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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/kernel.h>
13#include <linux/sched.h>
14#include <linux/mm.h>
15#include <linux/smp.h>
16#include <linux/smp_lock.h>
17#include <linux/errno.h>
18#include <linux/ptrace.h>
19#include <linux/user.h>
20#include <linux/slab.h>
21#include <linux/security.h>
Jesper Juhl7ed20e12005-05-01 08:59:14 -070022#include <linux/signal.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
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 */
39static inline int get_stack_long(struct task_struct *task, int offset)
40{
41 unsigned char *stack;
42
Al Viro3cf0f4e2006-01-12 01:05:44 -080043 stack = (unsigned char *)task_pt_regs(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 stack += offset;
45 return (*((int *)stack));
46}
47
48/*
49 * This routine will put a word on the process kernel stack.
50 */
51static inline int put_stack_long(struct task_struct *task, int offset,
52 unsigned long data)
53{
54 unsigned char *stack;
55
Al Viro3cf0f4e2006-01-12 01:05:44 -080056 stack = (unsigned char *)task_pt_regs(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 stack += offset;
58 *(unsigned long *) stack = data;
59 return 0;
60}
61
62/*
63 * Called by kernel/ptrace.c when detaching..
64 *
65 * Make sure single step bits etc are not set.
66 */
67void ptrace_disable(struct task_struct *child)
68{
69 /* nothing to do.. */
70}
71
Christoph Hellwig481bed42005-11-07 00:59:47 -080072long arch_ptrace(struct task_struct *child, long request, long addr, long data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073{
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 struct user * dummy = NULL;
75 int ret;
76
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 switch (request) {
78 /* when I and D space are separate, these will need to be fixed. */
79 case PTRACE_PEEKTEXT: /* read word at location addr. */
80 case PTRACE_PEEKDATA: {
81 unsigned long tmp;
82 int copied;
83
84 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
85 ret = -EIO;
86 if (copied != sizeof(tmp))
87 break;
88 ret = put_user(tmp,(unsigned long *) data);
89 break;
90 }
91
92 /* read the word at location addr in the USER area. */
93 case PTRACE_PEEKUSR: {
94 unsigned long tmp;
95
96 ret = -EIO;
97 if ((addr & 3) || addr < 0 ||
98 addr > sizeof(struct user) - 3)
99 break;
100
101 if (addr < sizeof(struct pt_regs))
102 tmp = get_stack_long(child, addr);
103 else if (addr >= (long) &dummy->fpu &&
104 addr < (long) &dummy->u_fpvalid) {
105 if (!tsk_used_math(child)) {
106 if (addr == (long)&dummy->fpu.fpscr)
107 tmp = FPSCR_INIT;
108 else
109 tmp = 0;
110 } else
111 tmp = ((long *)&child->thread.fpu)
112 [(addr - (long)&dummy->fpu) >> 2];
113 } else if (addr == (long) &dummy->u_fpvalid)
114 tmp = !!tsk_used_math(child);
115 else
116 tmp = 0;
117 ret = put_user(tmp, (unsigned long *)data);
118 break;
119 }
120
121 /* when I and D space are separate, this will have to be fixed. */
122 case PTRACE_POKETEXT: /* write the word at location addr. */
123 case PTRACE_POKEDATA:
124 ret = 0;
125 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
126 break;
127 ret = -EIO;
128 break;
129
130 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
131 ret = -EIO;
132 if ((addr & 3) || addr < 0 ||
133 addr > sizeof(struct user) - 3)
134 break;
135
136 if (addr < sizeof(struct pt_regs))
137 ret = put_stack_long(child, addr, data);
138 else if (addr >= (long) &dummy->fpu &&
139 addr < (long) &dummy->u_fpvalid) {
140 set_stopped_child_used_math(child);
141 ((long *)&child->thread.fpu)
142 [(addr - (long)&dummy->fpu) >> 2] = data;
143 ret = 0;
144 } else if (addr == (long) &dummy->u_fpvalid) {
145 conditional_stopped_child_used_math(data, child);
146 ret = 0;
147 }
148 break;
149
150 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
151 case PTRACE_CONT: { /* restart after signal. */
152 ret = -EIO;
Jesper Juhl7ed20e12005-05-01 08:59:14 -0700153 if (!valid_signal(data))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 break;
155 if (request == PTRACE_SYSCALL)
156 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
157 else
158 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
159 child->exit_code = data;
160 wake_up_process(child);
161 ret = 0;
162 break;
163 }
164
165/*
166 * make the child exit. Best I can do is send it a sigkill.
