[PATCH] unify sys_ptrace prototype
[linux-3.10.git] / arch / mips / kernel / ptrace.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1992 Ross Biro
7  * Copyright (C) Linus Torvalds
8  * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
9  * Copyright (C) 1996 David S. Miller
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 1999 MIPS Technologies, Inc.
12  * Copyright (C) 2000 Ulf Carlsson
13  *
14  * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
15  * binaries.
16  */
17 #include <linux/config.h>
18 #include <linux/compiler.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/mm.h>
22 #include <linux/errno.h>
23 #include <linux/ptrace.h>
24 #include <linux/audit.h>
25 #include <linux/smp.h>
26 #include <linux/smp_lock.h>
27 #include <linux/user.h>
28 #include <linux/security.h>
29 #include <linux/signal.h>
30
31 #include <asm/byteorder.h>
32 #include <asm/cpu.h>
33 #include <asm/dsp.h>
34 #include <asm/fpu.h>
35 #include <asm/mipsregs.h>
36 #include <asm/mipsmtregs.h>
37 #include <asm/pgtable.h>
38 #include <asm/page.h>
39 #include <asm/system.h>
40 #include <asm/uaccess.h>
41 #include <asm/bootinfo.h>
42 #include <asm/reg.h>
43
44 /*
45  * Called by kernel/ptrace.c when detaching..
46  *
47  * Make sure single step bits etc are not set.
48  */
49 void ptrace_disable(struct task_struct *child)
50 {
51         /* Nothing to do.. */
52 }
53
54 /*
55  * Read a general register set.  We always use the 64-bit format, even
56  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
57  * Registers are sign extended to fill the available space.
58  */
59 int ptrace_getregs (struct task_struct *child, __s64 __user *data)
60 {
61         struct pt_regs *regs;
62         int i;
63
64         if (!access_ok(VERIFY_WRITE, data, 38 * 8))
65                 return -EIO;
66
67         regs = (struct pt_regs *) ((unsigned long) child->thread_info +
68                THREAD_SIZE - 32 - sizeof(struct pt_regs));
69
70         for (i = 0; i < 32; i++)
71                 __put_user (regs->regs[i], data + i);
72         __put_user (regs->lo, data + EF_LO - EF_R0);
73         __put_user (regs->hi, data + EF_HI - EF_R0);
74         __put_user (regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
75         __put_user (regs->cp0_badvaddr, data + EF_CP0_BADVADDR - EF_R0);
76         __put_user (regs->cp0_status, data + EF_CP0_STATUS - EF_R0);
77         __put_user (regs->cp0_cause, data + EF_CP0_CAUSE - EF_R0);
78
79         return 0;
80 }
81
82 /*
83  * Write a general register set.  As for PTRACE_GETREGS, we always use
84  * the 64-bit format.  On a 32-bit kernel only the lower order half
85  * (according to endianness) will be used.
86  */
87 int ptrace_setregs (struct task_struct *child, __s64 __user *data)
88 {
89         struct pt_regs *regs;
90         int i;
91
92         if (!access_ok(VERIFY_READ, data, 38 * 8))
93                 return -EIO;
94
95         regs = (struct pt_regs *) ((unsigned long) child->thread_info +
96                THREAD_SIZE - 32 - sizeof(struct pt_regs));
97
98         for (i = 0; i < 32; i++)
99                 __get_user (regs->regs[i], data + i);
100         __get_user (regs->lo, data + EF_LO - EF_R0);
101         __get_user (regs->hi, data + EF_HI - EF_R0);
102         __get_user (regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
103
104         /* badvaddr, status, and cause may not be written.  */
105
106         return 0;
107 }
108
109 int ptrace_getfpregs (struct task_struct *child, __u32 __user *data)
110 {
111         int i;
112
113         if (!access_ok(VERIFY_WRITE, data, 33 * 8))
114                 return -EIO;
115
116         if (tsk_used_math(child)) {
117                 fpureg_t *fregs = get_fpu_regs(child);
118                 for (i = 0; i < 32; i++)
119                         __put_user (fregs[i], i + (__u64 __user *) data);
120         } else {
121                 for (i = 0; i < 32; i++)
122                         __put_user ((__u64) -1, i + (__u64 __user *) data);
123         }
124
125         if (cpu_has_fpu) {
126                 unsigned int flags, tmp;
127
128                 __put_user (child->thread.fpu.hard.fcr31, data + 64);
129
130                 preempt_disable();
131                 if (cpu_has_mipsmt) {
132                         unsigned int vpflags = dvpe();
133                         flags = read_c0_status();
134                         __enable_fpu();
135                         __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
