Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Kernel support for the ptrace() and syscall tracing interfaces. | |
3 | * | |
4 | * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc. | |
5 | * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx> | |
6 | * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org> | |
7 | */ | |
8 | ||
9 | #include <linux/kernel.h> | |
10 | #include <linux/sched.h> | |
11 | #include <linux/mm.h> | |
12 | #include <linux/smp.h> | |
1da177e4 LT |
13 | #include <linux/errno.h> |
14 | #include <linux/ptrace.h> | |
15 | #include <linux/user.h> | |
16 | #include <linux/personality.h> | |
17 | #include <linux/security.h> | |
18 | #include <linux/compat.h> | |
7ed20e1a | 19 | #include <linux/signal.h> |
1da177e4 LT |
20 | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/pgtable.h> | |
23 | #include <asm/system.h> | |
24 | #include <asm/processor.h> | |
0013a854 | 25 | #include <asm/asm-offsets.h> |
1da177e4 LT |
26 | |
27 | /* PSW bits we allow the debugger to modify */ | |
28 | #define USER_PSW_BITS (PSW_N | PSW_V | PSW_CB) | |
29 | ||
30 | #undef DEBUG_PTRACE | |
31 | ||
32 | #ifdef DEBUG_PTRACE | |
33 | #define DBG(x...) printk(x) | |
34 | #else | |
35 | #define DBG(x...) | |
36 | #endif | |
37 | ||
a8f44e38 | 38 | #ifdef CONFIG_64BIT |
1da177e4 LT |
39 | |
40 | /* This function is needed to translate 32 bit pt_regs offsets in to | |
41 | * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel | |
42 | * will request offset 12 if it wants gr3, but the lower 32 bits of | |
43 | * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4). | |
44 | * This code relies on a 32 bit pt_regs being comprised of 32 bit values | |
45 | * except for the fp registers which (a) are 64 bits, and (b) follow | |
46 | * the gr registers at the start of pt_regs. The 32 bit pt_regs should | |
47 | * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[] | |
48 | * being 64 bit in both cases. | |
49 | */ | |
50 | ||
51 | static long translate_usr_offset(long offset) | |
52 | { | |
53 | if (offset < 0) | |
54 | return -1; | |
55 | else if (offset <= 32*4) /* gr[0..31] */ | |
56 | return offset * 2 + 4; | |
57 | else if (offset <= 32*4+32*8) /* gr[0..31] + fr[0..31] */ | |
58 | return offset + 32*4; | |
59 | else if (offset < sizeof(struct pt_regs)/2 + 32*4) | |
60 | return offset * 2 + 4 - 32*8; | |
61 | else | |
62 | return -1; | |
63 | } | |
64 | #endif | |
65 | ||
66 | /* | |
67 | * Called by kernel/ptrace.c when detaching.. | |
68 | * | |
69 | * Make sure single step bits etc are not set. | |
70 | */ | |
71 | void ptrace_disable(struct task_struct *child) | |
72 | { | |
73 | /* make sure the trap bits are not set */ | |
74 | pa_psw(child)->r = 0; | |
75 | pa_psw(child)->t = 0; | |
76 | pa_psw(child)->h = 0; | |
77 | pa_psw(child)->l = 0; | |
78 | } | |
79 | ||
481bed45 | 80 | long arch_ptrace(struct task_struct *child, long request, long addr, long data) |
1da177e4 | 81 | { |
1da177e4 LT |
82 | long ret; |
83 | #ifdef DEBUG_PTRACE | |
84 | long oaddr=addr, odata=data; | |
85 | #endif | |
86 | ||
1da177e4 LT |
87 | switch (request) { |
88 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
89 | case PTRACE_PEEKDATA: { | |
a8f44e38 | 90 | #ifdef CONFIG_64BIT |
a3ea84fa | 91 | if (__is_compat_task(child)) { |
76647323 | 92 | int copied; |
1da177e4 LT |
93 | unsigned int tmp; |
94 | ||
95 | addr &= 0xffffffffL; | |
