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
get_reg(struct task_struct * task,unsigned long regno,unsigned long __user * datap)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
put_reg(struct task_struct * task,unsigned long regno,unsigned long data)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
is_user_addr_valid(struct task_struct * child,unsigned long start,unsigned long len)118 is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len)
119 {
120 bool valid;
121 struct vm_area_struct *vma;
122 struct sram_list_struct *sraml;
123
124 /* overflow */
125 if (start + len < start)
126 return -EIO;
127
128 down_read(&child->mm->mmap_sem);
129 vma = find_vma(child->mm, start);
130 valid = vma && start >= vma->vm_start && start + len <= vma->vm_end;
131 up_read(&child->mm->mmap_sem);
132 if (valid)
133 return 0;
134
135 for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
136 if (start >= (unsigned long)sraml->addr
137 && start + len < (unsigned long)sraml->addr + sraml->length)
138 return 0;
139
140 if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
141 return 0;
142
143 #ifdef CONFIG_APP_STACK_L1
144 if (child->mm->context.l1_stack_save)
145 if (start >= (unsigned long)l1_stack_base &&
146 start + len < (unsigned long)l1_stack_base + l1_stack_len)
147 return 0;
148 #endif
149
150 return -EIO;
151 }
152
153 /*
154 * retrieve the contents of Blackfin userspace general registers
155 */
genregs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)156 static int genregs_get(struct task_struct *target,
157 const struct user_regset *regset,
158 unsigned int pos, unsigned int count,
159 void *kbuf, void __user *ubuf)
160 {
161 struct pt_regs *regs = task_pt_regs(target);
162 int ret;
163
164 /* This sucks ... */
165 regs->usp = target->thread.usp;
166
167 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
168 regs, 0, sizeof(*regs));
169 if (ret < 0)
170 return ret;
171
172 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
173 sizeof(*regs), -1);
174 }
175
176 /*
177 * update the contents of the Blackfin userspace general registers
178 */
genregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)179 static int genregs_set(struct task_struct *target,
180 const struct user_regset *regset,
181 unsigned int pos, unsigned int count,
182 const void *kbuf, const void __user *ubuf)
183 {
184 struct pt_regs *regs = task_pt_regs(target);
185 int ret;
186
187 /* Don't let people set SYSCFG (it's at the end of pt_regs) */
188 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
189 regs, 0, PT_SYSCFG);
190 if (ret < 0)
191 return ret;
192
193 /* This sucks ... */
194 target->thread.usp = regs->usp;
195 /* regs->retx = regs->pc; */
196
197 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
198 PT_SYSCFG, -1);
199 }
200
201 /*
202 * Define the register sets available on the Blackfin under Linux
203 */
204 enum bfin_regset {
205 REGSET_GENERAL,
206 };
207
208 static const struct user_regset bfin_regsets[] = {
209 [REGSET_GENERAL] = {
210 .core_note_type = NT_PRSTATUS,
211 .n = sizeof(struct pt_regs) / sizeof(long),
212 .size = sizeof(long),
213 .align = sizeof(long),
214 .get = genregs_get,
215 .set = genregs_set,
216 },
217 };
218
219 static const struct user_regset_view user_bfin_native_view = {
220 .name = "Blackfin",
221 .e_machine = EM_BLACKFIN,
222 .regsets = bfin_regsets,
223 .n = ARRAY_SIZE(bfin_regsets),
224 };
225
task_user_regset_view(struct task_struct * task)226 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
227 {
228 return &user_bfin_native_view;
229 }
230
user_enable_single_step(struct task_struct * child)231 void user_enable_single_step(struct task_struct *child)
232 {
233 struct pt_regs *regs = task_pt_regs(child);
234 regs->syscfg |= SYSCFG_SSSTEP;
235
236 set_tsk_thread_flag(child, TIF_SINGLESTEP);
237 }
238
user_disable_single_step(struct task_struct * child)239 void user_disable_single_step(struct task_struct *child)
240 {
241 struct pt_regs *regs = task_pt_regs(child);
242 regs->syscfg &= ~SYSCFG_SSSTEP;
243
244 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
245 }
246
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)247 long arch_ptrace(struct task_struct *child, long request,
248 unsigned long addr, unsigned long data)
249 {
250 int ret;
