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1da177e4 LT |
1 | /* |
2 | * linux/arch/sh/kernel/ptrace.c | |
3 | * | |
4 | * Original x86 implementation: | |
5 | * By Ross Biro 1/23/92 | |
6 | * edited by Linus Torvalds | |
7 | * | |
8 | * SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka | |
9 | * | |
10 | */ | |
11 | ||
12 | #include <linux/config.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/smp.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/ptrace.h> | |
20 | #include <linux/user.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/security.h> | |
23 | ||
24 | #include <asm/io.h> | |
25 | #include <asm/uaccess.h> | |
26 | #include <asm/pgtable.h> | |
27 | #include <asm/system.h> | |
28 | #include <asm/processor.h> | |
29 | #include <asm/mmu_context.h> | |
30 | ||
31 | /* | |
32 | * does not yet catch signals sent when the child dies. | |
33 | * in exit.c or in signal.c. | |
34 | */ | |
35 | ||
36 | /* | |
37 | * This routine will get a word off of the process kernel stack. | |
38 | */ | |
39 | static inline int get_stack_long(struct task_struct *task, int offset) | |
40 | { | |
41 | unsigned char *stack; | |
42 | ||
43 | stack = (unsigned char *) | |
44 | task->thread_info + THREAD_SIZE - sizeof(struct pt_regs) | |
45 | #ifdef CONFIG_SH_DSP | |
46 | - sizeof(struct pt_dspregs) | |
47 | #endif | |
48 | - sizeof(unsigned long); | |
49 | stack += offset; | |
50 | return (*((int *)stack)); | |
51 | } | |
52 | ||
53 | /* | |
54 | * This routine will put a word on the process kernel stack. | |
55 | */ | |
56 | static inline int put_stack_long(struct task_struct *task, int offset, | |
57 | unsigned long data) | |
58 | { | |
59 | unsigned char *stack; | |
60 | ||
61 | stack = (unsigned char *) | |
62 | task->thread_info + THREAD_SIZE - sizeof(struct pt_regs) | |
63 | #ifdef CONFIG_SH_DSP | |
64 | - sizeof(struct pt_dspregs) | |
65 | #endif | |
66 | - sizeof(unsigned long); | |
67 | stack += offset; | |
68 | *(unsigned long *) stack = data; | |
69 | return 0; | |
70 | } | |
71 | ||
72 | /* | |
73 | * Called by kernel/ptrace.c when detaching.. | |
74 | * | |
75 | * Make sure single step bits etc are not set. | |
76 | */ | |
77 | void ptrace_disable(struct task_struct *child) | |
78 | { | |
79 | /* nothing to do.. */ | |
80 | } | |
81 | ||
82 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) | |
83 | { | |
84 | struct task_struct *child; | |
85 | struct user * dummy = NULL; | |
86 | int ret; | |
87 | ||
88 | lock_kernel(); | |
89 | ret = -EPERM; | |
90 | if (request == PTRACE_TRACEME) { | |
91 | /* are we already being traced? */ | |
92 | if (current->ptrace & PT_PTRACED) | |
93 | goto out; | |
94 | ret = security_ptrace(current->parent, current); | |
95 | if (ret) | |
96 | goto out; | |
97 | /* set the ptrace bit in the process flags. */ | |
98 | current->ptrace |= PT_PTRACED; | |
99 | ret = 0; | |
100 | goto out; | |
101 | } | |
102 | ret = -ESRCH; | |
103 | read_lock(&tasklist_lock); | |
104 | child = find_task_by_pid(pid); | |
105 | if (child) | |
106 | get_task_struct(child); | |
107 | read_unlock(&tasklist_lock); | |
108 | if (!child) | |
109 | goto out; | |
110 | ||
111 | ret = -EPERM; | |
112 | if (pid == 1) /* you may not mess with init */ | |
113 | goto out_tsk; | |
114 | ||
115 | if (request == PTRACE_ATTACH) { | |
116 | ret = ptrace_attach(child); | |
117 | goto out_tsk; | |
118 | } | |
119 | ||
120 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
121 | if (ret < 0) | |
122 | goto out_tsk; | |
123 | ||
124 | switch (request) { | |
125 | /* when I and D space are separate, these will need to be fixed. */ | |
126 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
127 | case PTRACE_PEEKDATA: { | |
128 | unsigned long tmp; | |
129 | int copied; | |
130 | ||
131 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
132 | ret = -EIO; | |
133 | if (copied != sizeof(tmp)) | |
134 | break; | |
135 | ret = put_user(tmp,(unsigned long *) data); | |
136 | break; | |
137 | } | |
138 | ||
139 | /* read the word at location addr in the USER area. */ | |
140 | case PTRACE_PEEKUSR: { | |
141 | unsigned long tmp; | |
142 | ||
143 | ret = -EIO; | |
144 | if ((addr & 3) || addr < 0 || | |
145 | addr > sizeof(struct user) - 3) | |
146 | break; | |
147 | ||
148 | if (addr < sizeof(struct pt_regs)) | |
149 | tmp = get_stack_long(child, addr); | |
150 | else if (addr >= (long) &dummy->fpu && | |
151 | addr < (long) &dummy->u_fpvalid) { | |
152 | if (!tsk_used_math(child)) { | |
153 | if (addr == (long)&dummy->fpu.fpscr) | |
154 | tmp = FPSCR_INIT; | |
155 | else | |
156 | tmp = 0; | |
157 | } else | |
158 | tmp = ((long *)&child->thread.fpu) | |
159 | [(addr - (long)&dummy->fpu) >> 2]; | |
160 | } else if (addr == (long) &dummy->u_fpvalid) | |
161 | tmp = !!tsk_used_math(child); | |
162 | else | |
163 | tmp = 0; | |
164 | ret = put_user(tmp, (unsigned long *)data); | |