136                         write_c0_status(flags);
137                         evpe(vpflags);
138                 } else {
139                         flags = read_c0_status();
140                         __enable_fpu();
141                         __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
142                         write_c0_status(flags);
143                 }
144                 preempt_enable();
145                 __put_user (tmp, data + 65);
146         } else {
147                 __put_user (child->thread.fpu.soft.fcr31, data + 64);
148                 __put_user ((__u32) 0, data + 65);
149         }
150
151         return 0;
152 }
153
154 int ptrace_setfpregs (struct task_struct *child, __u32 __user *data)
155 {
156         fpureg_t *fregs;
157         int i;
158
159         if (!access_ok(VERIFY_READ, data, 33 * 8))
160                 return -EIO;
161
162         fregs = get_fpu_regs(child);
163
164         for (i = 0; i < 32; i++)
165                 __get_user (fregs[i], i + (__u64 __user *) data);
166
167         if (cpu_has_fpu)
168                 __get_user (child->thread.fpu.hard.fcr31, data + 64);
169         else
170                 __get_user (child->thread.fpu.soft.fcr31, data + 64);
171
172         /* FIR may not be written.  */
173
174         return 0;
175 }
176
177 asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
178 {
179         struct task_struct *child;
180         int ret;
181
182 #if 0
183         printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
184                (int) request, (int) pid, (unsigned long) addr,
185                (unsigned long) data);
186 #endif
187         lock_kernel();
188         ret = -EPERM;
189         if (request == PTRACE_TRACEME) {
190                 /* are we already being traced? */
191                 if (current->ptrace & PT_PTRACED)
192                         goto out;
193                 if ((ret = security_ptrace(current->parent, current)))
194                         goto out;
195                 /* set the ptrace bit in the process flags. */
196                 current->ptrace |= PT_PTRACED;
197                 ret = 0;
198                 goto out;
199         }
200         ret = -ESRCH;
201         read_lock(&tasklist_lock);
202         child = find_task_by_pid(pid);
203         if (child)
204                 get_task_struct(child);
205         read_unlock(&tasklist_lock);
206         if (!child)
207                 goto out;
208
209         ret = -EPERM;
210         if (pid == 1)           /* you may not mess with init */
211                 goto out_tsk;
212
213         if (request == PTRACE_ATTACH) {
214                 ret = ptrace_attach(child);
215                 goto out_tsk;
216         }
217
218         ret = ptrace_check_attach(child, request == PTRACE_KILL);
219         if (ret < 0)
220                 goto out_tsk;
221
222         switch (request) {
223         /* when I and D space are separate, these will need to be fixed. */
224         case PTRACE_PEEKTEXT: /* read word at location addr. */
225         case PTRACE_PEEKDATA: {
226                 unsigned long tmp;
227                 int copied;
228
229                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
230                 ret = -EIO;
231                 if (copied != sizeof(tmp))
232                         break;
233                 ret = put_user(tmp,(unsigned long __user *) data);
234                 break;
235         }
236
237         /* Read the word at location addr in the USER area. */
238         case PTRACE_PEEKUSR: {
239                 struct pt_regs *regs;
240                 unsigned long tmp = 0;
241
242                 regs = (struct pt_regs *) ((unsigned long) child->thread_info +
243                        THREAD_SIZE - 32 - sizeof(struct pt_regs));
244                 ret = 0;  /* Default return value. */
245
246                 switch (addr) {
247                 case 0 ... 31:
248                         tmp = regs->regs[addr];
249                         break;
250                 case FPR_BASE ... FPR_BASE + 31:
251                         if (tsk_used_math(child)) {
252                                 fpureg_t *fregs = get_fpu_regs(child);
253
254 #ifdef CONFIG_32BIT
255                                 /*
256                                  * The odd registers are actually the high
257                                  * order bits of the values stored in the even
258                                  * registers - unless we're using r2k_switch.S.
