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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) | |
3 | * Licensed under the GPL | |
4 | */ | |
5 | ||
6 | #include "linux/sched.h" | |
7 | #include "linux/mm.h" | |
8 | #include "linux/errno.h" | |
9 | #include "linux/smp_lock.h" | |
10 | #include "linux/security.h" | |
11 | #include "linux/ptrace.h" | |
12 | #include "linux/audit.h" | |
13 | #ifdef CONFIG_PROC_MM | |
14 | #include "linux/proc_mm.h" | |
15 | #endif | |
16 | #include "asm/ptrace.h" | |
17 | #include "asm/uaccess.h" | |
18 | #include "kern_util.h" | |
19 | #include "skas_ptrace.h" | |
20 | #include "sysdep/ptrace.h" | |
21 | ||
22 | /* | |
23 | * Called by kernel/ptrace.c when detaching.. | |
24 | */ | |
25 | void ptrace_disable(struct task_struct *child) | |
26 | { | |
27 | child->ptrace &= ~PT_DTRACE; | |
28 | child->thread.singlestep_syscall = 0; | |
29 | } | |
30 | ||
31 | long sys_ptrace(long request, long pid, long addr, long data) | |
32 | { | |
33 | struct task_struct *child; | |
34 | int i, ret; | |
35 | ||
36 | lock_kernel(); | |
37 | ret = -EPERM; | |
38 | if (request == PTRACE_TRACEME) { | |
39 | /* are we already being traced? */ | |
40 | if (current->ptrace & PT_PTRACED) | |
41 | goto out; | |
42 | ||
43 | ret = security_ptrace(current->parent, current); | |
44 | if (ret) | |
45 | goto out; | |
46 | ||
47 | /* set the ptrace bit in the process flags. */ | |
48 | current->ptrace |= PT_PTRACED; | |
49 | ret = 0; | |
50 | goto out; | |
51 | } | |
52 | ret = -ESRCH; | |
53 | read_lock(&tasklist_lock); | |
54 | child = find_task_by_pid(pid); | |
55 | if (child) | |
56 | get_task_struct(child); | |
57 | read_unlock(&tasklist_lock); | |
58 | if (!child) | |
59 | goto out; | |
60 | ||
61 | ret = -EPERM; | |
62 | if (pid == 1) /* you may not mess with init */ | |
63 | goto out_tsk; | |
64 | ||
65 | if (request == PTRACE_ATTACH) { | |
66 | ret = ptrace_attach(child); | |
67 | goto out_tsk; | |
68 | } | |
69 | ||
70 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
71 | if (ret < 0) | |
72 | goto out_tsk; | |
73 | ||
74 | switch (request) { | |
75 | /* when I and D space are separate, these will need to be fixed. */ | |
76 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
77 | case PTRACE_PEEKDATA: { | |
78 | unsigned long tmp; | |
79 | int copied; | |
80 | ||
81 | ret = -EIO; | |
82 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
83 | if (copied != sizeof(tmp)) | |
84 | break; | |
85 | ret = put_user(tmp, (unsigned long __user *) data); | |
86 | break; | |
87 | } | |
88 | ||
89 | /* read the word at location addr in the USER area. */ | |
90 | case PTRACE_PEEKUSR: { | |
91 | unsigned long tmp; | |
92 | ||
93 | ret = -EIO; | |
94 | if ((addr & 3) || addr < 0) | |
95 | break; | |
96 | ||
97 | tmp = 0; /* Default return condition */ | |
98 | if(addr < MAX_REG_OFFSET){ | |
99 | tmp = getreg(child, addr); | |
100 | } | |
101 | else if((addr >= offsetof(struct user, u_debugreg[0])) && | |
102 | (addr <= offsetof(struct user, u_debugreg[7]))){ | |
103 | addr -= offsetof(struct user, u_debugreg[0]); | |
104 | addr = addr >> 2; | |
105 | tmp = child->thread.arch.debugregs[addr]; | |
106 | } | |
107 | ret = put_user(tmp, (unsigned long __user *) data); | |
108 | break; | |
109 | } | |
110 | ||
111 | /* when I and D space are separate, this will have to be fixed. */ | |
112 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
113 | case PTRACE_POKEDATA: | |
114 | ret = -EIO; | |
115 | if (access_process_vm(child, addr, &data, sizeof(data), | |
116 | 1) != sizeof(data)) | |
117 | break; | |
118 | ret = 0; | |
119 | break; | |
120 | ||
121 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ | |
122 | ret = -EIO; | |
123 | if ((addr & 3) || addr < 0) | |
124 | break; | |
125 | ||
126 | if (addr < MAX_REG_OFFSET) { | |
127 | ret = putreg(child, addr, data); | |
128 | break; | |
129 | } | |
130 | #if 0 /* XXX x86_64 */ | |
131 | else if((addr >= offsetof(struct user, u_debugreg[0])) && | |
132 | (addr <= offsetof(struct user, u_debugreg[7]))){ | |
