Merge branch 'linus' into tracing/urgent
[linux-2.6] / arch / sh / kernel / ptrace_32.c
1 /*
2  * SuperH process tracing
3  *
4  * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
5  * Copyright (C) 2002 - 2008  Paul Mundt
6  *
7  * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
8  *
9  * This file is subject to the terms and conditions of the GNU General Public
10  * License.  See the file "COPYING" in the main directory of this archive
11  * for more details.
12  */
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/mm.h>
16 #include <linux/smp.h>
17 #include <linux/errno.h>
18 #include <linux/ptrace.h>
19 #include <linux/user.h>
20 #include <linux/slab.h>
21 #include <linux/security.h>
22 #include <linux/signal.h>
23 #include <linux/io.h>
24 #include <linux/audit.h>
25 #include <linux/seccomp.h>
26 #include <linux/tracehook.h>
27 #include <linux/elf.h>
28 #include <linux/regset.h>
29 #include <asm/uaccess.h>
30 #include <asm/pgtable.h>
31 #include <asm/system.h>
32 #include <asm/processor.h>
33 #include <asm/mmu_context.h>
34 #include <asm/syscalls.h>
35 #include <asm/fpu.h>
36
37 /*
38  * This routine will get a word off of the process kernel stack.
39  */
40 static inline int get_stack_long(struct task_struct *task, int offset)
41 {
42         unsigned char *stack;
43
44         stack = (unsigned char *)task_pt_regs(task);
45         stack += offset;
46         return (*((int *)stack));
47 }
48
49 /*
50  * This routine will put a word on the process kernel stack.
51  */
52 static inline int put_stack_long(struct task_struct *task, int offset,
53                                  unsigned long data)
54 {
55         unsigned char *stack;
56
57         stack = (unsigned char *)task_pt_regs(task);
58         stack += offset;
59         *(unsigned long *) stack = data;
60         return 0;
61 }
62
63 void user_enable_single_step(struct task_struct *child)
64 {
65         /* Next scheduling will set up UBC */
66         if (child->thread.ubc_pc == 0)
67                 ubc_usercnt += 1;
68
69         child->thread.ubc_pc = get_stack_long(child,
70                                 offsetof(struct pt_regs, pc));
71
72         set_tsk_thread_flag(child, TIF_SINGLESTEP);
73 }
74
75 void user_disable_single_step(struct task_struct *child)
76 {
77         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
78
79         /*
80          * Ensure the UBC is not programmed at the next context switch.
81          *
82          * Normally this is not needed but there are sequences such as
83          * singlestep, signal delivery, and continue that leave the
84          * ubc_pc non-zero leading to spurious SIGTRAPs.
85          */
86         if (child->thread.ubc_pc != 0) {
87                 ubc_usercnt -= 1;
88                 child->thread.ubc_pc = 0;
89         }
90 }
91
92 /*
93  * Called by kernel/ptrace.c when detaching..
94  *
95  * Make sure single step bits etc are not set.
96  */
97 void ptrace_disable(struct task_struct *child)
98 {
99         user_disable_single_step(child);
100 }
101
102 static int genregs_get(struct task_struct *target,
103                        const struct user_regset *regset,
104                        unsigned int pos, unsigned int count,
105                        void *kbuf, void __user *ubuf)
106 {
107         const struct pt_regs *regs = task_pt_regs(target);
108         int ret;
109
110         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
111                                   regs->regs,
112                                   0, 16 * sizeof(unsigned long));
113         if (!ret)
114                 /* PC, PR, SR, GBR, MACH, MACL, TRA */
115                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
116                                           &regs->pc,
117                                           offsetof(struct pt_regs, pc),
118                                           sizeof(struct pt_regs));
119         if (!ret)
120                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
121                                                sizeof(struct pt_regs), -1);
122
123         return ret;
124 }
125
126 static int genregs_set(struct task_struct *target,
127                        const struct user_regset *regset,
128                        unsigned int pos, unsigned int count,
129                        const void *kbuf, const void __user *ubuf)
130 {
131         struct pt_regs *regs = task_pt_regs(target);
132         int ret;
133
134         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
135                                  regs->regs,
136                                  0, 16 * sizeof(unsigned long));
137         if (!ret && count > 0)
138                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
139                                          &regs->pc,
140                                          offsetof(struct pt_regs, pc),
141                                          sizeof(struct pt_regs));
142         if (!ret)
143                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
144                                                 sizeof(struct pt_regs), -1);
145
146         return ret;
147 }
148
149 #ifdef CONFIG_SH_FPU
150 int fpregs_get(struct task_struct *target,
151                const struct user_regset *regset,
152                unsigned int pos, unsigned int count,
153                void *kbuf, void __user *ubuf)
154 {
155         int ret;
156
157         ret = init_fpu(target);
158         if (ret)
159                 return ret;
160
161         if ((boot_cpu_data.flags & CPU_HAS_FPU))
162                 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
163                                            &target->thread.fpu.hard, 0, -1);
164
165         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
166                                    &target->thread.fpu.soft, 0, -1);