165 | break; | |
166 | } | |
167 | ||
168 | /* when I and D space are separate, this will have to be fixed. */ | |
169 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
170 | case PTRACE_POKEDATA: | |
171 | ret = 0; | |
172 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
173 | break; | |
174 | ret = -EIO; | |
175 | break; | |
176 | ||
177 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ | |
178 | ret = -EIO; | |
179 | if ((addr & 3) || addr < 0 || | |
180 | addr > sizeof(struct user) - 3) | |
181 | break; | |
182 | ||
183 | if (addr < sizeof(struct pt_regs)) | |
184 | ret = put_stack_long(child, addr, data); | |
185 | else if (addr >= (long) &dummy->fpu && | |
186 | addr < (long) &dummy->u_fpvalid) { | |
187 | set_stopped_child_used_math(child); | |
188 | ((long *)&child->thread.fpu) | |
189 | [(addr - (long)&dummy->fpu) >> 2] = data; | |
190 | ret = 0; | |
191 | } else if (addr == (long) &dummy->u_fpvalid) { | |
192 | conditional_stopped_child_used_math(data, child); | |
193 | ret = 0; | |
194 | } | |
195 | break; | |
196 | ||
197 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
198 | case PTRACE_CONT: { /* restart after signal. */ | |
199 | ret = -EIO; | |
200 | if ((unsigned long) data > _NSIG) | |
201 | break; | |
202 | if (request == PTRACE_SYSCALL) | |
203 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
204 | else | |
205 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
206 | child->exit_code = data; | |
207 | wake_up_process(child); | |
208 | ret = 0; | |
209 | break; | |
210 | } | |
211 | ||
212 | /* | |
213 | * make the child exit. Best I can do is send it a sigkill. | |
214 | * perhaps it should be put in the status that it wants to | |
215 | * exit. | |
216 | */ | |
217 | case PTRACE_KILL: { | |
218 | ret = 0; | |
219 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
220 | break; | |
221 | child->exit_code = SIGKILL; | |
222 | wake_up_process(child); | |
223 | break; | |
224 | } | |
225 | ||
226 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ | |
227 | long pc; | |
228 | struct pt_regs *dummy = NULL; | |
229 | ||
230 | ret = -EIO; | |
231 | if ((unsigned long) data > _NSIG) | |
232 | break; | |
233 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
234 | if ((child->ptrace & PT_DTRACE) == 0) { | |
235 | /* Spurious delayed TF traps may occur */ | |
236 | child->ptrace |= PT_DTRACE; | |
237 | } | |
238 | ||
239 | pc = get_stack_long(child, (long)&dummy->pc); | |
240 | ||
241 | /* Next scheduling will set up UBC */ | |
242 | if (child->thread.ubc_pc == 0) | |
243 | ubc_usercnt += 1; | |
244 | child->thread.ubc_pc = pc; | |
245 | ||
246 | child->exit_code = data; | |
247 | /* give it a chance to run. */ | |
248 | wake_up_process(child); | |
249 | ret = 0; | |
250 | break; | |
251 | } | |
252 | ||
253 | case PTRACE_DETACH: /* detach a process that was attached. */ | |
254 | ret = ptrace_detach(child, data); | |
255 | break; | |
256 | ||
257 | #ifdef CONFIG_SH_DSP | |
258 | case PTRACE_GETDSPREGS: { | |
259 | unsigned long dp; | |
260 | ||
261 | ret = -EIO; | |
262 | dp = ((unsigned long) child) + THREAD_SIZE - | |
263 | sizeof(struct pt_dspregs); | |
264 | if (*((int *) (dp - 4)) == SR_FD) { | |
265 | copy_to_user(addr, (void *) dp, | |
266 | sizeof(struct pt_dspregs)); | |
267 | ret = 0; | |
268 | } | |
269 | break; | |
270 | } | |
271 | ||
272 | case PTRACE_SETDSPREGS: { | |
273 | unsigned long dp; | |
274 | int i; | |
275 | ||
276 | ret = -EIO; | |
277 | dp = ((unsigned long) child) + THREAD_SIZE - | |
278 | sizeof(struct pt_dspregs); | |
279 | if (*((int *) (dp - 4)) == SR_FD) { | |
280 | copy_from_user((void *) dp, addr, | |
281 | sizeof(struct pt_dspregs)); | |
282 | ret = 0; | |
283 | } | |
284 | break; | |
285 | } | |
286 | #endif | |
287 | default: | |
288 | ret = ptrace_request(child, request, addr, data); | |
289 | break; | |
290 | } | |
291 | out_tsk: | |
292 | put_task_struct(child); | |
293 | out: | |
294 | unlock_kernel(); | |
295 | return ret; | |
296 | } | |
297 | ||
298 | asmlinkage void do_syscall_trace(void) | |
299 | { | |
300 | struct task_struct *tsk = current; | |
301 | ||
302 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
303 | return; | |
304 | if (!(tsk->ptrace & PT_PTRACED)) | |
305 | return; | |
306 | /* the 0x80 provides a way for the tracing parent to distinguish | |
307 | between a syscall stop and SIGTRAP delivery */ | |
308 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
309 | ? 0x80 : 0)); | |
310 | ||
311 | /* | |
312 | * this isn't the same as continuing with a signal, but it will do | |
313 | * for normal use. strace only continues with a signal if the | |
314 | * stopping signal is not SIGTRAP. -brl | |
315 | */ | |
316 | if (tsk->exit_code) { | |
317 | send_sig(tsk->exit_code, tsk, 1); | |
318 | tsk->exit_code = 0; | |
319 | } | |
320 | } |