167 * perhaps it should be put in the status that it wants to
168 * exit.
169 */
170 case PTRACE_KILL: {
171 ret = 0;
172 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
173 break;
174 child->exit_code = SIGKILL;
175 wake_up_process(child);
176 break;
177 }
178
179 case PTRACE_SINGLESTEP: { /* set the trap flag. */
180 long pc;
181 struct pt_regs *dummy = NULL;
182
183 ret = -EIO;
Jesper Juhl7ed20e12005-05-01 08:59:14 -0700184 if (!valid_signal(data))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 break;
186 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
187 if ((child->ptrace & PT_DTRACE) == 0) {
188 /* Spurious delayed TF traps may occur */
189 child->ptrace |= PT_DTRACE;
190 }
191
192 pc = get_stack_long(child, (long)&dummy->pc);
193
194 /* Next scheduling will set up UBC */
195 if (child->thread.ubc_pc == 0)
196 ubc_usercnt += 1;
197 child->thread.ubc_pc = pc;
198
199 child->exit_code = data;
200 /* give it a chance to run. */
201 wake_up_process(child);
202 ret = 0;
203 break;
204 }
205
206 case PTRACE_DETACH: /* detach a process that was attached. */
207 ret = ptrace_detach(child, data);
208 break;
209
210#ifdef CONFIG_SH_DSP
211 case PTRACE_GETDSPREGS: {
212 unsigned long dp;
213
214 ret = -EIO;
215 dp = ((unsigned long) child) + THREAD_SIZE -
216 sizeof(struct pt_dspregs);
217 if (*((int *) (dp - 4)) == SR_FD) {
218 copy_to_user(addr, (void *) dp,
219 sizeof(struct pt_dspregs));
220 ret = 0;
221 }
222 break;
223 }
224
225 case PTRACE_SETDSPREGS: {
226 unsigned long dp;
227 int i;
228
229 ret = -EIO;
230 dp = ((unsigned long) child) + THREAD_SIZE -
231 sizeof(struct pt_dspregs);
232 if (*((int *) (dp - 4)) == SR_FD) {
233 copy_from_user((void *) dp, addr,
234 sizeof(struct pt_dspregs));
235 ret = 0;
236 }
237 break;
238 }
239#endif
240 default:
241 ret = ptrace_request(child, request, addr, data);
242 break;
243 }
Christoph Hellwig481bed42005-11-07 00:59:47 -0800244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 return ret;
246}
247
248asmlinkage void do_syscall_trace(void)
249{
250 struct task_struct *tsk = current;
251
252 if (!test_thread_flag(TIF_SYSCALL_TRACE))
253 return;
254 if (!(tsk->ptrace & PT_PTRACED))
255 return;
256 /* the 0x80 provides a way for the tracing parent to distinguish
257 between a syscall stop and SIGTRAP delivery */
258 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
259 ? 0x80 : 0));
260
261 /*
262 * this isn't the same as continuing with a signal, but it will do
263 * for normal use. strace only continues with a signal if the
264 * stopping signal is not SIGTRAP. -brl
265 */
266 if (tsk->exit_code) {
267 send_sig(tsk->exit_code, tsk, 1);
268 tsk->exit_code = 0;
269 }
270}