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1da177e4 LT |
1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 1992 Ross Biro | |
7 | * Copyright (C) Linus Torvalds | |
8 | * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle | |
9 | * Copyright (C) 1996 David S. Miller | |
10 | * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com | |
11 | * Copyright (C) 1999 MIPS Technologies, Inc. | |
12 | * Copyright (C) 2000 Ulf Carlsson | |
13 | * | |
14 | * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit | |
15 | * binaries. | |
16 | */ | |
17 | #include <linux/config.h> | |
18 | #include <linux/compiler.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/sched.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/ptrace.h> | |
24 | #include <linux/audit.h> | |
25 | #include <linux/smp.h> | |
26 | #include <linux/smp_lock.h> | |
27 | #include <linux/user.h> | |
28 | #include <linux/security.h> | |
29 | #include <linux/audit.h> | |
30 | ||
31 | #include <asm/cpu.h> | |
32 | #include <asm/fpu.h> | |
33 | #include <asm/mipsregs.h> | |
34 | #include <asm/pgtable.h> | |
35 | #include <asm/page.h> | |
36 | #include <asm/system.h> | |
37 | #include <asm/uaccess.h> | |
38 | #include <asm/bootinfo.h> | |
39 | ||
40 | /* | |
41 | * Called by kernel/ptrace.c when detaching.. | |
42 | * | |
43 | * Make sure single step bits etc are not set. | |
44 | */ | |
45 | void ptrace_disable(struct task_struct *child) | |
46 | { | |
47 | /* Nothing to do.. */ | |
48 | } | |
49 | ||
50 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) | |
51 | { | |
52 | struct task_struct *child; | |
53 | int ret; | |
54 | ||
55 | #if 0 | |
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 | lock_kernel(); | |
61 | ret = -EPERM; | |
62 | if (request == PTRACE_TRACEME) { | |
63 | /* are we already being traced? */ | |
64 | if (current->ptrace & PT_PTRACED) | |
65 | goto out; | |
66 | if ((ret = security_ptrace(current->parent, current))) | |
67 | goto out; | |
68 | /* set the ptrace bit in the process flags. */ | |
69 | current->ptrace |= PT_PTRACED; | |
70 | ret = 0; | |
71 | goto out; | |
72 | } | |
73 | ret = -ESRCH; | |
74 | read_lock(&tasklist_lock); | |
75 | child = find_task_by_pid(pid); | |
76 | if (child) | |
77 | get_task_struct(child); | |
78 | read_unlock(&tasklist_lock); | |
79 | if (!child) | |
80 | goto out; | |
81 | ||
82 | ret = -EPERM; | |
83 | if (pid == 1) /* you may not mess with init */ | |
84 | goto out_tsk; | |
85 | ||
86 | if (request == PTRACE_ATTACH) { | |
87 | ret = ptrace_attach(child); | |
88 | goto out_tsk; | |
89 | } | |
90 | ||
91 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
92 | if (ret < 0) | |
93 | goto out_tsk; | |
94 | ||
95 | switch (request) { | |
96 | /* when I and D space are separate, these will need to be fixed. */ | |
97 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
98 | case PTRACE_PEEKDATA: { | |
99 | unsigned long tmp; | |
100 | int copied; | |
101 | ||
102 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
103 | ret = -EIO; | |
104 | if (copied != sizeof(tmp)) | |
105 | break; | |
106 | ret = put_user(tmp,(unsigned long *) data); | |
107 | break; | |
108 | } | |
109 | ||
110 | /* Read the word at location addr in the USER area. */ | |
111 | case PTRACE_PEEKUSR: { | |
112 | struct pt_regs *regs; | |
113 | unsigned long tmp = 0; | |
114 | ||
