Remove obsolete #include <linux/config.h>
[linux-2.6.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/compiler.h>
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/mm.h>
21 #include <linux/errno.h>
22 #include <linux/ptrace.h>
23 #include <linux/audit.h>
24 #include <linux/smp.h>
25 #include <linux/smp_lock.h>
26 #include <linux/user.h>
27 #include <linux/security.h>
28 #include <linux/signal.h>
29
30 #include <asm/byteorder.h>
31 #include <asm/cpu.h>
32 #include <asm/dsp.h>
33 #include <asm/fpu.h>
34 #include <asm/mipsregs.h>
35 #include <asm/mipsmtregs.h>
36 #include <asm/pgtable.h>
37 #include <asm/page.h>
38 #include <asm/system.h>
39 #include <asm/uaccess.h>
40 #include <asm/bootinfo.h>
41 #include <asm/reg.h>
42
43 /*
44  * Called by kernel/ptrace.c when detaching..
45  *
46  * Make sure single step bits etc are not set.
47  */
48 void ptrace_disable(struct task_struct *child)
49 {
50         /* Nothing to do.. */
51 }
52
53 /*
54  * Read a general register set.  We always use the 64-bit format, even
55  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
56  * Registers are sign extended to fill the available space.
57  */
58 int ptrace_getregs (struct task_struct *child, __s64 __user *data)
59 {
60         struct pt_regs *regs;
61         int i;
62
63         if (!access_ok(VERIFY_WRITE, data, 38 * 8))
64                 return -EIO;
65
66         regs = task_pt_regs(child);
67
68         for (i = 0; i < 32; i++)
69                 __put_user (regs->regs[i], data + i);
70         __put_user (regs->lo, data + EF_LO - EF_R0);
71         __put_user (regs->hi, data + EF_HI - EF_R0);
72         __put_user (regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
73         __put_user (regs->cp0_badvaddr, data + EF_CP0_BADVADDR - EF_R0);
74         __put_user (regs->cp0_status, data + EF_CP0_STATUS - EF_R0);
75         __put_user (regs->cp0_cause, data + EF_CP0_CAUSE - EF_R0);
76
77         return 0;
78 }
79
80 /*
81  * Write a general register set.  As for PTRACE_GETREGS, we always use
82  * the 64-bit format.  On a 32-bit kernel only the lower order half
83  * (according to endianness) will be used.
84  */
85 int ptrace_setregs (struct task_struct *child, __s64 __user *data)
86 {
87         struct pt_regs *regs;
88         int i;
89
90         if (!access_ok(VERIFY_READ, data, 38 * 8))
91                 return -EIO;
92
93         regs = task_pt_regs(child);
94
95         for (i = 0; i < 32; i++)
96                 __get_user (regs->regs[i], data + i);
97         __get_user (regs->lo, data + EF_LO - EF_R0);
98         __get_user (regs->hi, data + EF_HI - EF_R0);
99         __get_user (regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
100
101         /* badvaddr, status, and cause may not be written.  */
102
103         return 0;
104 }
105
106 int ptrace_getfpregs (struct task_struct *child, __u32 __user *data)
107 {
108         int i;
109
110         if (!access_ok(VERIFY_WRITE, data, 33 * 8))
111                 return -EIO;
112
113         if (tsk_used_math(child)) {
114                 fpureg_t *fregs = get_fpu_regs(child);
115                 for (i = 0; i < 32; i++)
116                         __put_user (fregs[i], i + (__u64 __user *) data);
117         } else {
118                 for (i = 0; i < 32; i++)
119                         __put_user ((__u64) -1, i + (__u64 __user *) data);
120         }
121
122         __put_user (child->thread.fpu.fcr31, data + 64);
123
124         if (cpu_has_fpu) {
125                 unsigned int flags, tmp;
126
127                 preempt_disable();
128                 if (cpu_has_mipsmt) {
129                         unsigned int vpflags = dvpe();
130                         flags = read_c0_status();
131                         __enable_fpu();
132                         __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
133                         write_c0_status(flags);
134                         evpe(vpflags);
135                 } else {
136                         flags = read_c0_status();
137                         __enable_fpu();
138                         __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
139                         write_c0_status(flags);
140                 }
141                 preempt_enable();
142                 __put_user (tmp, data + 65);
143         } else {
144                 __put_user ((__u32) 0, data + 65);
145         }
146
147         return 0;
148 }
149
150 int ptrace_setfpregs (struct task_struct *child, __u32 __user *data)
151 {
152         fpureg_t *fregs;
153         int i;
154
155         if (!access_ok(VERIFY_READ, data, 33 * 8))
156                 return -EIO;
157
158         fregs = get_fpu_regs(child);
159
160         for (i = 0; i < 32; i++)
161                 __get_user (fregs[i], i + (__u64 __user *) data);
162
163         __get_user (child->thread.fpu.fcr31, data + 64);
164
165         /* FIR may not be written.  */
166
167         return 0;
168 }
169
170 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
171 {
172         int ret;
173
174         switch (request) {
175         /* when I and D space are separate, these will need to be fixed. */
176         case PTRACE_PEEKTEXT: /* read word at location addr. */
177         case PTRACE_PEEKDATA: {
178                 unsigned long tmp;
179                 int copied;
180
181                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
182                 ret = -EIO;
183                 if (copied != sizeof(tmp))
184                         break;
185                 ret = put_user(tmp,(unsigned long __user *) data);
186                 break;
187         }
188
189         /* Read the word at location addr in the USER area. */
190         case PTRACE_PEEKUSR: {
191                 struct pt_regs *regs;
192                 unsigned long tmp = 0;
193
194                 regs = task_pt_regs(child);
195                 ret = 0;  /* Default return value. */
196
197                 switch (addr) {
198                 case 0 ... 31:
199                         tmp = regs->regs[addr];
200                         break;
201                 case FPR_BASE ... FPR_BASE + 31:
202                         if (tsk_used_math(child)) {
203                                 fpureg_t *fregs = get_fpu_regs(child);
204
205 #ifdef CONFIG_32BIT
206                                 /*
207                                  * The odd registers are actually the high
208                                  * order bits of the values stored in the even
209                                  * registers - unless we're using r2k_switch.S.