167 }
168
169 static int fpregs_set(struct task_struct *target,
170                        const struct user_regset *regset,
171                        unsigned int pos, unsigned int count,
172                        const void *kbuf, const void __user *ubuf)
173 {
174         int ret;
175
176         ret = init_fpu(target);
177         if (ret)
178                 return ret;
179
180         set_stopped_child_used_math(target);
181
182         if ((boot_cpu_data.flags & CPU_HAS_FPU))
183                 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
184                                           &target->thread.fpu.hard, 0, -1);
185
186         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
187                                   &target->thread.fpu.soft, 0, -1);
188 }
189
190 static int fpregs_active(struct task_struct *target,
191                          const struct user_regset *regset)
192 {
193         return tsk_used_math(target) ? regset->n : 0;
194 }
195 #endif
196
197 #ifdef CONFIG_SH_DSP
198 static int dspregs_get(struct task_struct *target,
199                        const struct user_regset *regset,
200                        unsigned int pos, unsigned int count,
201                        void *kbuf, void __user *ubuf)
202 {
203         const struct pt_dspregs *regs = task_pt_dspregs(target);
204         int ret;
205
206         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
207                                   0, sizeof(struct pt_dspregs));
208         if (!ret)
209                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
210                                                sizeof(struct pt_dspregs), -1);
211
212         return ret;
213 }
214
215 static int dspregs_set(struct task_struct *target,
216                        const struct user_regset *regset,
217                        unsigned int pos, unsigned int count,
218                        const void *kbuf, const void __user *ubuf)
219 {
220         struct pt_dspregs *regs = task_pt_dspregs(target);
221         int ret;
222
223         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
224                                  0, sizeof(struct pt_dspregs));
225         if (!ret)
226                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
227                                                 sizeof(struct pt_dspregs), -1);
228
229         return ret;
230 }
231
232 static int dspregs_active(struct task_struct *target,
233                           const struct user_regset *regset)
234 {
235         struct pt_regs *regs = task_pt_regs(target);
236
237         return regs->sr & SR_DSP ? regset->n : 0;
238 }
239 #endif
240
241 /*
242  * These are our native regset flavours.
243  */
244 enum sh_regset {
245         REGSET_GENERAL,
246 #ifdef CONFIG_SH_FPU
247         REGSET_FPU,
248 #endif
249 #ifdef CONFIG_SH_DSP
250         REGSET_DSP,
251 #endif
252 };
253
254 static const struct user_regset sh_regsets[] = {
255         /*
256          * Format is:
257          *      R0 --> R15
258          *      PC, PR, SR, GBR, MACH, MACL, TRA
259          */
260         [REGSET_GENERAL] = {
261                 .core_note_type = NT_PRSTATUS,
262                 .n              = ELF_NGREG,
263                 .size           = sizeof(long),
264                 .align          = sizeof(long),
265                 .get            = genregs_get,
266                 .set            = genregs_set,
267         },
268
269 #ifdef CONFIG_SH_FPU
270         [REGSET_FPU] = {
271                 .core_note_type = NT_PRFPREG,
272                 .n              = sizeof(struct user_fpu_struct) / sizeof(long),
273                 .size           = sizeof(long),
274                 .align          = sizeof(long),
275                 .get            = fpregs_get,
276                 .set            = fpregs_set,
277                 .active         = fpregs_active,
278         },
279 #endif
280
281 #ifdef CONFIG_SH_DSP
282         [REGSET_DSP] = {
283                 .n              = sizeof(struct pt_dspregs) / sizeof(long),
284                 .size           = sizeof(long),
285                 .align          = sizeof(long),
286                 .get            = dspregs_get,
287                 .set            = dspregs_set,
288                 .active         = dspregs_active,
289         },
290 #endif
291 };
292
293 static const struct user_regset_view user_sh_native_view = {
294         .name           = "sh",
295         .e_machine      = EM_SH,
296         .regsets        = sh_regsets,
297         .n              = ARRAY_SIZE(sh_regsets),
298 };
299
300 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
301 {
302         return &user_sh_native_view;
303 }
304
305 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
306 {
307         struct user * dummy = NULL;
308         unsigned long __user *datap = (unsigned long __user *)data;
309         int ret;
310
311         switch (request) {
312         /* read the word at location addr in the USER area. */
313         case PTRACE_PEEKUSR: {
314                 unsigned long tmp;
315
316                 ret = -EIO;
317                 if ((addr & 3) || addr < 0 ||
318                     addr > sizeof(struct user) - 3)
319                         break;
320
321                 if (addr < sizeof(struct pt_regs))
322                         tmp = get_stack_long(child, addr);
323                 else if (addr >= (long) &dummy->fpu &&
324                          addr < (long) &dummy->u_fpvalid) {
325                         if (!tsk_used_math(child)) {
326                                 if (addr == (long)&dummy->fpu.fpscr)
327                                         tmp = FPSCR_INIT;
328                                 else
329                                         tmp = 0;
330                         } else
