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 #include <asm/mmu_context.h>
31
32 /*
33 * does not yet catch signals sent when the child dies.
34 * in exit.c or in signal.c.
35 */
36
37 /*
38 * Get contents of register REGNO in task TASK.
39 */
40 static inline long
get_reg(struct task_struct * task,unsigned long regno,unsigned long __user * datap)41 get_reg(struct task_struct *task, unsigned long regno,
42 unsigned long __user *datap)
43 {
44 long tmp;
45 struct pt_regs *regs = task_pt_regs(task);
46
47 if (regno & 3 || regno > PT_LAST_PSEUDO)
48 return -EIO;
49
50 switch (regno) {
51 case PT_TEXT_ADDR:
52 tmp = task->mm->start_code;
53 break;
54 case PT_TEXT_END_ADDR:
55 tmp = task->mm->end_code;
56 break;
57 case PT_DATA_ADDR:
58 tmp = task->mm->start_data;
59 break;
60 case PT_USP:
61 tmp = task->thread.usp;
62 break;
63 default:
64 if (regno < sizeof(*regs)) {
65 void *reg_ptr = regs;
66 tmp = *(long *)(reg_ptr + regno);
67 } else
68 return -EIO;
69 }
70
71 return put_user(tmp, datap);
72 }
73
74 /*
75 * Write contents of register REGNO in task TASK.
76 */
77 static inline int
put_reg(struct task_struct * task,unsigned long regno,unsigned long data)78 put_reg(struct task_struct *task, unsigned long regno, unsigned long data)
79 {
80 struct pt_regs *regs = task_pt_regs(task);
81
82 if (regno & 3 || regno > PT_LAST_PSEUDO)
83 return -EIO;
84
85 switch (regno) {
86 case PT_PC:
87 /*********************************************************************/
88 /* At this point the kernel is most likely in exception. */
89 /* The RETX register will be used to populate the pc of the process. */
90 /*********************************************************************/
91 regs->retx = data;
92 regs->pc = data;
93 break;
94 case PT_RETX:
95 break; /* regs->retx = data; break; */
96 case PT_USP:
97 regs->usp = data;
98 task->thread.usp = data;
99 break;
100 case PT_SYSCFG: /* don't let userspace screw with this */
101 if ((data & ~1) != 0x6)
102 pr_warning("ptrace: ignore syscfg write of %#lx\n", data);
103 break; /* regs->syscfg = data; break; */
104 default:
105 if (regno < sizeof(*regs)) {
106 void *reg_offset = regs;
107 *(long *)(reg_offset + regno) = data;
108 }
109 /* Ignore writes to pseudo registers */
110 }
111
112 return 0;
113 }
114
115 /*
116 * check that an address falls within the bounds of the target process's memory mappings
117 */
118 int
is_user_addr_valid(struct task_struct * child,unsigned long start,unsigned long len)119 is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len)
120 {
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 vma = find_vma(child->mm, start);
129 if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
130 return 0;
131
132 for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
133 if (start >= (unsigned long)sraml->addr
134 && start + len < (unsigned long)sraml->addr + sraml->length)
135 return 0;
136
137 if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
138 return 0;
139
140 #ifdef CONFIG_APP_STACK_L1
141 if (child->mm->context.l1_stack_save)
142 if (start >= (unsigned long)l1_stack_base &&
143 start + len < (unsigned long)l1_stack_base + l1_stack_len)
144 return 0;
145 #endif
146
147 return -EIO;
148 }
149
150 /*
151 * retrieve the contents of Blackfin userspace general registers
152 */
genregs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)153 static int genregs_get(struct task_struct *target,
154 const struct user_regset *regset,
155 unsigned int pos, unsigned int count,