210                                  */
211                                 if (addr & 1)
212                                         tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
213                                 else
214                                         tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
215 #endif
216 #ifdef CONFIG_64BIT
217                                 tmp = fregs[addr - FPR_BASE];
218 #endif
219                         } else {
220                                 tmp = -1;       /* FP not yet used  */
221                         }
222                         break;
223                 case PC:
224                         tmp = regs->cp0_epc;
225                         break;
226                 case CAUSE:
227                         tmp = regs->cp0_cause;
228                         break;
229                 case BADVADDR:
230                         tmp = regs->cp0_badvaddr;
231                         break;
232                 case MMHI:
233                         tmp = regs->hi;
234                         break;
235                 case MMLO:
236                         tmp = regs->lo;
237                         break;
238                 case FPC_CSR:
239                         tmp = child->thread.fpu.fcr31;
240                         break;
241                 case FPC_EIR: { /* implementation / version register */
242                         unsigned int flags;
243 #ifdef CONFIG_MIPS_MT_SMTC
244                         unsigned int irqflags;
245                         unsigned int mtflags;
246 #endif /* CONFIG_MIPS_MT_SMTC */
247
248                         if (!cpu_has_fpu)
249                                 break;
250
251 #ifdef CONFIG_MIPS_MT_SMTC
252                         /* Read-modify-write of Status must be atomic */
253                         local_irq_save(irqflags);
254                         mtflags = dmt();
255 #endif /* CONFIG_MIPS_MT_SMTC */
256
257                         preempt_disable();
258                         if (cpu_has_mipsmt) {
259                                 unsigned int vpflags = dvpe();
260                                 flags = read_c0_status();
261                                 __enable_fpu();
262                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
263                                 write_c0_status(flags);
264                                 evpe(vpflags);
265                         } else {
266                                 flags = read_c0_status();
267                                 __enable_fpu();
268                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
269                                 write_c0_status(flags);
270                         }
271 #ifdef CONFIG_MIPS_MT_SMTC
272                         emt(mtflags);
273                         local_irq_restore(irqflags);
274 #endif /* CONFIG_MIPS_MT_SMTC */
275                         preempt_enable();
276                         break;
277                 }
278                 case DSP_BASE ... DSP_BASE + 5: {
279                         dspreg_t *dregs;
280
281                         if (!cpu_has_dsp) {
282                                 tmp = 0;
283                                 ret = -EIO;
284                                 goto out;
285                         }
286                         dregs = __get_dsp_regs(child);
287                         tmp = (unsigned long) (dregs[addr - DSP_BASE]);
288                         break;
289                 }
290                 case DSP_CONTROL:
291                         if (!cpu_has_dsp) {
292                                 tmp = 0;
293                                 ret = -EIO;
294                                 goto out;
295                         }
296                         tmp = child->thread.dsp.dspcontrol;
297                         break;
298                 default:
299                         tmp = 0;
300                         ret = -EIO;
301                         goto out;
302                 }
303                 ret = put_user(tmp, (unsigned long __user *) data);
304                 break;
305         }
306
307         /* when I and D space are separate, this will have to be fixed. */
308         case PTRACE_POKETEXT: /* write the word at location addr. */
309         case PTRACE_POKEDATA:
310                 ret = 0;
311                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
312                     == sizeof(data))
313                         break;
314                 ret = -EIO;
315                 break;
316
317         case PTRACE_POKEUSR: {
318                 struct pt_regs *regs;
319                 ret = 0;
320                 regs = task_pt_regs(child);
321
322                 switch (addr) {
323                 case 0 ... 31:
324                         regs->regs[addr] = data;
325                         break;
326                 case FPR_BASE ... FPR_BASE + 31: {
327                         fpureg_t *fregs = get_fpu_regs(child);
328
329                         if (!tsk_used_math(child)) {
330                                 /* FP not yet used  */
331                                 memset(&child->thread.fpu, ~0,
332                                        sizeof(child->thread.fpu));
333                                 child->thread.fpu.fcr31 = 0;
334                         }
335 #ifdef CONFIG_32BIT
336                         /*
337                          * The odd registers are actually the high order bits
338                          * of the values stored in the even registers - unless
339                          * we're using r2k_switch.S.
