43eb969405d1657bd0aba85b2528e9d28296bd55
[linux-2.6.git] / arch / blackfin / kernel / ptrace.c
1 /*
2  * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
3  * these modifications are Copyright 2004-2010 Analog Devices Inc.
4  *
5  * Licensed under the GPL-2
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/mm.h>
11 #include <linux/smp.h>
12 #include <linux/elf.h>
13 #include <linux/errno.h>
14 #include <linux/ptrace.h>
15 #include <linux/user.h>
16 #include <linux/regset.h>
17 #include <linux/signal.h>
18 #include <linux/tracehook.h>
19 #include <linux/uaccess.h>
20
21 #include <asm/page.h>
22 #include <asm/pgtable.h>
23 #include <asm/system.h>
24 #include <asm/processor.h>
25 #include <asm/asm-offsets.h>
26 #include <asm/dma.h>
27 #include <asm/fixed_code.h>
28 #include <asm/cacheflush.h>
29 #include <asm/mem_map.h>
30
31 /*
32  * does not yet catch signals sent when the child dies.
33  * in exit.c or in signal.c.
34  */
35
36 /*
37  * Get contents of register REGNO in task TASK.
38  */
39 static inline long
40 get_reg(struct task_struct *task, long regno, unsigned long __user *datap)
41 {
42         long tmp;
43         struct pt_regs *regs = task_pt_regs(task);
44
45         if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
46                 return -EIO;
47
48         switch (regno) {
49         case PT_TEXT_ADDR:
50                 tmp = task->mm->start_code;
51                 break;
52         case PT_TEXT_END_ADDR:
53                 tmp = task->mm->end_code;
54                 break;
55         case PT_DATA_ADDR:
56                 tmp = task->mm->start_data;
57                 break;
58         case PT_USP:
59                 tmp = task->thread.usp;
60                 break;
61         default:
62                 if (regno < sizeof(*regs)) {
63                         void *reg_ptr = regs;
64                         tmp = *(long *)(reg_ptr + regno);
65                 } else
66                         return -EIO;
67         }
68
69         return put_user(tmp, datap);
70 }
71
72 /*
73  * Write contents of register REGNO in task TASK.
74  */
75 static inline int
76 put_reg(struct task_struct *task, long regno, unsigned long data)
77 {
78         struct pt_regs *regs = task_pt_regs(task);
79
80         if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
81                 return -EIO;
82
83         switch (regno) {
84         case PT_PC:
85                 /*********************************************************************/
86                 /* At this point the kernel is most likely in exception.             */
87                 /* The RETX register will be used to populate the pc of the process. */
88                 /*********************************************************************/
89                 regs->retx = data;
90                 regs->pc = data;
91                 break;
92         case PT_RETX:
93                 break;          /* regs->retx = data; break; */
94         case PT_USP:
95                 regs->usp = data;
96                 task->thread.usp = data;
97                 break;
98         case PT_SYSCFG: /* don't let userspace screw with this */
99                 if ((data & ~1) != 0x6)
100                         pr_warning("ptrace: ignore syscfg write of %#lx\n", data);
101                 break;          /* regs->syscfg = data; break; */
102         default:
103                 if (regno < sizeof(*regs)) {
104                         void *reg_offset = regs;
105                         *(long *)(reg_offset + regno) = data;
106                 }
107                 /* Ignore writes to pseudo registers */
108         }
109
110         return 0;
111 }
112
113 /*
114  * check that an address falls within the bounds of the target process's memory mappings
115  */
116 static inline int is_user_addr_valid(struct task_struct *child,
117                                      unsigned long start, unsigned long len)
118 {
119         struct vm_area_struct *vma;
120         struct sram_list_struct *sraml;
121
122         /* overflow */
123         if (start + len < start)
124                 return -EIO;
125
126         vma = find_vma(child->mm, start);
127         if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
128                         return 0;
129
130         for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
131                 if (start >= (unsigned long)sraml->addr
132                     && start + len < (unsigned long)sraml->addr + sraml->length)
133                         return 0;
134
135         if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
136                 return 0;
137
138         return -EIO;
139 }
140
141 /*
142  * retrieve the contents of Blackfin userspace general registers
143  */
144 static int genregs_get(struct task_struct *target,
145                        const struct user_regset *regset,
146                        unsigned int pos, unsigned int count,
147                        void *kbuf, void __user *ubuf)
148 {
149         struct pt_regs *regs = task_pt_regs(target);
150         int ret;
151
152         /* This sucks ... */
153         regs->usp = target->thread.usp;
154
155         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
156                                   regs, 0, sizeof(*regs));
