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1 | /* |
2 | * linux/arch/m68knommu/kernel/ptrace.c | |
3 | * | |
4 | * Copyright (C) 1994 by Hamish Macdonald | |
5 | * Taken from linux/kernel/ptrace.c and modified for M680x0. | |
6 | * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds | |
7 | * | |
8 | * This file is subject to the terms and conditions of the GNU General | |
9 | * Public License. See the file COPYING in the main directory of | |
10 | * this archive for more details. | |
11 | */ | |
12 | ||
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/config.h> | |
22 | ||
23 | #include <asm/uaccess.h> | |
24 | #include <asm/page.h> | |
25 | #include <asm/pgtable.h> | |
26 | #include <asm/system.h> | |
27 | #include <asm/processor.h> | |
28 | ||
29 | /* | |
30 | * does not yet catch signals sent when the child dies. | |
31 | * in exit.c or in signal.c. | |
32 | */ | |
33 | ||
34 | /* determines which bits in the SR the user has access to. */ | |
35 | /* 1 = access 0 = no access */ | |
36 | #define SR_MASK 0x001f | |
37 | ||
38 | /* sets the trace bits. */ | |
39 | #define TRACE_BITS 0x8000 | |
40 | ||
41 | /* Find the stack offset for a register, relative to thread.esp0. */ | |
42 | #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg) | |
43 | #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \ | |
44 | - sizeof(struct switch_stack)) | |
45 | /* Mapping from PT_xxx to the stack offset at which the register is | |
46 | saved. Notice that usp has no stack-slot and needs to be treated | |
47 | specially (see get_reg/put_reg below). */ | |
48 | static int regoff[] = { | |
49 | PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4), | |
50 | PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0), | |
51 | PT_REG(a1), PT_REG(a2), SW_REG(a3), SW_REG(a4), | |
52 | SW_REG(a5), SW_REG(a6), PT_REG(d0), -1, | |
53 | PT_REG(orig_d0), PT_REG(sr), PT_REG(pc), | |
54 | }; | |
55 | ||
56 | /* | |
57 | * Get contents of register REGNO in task TASK. | |
58 | */ | |
59 | static inline long get_reg(struct task_struct *task, int regno) | |
60 | { | |
61 | unsigned long *addr; | |
62 | ||
63 | if (regno == PT_USP) | |
64 | addr = &task->thread.usp; | |
65 | else if (regno < sizeof(regoff)/sizeof(regoff[0])) | |
66 | addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); | |
67 | else | |
68 | return 0; | |
69 | return *addr; | |
70 | } | |
71 | ||
72 | /* | |
73 | * Write contents of register REGNO in task TASK. | |
74 | */ | |
75 | static inline int put_reg(struct task_struct *task, int regno, | |
76 | unsigned long data) | |
77 | { | |
78 | unsigned long *addr; | |
79 | ||
80 | if (regno == PT_USP) | |
81 | addr = &task->thread.usp; | |
82 | else if (regno < sizeof(regoff)/sizeof(regoff[0])) | |
83 | addr = (unsigned long *) (task->thread.esp0 + regoff[regno]); | |
84 | else | |
85 | return -1; | |
86 | *addr = data; | |
87 | return 0; | |
88 | } | |
89 | ||
90 | /* | |
91 | * Called by kernel/ptrace.c when detaching.. | |
92 | * | |
93 | * Make sure the single step bit is not set. | |
94 | */ | |
95 | void ptrace_disable(struct task_struct *child) | |
96 | { | |
97 | unsigned long tmp; | |
98 | /* make sure the single step bit is not set. */ | |
99 | tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); | |
100 | put_reg(child, PT_SR, tmp); | |
101 | } | |
102 | ||
103 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) | |
104 | { | |
105 | struct task_struct *child; | |
106 | int ret; | |
107 | ||
108 | lock_kernel(); | |
109 | ret = -EPERM; | |
110 | if (request == PTRACE_TRACEME) { | |
111 | /* are we already being traced? */ | |
112 | if (current->ptrace & PT_PTRACED) | |
113 | goto out; | |
114 | /* set the ptrace bit in the process flags. */ | |
115 | current->ptrace |= PT_PTRACED; | |
116 | ret = 0; | |
117 | goto out; | |
118 | } | |
119 | ret = -ESRCH; | |
120 | read_lock(&tasklist_lock); | |
121 | child = find_task_by_pid(pid); | |
122 | if (child) | |
123 | get_task_struct(child); | |
