[MIPS] VI: TRACE_IRQS_OFF clobbers $v0, so save & restore around call.
[linux-2.6] / arch / mips / kernel / ptrace32.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/smp.h>
24 #include <linux/smp_lock.h>
25 #include <linux/user.h>
26 #include <linux/security.h>
27
28 #include <asm/cpu.h>
29 #include <asm/dsp.h>
30 #include <asm/fpu.h>
31 #include <asm/mipsregs.h>
32 #include <asm/mipsmtregs.h>
33 #include <asm/pgtable.h>
34 #include <asm/page.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/bootinfo.h>
38
39 int ptrace_getregs (struct task_struct *child, __s64 __user *data);
40 int ptrace_setregs (struct task_struct *child, __s64 __user *data);
41
42 int ptrace_getfpregs (struct task_struct *child, __u32 __user *data);
43 int ptrace_setfpregs (struct task_struct *child, __u32 __user *data);
44
45 /*
46  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
47  * work.  I don't know how to fix this.
48  */
49 asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
50 {
51         struct task_struct *child;
52         int ret;
53
54 #if 0
55         printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
56                (int) request, (int) pid, (unsigned long) addr,
57                (unsigned long) data);
58 #endif
59         lock_kernel();
60         if (request == PTRACE_TRACEME) {
61                 ret = ptrace_traceme();
62                 goto out;
63         }
64
65         child = ptrace_get_task_struct(pid);
66         if (IS_ERR(child)) {
67                 ret = PTR_ERR(child);
68                 goto out;
69         }
70
71         if (request == PTRACE_ATTACH) {
72                 ret = ptrace_attach(child);
73                 goto out_tsk;
74         }
75
76         ret = ptrace_check_attach(child, request == PTRACE_KILL);
77         if (ret < 0)
78                 goto out_tsk;
79
80         switch (request) {
81         /* when I and D space are separate, these will need to be fixed. */
82         case PTRACE_PEEKTEXT: /* read word at location addr. */
83         case PTRACE_PEEKDATA: {
84                 unsigned int tmp;
85                 int copied;
86
87                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
88                 ret = -EIO;
89                 if (copied != sizeof(tmp))
90                         break;
91                 ret = put_user(tmp, (unsigned int __user *) (unsigned long) data);
92                 break;
93         }
94
95         /*
96          * Read 4 bytes of the other process' storage
97          *  data is a pointer specifying where the user wants the
98          *      4 bytes copied into
99          *  addr is a pointer in the user's storage that contains an 8 byte
100          *      address in the other process of the 4 bytes that is to be read
101          * (this is run in a 32-bit process looking at a 64-bit process)
102          * when I and D space are separate, these will need to be fixed.
103          */
104         case PTRACE_PEEKTEXT_3264:
105         case PTRACE_PEEKDATA_3264: {
106                 u32 tmp;
107                 int copied;
108                 u32 __user * addrOthers;
109
110                 ret = -EIO;
111
112                 /* Get the addr in the other process that we want to read */
113                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
114                         break;
115
116                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
117                                 sizeof(tmp), 0);
118                 if (copied != sizeof(tmp))
119                         break;
120                 ret = put_user(tmp, (u32 __user *) (unsigned long) data);
121                 break;
122         }
123
124         /* Read the word at location addr in the USER area. */
125         case PTRACE_PEEKUSR: {
126                 struct pt_regs *regs;
127                 unsigned int tmp;
128
129                 regs = task_pt_regs(child);
130                 ret = 0;  /* Default return value. */
131
132                 switch (addr) {
133                 case 0 ... 31:
134                         tmp = regs->regs[addr];
135                         break;
136                 case FPR_BASE ... FPR_BASE + 31:
137                         if (tsk_used_math(child)) {
138                                 fpureg_t *fregs = get_fpu_regs(child);
139
140                                 /*
141                                  * The odd registers are actually the high
142                                  * order bits of the values stored in the even
143                                  * registers - unless we're using r2k_switch.S.
