Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.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/processor.h>
24 #include <asm/asm-offsets.h>
25 #include <asm/dma.h>
26 #include <asm/fixed_code.h>
27 #include <asm/cacheflush.h>
28 #include <asm/mem_map.h>
29 #include <asm/mmu_context.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, unsigned long regno,
41         unsigned long __user *datap)
42 {
43         long tmp;
44         struct pt_regs *regs = task_pt_regs(task);
45
46         if (regno & 3 || regno > PT_LAST_PSEUDO)
47                 return -EIO;
48
49         switch (regno) {
50         case PT_TEXT_ADDR:
51                 tmp = task->mm->start_code;
52                 break;
53         case PT_TEXT_END_ADDR:
54                 tmp = task->mm->end_code;
55                 break;
56         case PT_DATA_ADDR:
57                 tmp = task->mm->start_data;
58                 break;
59         case PT_USP:
60                 tmp = task->thread.usp;
61                 break;
62         default:
63                 if (regno < sizeof(*regs)) {
64                         void *reg_ptr = regs;
65                         tmp = *(long *)(reg_ptr + regno);
66                 } else
67                         return -EIO;
68         }
69
70         return put_user(tmp, datap);
71 }
72
73 /*
74  * Write contents of register REGNO in task TASK.
75  */
76 static inline int
77 put_reg(struct task_struct *task, unsigned long regno, unsigned long data)
78 {
79         struct pt_regs *regs = task_pt_regs(task);
80
81         if (regno & 3 || regno > PT_LAST_PSEUDO)
82                 return -EIO;
83
84         switch (regno) {
85         case PT_PC:
86                 /*********************************************************************/
87                 /* At this point the kernel is most likely in exception.             */
88                 /* The RETX register will be used to populate the pc of the process. */
89                 /*********************************************************************/
90                 regs->retx = data;
91                 regs->pc = data;
92                 break;
93         case PT_RETX:
94                 break;          /* regs->retx = data; break; */
95         case PT_USP:
96                 regs->usp = data;
97                 task->thread.usp = data;
98                 break;
99         case PT_SYSCFG: /* don't let userspace screw with this */
100                 if ((data & ~1) != 0x6)
101                         pr_warning("ptrace: ignore syscfg write of %#lx\n", data);
102                 break;          /* regs->syscfg = data; break; */
103         default:
104                 if (regno < sizeof(*regs)) {
105                         void *reg_offset = regs;
106                         *(long *)(reg_offset + regno) = data;
107                 }
108                 /* Ignore writes to pseudo registers */
109         }
110
111         return 0;
112 }
113
114 /*
115  * check that an address falls within the bounds of the target process's memory mappings
116  */
117 int
118 is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len)
119 {
120         struct vm_area_struct *vma;
121         struct sram_list_struct *sraml;
122
123         /* overflow */
124         if (start + len < start)
125                 return -EIO;
126
127         vma = find_vma(child->mm, start);
128         if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
129                         return 0;
130
131         for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
132                 if (start >= (unsigned long)sraml->addr
133                     && start + len < (unsigned long)sraml->addr + sraml->length)
134                         return 0;
135
136         if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
137                 return 0;
138
139 #ifdef CONFIG_APP_STACK_L1
140         if (child->mm->context.l1_stack_save)
141                 if (start >= (unsigned long)l1_stack_base &&
142                         start + len < (unsigned long)l1_stack_base + l1_stack_len)
143                         return 0;
144 #endif
145
146         return -EIO;
147 }
148
149 /*
150  * retrieve the contents of Blackfin userspace general registers
151  */
152 static int genregs_get(struct task_struct *target,
153                        const struct user_regset *regset,
154                        unsigned int pos, unsigned int count,
155                        void *kbuf, void __user *ubuf)
156 {
157         struct pt_regs *regs = task_pt_regs(target);
158         int ret;
159
160         /* This sucks ... */
161         regs->usp = target->thread.usp;
162
163         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
164                                   regs, 0, sizeof(*regs));
165         if (ret < 0)
166                 return ret;
167
168         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
169                                         sizeof(*regs), -1);
