AMD64 - Refactor uio_resid and size_t assumptions.
[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 int
249 sys_linux_ptrace(struct linux_ptrace_args *uap)
250 {
251         struct thread *td = curthread;
252         struct proc *curp = td->td_proc;
253         union {
254                 struct linux_pt_reg     reg;
255                 struct linux_pt_fpreg   fpreg;
256                 struct linux_pt_fpxreg  fpxreg;
257         } r;
258         union {
259                 struct reg              bsd_reg;
260                 struct fpreg            bsd_fpreg;
261                 struct dbreg            bsd_dbreg;
262         } u;
263         void *addr;
264         pid_t pid;
265         int error, req;
266
267         error = 0;
268
269         /* by default, just copy data intact */
270         req  = uap->req;
271         pid  = (pid_t)uap->pid;
272         addr = (void *)uap->addr;
273
274         switch (req) {
275         case PTRACE_TRACEME:
276         case PTRACE_POKETEXT:
277         case PTRACE_POKEDATA:
278         case PTRACE_KILL:
279                 error = kern_ptrace(curp, req, pid, addr, uap->data,
280                                     &uap->sysmsg_iresult);
281                 break;
282         case PTRACE_PEEKTEXT:
283         case PTRACE_PEEKDATA: {
284                 /* need to preserve return value, use dummy */
285                 l_int rval = 0;
286                 error = kern_ptrace(curp, req, pid, addr, 0, &rval);
287                 if (error == 0) {
288                         error = copyout(&rval, (caddr_t)uap->data, sizeof(l_int));
289                 }
290                 break;
291         }
292         case PTRACE_DETACH:
293                 error = kern_ptrace(curp, PT_DETACH, pid, (void *)1,
294                                     map_signum(uap->data),
295                                     &uap->sysmsg_iresult);
296                 break;
297         case PTRACE_SINGLESTEP:
298         case PTRACE_CONT:
299                 error = kern_ptrace(curp, req, pid, (void *)1,
300                                     map_signum(uap->data),
301                                     &uap->sysmsg_iresult);
302                 break;
303         case PTRACE_ATTACH:
304                 error = kern_ptrace(curp, PT_ATTACH, pid, addr, uap->data,
305                                     &uap->sysmsg_iresult);
306                 break;
307         case PTRACE_GETREGS:
308                 /* Linux is using data where FreeBSD is using addr */
309                 error = kern_ptrace(curp, PT_GETREGS, pid, &u.bsd_reg, 0,
310                                     &uap->sysmsg_iresult);
311                 if (error == 0) {
312                         map_regs_to_linux(&u.bsd_reg, &r.reg);
313                         error = copyout(&r.reg, uap->data, sizeof(r.reg));
314                 }
315                 break;
316         case PTRACE_SETREGS:
317                 /* Linux is using data where FreeBSD is using addr */
318                 error = copyin((caddr_t)uap->data, &r.reg, sizeof(r.reg));
319                 if (error == 0) {
320                         map_regs_from_linux(&u.bsd_reg, &r.reg);
321                         error = kern_ptrace(curp, PT_SETREGS, pid, &u.bsd_reg,
322                                             0, &uap->sysmsg_iresult);
323                 }
324                 break;
325         case PTRACE_GETFPREGS:
326                 /* Linux is using data where FreeBSD is using addr */
327                 error = kern_ptrace(curp, PT_GETFPREGS, pid, &u.bsd_fpreg,
328                                     0, &uap->sysmsg_iresult);
329                 if (error == 0) {
330                         map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg);
331                         error = copyout(&r.fpreg, (caddr_t)uap->data,
332                             sizeof(r.fpreg));
333                 }
334                 break;
335         case PTRACE_SETFPREGS:
336                 /* Linux is using data where FreeBSD is using addr */
337                 error = copyin((caddr_t)uap->data, &r.fpreg, sizeof(r.fpreg));
338                 if (error == 0) {
339                         map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg);
340                         error = kern_ptrace(curp, PT_SETFPREGS, pid,
341                                             &u.bsd_fpreg,
342                                             0, &uap->sysmsg_iresult);
343                 }
344                 break;
345         case PTRACE_SETFPXREGS:
346 #ifndef CPU_DISABLE_SSE
347                 error = copyin((caddr_t)uap->data, &r.fpxreg,
348                     sizeof(r.fpxreg));
349                 if (error)
350                         break;
351 #endif
352                 /* FALL THROUGH */
353         case PTRACE_GETFPXREGS: {
354 #ifndef CPU_DISABLE_SSE
355                 struct proc *p;
356                 struct lwp *lp;
357
358                 if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) {
359                         static int once = 0;
360                         if (!once) {
361                                 kprintf("linux: savexmm != linux_pt_fpxreg\n");
362                                 once = 1;
363                         }
364                         error = EIO;
365                         break;
366                 }
367
