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-rw-r--r--arch/xtensa/kernel/ptrace.c407
1 files changed, 407 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
new file mode 100644
index 000000000000..9ef07a4dd2a2
--- /dev/null
+++ b/arch/xtensa/kernel/ptrace.c
@@ -0,0 +1,407 @@
1// TODO some minor issues
2/*
3 * This file is subject to the terms and conditions of the GNU General Public
4 * License. See the file "COPYING" in the main directory of this archive
5 * for more details.
6 *
7 * Copyright (C) 2001 - 2005 Tensilica Inc.
8 *
9 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
10 * Chris Zankel <chris@zankel.net>
11 * Scott Foehner<sfoehner@yahoo.com>,
12 * Kevin Chea
13 * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
14 */
15
16#include <linux/config.h>
17#include <linux/kernel.h>
18#include <linux/sched.h>
19#include <linux/mm.h>
20#include <linux/errno.h>
21#include <linux/ptrace.h>
22#include <linux/smp.h>
23#include <linux/smp_lock.h>
24#include <linux/security.h>
25
26#include <asm/pgtable.h>
27#include <asm/page.h>
28#include <asm/system.h>
29#include <asm/uaccess.h>
30#include <asm/ptrace.h>
31#include <asm/elf.h>
32
33#define TEST_KERNEL // verify kernel operations FIXME: remove
34
35
36/*
37 * Called by kernel/ptrace.c when detaching..
38 *
39 * Make sure single step bits etc are not set.
40 */
41
42void ptrace_disable(struct task_struct *child)
43{
44 /* Nothing to do.. */
45}
46
47int sys_ptrace(long request, long pid, long addr, long data)
48{
49 struct task_struct *child;
50 int ret = -EPERM;
51
52 lock_kernel();
53
54#if 0
55 if ((int)request != 1)
56 printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
57 (int) request, (int) pid, (unsigned long) addr,
58 (unsigned long) data);
59#endif
60
61 if (request == PTRACE_TRACEME) {
62
63 /* Are we already being traced? */
64
65 if (current->ptrace & PT_PTRACED)
66 goto out;
67
68 if ((ret = security_ptrace(current->parent, current)))
69 goto out;
70
71 /* Set the ptrace bit in the process flags. */
72
73 current->ptrace |= PT_PTRACED;
74 ret = 0;
75 goto out;
76 }
77
78 ret = -ESRCH;
79 read_lock(&tasklist_lock);
80 child = find_task_by_pid(pid);
81 if (child)
82 get_task_struct(child);
83 read_unlock(&tasklist_lock);
84 if (!child)
85 goto out;
86
87 ret = -EPERM;
88 if (pid == 1) /* you may not mess with init */
89 goto out;
90
91 if (request == PTRACE_ATTACH) {
92 ret = ptrace_attach(child);
93 goto out_tsk;
94 }
95
96 if ((ret = ptrace_check_attach(child, request == PTRACE_KILL)) < 0)
97 goto out_tsk;
98
99 switch (request) {
100 case PTRACE_PEEKTEXT: /* read word at location addr. */
101 case PTRACE_PEEKDATA:
102 {
103 unsigned long tmp;
104 int copied;
105
106 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
107 ret = -EIO;
108 if (copied != sizeof(tmp))
109 break;
110 ret = put_user(tmp,(unsigned long *) data);
111
112 goto out;
113 }
114
115 /* Read the word at location addr in the USER area. */
116
117 case PTRACE_PEEKUSR:
118 {
119 struct pt_regs *regs;
120 unsigned long tmp;
121
122 regs = xtensa_pt_regs(child);
123 tmp = 0; /* Default return value. */
124
125 switch(addr) {
126
127 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
128 {
129 int ar = addr - REG_AR_BASE - regs->windowbase * 4;
130 ar &= (XCHAL_NUM_AREGS - 1);
131 if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
132 tmp = regs->areg[ar];
133 else