259                                  */
260                                 if (addr & 1)
261                                         tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
262                                 else
263                                         tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
264 #endif
265 #ifdef CONFIG_64BIT
266                                 tmp = fregs[addr - FPR_BASE];
267 #endif
268                         } else {
269                                 tmp = -1;       /* FP not yet used  */
270                         }
271                         break;
272                 case PC:
273                         tmp = regs->cp0_epc;
274                         break;
275                 case CAUSE:
276                         tmp = regs->cp0_cause;
277                         break;
278                 case BADVADDR:
279                         tmp = regs->cp0_badvaddr;
280                         break;
281                 case MMHI:
282                         tmp = regs->hi;
283                         break;
284                 case MMLO:
285                         tmp = regs->lo;
286                         break;
287                 case FPC_CSR:
288                         if (cpu_has_fpu)
289                                 tmp = child->thread.fpu.hard.fcr31;
290                         else
291                                 tmp = child->thread.fpu.soft.fcr31;
292                         break;
293                 case FPC_EIR: { /* implementation / version register */
294                         unsigned int flags;
295
296                         if (!cpu_has_fpu)
297                                 break;
298
299                         preempt_disable();
300                         if (cpu_has_mipsmt) {
301                                 unsigned int vpflags = dvpe();
302                                 flags = read_c0_status();
303                                 __enable_fpu();
304                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
305                                 write_c0_status(flags);
306                                 evpe(vpflags);
307                         } else {
308                                 flags = read_c0_status();
309                                 __enable_fpu();
310                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
311                                 write_c0_status(flags);
312                         }
313                         preempt_enable();
314                         break;
315                 }
316                 case DSP_BASE ... DSP_BASE + 5: {
317                         dspreg_t *dregs;
318
319                         if (!cpu_has_dsp) {
320                                 tmp = 0;
321                                 ret = -EIO;
322                                 goto out_tsk;
323                         }
324                         if (child->thread.dsp.used_dsp) {
325                                 dregs = __get_dsp_regs(child);
326                                 tmp = (unsigned long) (dregs[addr - DSP_BASE]);
327                         } else {
328                                 tmp = -1;       /* DSP registers yet used  */
329                         }
330                         break;
331                 }
332                 case DSP_CONTROL:
333                         if (!cpu_has_dsp) {
334                                 tmp = 0;
335                                 ret = -EIO;
336                                 goto out_tsk;
337                         }
338                         tmp = child->thread.dsp.dspcontrol;
339                         break;
340                 default:
341                         tmp = 0;
342                         ret = -EIO;
343                         goto out_tsk;
344                 }
345                 ret = put_user(tmp, (unsigned long __user *) data);
346                 break;
347         }
348
349         /* when I and D space are separate, this will have to be fixed. */
350         case PTRACE_POKETEXT: /* write the word at location addr. */
351         case PTRACE_POKEDATA:
352                 ret = 0;
353                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
354                     == sizeof(data))
355                         break;
356                 ret = -EIO;
357                 break;
358
359         case PTRACE_POKEUSR: {
360                 struct pt_regs *regs;
361                 ret = 0;
362                 regs = (struct pt_regs *) ((unsigned long) child->thread_info +
363                        THREAD_SIZE - 32 - sizeof(struct pt_regs));
364
365                 switch (addr) {
366                 case 0 ... 31:
367                         regs->regs[addr] = data;
368                         break;
369                 case FPR_BASE ... FPR_BASE + 31: {
370                         fpureg_t *fregs = get_fpu_regs(child);
371
372                         if (!tsk_used_math(child)) {
373                                 /* FP not yet used  */
374                                 memset(&child->thread.fpu.hard, ~0,
375                                        sizeof(child->thread.fpu.hard));
376                                 child->thread.fpu.hard.fcr31 = 0;
377                         }
378 #ifdef CONFIG_32BIT
379                         /*
380                          * The odd registers are actually the high order bits
381                          * of the values stored in the even registers - unless
382                          * we're using r2k_switch.S.