124 | read_unlock(&tasklist_lock); | |
125 | if (!child) | |
126 | goto out; | |
127 | ||
128 | ret = -EPERM; | |
129 | if (pid == 1) /* you may not mess with init */ | |
130 | goto out_tsk; | |
131 | ||
132 | if (request == PTRACE_ATTACH) { | |
133 | ret = ptrace_attach(child); | |
134 | goto out_tsk; | |
135 | } | |
136 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
137 | if (ret < 0) | |
138 | goto out_tsk; | |
139 | ||
140 | switch (request) { | |
141 | /* when I and D space are separate, these will need to be fixed. */ | |
142 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
143 | case PTRACE_PEEKDATA: { | |
144 | unsigned long tmp; | |
145 | int copied; | |
146 | ||
147 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
148 | ret = -EIO; | |
149 | if (copied != sizeof(tmp)) | |
150 | break; | |
151 | ret = put_user(tmp,(unsigned long *) data); | |
152 | break; | |
153 | } | |
154 | ||
155 | /* read the word at location addr in the USER area. */ | |
156 | case PTRACE_PEEKUSR: { | |
157 | unsigned long tmp; | |
158 | ||
159 | ret = -EIO; | |
160 | if ((addr & 3) || addr < 0 || | |
161 | addr > sizeof(struct user) - 3) | |
162 | break; | |
163 | ||
164 | tmp = 0; /* Default return condition */ | |
165 | addr = addr >> 2; /* temporary hack. */ | |
166 | ret = -EIO; | |
167 | if (addr < 19) { | |
168 | tmp = get_reg(child, addr); | |
169 | if (addr == PT_SR) | |
170 | tmp >>= 16; | |
171 | } else if (addr >= 21 && addr < 49) { | |
172 | tmp = child->thread.fp[addr - 21]; | |
173 | #ifdef CONFIG_M68KFPU_EMU | |
174 | /* Convert internal fpu reg representation | |
175 | * into long double format | |
176 | */ | |
177 | if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) | |
178 | tmp = ((tmp & 0xffff0000) << 15) | | |
179 | ((tmp & 0x0000ffff) << 16); | |
180 | #endif | |
181 | } else if (addr == 49) { | |
182 | tmp = child->mm->start_code; | |
183 | } else if (addr == 50) { | |
184 | tmp = child->mm->start_data; | |
185 | } else if (addr == 51) { | |
186 | tmp = child->mm->end_code; | |
187 | } else | |
188 | break; | |
189 | ret = put_user(tmp,(unsigned long *) data); | |
190 | break; | |
191 | } | |
192 | ||
193 | /* when I and D space are separate, this will have to be fixed. */ | |
194 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
195 | case PTRACE_POKEDATA: | |
196 | ret = 0; | |
197 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
198 | break; | |
199 | ret = -EIO; | |
200 | break; | |
201 | ||
202 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ | |
203 | ret = -EIO; | |
204 | if ((addr & 3) || addr < 0 || | |
205 | addr > sizeof(struct user) - 3) | |
206 | break; | |
207 | ||
208 | addr = addr >> 2; /* temporary hack. */ | |
209 | ||
210 | if (addr == PT_SR) { | |
211 | data &= SR_MASK; | |
212 | data <<= 16; | |
213 | data |= get_reg(child, PT_SR) & ~(SR_MASK << 16); | |
214 | } | |
215 | if (addr < 19) { | |
216 | if (put_reg(child, addr, data)) | |
217 | break; | |
218 | ret = 0; | |
219 | break; | |
220 | } | |
221 | if (addr >= 21 && addr < 48) | |
222 | { | |
223 | #ifdef CONFIG_M68KFPU_EMU | |
224 | /* Convert long double format | |
225 | * into internal fpu reg representation | |
226 | */ | |
227 | if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) { | |
228 | data = (unsigned long)data << 15; | |
229 | data = (data & 0xffff0000) | | |
230 | ((data & 0x0000ffff) >> 1); | |
231 | } | |
232 | #endif | |
233 | child->thread.fp[addr - 21] = data; | |
234 | ret = 0; | |
235 | } | |
236 | break; | |
237 | ||
238 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
239 | case PTRACE_CONT: { /* restart after signal. */ | |
240 | long tmp; | |
241 | ||
242 | ret = -EIO; | |
243 | if ((unsigned long) data > _NSIG) | |
244 | break; | |
245 | if (request == PTRACE_SYSCALL) | |
246 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
247 | else | |
248 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
249 | child->exit_code = data; | |
