This source file includes following definitions.
- get_task
- get_stack_long
- put_stack_long
- get_long
- put_long
- find_vma
- read_long
- write_long
- sys_ptrace
- syscall_trace
1
2
3
4
5 #include <linux/head.h>
6 #include <linux/kernel.h>
7 #include <linux/sched.h>
8 #include <linux/mm.h>
9 #include <linux/errno.h>
10 #include <linux/ptrace.h>
11 #include <linux/user.h>
12
13 #include <asm/segment.h>
14 #include <asm/system.h>
15
16 #if 0
17
18
19
20
21
22
23
24 #define FLAG_MASK 0x00044dd5
25
26
27 #define TRAP_FLAG 0x100
28
29
30
31
32
33 #define MAGICNUMBER 68
34
35
36 static inline struct task_struct * get_task(int pid)
37 {
38 int i;
39
40 for (i = 1; i < NR_TASKS; i++) {
41 if (task[i] != NULL && (task[i]->pid == pid))
42 return task[i];
43 }
44 return NULL;
45 }
46
47
48
49
50
51
52
53 static inline int get_stack_long(struct task_struct *task, int offset)
54 {
55 unsigned char *stack;
56
57 stack = (unsigned char *)task->tss.esp0;
58 stack += offset;
59 return (*((int *)stack));
60 }
61
62
63
64
65
66
67
68 static inline int put_stack_long(struct task_struct *task, int offset,
69 unsigned long data)
70 {
71 unsigned char * stack;
72
73 stack = (unsigned char *) task->tss.esp0;
74 stack += offset;
75 *(unsigned long *) stack = data;
76 return 0;
77 }
78
79
80
81
82
83
84
85 static unsigned long get_long(struct vm_area_struct * vma, unsigned long addr)
86 {
87 unsigned long page;
88
89 repeat:
90 page = *PAGE_DIR_OFFSET(vma->vm_task, addr);
91 if (page & PAGE_PRESENT) {
92 page &= PAGE_MASK;
93 page += PAGE_PTR(addr);
94 page = *((unsigned long *) page);
95 }
96 if (!(page & PAGE_PRESENT)) {
97 do_no_page(vma, addr, 0);
98 goto repeat;
99 }
100
101 if (page >= high_memory)
102 return 0;
103 page &= PAGE_MASK;
104 page += addr & ~PAGE_MASK;
105 return *(unsigned long *) page;
106 }
107
108
109
110
111
112
113
114
115
116
117 static void put_long(struct vm_area_struct * vma, unsigned long addr,
118 unsigned long data)
119 {
120 unsigned long page, pte = 0;
121 int readonly = 0;
122
123 repeat:
124 page = *PAGE_DIR_OFFSET(vma->vm_task, addr);
125 if (page & PAGE_PRESENT) {
126 page &= PAGE_MASK;
127 page += PAGE_PTR(addr);
128 pte = page;
129 page = *((unsigned long *) page);
130 }
131 if (!(page & PAGE_PRESENT)) {
132 do_no_page(vma, addr, 0 );
133 goto repeat;
134 }
135 if (!(page & PAGE_RW)) {
136 if (!(page & PAGE_COW))
137 readonly = 1;
138 do_wp_page(vma, addr, PAGE_RW | PAGE_PRESENT);
139 goto repeat;
140 }
141
142 if (page >= high_memory)
143 return;
144
145 *(unsigned long *) pte |= (PAGE_DIRTY|PAGE_COW);
146 page &= PAGE_MASK;
147 page += addr & ~PAGE_MASK;
148 *(unsigned long *) page = data;
149 if (readonly) {
150 *(unsigned long *) pte &=~ (PAGE_RW|PAGE_COW);
151 invalidate();
152 }
153 }
154
155 static struct vm_area_struct * find_vma(struct task_struct * tsk, unsigned long addr)
156 {
157 struct vm_area_struct * vma;
158
159 addr &= PAGE_MASK;
160 for (vma = tsk->mm->mmap ; ; vma = vma->vm_next) {
161 if (!vma)
162 return NULL;
163 if (vma->vm_end > addr)
164 break;
165 }
166 if (vma->vm_start <= addr)
167 return vma;
168 if (!(vma->vm_flags & VM_GROWSDOWN))
169 return NULL;
170 if (vma->vm_end - addr > tsk->rlim[RLIMIT_STACK].rlim_cur)
171 return NULL;
172 vma->vm_offset -= vma->vm_start - addr;
173 vma->vm_start = addr;
174 return vma;
175 }
176
177
178
179
180
181 static int read_long(struct task_struct * tsk, unsigned long addr,
182 unsigned long * result)
183 {
184 struct vm_area_struct * vma = find_vma(tsk, addr);
185
186 if (!vma)
187 return -EIO;
188 if ((addr & ~PAGE_MASK) > PAGE_SIZE-sizeof(long)) {
189 unsigned long low,high;
190 struct vm_area_struct * vma_high = vma;
191
192 if (addr + sizeof(long) >= vma->vm_end) {
193 vma_high = vma->vm_next;