133 | addr -= offsetof(struct user, u_debugreg[0]); | |
134 | addr = addr >> 2; | |
135 | if((addr == 4) || (addr == 5)) break; | |
136 | child->thread.arch.debugregs[addr] = data; | |
137 | ret = 0; | |
138 | } | |
139 | #endif | |
140 | ||
141 | break; | |
142 | ||
143 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
144 | case PTRACE_CONT: { /* restart after signal. */ | |
145 | ret = -EIO; | |
146 | if ((unsigned long) data > _NSIG) | |
147 | break; | |
148 | ||
149 | child->ptrace &= ~PT_DTRACE; | |
150 | child->thread.singlestep_syscall = 0; | |
151 | if (request == PTRACE_SYSCALL) { | |
152 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
153 | } | |
154 | else { | |
155 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
156 | } | |
157 | child->exit_code = data; | |
158 | wake_up_process(child); | |
159 | ret = 0; | |
160 | break; | |
161 | } | |
162 | ||
163 | /* | |
164 | * make the child exit. Best I can do is send it a sigkill. | |
165 | * perhaps it should be put in the status that it wants to | |
166 | * exit. | |
167 | */ | |
168 | case PTRACE_KILL: { | |
169 | ret = 0; | |
170 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
171 | break; | |
172 | ||
173 | child->ptrace &= ~PT_DTRACE; | |
174 | child->thread.singlestep_syscall = 0; | |
175 | child->exit_code = SIGKILL; | |
176 | wake_up_process(child); | |
177 | break; | |
178 | } | |
179 | ||
180 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ | |
181 | ret = -EIO; | |
182 | if ((unsigned long) data > _NSIG) | |
183 | break; | |
184 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
185 | child->ptrace |= PT_DTRACE; | |
186 | child->thread.singlestep_syscall = 0; | |
187 | child->exit_code = data; | |
188 | /* give it a chance to run. */ | |
189 | wake_up_process(child); | |
190 | ret = 0; | |
191 | break; | |
192 | } | |
193 | ||
194 | case PTRACE_DETACH: | |
195 | /* detach a process that was attached. */ | |
196 | ret = ptrace_detach(child, data); | |
197 | break; | |
198 | ||
199 | #ifdef PTRACE_GETREGS | |
200 | case PTRACE_GETREGS: { /* Get all gp regs from the child. */ | |
201 | if (!access_ok(VERIFY_WRITE, (unsigned long *)data, | |
202 | MAX_REG_OFFSET)) { | |
203 | ret = -EIO; | |
204 | break; | |
205 | } | |
206 | for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { | |
207 | __put_user(getreg(child, i), | |
208 | (unsigned long __user *) data); | |
209 | data += sizeof(long); | |
210 | } | |
211 | ret = 0; | |
212 | break; | |
213 | } | |
214 | #endif | |
215 | #ifdef PTRACE_SETREGS | |
216 | case PTRACE_SETREGS: { /* Set all gp regs in the child. */ | |
217 | unsigned long tmp = 0; | |
218 | if (!access_ok(VERIFY_READ, (unsigned *)data, | |
219 | MAX_REG_OFFSET)) { | |
220 | ret = -EIO; | |
221 | break; | |
222 | } | |
223 | for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { | |
224 | __get_user(tmp, (unsigned long __user *) data); | |
225 | putreg(child, i, tmp); | |
226 | data += sizeof(long); | |
227 | } | |
228 | ret = 0; | |
229 | break; | |
230 | } | |
231 | #endif | |
232 | #ifdef PTRACE_GETFPREGS | |
233 | case PTRACE_GETFPREGS: /* Get the child FPU state. */ | |
234 | ret = get_fpregs(data, child); | |
235 | break; | |
236 | #endif | |
237 | #ifdef PTRACE_SETFPREGS | |
238 | case PTRACE_SETFPREGS: /* Set the child FPU state. */ | |
239 | ret = set_fpregs(data, child); | |
240 | break; | |
241 | #endif | |
242 | #ifdef PTRACE_GETFPXREGS | |
243 | case PTRACE_GETFPXREGS: /* Get the child FPU state. */ | |
244 | ret = get_fpxregs(data, child); | |
245 | break; | |
246 | #endif | |
247 | #ifdef PTRACE_SETFPXREGS | |
248 | case PTRACE_SETFPXREGS: /* Set the child FPU state. */ | |
249 | ret = set_fpxregs(data, child); | |
250 | break; | |
251 | #endif | |
252 | case PTRACE_FAULTINFO: { | |
253 | struct ptrace_faultinfo fault; | |
254 | ||
255 | fault = ((struct ptrace_faultinfo) | |
256 | { .is_write = child->thread.err, | |
257 | .addr = child->thread.cr2 }); | |
258 | ret = copy_to_user((unsigned long __user *) data, &fault, | |
259 | sizeof(fault)); | |