251 unsigned long __user *datap = (unsigned long __user *)data;
252 void *paddr = (void *)addr;
253
254 switch (request) {
255 /* when I and D space are separate, these will need to be fixed. */
256 case PTRACE_PEEKDATA:
257 pr_debug("ptrace: PEEKDATA\n");
258 /* fall through */
259 case PTRACE_PEEKTEXT: /* read word at location addr. */
260 {
261 unsigned long tmp = 0;
262 int copied = 0, to_copy = sizeof(tmp);
263
264 ret = -EIO;
265 pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
266 if (is_user_addr_valid(child, addr, to_copy) < 0)
267 break;
268 pr_debug("ptrace: user address is valid\n");
269
270 switch (bfin_mem_access_type(addr, to_copy)) {
271 case BFIN_MEM_ACCESS_CORE:
272 case BFIN_MEM_ACCESS_CORE_ONLY:
273 copied = access_process_vm(child, addr, &tmp,
274 to_copy, 0);
275 if (copied)
276 break;
277
278 /* hrm, why didn't that work ... maybe no mapping */
279 if (addr >= FIXED_CODE_START &&
280 addr + to_copy <= FIXED_CODE_END) {
281 copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
282 copied = to_copy;
283 } else if (addr >= BOOT_ROM_START) {
284 memcpy(&tmp, paddr, to_copy);
285 copied = to_copy;
286 }
287
288 break;
289 case BFIN_MEM_ACCESS_DMA:
290 if (safe_dma_memcpy(&tmp, paddr, to_copy))
291 copied = to_copy;
292 break;
293 case BFIN_MEM_ACCESS_ITEST:
294 if (isram_memcpy(&tmp, paddr, to_copy))
295 copied = to_copy;
296 break;
297 default:
298 copied = 0;
299 break;
300 }
301
302 pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
303 if (copied == to_copy)
304 ret = put_user(tmp, datap);
305 break;
306 }
307
308 /* when I and D space are separate, this will have to be fixed. */
309 case PTRACE_POKEDATA:
310 pr_debug("ptrace: PTRACE_PEEKDATA\n");
311 /* fall through */
312 case PTRACE_POKETEXT: /* write the word at location addr. */
313 {
314 int copied = 0, to_copy = sizeof(data);
315
316 ret = -EIO;
317 pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
318 addr, to_copy, data);
319 if (is_user_addr_valid(child, addr, to_copy) < 0)
320 break;
321 pr_debug("ptrace: user address is valid\n");
322
323 switch (bfin_mem_access_type(addr, to_copy)) {
324 case BFIN_MEM_ACCESS_CORE:
325 case BFIN_MEM_ACCESS_CORE_ONLY:
326 copied = access_process_vm(child, addr, &data,
327 to_copy, 1);
328 break;
329 case BFIN_MEM_ACCESS_DMA:
330 if (safe_dma_memcpy(paddr, &data, to_copy))
331 copied = to_copy;
332 break;
333 case BFIN_MEM_ACCESS_ITEST:
334 if (isram_memcpy(paddr, &data, to_copy))
335 copied = to_copy;
336 break;
337 default:
338 copied = 0;
339 break;
340 }
341
342 pr_debug("ptrace: copied size %d\n", copied);
343 if (copied == to_copy)
344 ret = 0;
345 break;
346 }
347
348 case PTRACE_PEEKUSR:
349 switch (addr) {
350 #ifdef CONFIG_BINFMT_ELF_FDPIC /* backwards compat */
351 case PT_FDPIC_EXEC:
352 request = PTRACE_GETFDPIC;
353 addr = PTRACE_GETFDPIC_EXEC;
354 goto case_default;
355 case PT_FDPIC_INTERP:
356 request = PTRACE_GETFDPIC;
357 addr = PTRACE_GETFDPIC_INTERP;
358 goto case_default;
359 #endif
360 default:
361 ret = get_reg(child, addr, datap);
362 }
363 pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
364 break;
365
366 case PTRACE_POKEUSR:
367 ret = put_reg(child, addr, data);
368 pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
369 break;
370
371 case PTRACE_GETREGS:
372 pr_debug("ptrace: PTRACE_GETREGS\n");
373 return copy_regset_to_user(child, &user_bfin_native_view,
374 REGSET_GENERAL,
375 0, sizeof(struct pt_regs),
376 datap);
377
378 case PTRACE_SETREGS:
379 pr_debug("ptrace: PTRACE_SETREGS\n");
380 return copy_regset_from_user(child, &user_bfin_native_view,
381 REGSET_GENERAL,
382 0, sizeof(struct pt_regs),
383 datap);
384
385 case_default:
386 default:
387 ret = ptrace_request(child, request, addr, data);
388 break;
389 }
390
391 return ret;
392 }
393
syscall_trace_enter(struct pt_regs * regs)394 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
395 {
396 int ret = 0;
397
398 if (test_thread_flag(TIF_SYSCALL_TRACE))
399 ret = tracehook_report_syscall_entry(regs);
400
401 return ret;
402 }
403
syscall_trace_leave(struct pt_regs * regs)404 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
405 {
406 int step;
407
408 step = test_thread_flag(TIF_SINGLESTEP);
409 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
410 tracehook_report_syscall_exit(regs, step);
411 }
412