170 }
171
172 /*
173  * update the contents of the Blackfin userspace general registers
174  */
175 static int genregs_set(struct task_struct *target,
176                        const struct user_regset *regset,
177                        unsigned int pos, unsigned int count,
178                        const void *kbuf, const void __user *ubuf)
179 {
180         struct pt_regs *regs = task_pt_regs(target);
181         int ret;
182
183         /* Don't let people set SYSCFG (it's at the end of pt_regs) */
184         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
185                                  regs, 0, PT_SYSCFG);
186         if (ret < 0)
187                 return ret;
188
189         /* This sucks ... */
190         target->thread.usp = regs->usp;
191         /* regs->retx = regs->pc; */
192
193         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
194                                         PT_SYSCFG, -1);
195 }
196
197 /*
198  * Define the register sets available on the Blackfin under Linux
199  */
200 enum bfin_regset {
201         REGSET_GENERAL,
202 };
203
204 static const struct user_regset bfin_regsets[] = {
205         [REGSET_GENERAL] = {
206                 .core_note_type = NT_PRSTATUS,
207                 .n              = sizeof(struct pt_regs) / sizeof(long),
208                 .size           = sizeof(long),
209                 .align          = sizeof(long),
210                 .get            = genregs_get,
211                 .set            = genregs_set,
212         },
213 };
214
215 static const struct user_regset_view user_bfin_native_view = {
216         .name      = "Blackfin",
217         .e_machine = EM_BLACKFIN,
218         .regsets   = bfin_regsets,
219         .n         = ARRAY_SIZE(bfin_regsets),
220 };
221
222 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
223 {
224         return &user_bfin_native_view;
225 }
226
227 void user_enable_single_step(struct task_struct *child)
228 {
229         struct pt_regs *regs = task_pt_regs(child);
230         regs->syscfg |= SYSCFG_SSSTEP;
231
232         set_tsk_thread_flag(child, TIF_SINGLESTEP);
233 }
234
235 void user_disable_single_step(struct task_struct *child)
236 {
237         struct pt_regs *regs = task_pt_regs(child);
238         regs->syscfg &= ~SYSCFG_SSSTEP;
239
240         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
241 }
242
243 long arch_ptrace(struct task_struct *child, long request,
244                  unsigned long addr, unsigned long data)
245 {
246         int ret;
247         unsigned long __user *datap = (unsigned long __user *)data;
248         void *paddr = (void *)addr;
249
250         switch (request) {
251                 /* when I and D space are separate, these will need to be fixed. */
252         case PTRACE_PEEKDATA:
253                 pr_debug("ptrace: PEEKDATA\n");
254                 /* fall through */
255         case PTRACE_PEEKTEXT:   /* read word at location addr. */
256                 {
257                         unsigned long tmp = 0;
258                         int copied = 0, to_copy = sizeof(tmp);
259
260                         ret = -EIO;
261                         pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
262                         if (is_user_addr_valid(child, addr, to_copy) < 0)
263                                 break;
264                         pr_debug("ptrace: user address is valid\n");
265
266                         switch (bfin_mem_access_type(addr, to_copy)) {
267                         case BFIN_MEM_ACCESS_CORE:
268                         case BFIN_MEM_ACCESS_CORE_ONLY:
269                                 copied = access_process_vm(child, addr, &tmp,
270                                                            to_copy, 0);
271                                 if (copied)
272                                         break;
273
274                                 /* hrm, why didn't that work ... maybe no mapping */
275                                 if (addr >= FIXED_CODE_START &&
276                                     addr + to_copy <= FIXED_CODE_END) {
277                                         copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
278                                         copied = to_copy;
279                                 } else if (addr >= BOOT_ROM_START) {
280                                         memcpy(&tmp, paddr, to_copy);
281                                         copied = to_copy;
282                                 }
283
284                                 break;
285                         case BFIN_MEM_ACCESS_DMA:
286                                 if (safe_dma_memcpy(&tmp, paddr, to_copy))
287                                         copied = to_copy;
288                                 break;
289                         case BFIN_MEM_ACCESS_ITEST:
290                                 if (isram_memcpy(&tmp, paddr, to_copy))
