21622f70b4a1f3fa02ce05f791dffae0a260dda6
[dragonfly.git] / sys / emulation / linux / i386 / linux_ptrace.c
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_flag & P_SYSTEM) != 0) {
385                         error = EINVAL;
386                         goto fail;
387                 }
388
389                 /* not being traced... */
390                 if ((p->p_flag & 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_flag & (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 }