331                                 tmp = ((long *)&child->thread.fpu)
332                                         [(addr - (long)&dummy->fpu) >> 2];
333                 } else if (addr == (long) &dummy->u_fpvalid)
334                         tmp = !!tsk_used_math(child);
335                 else
336                         tmp = 0;
337                 ret = put_user(tmp, datap);
338                 break;
339         }
340
341         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
342                 ret = -EIO;
343                 if ((addr & 3) || addr < 0 ||
344                     addr > sizeof(struct user) - 3)
345                         break;
346
347                 if (addr < sizeof(struct pt_regs))
348                         ret = put_stack_long(child, addr, data);
349                 else if (addr >= (long) &dummy->fpu &&
350                          addr < (long) &dummy->u_fpvalid) {
351                         set_stopped_child_used_math(child);
352                         ((long *)&child->thread.fpu)
353                                 [(addr - (long)&dummy->fpu) >> 2] = data;
354                         ret = 0;
355                 } else if (addr == (long) &dummy->u_fpvalid) {
356                         conditional_stopped_child_used_math(data, child);
357                         ret = 0;
358                 }
359                 break;
360
361         case PTRACE_GETREGS:
362                 return copy_regset_to_user(child, &user_sh_native_view,
363                                            REGSET_GENERAL,
364                                            0, sizeof(struct pt_regs),
365                                            (void __user *)data);
366         case PTRACE_SETREGS:
367                 return copy_regset_from_user(child, &user_sh_native_view,
368                                              REGSET_GENERAL,
369                                              0, sizeof(struct pt_regs),
370                                              (const void __user *)data);
371 #ifdef CONFIG_SH_FPU
372         case PTRACE_GETFPREGS:
373                 return copy_regset_to_user(child, &user_sh_native_view,
374                                            REGSET_FPU,
375                                            0, sizeof(struct user_fpu_struct),
376                                            (void __user *)data);
377         case PTRACE_SETFPREGS:
378                 return copy_regset_from_user(child, &user_sh_native_view,
379                                              REGSET_FPU,
380                                              0, sizeof(struct user_fpu_struct),
381                                              (const void __user *)data);
382 #endif
383 #ifdef CONFIG_SH_DSP
384         case PTRACE_GETDSPREGS:
385                 return copy_regset_to_user(child, &user_sh_native_view,
386                                            REGSET_DSP,
387                                            0, sizeof(struct pt_dspregs),
388                                            (void __user *)data);
389         case PTRACE_SETDSPREGS:
390                 return copy_regset_from_user(child, &user_sh_native_view,
391                                              REGSET_DSP,
392                                              0, sizeof(struct pt_dspregs),
393                                              (const void __user *)data);
394 #endif
395 #ifdef CONFIG_BINFMT_ELF_FDPIC
396         case PTRACE_GETFDPIC: {
397                 unsigned long tmp = 0;
398
399                 switch (addr) {
400                 case PTRACE_GETFDPIC_EXEC:
401                         tmp = child->mm->context.exec_fdpic_loadmap;
402                         break;
403                 case PTRACE_GETFDPIC_INTERP:
404                         tmp = child->mm->context.interp_fdpic_loadmap;
405                         break;
406                 default:
407                         break;
408                 }
409
410                 ret = 0;
411                 if (put_user(tmp, datap)) {
412                         ret = -EFAULT;
413                         break;
414                 }
415                 break;
416         }
417 #endif
418         default:
419                 ret = ptrace_request(child, request, addr, data);
420                 break;
421         }
422
423         return ret;
424 }
425
426 static inline int audit_arch(void)
427 {
428         int arch = EM_SH;
429
430 #ifdef CONFIG_CPU_LITTLE_ENDIAN
431         arch |= __AUDIT_ARCH_LE;
432 #endif
433
434         return arch;
435 }
436
437 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
438 {
439         long ret = 0;
440
441         secure_computing(regs->regs[0]);
442
443         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
444             tracehook_report_syscall_entry(regs))
445                 /*
446                  * Tracing decided this syscall should not happen.
447                  * We'll return a bogus call number to get an ENOSYS
448                  * error, but leave the original number in regs->regs[0].
449                  */
450                 ret = -1L;
451
452         if (unlikely(current->audit_context))
453                 audit_syscall_entry(audit_arch(), regs->regs[3],
454                                     regs->regs[4], regs->regs[5],
455                                     regs->regs[6], regs->regs[7]);
456
457         return ret ?: regs->regs[0];
458 }
459
460 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
461 {
462         int step;
463
464         if (unlikely(current->audit_context))
465                 audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
466                                    regs->regs[0]);
467
468         step = test_thread_flag(TIF_SINGLESTEP);
469         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
470                 tracehook_report_syscall_exit(regs, step);
471 }