156 void *kbuf, void __user *ubuf)
157 {
158 struct pt_regs *regs = task_pt_regs(target);
159 int ret;
160
161 /* This sucks ... */
162 regs->usp = target->thread.usp;
163
164 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
165 regs, 0, sizeof(*regs));
166 if (ret < 0)
167 return ret;
168
169 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
170 sizeof(*regs), -1);
171 }
172
173 /*
174 * update the contents of the Blackfin userspace general registers
175 */
genregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)176 static int genregs_set(struct task_struct *target,
177 const struct user_regset *regset,
178 unsigned int pos, unsigned int count,
179 const void *kbuf, const void __user *ubuf)
180 {
181 struct pt_regs *regs = task_pt_regs(target);
182 int ret;
183
184 /* Don't let people set SYSCFG (it's at the end of pt_regs) */
185 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
186 regs, 0, PT_SYSCFG);
187 if (ret < 0)
188 return ret;
189
190 /* This sucks ... */
191 target->thread.usp = regs->usp;
192 /* regs->retx = regs->pc; */
193
194 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
195 PT_SYSCFG, -1);
196 }
197
198 /*
199 * Define the register sets available on the Blackfin under Linux
200 */
201 enum bfin_regset {
202 REGSET_GENERAL,
203 };
204
205 static const struct user_regset bfin_regsets[] = {
206 [REGSET_GENERAL] = {
207 .core_note_type = NT_PRSTATUS,
208 .n = sizeof(struct pt_regs) / sizeof(long),
209 .size = sizeof(long),
210 .align = sizeof(long),
211 .get = genregs_get,
212 .set = genregs_set,
213 },
214 };
215
216 static const struct user_regset_view user_bfin_native_view = {
217 .name = "Blackfin",
218 .e_machine = EM_BLACKFIN,
219 .regsets = bfin_regsets,
220 .n = ARRAY_SIZE(bfin_regsets),
221 };
222
task_user_regset_view(struct task_struct * task)223 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
224 {
225 return &user_bfin_native_view;
226 }
227
user_enable_single_step(struct task_struct * child)228 void user_enable_single_step(struct task_struct *child)
229 {
230 struct pt_regs *regs = task_pt_regs(child);
231 regs->syscfg |= SYSCFG_SSSTEP;
232
233 set_tsk_thread_flag(child, TIF_SINGLESTEP);
234 }
235
user_disable_single_step(struct task_struct * child)236 void user_disable_single_step(struct task_struct *child)
237 {
238 struct pt_regs *regs = task_pt_regs(child);
239 regs->syscfg &= ~SYSCFG_SSSTEP;
240
241 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
242 }
243
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)244 long arch_ptrace(struct task_struct *child, long request,
245 unsigned long addr, unsigned long data)
246 {
247 int ret;
248 unsigned long __user *datap = (unsigned long __user *)data;
249 void *paddr = (void *)addr;
250
251 switch (request) {
252 /* when I and D space are separate, these will need to be fixed. */
253 case PTRACE_PEEKDATA:
254 pr_debug("ptrace: PEEKDATA\n");
255 /* fall through */
256 case PTRACE_PEEKTEXT: /* read word at location addr. */
257 {
258 unsigned long tmp = 0;
259 int copied = 0, to_copy = sizeof(tmp);
260
261 ret = -EIO;
262 pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
263 if (is_user_addr_valid(child, addr, to_copy) < 0)
264 break;
265 pr_debug("ptrace: user address is valid\n");
266
267 switch (bfin_mem_access_type(addr, to_copy)) {
268 case BFIN_MEM_ACCESS_CORE:
269 case BFIN_MEM_ACCESS_CORE_ONLY:
270 copied = access_process_vm(child, addr, &tmp,
271 to_copy, 0);
272 if (copied)
273 break;
274