134 ret = -EIO;
135 break;
136 }
137 case REG_A_BASE ... REG_A_BASE + 15:
138 tmp = regs->areg[addr - REG_A_BASE];
139 break;
140 case REG_PC:
141 tmp = regs->pc;
142 break;
143 case REG_PS:
144 /* Note: PS.EXCM is not set while user task is running;
145 * its being set in regs is for exception handling
146 * convenience. */
147 tmp = (regs->ps & ~XCHAL_PS_EXCM_MASK);
148 break;
149 case REG_WB:
150 tmp = regs->windowbase;
151 break;
152 case REG_WS:
153 tmp = regs->windowstart;
154 break;
155 case REG_LBEG:
156 tmp = regs->lbeg;
157 break;
158 case REG_LEND:
159 tmp = regs->lend;
160 break;
161 case REG_LCOUNT:
162 tmp = regs->lcount;
163 break;
164 case REG_SAR:
165 tmp = regs->sar;
166 break;
167 case REG_DEPC:
168 tmp = regs->depc;
169 break;
170 case REG_EXCCAUSE:
171 tmp = regs->exccause;
172 break;
173 case REG_EXCVADDR:
174 tmp = regs->excvaddr;
175 break;
176 case SYSCALL_NR:
177 tmp = regs->syscall;
178 break;
179 default:
180 tmp = 0;
181 ret = -EIO;
182 goto out;
183 }
184 ret = put_user(tmp, (unsigned long *) data);
185 goto out;
186 }
187
188 case PTRACE_POKETEXT: /* write the word at location addr. */
189 case PTRACE_POKEDATA:
190 if (access_process_vm(child, addr, &data, sizeof(data), 1)
191 == sizeof(data))
192 break;
193 ret = -EIO;
194 goto out;
195
196 case PTRACE_POKEUSR:
197 {
198 struct pt_regs *regs;
199 regs = xtensa_pt_regs(child);
200
201 switch (addr) {
202 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
203 {
204 int ar = addr - REG_AR_BASE - regs->windowbase * 4;
205 if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
206 regs->areg[ar & (XCHAL_NUM_AREGS - 1)] = data;
207 else
208 ret = -EIO;
209 break;
210 }
211 case REG_A_BASE ... REG_A_BASE + 15:
212 regs->areg[addr - REG_A_BASE] = data;
213 break;
214 case REG_PC:
215 regs->pc = data;
216 break;
217 case SYSCALL_NR:
218 regs->syscall = data;
219 break;
220#ifdef TEST_KERNEL
221 case REG_WB:
222 regs->windowbase = data;
223 break;
224 case REG_WS:
225 regs->windowstart = data;
226 break;
227#endif
228
229 default:
230 /* The rest are not allowed. */
231 ret = -EIO;
232 break;
233 }
234 break;
235 }
236
237 /* continue and stop at next (return from) syscall */
238 case PTRACE_SYSCALL:
239 case PTRACE_CONT: /* restart after signal. */
240 {
241 ret = -EIO;
242 if ((unsigned long) data > _NSIG)
243 break;
244 if (request == PTRACE_SYSCALL)
245 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
246 else
247 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
248 child->exit_code = data;
249 /* Make sure the single step bit is not set. */
250 child->ptrace &= ~PT_SINGLESTEP;
251 wake_up_process(child);
252 ret = 0;
253 break;
254 }
255
256 /*
257 * make the child exit. Best I can do is send it a sigkill.
258 * perhaps it should be put in the status that it wants to
259 * exit.
260 */
261 case PTRACE_KILL:
262 ret = 0;
263 if (child->state == EXIT_ZOMBIE) /* already dead */
264 break;
265 child->exit_code = SIGKILL;
266 child->ptrace &= ~PT_SINGLESTEP;
267 wake_up_process(child);
268 break;
269
270 case PTRACE_SINGLESTEP:
271 ret = -EIO;
272 if ((unsigned long) data > _NSIG)
273 break;
274 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
275 child->ptrace |= PT_SINGLESTEP;
276 child->exit_code = data;
277 wake_up_process(child);
278 ret = 0;
279 break;
280
281 case PTRACE_GETREGS:
282 {
283 /* 'data' points to user memory in which to write.