96 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
97 | ret = -EIO; | |
98 | if (copied != sizeof(tmp)) | |
99 | goto out_tsk; | |
100 | ret = put_user(tmp,(unsigned int *) data); | |
101 | DBG("sys_ptrace(PEEK%s, %d, %lx, %lx) returning %ld, data %x\n", | |
102 | request == PTRACE_PEEKTEXT ? "TEXT" : "DATA", | |
103 | pid, oaddr, odata, ret, tmp); | |
104 | } | |
105 | else | |
106 | #endif | |
76647323 | 107 | ret = generic_ptrace_peekdata(child, addr, data); |
1da177e4 LT |
108 | goto out_tsk; |
109 | } | |
110 | ||
111 | /* when I and D space are separate, this will have to be fixed. */ | |
112 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
113 | case PTRACE_POKEDATA: | |
114 | ret = 0; | |
a8f44e38 | 115 | #ifdef CONFIG_64BIT |
a3ea84fa | 116 | if (__is_compat_task(child)) { |
1da177e4 LT |
117 | unsigned int tmp = (unsigned int)data; |
118 | DBG("sys_ptrace(POKE%s, %d, %lx, %lx)\n", | |
119 | request == PTRACE_POKETEXT ? "TEXT" : "DATA", | |
120 | pid, oaddr, odata); | |
121 | addr &= 0xffffffffL; | |
122 | if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1) == sizeof(tmp)) | |
123 | goto out_tsk; | |
124 | } | |
125 | else | |
126 | #endif | |
127 | { | |
128 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
129 | goto out_tsk; | |
130 | } | |
131 | ret = -EIO; | |
132 | goto out_tsk; | |
133 | ||
134 | /* Read the word at location addr in the USER area. For ptraced | |
135 | processes, the kernel saves all regs on a syscall. */ | |
136 | case PTRACE_PEEKUSR: { | |
137 | ret = -EIO; | |
a8f44e38 | 138 | #ifdef CONFIG_64BIT |
a3ea84fa | 139 | if (__is_compat_task(child)) { |
1da177e4 LT |
140 | unsigned int tmp; |
141 | ||
142 | if (addr & (sizeof(int)-1)) | |
143 | goto out_tsk; | |
144 | if ((addr = translate_usr_offset(addr)) < 0) | |
145 | goto out_tsk; | |
146 | ||
147 | tmp = *(unsigned int *) ((char *) task_regs(child) + addr); | |
148 | ret = put_user(tmp, (unsigned int *) data); | |
149 | DBG("sys_ptrace(PEEKUSR, %d, %lx, %lx) returning %ld, addr %lx, data %x\n", | |
150 | pid, oaddr, odata, ret, addr, tmp); | |
151 | } | |
152 | else | |
153 | #endif | |
154 | { | |
155 | unsigned long tmp; | |
156 | ||
157 | if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs)) | |
158 | goto out_tsk; | |
159 | tmp = *(unsigned long *) ((char *) task_regs(child) + addr); | |
160 | ret = put_user(tmp, (unsigned long *) data); | |
161 | } | |
162 | goto out_tsk; | |
163 | } | |
164 | ||
165 | /* Write the word at location addr in the USER area. This will need | |
166 | to change when the kernel no longer saves all regs on a syscall. | |
167 | FIXME. There is a problem at the moment in that r3-r18 are only | |
168 | saved if the process is ptraced on syscall entry, and even then | |
169 | those values are overwritten by actual register values on syscall | |
170 | exit. */ | |
171 | case PTRACE_POKEUSR: | |
172 | ret = -EIO; | |
173 | /* Some register values written here may be ignored in | |
174 | * entry.S:syscall_restore_rfi; e.g. iaoq is written with | |
175 | * r31/r31+4, and not with the values in pt_regs. | |
176 | */ | |
177 | /* PT_PSW=0, so this is valid for 32 bit processes under 64 | |
178 | * bit kernels. | |
179 | */ | |
180 | if (addr == PT_PSW) { | |
181 | /* PT_PSW=0, so this is valid for 32 bit processes | |
182 | * under 64 bit kernels. | |
183 | * | |
184 | * Allow writing to Nullify, Divide-step-correction, | |
185 | * and carry/borrow bits. | |
