headers: smp_lock.h redux
[linux-block.git] / arch / blackfin / kernel / ptrace.c
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1/*
2 * File: arch/blackfin/kernel/ptrace.c
3 * Based on: Taken from linux/kernel/ptrace.c
4 * Author: linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
5 *
6 * Created: 1/23/92
7 * Description:
8 *
9 * Modified:
10 * Copyright 2004-2006 Analog Devices Inc.
11 *
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 */
29
30#include <linux/kernel.h>
31#include <linux/sched.h>
32#include <linux/mm.h>
33#include <linux/smp.h>
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34#include <linux/errno.h>
35#include <linux/ptrace.h>
36#include <linux/user.h>
37#include <linux/signal.h>
1f83b8f1 38#include <linux/uaccess.h>
1394f032 39
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40#include <asm/page.h>
41#include <asm/pgtable.h>
42#include <asm/system.h>
43#include <asm/processor.h>
44#include <asm/asm-offsets.h>
45#include <asm/dma.h>
26156397 46#include <asm/fixed_code.h>
7786ce82 47#include <asm/cacheflush.h>
dbc895f9 48#include <asm/mem_map.h>
1394f032 49
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50#define TEXT_OFFSET 0
51/*
52 * does not yet catch signals sent when the child dies.
53 * in exit.c or in signal.c.
54 */
55
56/* determines which bits in the SYSCFG reg the user has access to. */
57/* 1 = access 0 = no access */
58#define SYSCFG_MASK 0x0007 /* SYSCFG reg */
59/* sets the trace bits. */
60#define TRACE_BITS 0x0001
61
62/* Find the stack offset for a register, relative to thread.esp0. */
63#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
64
65/*
66 * Get the address of the live pt_regs for the specified task.
67 * These are saved onto the top kernel stack when the process
68 * is not running.
69 *
70 * Note: if a user thread is execve'd from kernel space, the
71 * kernel stack will not be empty on entry to the kernel, so
72 * ptracing these tasks will fail.
73 */
74static inline struct pt_regs *get_user_regs(struct task_struct *task)
75{
76 return (struct pt_regs *)
f7e4217b 77 ((unsigned long)task_stack_page(task) +
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78 (THREAD_SIZE - sizeof(struct pt_regs)));
79}
80
81/*
82 * Get all user integer registers.
83 */
8a86176c 84static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
1394f032 85{
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MF
86 struct pt_regs regs;
87 memcpy(&regs, get_user_regs(tsk), sizeof(regs));
88 regs.usp = tsk->thread.usp;
89 return copy_to_user(uregs, &regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
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90}
91
92/* Mapping from PT_xxx to the stack offset at which the register is
93 * saved. Notice that usp has no stack-slot and needs to be treated
94 * specially (see get_reg/put_reg below).
95 */
96
97/*
98 * Get contents of register REGNO in task TASK.
99 */
100static inline long get_reg(struct task_struct *task, int regno)
101{
102 unsigned char *reg_ptr;
103
104 struct pt_regs *regs =
f7e4217b 105 (struct pt_regs *)((unsigned long)task_stack_page(task) +
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106 (THREAD_SIZE - sizeof(struct pt_regs)));
107 reg_ptr = (char *)regs;
108
109 switch (regno) {
110 case PT_USP:
111 return task->thread.usp;
112 default:
113 if (regno <= 216)
114 return *(long *)(reg_ptr + regno);
115 }
116 /* slight mystery ... never seems to come here but kernel misbehaves without this code! */
117
118 printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
119 return 0;
120}
121
122/*
123 * Write contents of register REGNO in task TASK.
124 */
125static inline int
126put_reg(struct task_struct *task, int regno, unsigned long data)
127{
1f83b8f1 128 char *reg_ptr;
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129
130 struct pt_regs *regs =
f7e4217b 131 (struct pt_regs *)((unsigned long)task_stack_page(task) +
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132 (THREAD_SIZE - sizeof(struct pt_regs)));
133 reg_ptr = (char *)regs;
134
135 switch (regno) {
136 case PT_PC:
137 /*********************************************************************/
138 /* At this point the kernel is most likely in exception. */
139 /* The RETX register will be used to populate the pc of the process. */
140 /*********************************************************************/
141 regs->retx = data;
142 regs->pc = data;
143 break;
144 case PT_RETX:
145 break; /* regs->retx = data; break; */
146 case PT_USP:
147 regs->usp = data;
148 task->thread.usp = data;
149 break;
150 default:
151 if (regno <= 216)
1f83b8f1 152 *(long *)(reg_ptr + regno) = data;
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153 }
154 return 0;
155}
156
157/*
158 * check that an address falls within the bounds of the target process's memory mappings
159 */
160static inline int is_user_addr_valid(struct task_struct *child,
161 unsigned long start, unsigned long len)
162{
8feae131 163 struct vm_area_struct *vma;
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164 struct sram_list_struct *sraml;
165
3c08f1d1
MF
166 /* overflow */
167 if (start + len < start)
168 return -EIO;
169
8feae131
DH
170 vma = find_vma(child->mm, start);
171 if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
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172 return 0;
173
174 for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
175 if (start >= (unsigned long)sraml->addr
d207a8c7 176 && start + len < (unsigned long)sraml->addr + sraml->length)
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177 return 0;
178
d207a8c7 179 if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
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180 return 0;
181
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182 return -EIO;
183}
184
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185void ptrace_enable(struct task_struct *child)
186{
187 unsigned long tmp;
188 tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
189 put_reg(child, PT_SYSCFG, tmp);
190}
191
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192/*
193 * Called by kernel/ptrace.c when detaching..