368                 if ((p = pfind(uap->pid)) == NULL) {
369                         error = ESRCH;
370                         break;
371                 }
372
373                 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) {
374                         error = ESRCH;
375                         goto fail;
376                 }
377
378                 /* System processes can't be debugged. */
379                 if ((p->p_flag & P_SYSTEM) != 0) {
380                         error = EINVAL;
381                         goto fail;
382                 }
383
384                 /* not being traced... */
385                 if ((p->p_flag & P_TRACED) == 0) {
386                         error = EPERM;
387                         goto fail;
388                 }
389
390                 /* not being traced by YOU */
391                 if (p->p_pptr != curp) {
392                         error = EBUSY;
393                         goto fail;
394                 }
395
396                 /* not currently stopped */
397                 if ((p->p_flag & (P_TRACED|P_WAITED)) == 0) {
398                         error = EBUSY;
399                         goto fail;
400                 }
401
402                 /* XXX lwp */
403                 lp = FIRST_LWP_IN_PROC(p);
404
405                 if (req == PTRACE_GETFPXREGS) {
406                         LWPHOLD(lp);
407                         error = linux_proc_read_fpxregs(lp, &r.fpxreg);
408                         LWPRELE(lp);
409                         if (error == 0)
410                                 error = copyout(&r.fpxreg, (caddr_t)uap->data,
411                                     sizeof(r.fpxreg));
412                 } else {
413                         /* clear dangerous bits exactly as Linux does*/
414                         r.fpxreg.mxcsr &= 0xffbf;
415                         LWPHOLD(lp);
416                         error = linux_proc_write_fpxregs(lp, &r.fpxreg);
417                         LWPRELE(lp);
418                 }
419                 break;
420
421         fail:
422 #else
423                 error = EIO;
424 #endif
425                 break;
426         }
427         case PTRACE_PEEKUSR:
428         case PTRACE_POKEUSR: {
429                 error = EIO;
430
431                 /* check addr for alignment */
432                 if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1))
433                         break;
434                 /*
435                  * Allow linux programs to access register values in
436                  * user struct. We simulate this through PT_GET/SETREGS
437                  * as necessary.
438                  */
439                 if (uap->addr < sizeof(struct linux_pt_reg)) {
440                         error = kern_ptrace(curp, PT_GETREGS, pid, &u.bsd_reg,
441                                             0, &uap->sysmsg_iresult);
442                         if (error != 0)
443                                 break;
444
445                         map_regs_to_linux(&u.bsd_reg, &r.reg);
446                         if (req == PTRACE_PEEKUSR) {
447                                 error = copyout((char *)&r.reg + uap->addr,
448                                     (caddr_t)uap->data, sizeof(l_int));
449                                 break;
450                         }
451
452                         *(l_int *)((char *)&r.reg + uap->addr) =
453                             (l_int)uap->data;
454
455                         map_regs_from_linux(&u.bsd_reg, &r.reg);
456                         error = kern_ptrace(curp, PT_SETREGS, pid, &u.bsd_reg,
457                                             0, &uap->sysmsg_iresult);
458                 }
459
460                 /*
461                  * Simulate debug registers access
462                  */
463                 if (uap->addr >= LINUX_DBREG_OFFSET &&
464                     uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) {
465                         error = kern_ptrace(curp, PT_GETDBREGS, pid, 
466                                             &u.bsd_dbreg,
467                                             0, &uap->sysmsg_iresult);
468                         if (error != 0)
469                                 break;
470
471                         uap->addr -= LINUX_DBREG_OFFSET;
472                         if (req == PTRACE_PEEKUSR) {
473                                 error = copyout((char *)&u.bsd_dbreg +
474                                     uap->addr, (caddr_t)uap->data,
475                                     sizeof(l_int));
476                                 break;
477                         }
478
479                         *(l_int *)((char *)&u.bsd_dbreg + uap->addr) =
480                              uap->data;
481                         error = kern_ptrace(curp, PT_SETDBREGS, pid,
482                                             &u.bsd_dbreg,
483                                             0, &uap->sysmsg_iresult);
484                 }
485
486                 break;
487         }
488         case PTRACE_SYSCALL:
489                 /* fall through */
490         default:
491                 kprintf("linux: ptrace(%u, ...) not implemented\n",
492                     (unsigned int)uap->req);
493                 error = EINVAL;
494                 break;
495         }
496
497         return (error);
498 }