186 | * BEWARE, if you set N, and then single step, it won't | |
187 | * stop on the nullified instruction. | |
188 | */ | |
189 | DBG("sys_ptrace(POKEUSR, %d, %lx, %lx)\n", | |
190 | pid, oaddr, odata); | |
191 | data &= USER_PSW_BITS; | |
192 | task_regs(child)->gr[0] &= ~USER_PSW_BITS; | |
193 | task_regs(child)->gr[0] |= data; | |
194 | ret = 0; | |
195 | goto out_tsk; | |
196 | } | |
a8f44e38 | 197 | #ifdef CONFIG_64BIT |
a3ea84fa | 198 | if (__is_compat_task(child)) { |
1da177e4 LT |
199 | if (addr & (sizeof(int)-1)) |
200 | goto out_tsk; | |
201 | if ((addr = translate_usr_offset(addr)) < 0) | |
202 | goto out_tsk; | |
203 | DBG("sys_ptrace(POKEUSR, %d, %lx, %lx) addr %lx\n", | |
204 | pid, oaddr, odata, addr); | |
205 | if (addr >= PT_FR0 && addr <= PT_FR31 + 4) { | |
206 | /* Special case, fp regs are 64 bits anyway */ | |
207 | *(unsigned int *) ((char *) task_regs(child) + addr) = data; | |
208 | ret = 0; | |
209 | } | |
210 | else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) || | |
211 | addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 || | |
212 | addr == PT_SAR+4) { | |
213 | /* Zero the top 32 bits */ | |
214 | *(unsigned int *) ((char *) task_regs(child) + addr - 4) = 0; | |
215 | *(unsigned int *) ((char *) task_regs(child) + addr) = data; | |
216 | ret = 0; | |
217 | } | |
218 | goto out_tsk; | |
219 | } | |
220 | else | |
221 | #endif | |
222 | { | |
223 | if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs)) | |
224 | goto out_tsk; | |
225 | if ((addr >= PT_GR1 && addr <= PT_GR31) || | |
226 | addr == PT_IAOQ0 || addr == PT_IAOQ1 || | |
227 | (addr >= PT_FR0 && addr <= PT_FR31 + 4) || | |
228 | addr == PT_SAR) { | |
229 | *(unsigned long *) ((char *) task_regs(child) + addr) = data; | |
230 | ret = 0; | |
231 | } | |
232 | goto out_tsk; | |
233 | } | |
234 | ||
235 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
236 | case PTRACE_CONT: | |
237 | ret = -EIO; | |
238 | DBG("sys_ptrace(%s)\n", | |
239 | request == PTRACE_SYSCALL ? "SYSCALL" : "CONT"); | |
7ed20e1a | 240 | if (!valid_signal(data)) |
1da177e4 LT |
241 | goto out_tsk; |
242 | child->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP); | |
243 | if (request == PTRACE_SYSCALL) { | |
244 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
245 | } else { | |
246 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
247 | } | |
248 | child->exit_code = data; | |
249 | goto out_wake_notrap; | |
250 | ||
251 | case PTRACE_KILL: | |
252 | /* | |
253 | * make the child exit. Best I can do is send it a | |
254 | * sigkill. perhaps it should be put in the status | |
255 | * that it wants to exit. | |
256 | */ | |
83aceb5b | 257 | ret = 0; |
1da177e4 LT |
258 | DBG("sys_ptrace(KILL)\n"); |
259 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
260 | goto out_tsk; | |
261 | child->exit_code = SIGKILL; | |
262 | goto out_wake_notrap; | |
263 | ||
264 | case PTRACE_SINGLEBLOCK: | |
265 | DBG("sys_ptrace(SINGLEBLOCK)\n"); | |
266 | ret = -EIO; | |
7ed20e1a | 267 | if (!valid_signal(data)) |
1da177e4 LT |
268 | goto out_tsk; |
269 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
270 | child->ptrace &= ~PT_SINGLESTEP; | |
271 | child->ptrace |= PT_BLOCKSTEP; | |
272 | child->exit_code = data; | |
273 | ||
274 | /* Enable taken branch trap. */ | |
275 | pa_psw(child)->r = 0; | |
276 | pa_psw(child)->t = 1; | |
277 | pa_psw(child)->h = 0; | |