115 | regs = (struct pt_regs *) ((unsigned long) child->thread_info + | |
116 | THREAD_SIZE - 32 - sizeof(struct pt_regs)); | |
117 | ret = 0; /* Default return value. */ | |
118 | ||
119 | switch (addr) { | |
120 | case 0 ... 31: | |
121 | tmp = regs->regs[addr]; | |
122 | break; | |
123 | case FPR_BASE ... FPR_BASE + 31: | |
124 | if (tsk_used_math(child)) { | |
125 | fpureg_t *fregs = get_fpu_regs(child); | |
126 | ||
127 | #ifdef CONFIG_MIPS32 | |
128 | /* | |
129 | * The odd registers are actually the high | |
130 | * order bits of the values stored in the even | |
131 | * registers - unless we're using r2k_switch.S. | |
132 | */ | |
133 | if (addr & 1) | |
134 | tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32); | |
135 | else | |
136 | tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff); | |
137 | #endif | |
138 | #ifdef CONFIG_MIPS64 | |
139 | tmp = fregs[addr - FPR_BASE]; | |
140 | #endif | |
141 | } else { | |
142 | tmp = -1; /* FP not yet used */ | |
143 | } | |
144 | break; | |
145 | case PC: | |
146 | tmp = regs->cp0_epc; | |
147 | break; | |
148 | case CAUSE: | |
149 | tmp = regs->cp0_cause; | |
150 | break; | |
151 | case BADVADDR: | |
152 | tmp = regs->cp0_badvaddr; | |
153 | break; | |
154 | case MMHI: | |
155 | tmp = regs->hi; | |
156 | break; | |
157 | case MMLO: | |
158 | tmp = regs->lo; | |
159 | break; | |
160 | case FPC_CSR: | |
161 | if (cpu_has_fpu) | |
162 | tmp = child->thread.fpu.hard.fcr31; | |
163 | else | |
164 | tmp = child->thread.fpu.soft.fcr31; | |
165 | break; | |
166 | case FPC_EIR: { /* implementation / version register */ | |
167 | unsigned int flags; | |
168 | ||
169 | if (!cpu_has_fpu) | |
170 | break; | |
171 | ||
172 | flags = read_c0_status(); | |
173 | __enable_fpu(); | |
174 | __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp)); | |
175 | write_c0_status(flags); | |
176 | break; | |
177 | } | |
178 | default: | |
179 | tmp = 0; | |
180 | ret = -EIO; | |
181 | goto out_tsk; | |
182 | } | |
183 | ret = put_user(tmp, (unsigned long *) data); | |
184 | break; | |
185 | } | |
186 | ||
187 | /* when I and D space are separate, this will have to be fixed. */ | |
188 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
189 | case PTRACE_POKEDATA: | |
190 | ret = 0; | |
191 | if (access_process_vm(child, addr, &data, sizeof(data), 1) | |
192 | == sizeof(data)) | |
193 | break; | |
194 | ret = -EIO; | |
195 | break; | |
196 | ||
197 | case PTRACE_POKEUSR: { | |
198 | struct pt_regs *regs; | |
199 | ret = 0; | |
200 | regs = (struct pt_regs *) ((unsigned long) child->thread_info + | |
201 | THREAD_SIZE - 32 - sizeof(struct pt_regs)); | |
202 | ||
203 | switch (addr) { | |
204 | case 0 ... 31: | |
205 | regs->regs[addr] = data; | |
206 | break; | |
207 | case FPR_BASE ... FPR_BASE + 31: { | |
208 | fpureg_t *fregs = get_fpu_regs(child); | |
209 | ||
210 | if (!tsk_used_math(child)) { | |
211 | /* FP not yet used */ | |
212 | memset(&child->thread.fpu.hard, ~0, | |
213 | sizeof(child->thread.fpu.hard)); | |
214 | child->thread.fpu.hard.fcr31 = 0; | |
215 | } | |
216 | #ifdef CONFIG_MIPS32 | |
217 | /* | |
218 | * The odd registers are actually the high order bits | |
219 | * of the values stored in the even registers - unless | |
220 | * we're using r2k_switch.S. | |
221 | */ | |
222 | if (addr & 1) { | |
223 | fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff; | |
224 | fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32; | |