157         if (ret < 0)
158                 return ret;
159
160         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
161                                         sizeof(*regs), -1);
162 }
163
164 /*
165  * update the contents of the Blackfin userspace general registers
166  */
167 static int genregs_set(struct task_struct *target,
168                        const struct user_regset *regset,
169                        unsigned int pos, unsigned int count,
170                        const void *kbuf, const void __user *ubuf)
171 {
172         struct pt_regs *regs = task_pt_regs(target);
173         int ret;
174
175         /* Don't let people set SYSCFG (it's at the end of pt_regs) */
176         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
177                                  regs, 0, PT_SYSCFG);
178         if (ret < 0)
179                 return ret;
180
181         /* This sucks ... */
182         target->thread.usp = regs->usp;
183         /* regs->retx = regs->pc; */
184
185         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
186                                         PT_SYSCFG, -1);
187 }
188
189 /*
190  * Define the register sets available on the Blackfin under Linux
191  */
192 enum bfin_regset {
193         REGSET_GENERAL,
194 };
195
196 static const struct user_regset bfin_regsets[] = {
197         [REGSET_GENERAL] = {
198                 .core_note_type = NT_PRSTATUS,
199                 .n              = sizeof(struct pt_regs) / sizeof(long),
200                 .size           = sizeof(long),
201                 .align          = sizeof(long),
202                 .get            = genregs_get,
203                 .set            = genregs_set,
204         },
205 };
206
207 static const struct user_regset_view user_bfin_native_view = {
208         .name      = "Blackfin",
209         .e_machine = EM_BLACKFIN,
210         .regsets   = bfin_regsets,
211         .n         = ARRAY_SIZE(bfin_regsets),
212 };
213
214 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
215 {
216         return &user_bfin_native_view;
217 }
218
219 void user_enable_single_step(struct task_struct *child)
220 {
221         struct pt_regs *regs = task_pt_regs(child);
222         regs->syscfg |= SYSCFG_SSSTEP;
223
224         set_tsk_thread_flag(child, TIF_SINGLESTEP);
225 }
226
227 void user_disable_single_step(struct task_struct *child)
228 {
229         struct pt_regs *regs = task_pt_regs(child);
230         regs->syscfg &= ~SYSCFG_SSSTEP;
231
232         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
233 }
234
235 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
236 {
237         int ret;
238         unsigned long __user *datap = (unsigned long __user *)data;
239         void *paddr = (void *)addr;
240
241         switch (request) {
242                 /* when I and D space are separate, these will need to be fixed. */
243         case PTRACE_PEEKDATA:
244                 pr_debug("ptrace: PEEKDATA\n");
245                 /* fall through */
246         case PTRACE_PEEKTEXT:   /* read word at location addr. */
247                 {
248                         unsigned long tmp = 0;
249                         int copied = 0, to_copy = sizeof(tmp);
250
251                         ret = -EIO;
252                         pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
253                         if (is_user_addr_valid(child, addr, to_copy) < 0)
254                                 break;
255                         pr_debug("ptrace: user address is valid\n");
256
257                         switch (bfin_mem_access_type(addr, to_copy)) {
258                         case BFIN_MEM_ACCESS_CORE:
259                         case BFIN_MEM_ACCESS_CORE_ONLY:
260                                 copied = access_process_vm(child, addr, &tmp,
261                                                            to_copy, 0);
262                                 if (copied)
263                                         break;
264
265                                 /* hrm, why didn't that work ... maybe no mapping */
266                                 if (addr >= FIXED_CODE_START &&
267                                     addr + to_copy <= FIXED_CODE_END) {
268                                         copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
269                                         copied = to_copy;
270                                 } else if (addr >= BOOT_ROM_START) {
271                                         memcpy(&tmp, paddr, to_copy);
272                                         copied = to_copy;
273                                 }
274
275                                 break;
276                         case BFIN_MEM_ACCESS_DMA:
277                                 if (safe_dma_memcpy(&tmp, paddr, to_copy))
278                                         copied = to_copy;
279                                 break;
280                         case BFIN_MEM_ACCESS_ITEST:
281                                 if (isram_memcpy(&tmp, paddr, to_copy))
282                                         copied = to_copy;
283                                 break;
284                         default:
285                                 copied = 0;