250 | /* make sure the single step bit is not set. */ | |
251 | tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); | |
252 | put_reg(child, PT_SR, tmp); | |
253 | wake_up_process(child); | |
254 | ret = 0; | |
255 | break; | |
256 | } | |
257 | ||
258 | /* | |
259 | * make the child exit. Best I can do is send it a sigkill. | |
260 | * perhaps it should be put in the status that it wants to | |
261 | * exit. | |
262 | */ | |
263 | case PTRACE_KILL: { | |
264 | long tmp; | |
265 | ||
266 | ret = 0; | |
267 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
268 | break; | |
269 | child->exit_code = SIGKILL; | |
270 | /* make sure the single step bit is not set. */ | |
271 | tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); | |
272 | put_reg(child, PT_SR, tmp); | |
273 | wake_up_process(child); | |
274 | break; | |
275 | } | |
276 | ||
277 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ | |
278 | long tmp; | |
279 | ||
280 | ret = -EIO; | |
281 | if ((unsigned long) data > _NSIG) | |
282 | break; | |
283 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
284 | tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16); | |
285 | put_reg(child, PT_SR, tmp); | |
286 | ||
287 | child->exit_code = data; | |
288 | /* give it a chance to run. */ | |
289 | wake_up_process(child); | |
290 | ret = 0; | |
291 | break; | |
292 | } | |
293 | ||
294 | case PTRACE_DETACH: /* detach a process that was attached. */ | |
295 | ret = ptrace_detach(child, data); | |
296 | break; | |
297 | ||
298 | case PTRACE_GETREGS: { /* Get all gp regs from the child. */ | |
299 | int i; | |
300 | unsigned long tmp; | |
301 | for (i = 0; i < 19; i++) { | |
302 | tmp = get_reg(child, i); | |
303 | if (i == PT_SR) | |
304 | tmp >>= 16; | |
305 | if (put_user(tmp, (unsigned long *) data)) { | |
306 | ret = -EFAULT; | |
307 | break; | |
308 | } | |
309 | data += sizeof(long); | |
310 | } | |
311 | ret = 0; | |
312 | break; | |
313 | } | |
314 | ||
315 | case PTRACE_SETREGS: { /* Set all gp regs in the child. */ | |
316 | int i; | |
317 | unsigned long tmp; | |
318 | for (i = 0; i < 19; i++) { | |
319 | if (get_user(tmp, (unsigned long *) data)) { | |
320 | ret = -EFAULT; | |
321 | break; | |
322 | } | |
323 | if (i == PT_SR) { | |
324 | tmp &= SR_MASK; | |
325 | tmp <<= 16; | |
326 | tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16); | |
327 | } | |
328 | put_reg(child, i, tmp); | |
329 | data += sizeof(long); | |
330 | } | |
331 | ret = 0; | |
332 | break; | |
333 | } | |
334 | ||
335 | #ifdef PTRACE_GETFPREGS | |
336 | case PTRACE_GETFPREGS: { /* Get the child FPU state. */ | |
337 | ret = 0; | |
338 | if (copy_to_user((void *)data, &child->thread.fp, | |
339 | sizeof(struct user_m68kfp_struct))) | |
340 | ret = -EFAULT; | |
341 | break; | |
342 | } | |
343 | #endif | |
344 | ||
345 | #ifdef PTRACE_SETFPREGS | |
346 | case PTRACE_SETFPREGS: { /* Set the child FPU state. */ | |
347 | ret = 0; | |
348 | if (copy_from_user(&child->thread.fp, (void *)data, | |
349 | sizeof(struct user_m68kfp_struct))) | |
350 | ret = -EFAULT; | |
351 | break; | |
352 | } | |
353 | #endif | |
354 | ||
355 | default: | |
356 | ret = -EIO; | |
357 | break; | |
358 | } | |
359 | out_tsk: | |
360 | put_task_struct(child); | |
361 | out: | |
362 | unlock_kernel(); | |
363 | return ret; | |
364 | } | |
365 | ||
366 | asmlinkage void syscall_trace(void) | |
367 | { | |
368 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
369 | return; | |
370 | if (!(current->ptrace & PT_PTRACED)) | |
371 | return; | |
372 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
373 | ? 0x80 : 0)); | |
374 | /* | |
375 | * this isn't the same as continuing with a signal, but it will do | |
376 | * for normal use. strace only continues with a signal if the | |
377 | * stopping signal is not SIGTRAP. -brl | |
378 | */ | |
379 | if (current->exit_code) { | |
380 | send_sig(current->exit_code, current, 1); | |
381 | current->exit_code = 0; | |
382 | } | |
383 | } |