194 if (!vma_high || vma_high->vm_start != vma->vm_end)
195 return -EIO;
196 }
197 low = get_long(vma, addr & ~(sizeof(long)-1));
198 high = get_long(vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1));
199 switch (addr & (sizeof(long)-1)) {
200 case 1:
201 low >>= 8;
202 low |= high << 24;
203 break;
204 case 2:
205 low >>= 16;
206 low |= high << 16;
207 break;
208 case 3:
209 low >>= 24;
210 low |= high << 8;
211 break;
212 }
213 *result = low;
214 } else
215 *result = get_long(vma, addr);
216 return 0;
217 }
218
219
220
221
222
223 static int write_long(struct task_struct * tsk, unsigned long addr,
224 unsigned long data)
225 {
226 struct vm_area_struct * vma = find_vma(tsk, addr);
227
228 if (!vma)
229 return -EIO;
230 if ((addr & ~PAGE_MASK) > PAGE_SIZE-sizeof(long)) {
231 unsigned long low,high;
232 struct vm_area_struct * vma_high = vma;
233
234 if (addr + sizeof(long) >= vma->vm_end) {
235 vma_high = vma->vm_next;
236 if (!vma_high || vma_high->vm_start != vma->vm_end)
237 return -EIO;
238 }
239 low = get_long(vma, addr & ~(sizeof(long)-1));
240 high = get_long(vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1));
241 switch (addr & (sizeof(long)-1)) {
242 case 0:
243 low = data;
244 break;
245 case 1:
246 low &= 0x000000ff;
247 low |= data << 8;
248 high &= ~0xff;
249 high |= data >> 24;
250 break;
251 case 2:
252 low &= 0x0000ffff;
253 low |= data << 16;
254 high &= ~0xffff;
255 high |= data >> 16;
256 break;
257 case 3:
258 low &= 0x00ffffff;
259 low |= data << 24;
260 high &= ~0xffffff;
261 high |= data >> 8;
262 break;
263 }
264 put_long(vma, addr & ~(sizeof(long)-1),low);
265 put_long(vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1),high);
266 } else
267 put_long(vma, addr, data);
268 return 0;
269 }
270 #endif
271
272 asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
273 {
274 #if 1
275 return -ENOSYS;
276 #else
277 struct task_struct *child;
278 struct user * dummy;
279 int i;
280
281
282 dummy = NULL;
283
284 if (request == PTRACE_TRACEME) {
285
286 if (current->flags & PF_PTRACED)
287 return -EPERM;
288
289 current->flags |= PF_PTRACED;
290 return 0;
291 }
292 if (pid == 1)
293 return -EPERM;
294 if (!(child = get_task(pid)))
295 return -ESRCH;
296 if (request == PTRACE_ATTACH) {
297 if (child == current)
298 return -EPERM;
299 if ((!child->dumpable ||
300 (current->uid != child->euid) ||
301 (current->uid != child->uid) ||
302 (current->gid != child->egid) ||
303 (current->gid != child->gid)) && !suser())
304 return -EPERM;
305
306 if (child->flags & PF_PTRACED)
307 return -EPERM;
308 child->flags |= PF_PTRACED;
309 if (child->p_pptr != current) {
310 REMOVE_LINKS(child);
311 child->p_pptr = current;
312 SET_LINKS(child);
313 }
314 send_sig(SIGSTOP, child, 1);
315 return 0;
316 }
317 if (!(child->flags & PF_PTRACED))
318 return -ESRCH;
319 if (child->state != TASK_STOPPED) {
320 if (request != PTRACE_KILL)
321 return -ESRCH;
322 }
323 if (child->p_pptr != current)
324 return -ESRCH;
325
326 switch (request) {
327
328 case PTRACE_PEEKTEXT:
329 case PTRACE_PEEKDATA: {
330 unsigned long tmp;
331 int res;
332
333 res = read_long(child, addr, &tmp);
334 if (res < 0)
335 return res;
336 res = verify_area(VERIFY_WRITE, (void *) data, sizeof(long));
337 if (!res)
338 put_fs_long(tmp,(unsigned long *) data);
339 return res;
340 }
341
342
343 case PTRACE_PEEKUSR: {
344 unsigned long tmp;
345 int res;
346
347 if ((addr & 3) || addr < 0 ||
348 addr > sizeof(struct user) - 3)
349 return -EIO;
350
351 res = verify_area(VERIFY_WRITE, (void *) data, sizeof(long));
352 if (res)
353 return res;
354 tmp = 0;
355 if(addr < 17*sizeof(long)) {
356 addr = addr >> 2;
357
358 tmp = get_stack_long(child, sizeof(long)*addr - MAGICNUMBER);
359 if (addr == DS || addr == ES ||
360 addr == FS || addr == GS ||
