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-rw-r--r--arch/blackfin/kernel/ptrace.c430
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diff --git a/arch/blackfin/kernel/ptrace.c b/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>
34#include <linux/smp_lock.h>
35#include <linux/errno.h>
36#include <linux/ptrace.h>
37#include <linux/user.h>
38#include <linux/signal.h>
39
40#include <asm/uaccess.h>
41#include <asm/page.h>
42#include <asm/pgtable.h>
43#include <asm/system.h>
44#include <asm/processor.h>
45#include <asm/asm-offsets.h>
46#include <asm/dma.h>
47
48#define MAX_SHARED_LIBS 3
49#define TEXT_OFFSET 0
50/*
51 * does not yet catch signals sent when the child dies.
52 * in exit.c or in signal.c.
53 */
54
55/* determines which bits in the SYSCFG reg the user has access to. */
56/* 1 = access 0 = no access */
57#define SYSCFG_MASK 0x0007 /* SYSCFG reg */
58/* sets the trace bits. */
59#define TRACE_BITS 0x0001
60
61/* Find the stack offset for a register, relative to thread.esp0. */
62#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
63
64/*
65 * Get the address of the live pt_regs for the specified task.
66 * These are saved onto the top kernel stack when the process
67 * is not running.
68 *
69 * Note: if a user thread is execve'd from kernel space, the
70 * kernel stack will not be empty on entry to the kernel, so
71 * ptracing these tasks will fail.
72 */
73static inline struct pt_regs *get_user_regs(struct task_struct *task)
74{
75 return (struct pt_regs *)
76 ((unsigned long)task->thread_info +
77 (THREAD_SIZE - sizeof(struct pt_regs)));
78}
79
80/*
81 * Get all user integer registers.
82 */
83static inline int ptrace_getregs(struct task_struct *tsk, void __user * uregs)
84{
85 struct pt_regs *regs = get_user_regs(tsk);
86 return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
87}
88
89/* Mapping from PT_xxx to the stack offset at which the register is
90 * saved. Notice that usp has no stack-slot and needs to be treated
91 * specially (see get_reg/put_reg below).
92 */
93
94/*
95 * Get contents of register REGNO in task TASK.
96 */
97static inline long get_reg(struct task_struct *task, int regno)
98{
99 unsigned char *reg_ptr;
100
101 struct pt_regs *regs =
102 (struct pt_regs *)((unsigned long)task->thread_info +
103 (THREAD_SIZE - sizeof(struct pt_regs)));
104 reg_ptr = (char *)regs;
105
106 switch (regno) {
107 case PT_USP:
108 return task->thread.usp;
109 default:
110 if (regno <= 216)
111 return *(long *)(reg_ptr + regno);
112 }
113 /* slight mystery ... never seems to come here but kernel misbehaves without this code! */
114
115 printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
116 return 0;
117}
118
119/*
120 * Write contents of register REGNO in task TASK.
121 */
122static inline int
123put_reg(struct task_struct *task, int regno, unsigned long data)
124{
125 char * reg_ptr;
126
127 struct pt_regs *regs =
128 (struct pt_regs *)((unsigned long)task->thread_info +
129 (THREAD_SIZE - sizeof(struct pt_regs)));
130 reg_ptr = (char *)regs;
131
132 switch (regno) {
133 case PT_PC:
134 /*********************************************************************/
135 /* At this point the kernel is most likely in exception. */
136 /* The RETX register will be used to populate the pc of the process. */
137 /*********************************************************************/
138 regs->retx = data;
139 regs->pc = data;
140 break;
141 case PT_RETX:
142 break; /* regs->retx = data; break; */
143 case PT_USP:
144 regs->usp = data;
145 task->thread.usp = data;
146 break;
147 default:
148 if (regno <= 216)
149 *(long *)(reg_ptr + regno) = data;
150 }
151 return 0;
152}
153
154/*
155 * check that an address falls within the bounds of the target process's memory mappings
156 */
157static inline int is_user_addr_valid(struct task_struct *child,
158 unsigned long start, unsigned long len)
159{
160 struct vm_list_struct *vml;
161 struct sram_list_struct *sraml;
162
163 for (vml = child->mm->context.vmlist; vml; vml = vml->next)
164 if (start >= vml->vma->vm_start && start + len <= vml->vma->vm_end)
165 return 0;
166
167 for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
168 if (start >= (unsigned long)sraml->addr
169 && start + len <= (unsigned long)sraml->addr + sraml->length)
170 return 0;
171
172 return -EIO;
173}
174
175/*
176 * Called by kernel/ptrace.c when detaching..