286                                 break;
287                         }
288
289                         pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
290                         if (copied == to_copy)
291                                 ret = put_user(tmp, datap);
292                         break;
293                 }
294
295 #ifdef CONFIG_BINFMT_ELF_FDPIC
296         case PTRACE_GETFDPIC: {
297                 unsigned long tmp = 0;
298
299                 switch (addr) {
300                 case_PTRACE_GETFDPIC_EXEC:
301                 case PTRACE_GETFDPIC_EXEC:
302                         tmp = child->mm->context.exec_fdpic_loadmap;
303                         break;
304                 case_PTRACE_GETFDPIC_INTERP:
305                 case PTRACE_GETFDPIC_INTERP:
306                         tmp = child->mm->context.interp_fdpic_loadmap;
307                         break;
308                 default:
309                         break;
310                 }
311
312                 ret = put_user(tmp, datap);
313                 break;
314         }
315 #endif
316
317                 /* when I and D space are separate, this will have to be fixed. */
318         case PTRACE_POKEDATA:
319                 pr_debug("ptrace: PTRACE_PEEKDATA\n");
320                 /* fall through */
321         case PTRACE_POKETEXT:   /* write the word at location addr. */
322                 {
323                         int copied = 0, to_copy = sizeof(data);
324
325                         ret = -EIO;
326                         pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
327                                  addr, to_copy, data);
328                         if (is_user_addr_valid(child, addr, to_copy) < 0)
329                                 break;
330                         pr_debug("ptrace: user address is valid\n");
331
332                         switch (bfin_mem_access_type(addr, to_copy)) {
333                         case BFIN_MEM_ACCESS_CORE:
334                         case BFIN_MEM_ACCESS_CORE_ONLY:
335                                 copied = access_process_vm(child, addr, &data,
336                                                            to_copy, 1);
337                                 break;
338                         case BFIN_MEM_ACCESS_DMA:
339                                 if (safe_dma_memcpy(paddr, &data, to_copy))
340                                         copied = to_copy;
341                                 break;
342                         case BFIN_MEM_ACCESS_ITEST:
343                                 if (isram_memcpy(paddr, &data, to_copy))
344                                         copied = to_copy;
345                                 break;
346                         default:
347                                 copied = 0;
348                                 break;
349                         }
350
351                         pr_debug("ptrace: copied size %d\n", copied);
352                         if (copied == to_copy)
353                                 ret = 0;
354                         break;
355                 }
356
357         case PTRACE_PEEKUSR:
358                 switch (addr) {
359 #ifdef CONFIG_BINFMT_ELF_FDPIC  /* backwards compat */
360                 case PT_FDPIC_EXEC:   goto case_PTRACE_GETFDPIC_EXEC;
361                 case PT_FDPIC_INTERP: goto case_PTRACE_GETFDPIC_INTERP;
362 #endif
363                 default:
364                         ret = get_reg(child, addr, datap);
365                 }
366                 pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
367                 break;
368
369         case PTRACE_POKEUSR:
370                 ret = put_reg(child, addr, data);
371                 pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
372                 break;
373
374         case PTRACE_GETREGS:
375                 pr_debug("ptrace: PTRACE_GETREGS\n");
376                 return copy_regset_to_user(child, &user_bfin_native_view,
377                                            REGSET_GENERAL,
378                                            0, sizeof(struct pt_regs),
379                                            (void __user *)data);
380
381         case PTRACE_SETREGS:
382                 pr_debug("ptrace: PTRACE_SETREGS\n");
383                 return copy_regset_from_user(child, &user_bfin_native_view,
384                                              REGSET_GENERAL,
385                                              0, sizeof(struct pt_regs),
386                                              (const void __user *)data);
387
388         default:
389                 ret = ptrace_request(child, request, addr, data);
390                 break;
391         }
392
393         return ret;
394 }
395
396 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
397 {
398         int ret = 0;
399
400         if (test_thread_flag(TIF_SYSCALL_TRACE))
401                 ret = tracehook_report_syscall_entry(regs);
402
403         return ret;
404 }
405
406 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
407 {
408         int step;
409
410         step = test_thread_flag(TIF_SINGLESTEP);
411         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
412                 tracehook_report_syscall_exit(regs, step);
413 }