278 | pa_psw(child)->l = 0; | |
279 | goto out_wake; | |
280 | ||
281 | case PTRACE_SINGLESTEP: | |
282 | DBG("sys_ptrace(SINGLESTEP)\n"); | |
283 | ret = -EIO; | |
7ed20e1a | 284 | if (!valid_signal(data)) |
1da177e4 LT |
285 | goto out_tsk; |
286 | ||
287 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
288 | child->ptrace &= ~PT_BLOCKSTEP; | |
289 | child->ptrace |= PT_SINGLESTEP; | |
290 | child->exit_code = data; | |
291 | ||
292 | if (pa_psw(child)->n) { | |
293 | struct siginfo si; | |
294 | ||
295 | /* Nullified, just crank over the queue. */ | |
296 | task_regs(child)->iaoq[0] = task_regs(child)->iaoq[1]; | |
297 | task_regs(child)->iasq[0] = task_regs(child)->iasq[1]; | |
298 | task_regs(child)->iaoq[1] = task_regs(child)->iaoq[0] + 4; | |
299 | pa_psw(child)->n = 0; | |
300 | pa_psw(child)->x = 0; | |
301 | pa_psw(child)->y = 0; | |
302 | pa_psw(child)->z = 0; | |
303 | pa_psw(child)->b = 0; | |
304 | ptrace_disable(child); | |
305 | /* Don't wake up the child, but let the | |
306 | parent know something happened. */ | |
307 | si.si_code = TRAP_TRACE; | |
308 | si.si_addr = (void __user *) (task_regs(child)->iaoq[0] & ~3); | |
309 | si.si_signo = SIGTRAP; | |
310 | si.si_errno = 0; | |
311 | force_sig_info(SIGTRAP, &si, child); | |
312 | //notify_parent(child, SIGCHLD); | |
313 | //ret = 0; | |
314 | goto out_wake; | |
315 | } | |
316 | ||
317 | /* Enable recovery counter traps. The recovery counter | |
318 | * itself will be set to zero on a task switch. If the | |
319 | * task is suspended on a syscall then the syscall return | |
320 | * path will overwrite the recovery counter with a suitable | |
321 | * value such that it traps once back in user space. We | |
322 | * disable interrupts in the childs PSW here also, to avoid | |
323 | * interrupts while the recovery counter is decrementing. | |
324 | */ | |
325 | pa_psw(child)->r = 1; | |
326 | pa_psw(child)->t = 0; | |
327 | pa_psw(child)->h = 0; | |
328 | pa_psw(child)->l = 0; | |
329 | /* give it a chance to run. */ | |
330 | goto out_wake; | |
331 | ||
332 | case PTRACE_DETACH: | |
333 | ret = ptrace_detach(child, data); | |
334 | goto out_tsk; | |
335 | ||
336 | case PTRACE_GETEVENTMSG: | |
337 | ret = put_user(child->ptrace_message, (unsigned int __user *) data); | |
83aceb5b | 338 | goto out_tsk; |
1da177e4 LT |
339 | |
340 | default: | |
341 | ret = ptrace_request(child, request, addr, data); | |
83aceb5b | 342 | goto out_tsk; |
1da177e4 LT |
343 | } |
344 | ||
345 | out_wake_notrap: | |
346 | ptrace_disable(child); | |
347 | out_wake: | |
348 | wake_up_process(child); | |
349 | ret = 0; | |
350 | out_tsk: | |
481bed45 | 351 | DBG("arch_ptrace(%ld, %d, %lx, %lx) returning %ld\n", |
1da177e4 LT |
352 | request, pid, oaddr, odata, ret); |
353 | return ret; | |
354 | } | |
355 | ||
356 | void syscall_trace(void) | |
357 | { | |
358 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
359 | return; | |
360 | if (!(current->ptrace & PT_PTRACED)) | |
361 | return; | |
362 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
363 | ? 0x80 : 0)); | |
364 | /* | |
365 | * this isn't the same as continuing with a signal, but it will do | |
366 | * for normal use. strace only continues with a signal if the | |
367 | * stopping signal is not SIGTRAP. -brl | |
368 | */ | |
369 | if (current->exit_code) { | |
370 | send_sig(current->exit_code, current, 1); | |
371 | current->exit_code = 0; | |
372 | } | |
373 | } |