arch/um/kernel/ptrace.c: remove dead PROC_MM
[sfrench/cifs-2.6.git] / arch / um / kernel / ptrace.c
1 /*
2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5
6 #include "linux/audit.h"
7 #include "linux/ptrace.h"
8 #include "linux/sched.h"
9 #include "asm/uaccess.h"
10 #include "skas_ptrace.h"
11
12
13
14 void user_enable_single_step(struct task_struct *child)
15 {
16         child->ptrace |= PT_DTRACE;
17         child->thread.singlestep_syscall = 0;
18
19 #ifdef SUBARCH_SET_SINGLESTEPPING
20         SUBARCH_SET_SINGLESTEPPING(child, 1);
21 #endif
22 }
23
24 void user_disable_single_step(struct task_struct *child)
25 {
26         child->ptrace &= ~PT_DTRACE;
27         child->thread.singlestep_syscall = 0;
28
29 #ifdef SUBARCH_SET_SINGLESTEPPING
30         SUBARCH_SET_SINGLESTEPPING(child, 0);
31 #endif
32 }
33
34 /*
35  * Called by kernel/ptrace.c when detaching..
36  */
37 void ptrace_disable(struct task_struct *child)
38 {
39         user_disable_single_step(child);
40 }
41
42 extern int peek_user(struct task_struct * child, long addr, long data);
43 extern int poke_user(struct task_struct * child, long addr, long data);
44
45 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
46 {
47         int i, ret;
48         unsigned long __user *p = (void __user *)(unsigned long)data;
49
50         switch (request) {
51         /* read word at location addr. */
52         case PTRACE_PEEKTEXT:
53         case PTRACE_PEEKDATA:
54                 ret = generic_ptrace_peekdata(child, addr, data);
55                 break;
56
57         /* read the word at location addr in the USER area. */
58         case PTRACE_PEEKUSR:
59                 ret = peek_user(child, addr, data);
60                 break;
61
62         /* write the word at location addr. */
63         case PTRACE_POKETEXT:
64         case PTRACE_POKEDATA:
65                 ret = generic_ptrace_pokedata(child, addr, data);
66                 break;
67
68         /* write the word at location addr in the USER area */
69         case PTRACE_POKEUSR:
70                 ret = poke_user(child, addr, data);
71                 break;
72
73         case PTRACE_SYSEMU:
74         case PTRACE_SYSEMU_SINGLESTEP:
75                 ret = -EIO;
76                 break;
77
78 #ifdef PTRACE_GETREGS
79         case PTRACE_GETREGS: { /* Get all gp regs from the child. */
80                 if (!access_ok(VERIFY_WRITE, p, MAX_REG_OFFSET)) {
81                         ret = -EIO;
82                         break;
83                 }
84                 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
85                         __put_user(getreg(child, i), p);
86                         p++;
87                 }
88                 ret = 0;
89                 break;
90         }
91 #endif
92 #ifdef PTRACE_SETREGS
93         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
94                 unsigned long tmp = 0;
95                 if (!access_ok(VERIFY_READ, p, MAX_REG_OFFSET)) {
96                         ret = -EIO;
97                         break;
98                 }
99                 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
100                         __get_user(tmp, p);
101                         putreg(child, i, tmp);
102                         p++;
103                 }
104                 ret = 0;
105                 break;
106         }
107 #endif
108 #ifdef PTRACE_GETFPREGS
109         case PTRACE_GETFPREGS: /* Get the child FPU state. */
110                 ret = get_fpregs((struct user_i387_struct __user *) data,
111                                  child);
112                 break;
113 #endif
114 #ifdef PTRACE_SETFPREGS
115         case PTRACE_SETFPREGS: /* Set the child FPU state. */
116                 ret = set_fpregs((struct user_i387_struct __user *) data,
117                                  child);
118                 break;
119 #endif
120         case PTRACE_GET_THREAD_AREA:
121                 ret = ptrace_get_thread_area(child, addr,
122                                              (struct user_desc __user *) data);
123                 break;
124
125         case PTRACE_SET_THREAD_AREA:
126                 ret = ptrace_set_thread_area(child, addr,
127                                              (struct user_desc __user *) data);
128                 break;
129
130         case PTRACE_FAULTINFO: {
131                 /*
132                  * Take the info from thread->arch->faultinfo,
133                  * but transfer max. sizeof(struct ptrace_faultinfo).