383                          */
384                         if (addr & 1) {
385                                 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
386                                 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
387                         } else {
388                                 fregs[addr - FPR_BASE] &= ~0xffffffffLL;
389                                 fregs[addr - FPR_BASE] |= data;
390                         }
391 #endif
392 #ifdef CONFIG_64BIT
393                         fregs[addr - FPR_BASE] = data;
394 #endif
395                         break;
396                 }
397                 case PC:
398                         regs->cp0_epc = data;
399                         break;
400                 case MMHI:
401                         regs->hi = data;
402                         break;
403                 case MMLO:
404                         regs->lo = data;
405                         break;
406                 case FPC_CSR:
407                         if (cpu_has_fpu)
408                                 child->thread.fpu.hard.fcr31 = data;
409                         else
410                                 child->thread.fpu.soft.fcr31 = data;
411                         break;
412                 case DSP_BASE ... DSP_BASE + 5: {
413                         dspreg_t *dregs;
414
415                         if (!cpu_has_dsp) {
416                                 ret = -EIO;
417                                 break;
418                         }
419
420                         dregs = __get_dsp_regs(child);
421                         dregs[addr - DSP_BASE] = data;
422                         break;
423                 }
424                 case DSP_CONTROL:
425                         if (!cpu_has_dsp) {
426                                 ret = -EIO;
427                                 break;
428                         }
429                         child->thread.dsp.dspcontrol = data;
430                         break;
431                 default:
432                         /* The rest are not allowed. */
433                         ret = -EIO;
434                         break;
435                 }
436                 break;
437                 }
438
439         case PTRACE_GETREGS:
440                 ret = ptrace_getregs (child, (__u64 __user *) data);
441                 break;
442
443         case PTRACE_SETREGS:
444                 ret = ptrace_setregs (child, (__u64 __user *) data);
445                 break;
446
447         case PTRACE_GETFPREGS:
448                 ret = ptrace_getfpregs (child, (__u32 __user *) data);
449                 break;
450
451         case PTRACE_SETFPREGS:
452                 ret = ptrace_setfpregs (child, (__u32 __user *) data);
453                 break;
454
455         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
456         case PTRACE_CONT: { /* restart after signal. */
457                 ret = -EIO;
458                 if (!valid_signal(data))
459                         break;
460                 if (request == PTRACE_SYSCALL) {
461                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
462                 }
463                 else {
464                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
465                 }
466                 child->exit_code = data;
467                 wake_up_process(child);
468                 ret = 0;
469                 break;
470         }
471
472         /*
473          * make the child exit.  Best I can do is send it a sigkill.
474          * perhaps it should be put in the status that it wants to
475          * exit.
476          */
477         case PTRACE_KILL:
478                 ret = 0;
479                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
480                         break;
481                 child->exit_code = SIGKILL;
482                 wake_up_process(child);
483                 break;
484
485         case PTRACE_DETACH: /* detach a process that was attached. */
486                 ret = ptrace_detach(child, data);
487                 break;
488
489         case PTRACE_GET_THREAD_AREA:
490                 ret = put_user(child->thread_info->tp_value,
491                                 (unsigned long __user *) data);
492                 break;
493
494         default:
495                 ret = ptrace_request(child, request, addr, data);
496                 break;
497         }
498
499 out_tsk:
500         put_task_struct(child);
501 out:
502         unlock_kernel();
503         return ret;
504 }
505
506 static inline int audit_arch(void)
507 {
508         int arch = EM_MIPS;
509 #ifdef CONFIG_64BIT
510         arch |=  __AUDIT_ARCH_64BIT;
511 #endif
512 #if defined(__LITTLE_ENDIAN)
513         arch |=  __AUDIT_ARCH_LE;
514 #endif
515         return arch;
516 }
517
518 /*
519  * Notification of system call entry/exit
520  * - triggered by current->work.syscall_trace
521  */
522 asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
523 {
524         if (unlikely(current->audit_context) && entryexit)
525                 audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]),
526                                    regs->regs[2]);
527
528         if (!(current->ptrace & PT_PTRACED))
529                 goto out;
530         if (!test_thread_flag(TIF_SYSCALL_TRACE))
531                 goto out;
532
533         /* The 0x80 provides a way for the tracing parent to distinguish
534            between a syscall stop and SIGTRAP delivery */
535         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ?
536                                  0x80 : 0));
537
538         /*
539          * this isn't the same as continuing with a signal, but it will do
540          * for normal use.  strace only continues with a signal if the
541          * stopping signal is not SIGTRAP.  -brl
542          */
543         if (current->exit_code) {
544                 send_sig(current->exit_code, current, 1);
545                 current->exit_code = 0;
546         }
547  out:
548         if (unlikely(current->audit_context) && !entryexit)
549                 audit_syscall_entry(current, audit_arch(), regs->regs[2],
550                                     regs->regs[4], regs->regs[5],
551                                     regs->regs[6], regs->regs[7]);
552 }