361 addr == CS || addr == SS)
362 tmp &= 0xffff;
363 };
364 if(addr >= (long) &dummy->u_debugreg[0] &&
365 addr <= (long) &dummy->u_debugreg[7]){
366 addr -= (long) &dummy->u_debugreg[0];
367 addr = addr >> 2;
368 tmp = child->debugreg[addr];
369 };
370 put_fs_long(tmp,(unsigned long *) data);
371 return 0;
372 }
373
374
375 case PTRACE_POKETEXT:
376 case PTRACE_POKEDATA:
377 return write_long(child,addr,data);
378
379 case PTRACE_POKEUSR:
380 if ((addr & 3) || addr < 0 ||
381 addr > sizeof(struct user) - 3)
382 return -EIO;
383
384 addr = addr >> 2;
385
386 if (addr == ORIG_EAX)
387 return -EIO;
388 if (addr == DS || addr == ES ||
389 addr == FS || addr == GS ||
390 addr == CS || addr == SS) {
391 data &= 0xffff;
392 if (data && (data & 3) != 3)
393 return -EIO;
394 }
395 if (addr == EFL) {
396 data &= FLAG_MASK;
397 data |= get_stack_long(child, EFL*sizeof(long)-MAGICNUMBER) & ~FLAG_MASK;
398 }
399
400
401 if(addr < 17){
402 if (put_stack_long(child, sizeof(long)*addr-MAGICNUMBER, data))
403 return -EIO;
404 return 0;
405 };
406
407
408
409
410
411
412 addr = addr << 2;
413 if(addr >= (long) &dummy->u_debugreg[0] &&
414 addr <= (long) &dummy->u_debugreg[7]){
415
416 if(addr == (long) &dummy->u_debugreg[4]) return -EIO;
417 if(addr == (long) &dummy->u_debugreg[5]) return -EIO;
418 if(addr < (long) &dummy->u_debugreg[4] &&
419 ((unsigned long) data) >= 0xbffffffd) return -EIO;
420
421 if(addr == (long) &dummy->u_debugreg[7]) {
422 data &= ~DR_CONTROL_RESERVED;
423 for(i=0; i<4; i++)
424 if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
425 return -EIO;
426 };
427
428 addr -= (long) &dummy->u_debugreg;
429 addr = addr >> 2;
430 child->debugreg[addr] = data;
431 return 0;
432 };
433 return -EIO;
434
435 case PTRACE_SYSCALL:
436 case PTRACE_CONT: {
437 long tmp;
438
439 if ((unsigned long) data > NSIG)
440 return -EIO;
441 if (request == PTRACE_SYSCALL)
442 child->flags |= PF_TRACESYS;
443 else
444 child->flags &= ~PF_TRACESYS;
445 child->exit_code = data;
446 child->state = TASK_RUNNING;
447
448 tmp = get_stack_long(child, sizeof(long)*EFL-MAGICNUMBER) & ~TRAP_FLAG;
449 put_stack_long(child, sizeof(long)*EFL-MAGICNUMBER,tmp);
450 return 0;
451 }
452
453
454
455
456
457
458 case PTRACE_KILL: {
459 long tmp;
460
461 child->state = TASK_RUNNING;
462 child->exit_code = SIGKILL;
463
464 tmp = get_stack_long(child, sizeof(long)*EFL-MAGICNUMBER) & ~TRAP_FLAG;
465 put_stack_long(child, sizeof(long)*EFL-MAGICNUMBER,tmp);
466 return 0;
467 }
468
469 case PTRACE_SINGLESTEP: {
470 long tmp;
471
472 if ((unsigned long) data > NSIG)
473 return -EIO;
474 child->flags &= ~PF_TRACESYS;
475 tmp = get_stack_long(child, sizeof(long)*EFL-MAGICNUMBER) | TRAP_FLAG;
476 put_stack_long(child, sizeof(long)*EFL-MAGICNUMBER,tmp);
477 child->state = TASK_RUNNING;
478 child->exit_code = data;
479
480 return 0;
481 }
482
483 case PTRACE_DETACH: {
484 long tmp;
485
486 if ((unsigned long) data > NSIG)
487 return -EIO;
488 child->flags &= ~(PF_PTRACED|PF_TRACESYS);
489 child->state = TASK_RUNNING;
490 child->exit_code = data;
491 REMOVE_LINKS(child);
492 child->p_pptr = child->p_opptr;
493 SET_LINKS(child);
494
495 tmp = get_stack_long(child, sizeof(long)*EFL-MAGICNUMBER) & ~TRAP_FLAG;
496 put_stack_long(child, sizeof(long)*EFL-MAGICNUMBER,tmp);
497 return 0;
498 }
499
500 default:
501 return -EIO;
502 }
503 #endif
504 }
505
506 asmlinkage void syscall_trace(void)
507 {
508 if ((current->flags & (PF_PTRACED|PF_TRACESYS))
509 != (PF_PTRACED|PF_TRACESYS))
510 return;
511 current->exit_code = SIGTRAP;
512 current->state = TASK_STOPPED;
513 notify_parent(current);
514 schedule();
515
516
517
518
519
520 if (current->exit_code)
521 current->signal |= (1 << (current->exit_code - 1));
522 current->exit_code = 0;
523 }