275 /* hrm, why didn't that work ... maybe no mapping */
276 if (addr >= FIXED_CODE_START &&
277 addr + to_copy <= FIXED_CODE_END) {
278 copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
279 copied = to_copy;
280 } else if (addr >= BOOT_ROM_START) {
281 memcpy(&tmp, paddr, to_copy);
282 copied = to_copy;
283 }
284
285 break;
286 case BFIN_MEM_ACCESS_DMA:
287 if (safe_dma_memcpy(&tmp, paddr, to_copy))
288 copied = to_copy;
289 break;
290 case BFIN_MEM_ACCESS_ITEST:
291 if (isram_memcpy(&tmp, paddr, to_copy))
292 copied = to_copy;
293 break;
294 default:
295 copied = 0;
296 break;
297 }
298
299 pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
300 if (copied == to_copy)
301 ret = put_user(tmp, datap);
302 break;
303 }
304
305 /* when I and D space are separate, this will have to be fixed. */
306 case PTRACE_POKEDATA:
307 pr_debug("ptrace: PTRACE_PEEKDATA\n");
308 /* fall through */
309 case PTRACE_POKETEXT: /* write the word at location addr. */
310 {
311 int copied = 0, to_copy = sizeof(data);
312
313 ret = -EIO;
314 pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
315 addr, to_copy, data);
316 if (is_user_addr_valid(child, addr, to_copy) < 0)
317 break;
318 pr_debug("ptrace: user address is valid\n");
319
320 switch (bfin_mem_access_type(addr, to_copy)) {
321 case BFIN_MEM_ACCESS_CORE:
322 case BFIN_MEM_ACCESS_CORE_ONLY:
323 copied = access_process_vm(child, addr, &data,
324 to_copy, 1);
325 break;
326 case BFIN_MEM_ACCESS_DMA:
327 if (safe_dma_memcpy(paddr, &data, to_copy))
328 copied = to_copy;
329 break;
330 case BFIN_MEM_ACCESS_ITEST:
331 if (isram_memcpy(paddr, &data, to_copy))
332 copied = to_copy;
333 break;
334 default:
335 copied = 0;
336 break;
337 }
338
339 pr_debug("ptrace: copied size %d\n", copied);
340 if (copied == to_copy)
341 ret = 0;
342 break;
343 }
344
345 case PTRACE_PEEKUSR:
346 switch (addr) {
347 #ifdef CONFIG_BINFMT_ELF_FDPIC /* backwards compat */
348 case PT_FDPIC_EXEC:
349 request = PTRACE_GETFDPIC;
350 addr = PTRACE_GETFDPIC_EXEC;
351 goto case_default;
352 case PT_FDPIC_INTERP:
353 request = PTRACE_GETFDPIC;
354 addr = PTRACE_GETFDPIC_INTERP;
355 goto case_default;
356 #endif
357 default:
358 ret = get_reg(child, addr, datap);
359 }
360 pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
361 break;
362
363 case PTRACE_POKEUSR:
364 ret = put_reg(child, addr, data);
365 pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
366 break;
367
368 case PTRACE_GETREGS:
369 pr_debug("ptrace: PTRACE_GETREGS\n");
370 return copy_regset_to_user(child, &user_bfin_native_view,
371 REGSET_GENERAL,
372 0, sizeof(struct pt_regs),
373 datap);
374
375 case PTRACE_SETREGS:
376 pr_debug("ptrace: PTRACE_SETREGS\n");
377 return copy_regset_from_user(child, &user_bfin_native_view,
378 REGSET_GENERAL,
379 0, sizeof(struct pt_regs),
380 datap);
381
382 case_default:
383 default:
384 ret = ptrace_request(child, request, addr, data);
385 break;
386 }
387
388 return ret;
389 }
390
syscall_trace_enter(struct pt_regs * regs)391 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
392 {
393 int ret = 0;
394
395 if (test_thread_flag(TIF_SYSCALL_TRACE))
396 ret = tracehook_report_syscall_entry(regs);
397
398 return ret;
399 }
400
syscall_trace_leave(struct pt_regs * regs)401 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
402 {
403 int step;
404
405 step = test_thread_flag(TIF_SINGLESTEP);
406 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
407 tracehook_report_syscall_exit(regs, step);
408 }
409