.bsd_reg,
327 0, &uap->sysmsg_iresult);
328 }
329 break;
330 case PTRACE_GETFPREGS:
331 /* Linux is using data where FreeBSD is using addr */
332 error = kern_ptrace(curp, PT_GETFPREGS, pid, &u.bsd_fpreg,
333 0, &uap->sysmsg_iresult);
334 if (error == 0) {
335 map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg);
336 error = copyout(&r.fpreg, (caddr_t)uap->data,
337 sizeof(r.fpreg));
338 }
339 break;
340 case PTRACE_SETFPREGS:
341 /* Linux is using data where FreeBSD is using addr */
342 error = copyin((caddr_t)uap->data, &r.fpreg, sizeof(r.fpreg));
343 if (error == 0) {
344 map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg);
345 error = kern_ptrace(curp, PT_SETFPREGS, pid,
346 &u.bsd_fpreg,
347 0, &uap->sysmsg_iresult);
348 }
349 break;
350 case PTRACE_SETFPXREGS:
351 #ifndef CPU_DISABLE_SSE
352 error = copyin((caddr_t)uap->data, &r.fpxreg,
353 sizeof(r.fpxreg));
354 if (error)
355 break;
356 #endif
357 /* FALL THROUGH */
358 case PTRACE_GETFPXREGS: {
359 #ifndef CPU_DISABLE_SSE
360 struct proc *p;
361 struct lwp *lp;
362
363 if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) {
364 static int once = 0;
365 if (!once) {
366 kprintf("linux: savexmm != linux_pt_fpxreg\n");
367 once = 1;
368 }
369 error = EIO;
370 break;
371 }
372
373 if ((p = pfind(uap->pid)) == NULL) {
374 error = ESRCH;
375 break;
376 }
377
378 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) {
379 error = ESRCH;
380 goto fail;
381 }
382
383 /* System processes can't be debugged. */
384 if ((p->p_flags & P_SYSTEM) != 0) {
385 error = EINVAL;
386 goto fail;
387 }
388
389 /* not being traced... */
390 if ((p->p_flags & P_TRACED) == 0) {
391 error = EPERM;
392 goto fail;
393 }
394
395 /* not being traced by YOU */
396 if (p->p_pptr != curp) {
397 error = EBUSY;
398 goto fail;
399 }
400
401 /* not currently stopped */
402 if ((p->p_flags & (P_TRACED|P_WAITED)) == 0) {
403 error = EBUSY;
404 goto fail;
405 }
406
407 /* XXX lwp */
408 lp = FIRST_LWP_IN_PROC(p);
409
410 if (req == PTRACE_GETFPXREGS) {
411 LWPHOLD(lp);
412 error = linux_proc_read_fpxregs(lp, &r.fpxreg);
413 LWPRELE(lp);
414 if (error == 0)
415 error = copyout(&r.fpxreg, (caddr_t)uap->data,
416 sizeof(r.fpxreg));
417 } else {
418 /* clear dangerous bits exactly as Linux does*/
419 r.fpxreg.mxcsr &= 0xffbf;
420 LWPHOLD(lp);
421 error = linux_proc_write_fpxregs(lp, &r.fpxreg);
422 LWPRELE(lp);
423 }
424 break;
425
426 fail:
427 #else
428 error = EIO;
429 #endif
430 break;
431 }
432 case PTRACE_PEEKUSR:
433 case PTRACE_POKEUSR: {
434 error = EIO;
435
436 /* check addr for alignment */
437 if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1))
438 break;
439 /*
440 * Allow linux programs to access register values in
441 * user struct. We simulate this through PT_GET/SETREGS
442 * as necessary.
443 */
444 if (uap->addr < sizeof(struct linux_pt_reg)) {
445 error = kern_ptrace(curp, PT_GETREGS, pid, &u.bsd_reg,
446 0, &uap->sysmsg_iresult);
447 if (error != 0)
448 break;
449
450 map_regs_to_linux(&u.bsd_reg, &r.reg);
451 if (req == PTRACE_PEEKUSR) {
452 error = copyout((char *)&r.reg + uap->addr,
453 (caddr_t)uap->data, sizeof(l_int));
454 break;
455 }
456
457 *(l_int *)((char *)&r.reg + uap->addr) =
458 (l_int)uap->data;
459
460 map_regs_from_linux(&u.bsd_reg, &r.reg);
461 error = kern_ptrace(curp, PT_SETREGS, pid, &u.bsd_reg,
462 0, &uap->sysmsg_iresult);
463 }
464
465 /*
466 * Simulate debug registers access
467 */
468 if (uap->addr >= LINUX_DBREG_OFFSET &&
469 uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) {
470 error = kern_ptrace(curp, PT_GETDBREGS, pid,
471 &u.bsd_dbreg,
472 0, &uap->sysmsg_iresult);
473 if (error != 0)
474 break;
475
476 uap->addr -= LINUX_DBREG_OFFSET;
477 if (req == PTRACE_PEEKUSR) {
478 error = copyout((char *)&u.bsd_dbreg +
479 uap->addr, (caddr_t)uap->data,
480 sizeof(l_int));
481 break;
482 }
483
484 *(l_int *)((char *)&u.bsd_dbreg + uap->addr) =
485 uap->data;
486 error = kern_ptrace(curp, PT_SETDBREGS, pid,
487 &u.bsd_dbreg,
488 0, &uap->sysmsg_iresult);
489 }
490
491 break;
492 }
493 case PTRACE_SYSCALL:
494 /* fall through */
495 default:
496 kprintf("linux: ptrace(%u, ...) not implemented\n",
497 (unsigned int)uap->req);
498 error = EINVAL;
499 break;
500 }
501
502 /*
503 * Release held proces (if any) before returning.
504 */
505 if (p)
506 PRELE(p);
507 return (error);
508 }
DragonFly BSD