291                                         copied = to_copy;
292                                 break;
293                         default:
294                                 copied = 0;
295                                 break;
296                         }
297
298                         pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
299                         if (copied == to_copy)
300                                 ret = put_user(tmp, datap);
301                         break;
302                 }
303
304                 /* when I and D space are separate, this will have to be fixed. */
305         case PTRACE_POKEDATA:
306                 pr_debug("ptrace: PTRACE_PEEKDATA\n");
307                 /* fall through */
308         case PTRACE_POKETEXT:   /* write the word at location addr. */
309                 {
310                         int copied = 0, to_copy = sizeof(data);
311
312                         ret = -EIO;
313                         pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
314                                  addr, to_copy, data);
315                         if (is_user_addr_valid(child, addr, to_copy) < 0)
316                                 break;
317                         pr_debug("ptrace: user address is valid\n");
318
319                         switch (bfin_mem_access_type(addr, to_copy)) {
320                         case BFIN_MEM_ACCESS_CORE:
321                         case BFIN_MEM_ACCESS_CORE_ONLY:
322                                 copied = access_process_vm(child, addr, &data,
323                                                            to_copy, 1);
324                                 break;
325                         case BFIN_MEM_ACCESS_DMA:
326                                 if (safe_dma_memcpy(paddr, &data, to_copy))
327                                         copied = to_copy;
328                                 break;
329                         case BFIN_MEM_ACCESS_ITEST:
330                                 if (isram_memcpy(paddr, &data, to_copy))
331                                         copied = to_copy;
332                                 break;
333                         default:
334                                 copied = 0;
335                                 break;
336                         }
337
338                         pr_debug("ptrace: copied size %d\n", copied);
339                         if (copied == to_copy)
340                                 ret = 0;
341                         break;
342                 }
343
344         case PTRACE_PEEKUSR:
345                 switch (addr) {
346 #ifdef CONFIG_BINFMT_ELF_FDPIC  /* backwards compat */
347                 case PT_FDPIC_EXEC:
348                         request = PTRACE_GETFDPIC;
349                         addr = PTRACE_GETFDPIC_EXEC;
350                         goto case_default;
351                 case PT_FDPIC_INTERP:
352                         request = PTRACE_GETFDPIC;
353                         addr = PTRACE_GETFDPIC_INTERP;
354                         goto case_default;
355 #endif
356                 default:
357                         ret = get_reg(child, addr, datap);
358                 }
359                 pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
360                 break;
361
362         case PTRACE_POKEUSR:
363                 ret = put_reg(child, addr, data);
364                 pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
365                 break;
366
367         case PTRACE_GETREGS:
368                 pr_debug("ptrace: PTRACE_GETREGS\n");
369                 return copy_regset_to_user(child, &user_bfin_native_view,
370                                            REGSET_GENERAL,
371                                            0, sizeof(struct pt_regs),
372                                            datap);
373
374         case PTRACE_SETREGS:
375                 pr_debug("ptrace: PTRACE_SETREGS\n");
376                 return copy_regset_from_user(child, &user_bfin_native_view,
377                                              REGSET_GENERAL,
378                                              0, sizeof(struct pt_regs),
379                                              datap);
380
381         case_default:
382         default:
383                 ret = ptrace_request(child, request, addr, data);
384                 break;
385         }
386
387         return ret;
388 }
389
390 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
391 {
392         int ret = 0;
393
394         if (test_thread_flag(TIF_SYSCALL_TRACE))
395                 ret = tracehook_report_syscall_entry(regs);
396
397         return ret;
398 }
399
400 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
401 {
402         int step;
403
404         step = test_thread_flag(TIF_SINGLESTEP);
405         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
406                 tracehook_report_syscall_exit(regs, step);
407 }