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-rw-r--r--arch/mips/kernel/ptrace.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
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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 */
45void ptrace_disable(struct task_struct *child)
46{
47 /* Nothing to do.. */
48}
49
50asmlinkage 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
297out_tsk:
298 put_task_struct(child);
299out:
300 unlock_kernel();
301 return ret;
302}
303
304/*
305 * Notification of system call entry/exit
306 * - triggered by current->work.syscall_trace
307 */
308asmlinkage 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}
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