194 *
195 * Make sure the single step bit is not set.
196 */
197void ptrace_disable(struct task_struct *child)
198{
199 unsigned long tmp;
200 /* make sure the single step bit is not set. */
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201 tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS;
202 put_reg(child, PT_SYSCFG, tmp);
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203}
204
205long arch_ptrace(struct task_struct *child, long request, long addr, long data)
206{
207 int ret;
0ddeeca2 208 unsigned long __user *datap = (unsigned long __user *)data;
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209
210 switch (request) {
211 /* when I and D space are separate, these will need to be fixed. */
212 case PTRACE_PEEKDATA:
213 pr_debug("ptrace: PEEKDATA\n");
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214 /* fall through */
215 case PTRACE_PEEKTEXT: /* read word at location addr. */
216 {
217 unsigned long tmp = 0;
218 int copied;
219
220 ret = -EIO;
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221 pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %ld\n", addr, sizeof(data));
222 if (is_user_addr_valid(child, addr, sizeof(tmp)) < 0)
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223 break;
224 pr_debug("ptrace: user address is valid\n");
225
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226 if (L1_CODE_LENGTH != 0 && addr >= get_l1_code_start()
227 && addr + sizeof(tmp) <= get_l1_code_start() + L1_CODE_LENGTH) {
dabaad5b 228 safe_dma_memcpy (&tmp, (const void *)(addr), sizeof(tmp));
1394f032 229 copied = sizeof(tmp);
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230
231 } else if (L1_DATA_A_LENGTH != 0 && addr >= L1_DATA_A_START
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232 && addr + sizeof(tmp) <= L1_DATA_A_START + L1_DATA_A_LENGTH) {
233 memcpy(&tmp, (const void *)(addr), sizeof(tmp));
6546eae4 234 copied = sizeof(tmp);
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235
236 } else if (L1_DATA_B_LENGTH != 0 && addr >= L1_DATA_B_START
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237 && addr + sizeof(tmp) <= L1_DATA_B_START + L1_DATA_B_LENGTH) {
238 memcpy(&tmp, (const void *)(addr), sizeof(tmp));
6546eae4 239 copied = sizeof(tmp);
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240
241 } else if (addr >= FIXED_CODE_START
dabaad5b 242 && addr + sizeof(tmp) <= FIXED_CODE_END) {
7786ce82 243 copy_from_user_page(0, 0, 0, &tmp, (const void *)(addr), sizeof(tmp));
26156397 244 copied = sizeof(tmp);
d207a8c7 245
26156397 246 } else
dabaad5b 247 copied = access_process_vm(child, addr, &tmp,
26156397 248 sizeof(tmp), 0);
d207a8c7 249
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250 pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
251 if (copied != sizeof(tmp))
252 break;
0ddeeca2 253 ret = put_user(tmp, datap);
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254 break;
255 }
256
257 /* read the word at location addr in the USER area. */
258 case PTRACE_PEEKUSR:
259 {
260 unsigned long tmp;
261 ret = -EIO;
262 tmp = 0;
263 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
264 printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
265 "0 - %x sizeof(pt_regs) is %lx\n",
266 (int)addr, sizeof(struct pt_regs));
267 break;
268 }
269 if (addr == sizeof(struct pt_regs)) {
270 /* PT_TEXT_ADDR */
271 tmp = child->mm->start_code + TEXT_OFFSET;
272 } else if (addr == (sizeof(struct pt_regs) + 4)) {
273 /* PT_TEXT_END_ADDR */
274 tmp = child->mm->end_code;
275 } else if (addr == (sizeof(struct pt_regs) + 8)) {
276 /* PT_DATA_ADDR */
277 tmp = child->mm->start_data;
278#ifdef CONFIG_BINFMT_ELF_FDPIC
279 } else if (addr == (sizeof(struct pt_regs) + 12)) {
280 tmp = child->mm->context.exec_fdpic_loadmap;
281 } else if (addr == (sizeof(struct pt_regs) + 16)) {
282 tmp = child->mm->context.interp_fdpic_loadmap;
283#endif
284 } else {
285 tmp = get_reg(child, addr);
286 }
0ddeeca2 287 ret = put_user(tmp, datap);
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288 break;
289 }
290
291 /* when I and D space are separate, this will have to be fixed. */
292 case PTRACE_POKEDATA:
d3ab3a62 293 pr_debug("ptrace: PTRACE_PEEKDATA\n");
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294 /* fall through */
295 case PTRACE_POKETEXT: /* write the word at location addr. */
296 {
297 int copied;
298
299 ret = -EIO;
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300 pr_debug("ptrace: POKETEXT at addr 0x%08lx + %ld bytes %lx\n",
301 addr, sizeof(data), data);
302 if (is_user_addr_valid(child, addr, sizeof(data)) < 0)
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303 break;
304 pr_debug("ptrace: user address is valid\n");
305
8f65873e
GY
306 if (L1_CODE_LENGTH != 0 && addr >= get_l1_code_start()