225 | } else { | |
226 | fregs[addr - FPR_BASE] &= ~0xffffffffLL; | |
227 | fregs[addr - FPR_BASE] |= data; | |
228 | } | |
229 | #endif | |
230 | #ifdef CONFIG_MIPS64 | |
231 | fregs[addr - FPR_BASE] = data; | |
232 | #endif | |
233 | break; | |
234 | } | |
235 | case PC: | |
236 | regs->cp0_epc = data; | |
237 | break; | |
238 | case MMHI: | |
239 | regs->hi = data; | |
240 | break; | |
241 | case MMLO: | |
242 | regs->lo = data; | |
243 | break; | |
244 | case FPC_CSR: | |
245 | if (cpu_has_fpu) | |
246 | child->thread.fpu.hard.fcr31 = data; | |
247 | else | |
248 | child->thread.fpu.soft.fcr31 = data; | |
249 | break; | |
250 | default: | |
251 | /* The rest are not allowed. */ | |
252 | ret = -EIO; | |
253 | break; | |
254 | } | |
255 | break; | |
256 | } | |
257 | ||
258 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
259 | case PTRACE_CONT: { /* restart after signal. */ | |
260 | ret = -EIO; | |
261 | if ((unsigned long) data > _NSIG) | |
262 | break; | |
263 | if (request == PTRACE_SYSCALL) { | |
264 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
265 | } | |
266 | else { | |
267 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
268 | } | |
269 | child->exit_code = data; | |
270 | wake_up_process(child); | |
271 | ret = 0; | |
272 | break; | |
273 | } | |
274 | ||
275 | /* | |
276 | * make the child exit. Best I can do is send it a sigkill. | |
277 | * perhaps it should be put in the status that it wants to | |
278 | * exit. | |
279 | */ | |
280 | case PTRACE_KILL: | |
281 | ret = 0; | |
282 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
283 | break; | |
284 | child->exit_code = SIGKILL; | |
285 | wake_up_process(child); | |
286 | break; | |
287 | ||
288 | case PTRACE_DETACH: /* detach a process that was attached. */ | |
289 | ret = ptrace_detach(child, data); | |
290 | break; | |
291 | ||
292 | default: | |
293 | ret = ptrace_request(child, request, addr, data); | |
294 | break; | |
295 | } | |
296 | ||
297 | out_tsk: | |
298 | put_task_struct(child); | |
299 | out: | |
300 | unlock_kernel(); | |
301 | return ret; | |
302 | } | |
303 | ||
304 | /* | |
305 | * Notification of system call entry/exit | |
306 | * - triggered by current->work.syscall_trace | |
307 | */ | |
308 | asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit) | |
309 | { | |
310 | if (unlikely(current->audit_context)) { | |
311 | if (!entryexit) | |
312 | audit_syscall_entry(current, regs->regs[2], | |
313 | regs->regs[4], regs->regs[5], | |
314 | regs->regs[6], regs->regs[7]); | |
315 | else | |
316 | audit_syscall_exit(current, regs->regs[2]); | |
317 | } | |
318 | ||
319 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
320 | return; | |
321 | if (!(current->ptrace & PT_PTRACED)) | |
322 | return; | |
323 | ||
324 | /* The 0x80 provides a way for the tracing parent to distinguish | |
325 | between a syscall stop and SIGTRAP delivery */ | |
326 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? | |
327 | 0x80 : 0)); | |
328 | ||
329 | /* | |
330 | * this isn't the same as continuing with a signal, but it will do | |
331 | * for normal use. strace only continues with a signal if the | |
332 | * stopping signal is not SIGTRAP. -brl | |
333 | */ | |
334 | if (current->exit_code) { | |
335 | send_sig(current->exit_code, current, 1); | |
336 | current->exit_code = 0; | |
337 | } | |
338 | } |