284 * Mainly due to the non-live register values, we
285 * reformat the register values into something more
286 * standard. For convenience, we use the handy
287 * elf_gregset_t format. */
288
289 xtensa_gregset_t format;
290 struct pt_regs *regs = xtensa_pt_regs(child);
291
292 do_copy_regs (&format, regs, child);
293
294 /* Now, copy to user space nice and easy... */
295 ret = 0;
296 if (copy_to_user((void *)data, &format, sizeof(elf_gregset_t)))
297 ret = -EFAULT;
298 break;
299 }
300
301 case PTRACE_SETREGS:
302 {
303 /* 'data' points to user memory that contains the new
304 * values in the elf_gregset_t format. */
305
306 xtensa_gregset_t format;
307 struct pt_regs *regs = xtensa_pt_regs(child);
308
309 if (copy_from_user(&format,(void *)data,sizeof(elf_gregset_t))){
310 ret = -EFAULT;
311 break;
312 }
313
314 /* FIXME: Perhaps we want some sanity checks on
315 * these user-space values? See ARM version. Are
316 * debuggers a security concern? */
317
318 do_restore_regs (&format, regs, child);
319
320 ret = 0;
321 break;
322 }
323
324 case PTRACE_GETFPREGS:
325 {
326 /* 'data' points to user memory in which to write.
327 * For convenience, we use the handy
328 * elf_fpregset_t format. */
329
330 elf_fpregset_t fpregs;
331 struct pt_regs *regs = xtensa_pt_regs(child);
332
333 do_save_fpregs (&fpregs, regs, child);
334
335 /* Now, copy to user space nice and easy... */
336 ret = 0;
337 if (copy_to_user((void *)data, &fpregs, sizeof(elf_fpregset_t)))
338 ret = -EFAULT;
339
340 break;
341 }
342
343 case PTRACE_SETFPREGS:
344 {
345 /* 'data' points to user memory that contains the new
346 * values in the elf_fpregset_t format.
347 */
348 elf_fpregset_t fpregs;
349 struct pt_regs *regs = xtensa_pt_regs(child);
350
351 ret = 0;
352 if (copy_from_user(&fpregs, (void *)data, sizeof(elf_fpregset_t))) {
353 ret = -EFAULT;
354 break;
355 }
356
357 if (do_restore_fpregs (&fpregs, regs, child))
358 ret = -EIO;
359 break;
360 }
361
362 case PTRACE_GETFPREGSIZE:
363 /* 'data' points to 'unsigned long' set to the size
364 * of elf_fpregset_t
365 */
366 ret = put_user(sizeof(elf_fpregset_t), (unsigned long *) data);
367 break;
368
369 case PTRACE_DETACH: /* detach a process that was attached. */
370 ret = ptrace_detach(child, data);
371 break;
372
373 default:
374 ret = ptrace_request(child, request, addr, data);
375 goto out;
376 }
377out_tsk:
378 put_task_struct(child);
379out:
380 unlock_kernel();
381 return ret;
382}
383
384void do_syscall_trace(void)
385{
386 if (!test_thread_flag(TIF_SYSCALL_TRACE))
387 return;
388
389 if (!(current->ptrace & PT_PTRACED))
390 return;
391
392 /*
393 * The 0x80 provides a way for the tracing parent to distinguish
394 * between a syscall stop and SIGTRAP delivery
395 */
396 ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
397
398 /*
399 * this isn't the same as continuing with a signal, but it will do
400 * for normal use. strace only continues with a signal if the
401 * stopping signal is not SIGTRAP. -brl
402 */
403 if (current->exit_code) {
404 send_sig(current->exit_code, current, 1);
405 current->exit_code = 0;
406 }
407}
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