177 *
178 * Make sure the single step bit is not set.
179 */
180void ptrace_disable(struct task_struct *child)
181{
182 unsigned long tmp;
183 /* make sure the single step bit is not set. */
184 tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
185 put_reg(child, PT_SR, tmp);
186}
187
188long arch_ptrace(struct task_struct *child, long request, long addr, long data)
189{
190 int ret;
191 int add = 0;
192
193 switch (request) {
194 /* when I and D space are separate, these will need to be fixed. */
195 case PTRACE_PEEKDATA:
196 pr_debug("ptrace: PEEKDATA\n");
197 add = MAX_SHARED_LIBS * 4; /* space between text and data */
198 /* fall through */
199 case PTRACE_PEEKTEXT: /* read word at location addr. */
200 {
201 unsigned long tmp = 0;
202 int copied;
203
204 ret = -EIO;
205 pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + add %d %ld\n", addr, add,
206 sizeof(data));
207 if (is_user_addr_valid(child, addr + add, sizeof(tmp)) < 0)
208 break;
209 pr_debug("ptrace: user address is valid\n");
210
211#if L1_CODE_LENGTH != 0
212 if (addr + add >= L1_CODE_START
213 && addr + add + sizeof(tmp) <= L1_CODE_START + L1_CODE_LENGTH) {
214 safe_dma_memcpy (&tmp, (const void *)(addr + add), sizeof(tmp));
215 copied = sizeof(tmp);
216 } else
217#endif
218 copied =
219 access_process_vm(child, addr + add, &tmp,
220 sizeof(tmp), 0);
221 pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
222 if (copied != sizeof(tmp))
223 break;
224 ret = put_user(tmp, (unsigned long *)data);
225 break;
226 }
227
228 /* read the word at location addr in the USER area. */
229 case PTRACE_PEEKUSR:
230 {
231 unsigned long tmp;
232 ret = -EIO;
233 tmp = 0;
234 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
235 printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
236 "0 - %x sizeof(pt_regs) is %lx\n",
237 (int)addr, sizeof(struct pt_regs));
238 break;
239 }
240 if (addr == sizeof(struct pt_regs)) {
241 /* PT_TEXT_ADDR */
242 tmp = child->mm->start_code + TEXT_OFFSET;
243 } else if (addr == (sizeof(struct pt_regs) + 4)) {
244 /* PT_TEXT_END_ADDR */
245 tmp = child->mm->end_code;
246 } else if (addr == (sizeof(struct pt_regs) + 8)) {
247 /* PT_DATA_ADDR */
248 tmp = child->mm->start_data;
249#ifdef CONFIG_BINFMT_ELF_FDPIC
250 } else if (addr == (sizeof(struct pt_regs) + 12)) {
251 tmp = child->mm->context.exec_fdpic_loadmap;
252 } else if (addr == (sizeof(struct pt_regs) + 16)) {
253 tmp = child->mm->context.interp_fdpic_loadmap;
254#endif
255 } else {
256 tmp = get_reg(child, addr);
257 }
258 ret = put_user(tmp, (unsigned long *)data);
259 break;
260 }
261
262 /* when I and D space are separate, this will have to be fixed. */
263 case PTRACE_POKEDATA:
264 printk(KERN_NOTICE "ptrace: PTRACE_PEEKDATA\n");
265 /* fall through */
266 case PTRACE_POKETEXT: /* write the word at location addr. */
267 {
268 int copied;
269
270 ret = -EIO;
271 pr_debug("ptrace: POKETEXT at addr 0x%08lx + add %d %ld bytes %lx\n",
272 addr, add, sizeof(data), data);
273 if (is_user_addr_valid(child, addr + add, sizeof(data)) < 0)
274 break;
275 pr_debug("ptrace: user address is valid\n");
276
277#if L1_CODE_LENGTH != 0
278 if (addr + add >= L1_CODE_START
279 && addr + add + sizeof(data) <= L1_CODE_START + L1_CODE_LENGTH) {
280 safe_dma_memcpy ((void *)(addr + add), &data, sizeof(data));
281 copied = sizeof(data);
282 } else
283#endif
284 copied =
285 access_process_vm(child, addr + add, &data,
286 sizeof(data), 1);
287 pr_debug("ptrace: copied size %d\n", copied);