144                                  */
145                                 if (addr & 1)
146                                         tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
147                                 else
148                                         tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
149                         } else {
150                                 tmp = -1;       /* FP not yet used  */
151                         }
152                         break;
153                 case PC:
154                         tmp = regs->cp0_epc;
155                         break;
156                 case CAUSE:
157                         tmp = regs->cp0_cause;
158                         break;
159                 case BADVADDR:
160                         tmp = regs->cp0_badvaddr;
161                         break;
162                 case MMHI:
163                         tmp = regs->hi;
164                         break;
165                 case MMLO:
166                         tmp = regs->lo;
167                         break;
168                 case FPC_CSR:
169                         tmp = child->thread.fpu.fcr31;
170                         break;
171                 case FPC_EIR: { /* implementation / version register */
172                         unsigned int flags;
173 #ifdef CONFIG_MIPS_MT_SMTC
174                         unsigned int irqflags;
175                         unsigned int mtflags;
176 #endif /* CONFIG_MIPS_MT_SMTC */
177
178                         preempt_disable();
179                         if (!cpu_has_fpu) {
180                                 preempt_enable();
181                                 tmp = 0;
182                                 break;
183                         }
184
185 #ifdef CONFIG_MIPS_MT_SMTC
186                         /* Read-modify-write of Status must be atomic */
187                         local_irq_save(irqflags);
188                         mtflags = dmt();
189 #endif /* CONFIG_MIPS_MT_SMTC */
190
191                         if (cpu_has_mipsmt) {
192                                 unsigned int vpflags = dvpe();
193                                 flags = read_c0_status();
194                                 __enable_fpu();
195                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
196                                 write_c0_status(flags);
197                                 evpe(vpflags);
198                         } else {
199                                 flags = read_c0_status();
200                                 __enable_fpu();
201                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
202                                 write_c0_status(flags);
203                         }
204 #ifdef CONFIG_MIPS_MT_SMTC
205                         emt(mtflags);
206                         local_irq_restore(irqflags);
207 #endif /* CONFIG_MIPS_MT_SMTC */
208                         preempt_enable();
209                         break;
210                 }
211                 case DSP_BASE ... DSP_BASE + 5: {
212                         dspreg_t *dregs;
213
214                         if (!cpu_has_dsp) {
215                                 tmp = 0;
216                                 ret = -EIO;
217                                 goto out_tsk;
218                         }
219                         dregs = __get_dsp_regs(child);
220                         tmp = (unsigned long) (dregs[addr - DSP_BASE]);
221                         break;
222                 }
223                 case DSP_CONTROL:
224                         if (!cpu_has_dsp) {
225                                 tmp = 0;
226                                 ret = -EIO;
227                                 goto out_tsk;
228                         }
229                         tmp = child->thread.dsp.dspcontrol;
230                         break;
231                 default:
232                         tmp = 0;
233                         ret = -EIO;
234                         goto out_tsk;
235                 }
236                 ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
237                 break;
238         }
239
240         /* when I and D space are separate, this will have to be fixed. */
241         case PTRACE_POKETEXT: /* write the word at location addr. */
242         case PTRACE_POKEDATA:
243                 ret = 0;
244                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
245                     == sizeof(data))
246                         break;
247                 ret = -EIO;
248                 break;
249
250         /*
251          * Write 4 bytes into the other process' storage
252          *  data is the 4 bytes that the user wants written
253          *  addr is a pointer in the user's storage that contains an
254          *      8 byte address in the other process where the 4 bytes
255          *      that is to be written
256          * (this is run in a 32-bit process looking at a 64-bit process)
257          * when I and D space are separate, these will need to be fixed.
258          */
259         case PTRACE_POKETEXT_3264:
260         case PTRACE_POKEDATA_3264: {
261                 u32 __user * addrOthers;
262
263                 /* Get the addr in the other process that we want to write into */
264                 ret = -EIO;
265                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
266                         break;
267                 ret = 0;
268                 if (access_process_vm(child, (u64)addrOthers, &data,
269                                         sizeof(data), 1) == sizeof(data))
270                         break;
271                 ret = -EIO;
272                 break;
273         }
274
275         case PTRACE_POKEUSR: {
276                 struct pt_regs *regs;
277                 ret = 0;
278                 regs = task_pt_regs(child);
279
280                 switch (addr) {
281                 case 0 ... 31:
282                         regs->regs[addr] = data;
283                         break;
284                 case FPR_BASE ... FPR_BASE + 31: {
285                         fpureg_t *fregs = get_fpu_regs(child);
286
287                         if (!tsk_used_math(child)) {
288                                 /* FP not yet used  */
289                                 memset(&child->thread.fpu, ~0,
290                                        sizeof(child->thread.fpu));
291                                 child->thread.fpu.fcr31 = 0;
292                         }
293                         /*
294                          * The odd registers are actually the high order bits
295                          * of the values stored in the even registers - unless
296                          * we're using r2k_switch.S.