307 && addr + sizeof(data) <= get_l1_code_start() + L1_CODE_LENGTH) {
dabaad5b 308 safe_dma_memcpy ((void *)(addr), &data, sizeof(data));
1394f032 309 copied = sizeof(data);
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310
311 } else if (L1_DATA_A_LENGTH != 0 && addr >= L1_DATA_A_START
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312 && addr + sizeof(data) <= L1_DATA_A_START + L1_DATA_A_LENGTH) {
313 memcpy((void *)(addr), &data, sizeof(data));
6546eae4 314 copied = sizeof(data);
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315
316 } else if (L1_DATA_B_LENGTH != 0 && addr >= L1_DATA_B_START
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317 && addr + sizeof(data) <= L1_DATA_B_START + L1_DATA_B_LENGTH) {
318 memcpy((void *)(addr), &data, sizeof(data));
6546eae4 319 copied = sizeof(data);
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320
321 } else if (addr >= FIXED_CODE_START
dabaad5b 322 && addr + sizeof(data) <= FIXED_CODE_END) {
7786ce82 323 copy_to_user_page(0, 0, 0, (void *)(addr), &data, sizeof(data));
26156397 324 copied = sizeof(data);
d207a8c7 325
26156397 326 } else
dabaad5b 327 copied = access_process_vm(child, addr, &data,
26156397 328 sizeof(data), 1);
d207a8c7 329
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330 pr_debug("ptrace: copied size %d\n", copied);
331 if (copied != sizeof(data))
332 break;
333 ret = 0;
334 break;
335 }
336
337 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
338 ret = -EIO;
339 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
340 printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
341 break;
342 }
343
344 if (addr >= (sizeof(struct pt_regs))) {
345 ret = 0;
346 break;
347 }
348 if (addr == PT_SYSCFG) {
349 data &= SYSCFG_MASK;
350 data |= get_reg(child, PT_SYSCFG);
351 }
352 ret = put_reg(child, addr, data);
353 break;
354
355 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
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356 case PTRACE_CONT: /* restart after signal. */
357 pr_debug("ptrace: syscall/cont\n");
1394f032 358
cb4c173d
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359 ret = -EIO;
360 if (!valid_signal(data))
1394f032 361 break;
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MF
362 if (request == PTRACE_SYSCALL)
363 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
364 else
365 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
366 child->exit_code = data;
367 ptrace_disable(child);
368 pr_debug("ptrace: before wake_up_process\n");
369 wake_up_process(child);
370 ret = 0;
371 break;
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372
373 /*
374 * make the child exit. Best I can do is send it a sigkill.
375 * perhaps it should be put in the status that it wants to
376 * exit.
377 */
378 case PTRACE_KILL:
cb4c173d
MF
379 ret = 0;
380 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
1394f032 381 break;
cb4c173d
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382 child->exit_code = SIGKILL;
383 ptrace_disable(child);
384 wake_up_process(child);
385 break;
1394f032 386
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MF
387 case PTRACE_SINGLESTEP: /* set the trap flag. */
388 pr_debug("ptrace: single step\n");
389 ret = -EIO;
390 if (!valid_signal(data))
1394f032 391 break;
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MF
392 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
393 ptrace_enable(child);
394 child->exit_code = data;
395 wake_up_process(child);
396 ret = 0;
397 break;
1394f032 398
1394f032 399 case PTRACE_GETREGS:
d3ab3a62
MF
400 /* Get all gp regs from the child. */
401 ret = ptrace_getregs(child, datap);
402 break;
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403
404 case PTRACE_SETREGS:
d3ab3a62
MF
405 printk(KERN_WARNING "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
406 /* Set all gp regs in the child. */
407 ret = 0;
408 break;
409
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410 default:
411 ret = ptrace_request(child, request, addr, data);
412 break;
413 }
414
415 return ret;
416}
417
418asmlinkage void syscall_trace(void)
419{
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420 if (!test_thread_flag(TIF_SYSCALL_TRACE))
421 return;
422
423 if (!(current->ptrace & PT_PTRACED))
424 return;
425
426 /* the 0x80 provides a way for the tracing parent to distinguish
427 * between a syscall stop and SIGTRAP delivery
428 */
429 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
430 ? 0x80 : 0));
431
432 /*
433 * this isn't the same as continuing with a signal, but it will do
434 * for normal use. strace only continues with a signal if the
435 * stopping signal is not SIGTRAP. -brl
436 */
437 if (current->exit_code) {
438 send_sig(current->exit_code, current, 1);
439 current->exit_code = 0;
440 }
441}