134                  * On i386, ptrace_faultinfo is smaller!
135                  */
136                 ret = copy_to_user(p, &child->thread.arch.faultinfo,
137                                    sizeof(struct ptrace_faultinfo));
138                 break;
139         }
140
141 #ifdef PTRACE_LDT
142         case PTRACE_LDT: {
143                 struct ptrace_ldt ldt;
144
145                 if (copy_from_user(&ldt, p, sizeof(ldt))) {
146                         ret = -EIO;
147                         break;
148                 }
149
150                 /*
151                  * This one is confusing, so just punt and return -EIO for
152                  * now
153                  */
154                 ret = -EIO;
155                 break;
156         }
157 #endif
158 #ifdef PTRACE_ARCH_PRCTL
159         case PTRACE_ARCH_PRCTL:
160                 /* XXX Calls ptrace on the host - needs some SMP thinking */
161                 ret = arch_prctl(child, data, (void *) addr);
162                 break;
163 #endif
164         default:
165                 ret = ptrace_request(child, request, addr, data);
166                 if (ret == -EIO)
167                         ret = subarch_ptrace(child, request, addr, data);
168                 break;
169         }
170
171         return ret;
172 }
173
174 static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
175                   int error_code)
176 {
177         struct siginfo info;
178
179         memset(&info, 0, sizeof(info));
180         info.si_signo = SIGTRAP;
181         info.si_code = TRAP_BRKPT;
182
183         /* User-mode eip? */
184         info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL;
185
186         /* Send us the fake SIGTRAP */
187         force_sig_info(SIGTRAP, &info, tsk);
188 }
189
190 /*
191  * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
192  * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
193  */
194 void syscall_trace(struct uml_pt_regs *regs, int entryexit)
195 {
196         int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit;
197         int tracesysgood;
198
199         if (unlikely(current->audit_context)) {
200                 if (!entryexit)
201                         audit_syscall_entry(HOST_AUDIT_ARCH,
202                                             UPT_SYSCALL_NR(regs),
203                                             UPT_SYSCALL_ARG1(regs),
204                                             UPT_SYSCALL_ARG2(regs),
205                                             UPT_SYSCALL_ARG3(regs),
206                                             UPT_SYSCALL_ARG4(regs));
207                 else audit_syscall_exit(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)),
208                                         UPT_SYSCALL_RET(regs));
209         }
210
211         /* Fake a debug trap */
212         if (is_singlestep)
213                 send_sigtrap(current, regs, 0);
214
215         if (!test_thread_flag(TIF_SYSCALL_TRACE))
216                 return;
217
218         if (!(current->ptrace & PT_PTRACED))
219                 return;
220
221         /*
222          * the 0x80 provides a way for the tracing parent to distinguish
223          * between a syscall stop and SIGTRAP delivery
224          */
225         tracesysgood = (current->ptrace & PT_TRACESYSGOOD);
226         ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0));
227
228         if (entryexit) /* force do_signal() --> is_syscall() */
229                 set_thread_flag(TIF_SIGPENDING);
230
231         /*
232          * this isn't the same as continuing with a signal, but it will do
233          * for normal use.  strace only continues with a signal if the
234          * stopping signal is not SIGTRAP.  -brl
235          */
236         if (current->exit_code) {
237                 send_sig(current->exit_code, current, 1);
238                 current->exit_code = 0;
239         }
240 }