297                          */
298                         if (addr & 1) {
299                                 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
300                                 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
301                         } else {
302                                 fregs[addr - FPR_BASE] &= ~0xffffffffLL;
303                                 /* Must cast, lest sign extension fill upper
304                                    bits!  */
305                                 fregs[addr - FPR_BASE] |= (unsigned int)data;
306                         }
307                         break;
308                 }
309                 case PC:
310                         regs->cp0_epc = data;
311                         break;
312                 case MMHI:
313                         regs->hi = data;
314                         break;
315                 case MMLO:
316                         regs->lo = data;
317                         break;
318                 case FPC_CSR:
319                         child->thread.fpu.fcr31 = data;
320                         break;
321                 case DSP_BASE ... DSP_BASE + 5: {
322                         dspreg_t *dregs;
323
324                         if (!cpu_has_dsp) {
325                                 ret = -EIO;
326                                 break;
327                         }
328
329                         dregs = __get_dsp_regs(child);
330                         dregs[addr - DSP_BASE] = data;
331                         break;
332                 }
333                 case DSP_CONTROL:
334                         if (!cpu_has_dsp) {
335                                 ret = -EIO;
336                                 break;
337                         }
338                         child->thread.dsp.dspcontrol = data;
339                         break;
340                 default:
341                         /* The rest are not allowed. */
342                         ret = -EIO;
343                         break;
344                 }
345                 break;
346                 }
347
348         case PTRACE_GETREGS:
349                 ret = ptrace_getregs (child, (__u64 __user *) (__u64) data);
350                 break;
351
352         case PTRACE_SETREGS:
353                 ret = ptrace_setregs (child, (__u64 __user *) (__u64) data);
354                 break;
355
356         case PTRACE_GETFPREGS:
357                 ret = ptrace_getfpregs (child, (__u32 __user *) (__u64) data);
358                 break;
359
360         case PTRACE_SETFPREGS:
361                 ret = ptrace_setfpregs (child, (__u32 __user *) (__u64) data);
362                 break;
363
364         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
365         case PTRACE_CONT: { /* restart after signal. */
366                 ret = -EIO;
367                 if (!valid_signal(data))
368                         break;
369                 if (request == PTRACE_SYSCALL) {
370                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
371                 }
372                 else {
373                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
374                 }
375                 child->exit_code = data;
376                 wake_up_process(child);
377                 ret = 0;
378                 break;
379         }
380
381         /*
382          * make the child exit.  Best I can do is send it a sigkill.
383          * perhaps it should be put in the status that it wants to
384          * exit.
385          */
386         case PTRACE_KILL:
387                 ret = 0;
388                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
389                         break;
390                 child->exit_code = SIGKILL;
391                 wake_up_process(child);
392                 break;
393
394         case PTRACE_GET_THREAD_AREA:
395                 ret = put_user(task_thread_info(child)->tp_value,
396                                 (unsigned int __user *) (unsigned long) data);
397                 break;
398
399         case PTRACE_DETACH: /* detach a process that was attached. */
400                 ret = ptrace_detach(child, data);
401                 break;
402
403         case PTRACE_GETEVENTMSG:
404                 ret = put_user(child->ptrace_message,
405                                (unsigned int __user *) (unsigned long) data);
406                 break;
407
408         case PTRACE_GET_THREAD_AREA_3264:
409                 ret = put_user(task_thread_info(child)->tp_value,
410                                 (unsigned long __user *) (unsigned long) data);
411                 break;
412
413         default:
414                 ret = ptrace_request(child, request, addr, data);
415                 break;
416         }
417
418 out_tsk:
419         put_task_struct(child);
420 out:
421         unlock_kernel();
422         return ret;
423 }