340                          */
341                         if (addr & 1) {
342                                 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
343                                 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
344                         } else {
345                                 fregs[addr - FPR_BASE] &= ~0xffffffffLL;
346                                 fregs[addr - FPR_BASE] |= data;
347                         }
348 #endif
349 #ifdef CONFIG_64BIT
350                         fregs[addr - FPR_BASE] = data;
351 #endif
352                         break;
353                 }
354                 case PC:
355                         regs->cp0_epc = data;
356                         break;
357                 case MMHI:
358                         regs->hi = data;
359                         break;
360                 case MMLO:
361                         regs->lo = data;
362                         break;
363                 case FPC_CSR:
364                         child->thread.fpu.fcr31 = data;
365                         break;
366                 case DSP_BASE ... DSP_BASE + 5: {
367                         dspreg_t *dregs;
368
369                         if (!cpu_has_dsp) {
370                                 ret = -EIO;
371                                 break;
372                         }
373
374                         dregs = __get_dsp_regs(child);
375                         dregs[addr - DSP_BASE] = data;
376                         break;
377                 }
378                 case DSP_CONTROL:
379                         if (!cpu_has_dsp) {
380                                 ret = -EIO;
381                                 break;
382                         }
383                         child->thread.dsp.dspcontrol = data;
384                         break;
385                 default:
386                         /* The rest are not allowed. */
387                         ret = -EIO;
388                         break;
389                 }
390                 break;
391                 }
392
393         case PTRACE_GETREGS:
394                 ret = ptrace_getregs (child, (__u64 __user *) data);
395                 break;
396
397         case PTRACE_SETREGS:
398                 ret = ptrace_setregs (child, (__u64 __user *) data);
399                 break;
400
401         case PTRACE_GETFPREGS:
402                 ret = ptrace_getfpregs (child, (__u32 __user *) data);
403                 break;
404
405         case PTRACE_SETFPREGS:
406                 ret = ptrace_setfpregs (child, (__u32 __user *) data);
407                 break;
408
409         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
410         case PTRACE_CONT: { /* restart after signal. */
411                 ret = -EIO;
412                 if (!valid_signal(data))
413                         break;
414                 if (request == PTRACE_SYSCALL) {
415                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
416                 }
417                 else {
418                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
419                 }
420                 child->exit_code = data;
421                 wake_up_process(child);
422                 ret = 0;
423                 break;
424         }
425
426         /*
427          * make the child exit.  Best I can do is send it a sigkill.
428          * perhaps it should be put in the status that it wants to
429          * exit.
430          */
431         case PTRACE_KILL:
432                 ret = 0;
433                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
434                         break;
435                 child->exit_code = SIGKILL;
436                 wake_up_process(child);
437                 break;
438
439         case PTRACE_DETACH: /* detach a process that was attached. */
440                 ret = ptrace_detach(child, data);
441                 break;
442
443         case PTRACE_GET_THREAD_AREA:
444                 ret = put_user(task_thread_info(child)->tp_value,
445                                 (unsigned long __user *) data);
446                 break;
447
448         default:
449                 ret = ptrace_request(child, request, addr, data);
450                 break;
451         }
452  out:
453         return ret;
454 }
455
456 static inline int audit_arch(void)
457 {
458         int arch = EM_MIPS;
459 #ifdef CONFIG_64BIT
460         arch |=  __AUDIT_ARCH_64BIT;
461 #endif
462 #if defined(__LITTLE_ENDIAN)
463         arch |=  __AUDIT_ARCH_LE;
464 #endif
465         return arch;
466 }
467
468 /*
469  * Notification of system call entry/exit
470  * - triggered by current->work.syscall_trace
471  */
472 asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
473 {
474         if (unlikely(current->audit_context) && entryexit)
475                 audit_syscall_exit(AUDITSC_RESULT(regs->regs[2]),
476                                    regs->regs[2]);
477
478         if (!(current->ptrace & PT_PTRACED))
479                 goto out;
480         if (!test_thread_flag(TIF_SYSCALL_TRACE))
481                 goto out;
482
483         /* The 0x80 provides a way for the tracing parent to distinguish
484            between a syscall stop and SIGTRAP delivery */
485         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ?
486                                  0x80 : 0));
487
488         /*
489          * this isn't the same as continuing with a signal, but it will do
490          * for normal use.  strace only continues with a signal if the
491          * stopping signal is not SIGTRAP.  -brl
492          */
493         if (current->exit_code) {
494                 send_sig(current->exit_code, current, 1);
495                 current->exit_code = 0;
496         }
497  out:
498         if (unlikely(current->audit_context) && !entryexit)
499                 audit_syscall_entry(audit_arch(), regs->regs[2],
500                                     regs->regs[4], regs->regs[5],
501                                     regs->regs[6], regs->regs[7]);
502 }