288 if (copied != sizeof(data))
289 break;
290 ret = 0;
291 break;
292 }
293
294 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
295 ret = -EIO;
296 if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
297 printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
298 break;
299 }
300
301 if (addr >= (sizeof(struct pt_regs))) {
302 ret = 0;
303 break;
304 }
305 if (addr == PT_SYSCFG) {
306 data &= SYSCFG_MASK;
307 data |= get_reg(child, PT_SYSCFG);
308 }
309 ret = put_reg(child, addr, data);
310 break;
311
312 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
313 case PTRACE_CONT:
314 { /* restart after signal. */
315 long tmp;
316
317 pr_debug("ptrace_cont\n");
318
319 ret = -EIO;
320 if (!valid_signal(data))
321 break;
322 if (request == PTRACE_SYSCALL)
323 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
324 else
325 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
326
327 child->exit_code = data;
328 /* make sure the single step bit is not set. */
329 tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
330 put_reg(child, PT_SYSCFG, tmp);
331 pr_debug("before wake_up_process\n");
332 wake_up_process(child);
333 ret = 0;
334 break;
335 }
336
337 /*
338 * make the child exit. Best I can do is send it a sigkill.
339 * perhaps it should be put in the status that it wants to
340 * exit.
341 */
342 case PTRACE_KILL:
343 {
344 long tmp;
345 ret = 0;
346 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
347 break;
348 child->exit_code = SIGKILL;
349 /* make sure the single step bit is not set. */
350 tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
351 put_reg(child, PT_SYSCFG, tmp);
352 wake_up_process(child);
353 break;
354 }
355
356 case PTRACE_SINGLESTEP:
357 { /* set the trap flag. */
358 long tmp;
359
360 pr_debug("single step\n");
361 ret = -EIO;
362 if (!valid_signal(data))
363 break;
364 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
365
366 tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
367 put_reg(child, PT_SYSCFG, tmp);
368
369 child->exit_code = data;
370 /* give it a chance to run. */
371 wake_up_process(child);
372 ret = 0;
373 break;
374 }
375
376 case PTRACE_DETACH:
377 { /* detach a process that was attached. */
378 ret = ptrace_detach(child, data);
379 break;
380 }
381
382 case PTRACE_GETREGS:
383 {
384
385 /* Get all gp regs from the child. */
386 ret = ptrace_getregs(child, (void __user *)data);
387 break;
388 }
389
390 case PTRACE_SETREGS:
391 {
392 printk(KERN_NOTICE
393 "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
394 /* Set all gp regs in the child. */
395 ret = 0;
396 break;
397 }
398 default:
399 ret = ptrace_request(child, request, addr, data);
400 break;
401 }
402
403 return ret;
404}
405
406asmlinkage void syscall_trace(void)
407{
408
409 if (!test_thread_flag(TIF_SYSCALL_TRACE))
410 return;
411
412 if (!(current->ptrace & PT_PTRACED))
413 return;
414
415 /* the 0x80 provides a way for the tracing parent to distinguish
416 * between a syscall stop and SIGTRAP delivery
417 */
418 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
419 ? 0x80 : 0));
420
421 /*
422 * this isn't the same as continuing with a signal, but it will do
423 * for normal use. strace only continues with a signal if the
424 * stopping signal is not SIGTRAP. -brl
425 */
426 if (current->exit_code) {
427 send_sig(current->exit_code, current, 1);
428 current->exit_code = 0;
429 }
430}
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