260 | if(ret) | |
261 | break; | |
262 | break; | |
263 | } | |
264 | case PTRACE_SIGPENDING: | |
265 | ret = copy_to_user((unsigned long __user *) data, | |
266 | &child->pending.signal, | |
267 | sizeof(child->pending.signal)); | |
268 | break; | |
269 | ||
270 | case PTRACE_LDT: { | |
271 | struct ptrace_ldt ldt; | |
272 | ||
273 | if(copy_from_user(&ldt, (unsigned long __user *) data, | |
274 | sizeof(ldt))){ | |
275 | ret = -EIO; | |
276 | break; | |
277 | } | |
278 | ||
279 | /* This one is confusing, so just punt and return -EIO for | |
280 | * now | |
281 | */ | |
282 | ret = -EIO; | |
283 | break; | |
284 | } | |
285 | #ifdef CONFIG_PROC_MM | |
286 | case PTRACE_SWITCH_MM: { | |
287 | struct mm_struct *old = child->mm; | |
288 | struct mm_struct *new = proc_mm_get_mm(data); | |
289 | ||
290 | if(IS_ERR(new)){ | |
291 | ret = PTR_ERR(new); | |
292 | break; | |
293 | } | |
294 | ||
295 | atomic_inc(&new->mm_users); | |
296 | child->mm = new; | |
297 | child->active_mm = new; | |
298 | mmput(old); | |
299 | ret = 0; | |
300 | break; | |
301 | } | |
302 | #endif | |
303 | default: | |
304 | ret = ptrace_request(child, request, addr, data); | |
305 | break; | |
306 | } | |
307 | out_tsk: | |
308 | put_task_struct(child); | |
309 | out: | |
310 | unlock_kernel(); | |
311 | return ret; | |
312 | } | |
313 | ||
314 | void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs, | |
315 | int error_code) | |
316 | { | |
317 | struct siginfo info; | |
318 | ||
319 | memset(&info, 0, sizeof(info)); | |
320 | info.si_signo = SIGTRAP; | |
321 | info.si_code = TRAP_BRKPT; | |
322 | ||
323 | /* User-mode eip? */ | |
324 | info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; | |
325 | ||
326 | /* Send us the fakey SIGTRAP */ | |
327 | force_sig_info(SIGTRAP, &info, tsk); | |
328 | } | |
329 | ||
330 | /* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and | |
331 | * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check | |
332 | */ | |
333 | void syscall_trace(union uml_pt_regs *regs, int entryexit) | |
334 | { | |
335 | int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; | |
336 | int tracesysgood; | |
337 | ||
338 | if (unlikely(current->audit_context)) { | |
339 | if (!entryexit) | |
340 | audit_syscall_entry(current, | |
341 | UPT_SYSCALL_NR(®s->regs), | |
342 | UPT_SYSCALL_ARG1(®s->regs), | |
343 | UPT_SYSCALL_ARG2(®s->regs), | |
344 | UPT_SYSCALL_ARG3(®s->regs), | |
345 | UPT_SYSCALL_ARG4(®s->regs)); | |
346 | else | |
347 | audit_syscall_exit(current, | |
348 | UPT_SYSCALL_RET(®s->regs)); | |
349 | } | |
350 | ||
351 | /* Fake a debug trap */ | |
352 | if (is_singlestep) | |
353 | send_sigtrap(current, regs, 0); | |
354 | ||
355 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
356 | return; | |
357 | ||
358 | if (!(current->ptrace & PT_PTRACED)) | |
359 | return; | |
360 | ||
361 | /* the 0x80 provides a way for the tracing parent to distinguish | |
362 | between a syscall stop and SIGTRAP delivery */ | |
363 | tracesysgood = (current->ptrace & PT_TRACESYSGOOD); | |
364 | ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); | |
365 | ||
366 | if (entryexit) /* force do_signal() --> is_syscall() */ | |
367 | set_thread_flag(TIF_SIGPENDING); | |
368 | ||
369 | /* this isn't the same as continuing with a signal, but it will do | |
370 | * for normal use. strace only continues with a signal if the | |
371 | * stopping signal is not SIGTRAP. -brl | |
372 | */ | |
373 | if (current->exit_code) { | |
374 | send_sig(current->exit_code, current, 1); | |
375 | current->exit_code = 0; | |
376 | } | |
377 | } | |
378 | ||
379 | /* | |
380 | * Overrides for Emacs so that we follow Linus's tabbing style. | |
381 | * Emacs will notice this stuff at the end of the file and automatically | |
382 | * adjust the settings for this buffer only. This must remain at the end | |
383 | * of the file. | |
384 | * --------------------------------------------------------------------------- | |
385 | * Local variables: | |
386 | * c-file-style: "linux" | |
387 | * End: | |
388 | */ |