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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/ptrace.c | |
3 | * | |
4 | * By Ross Biro 1/23/92 | |
5 | * edited by Linus Torvalds | |
6 | * ARM modifications Copyright (C) 2000 Russell King | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
1da177e4 LT |
12 | #include <linux/kernel.h> |
13 | #include <linux/sched.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/smp.h> | |
1da177e4 LT |
16 | #include <linux/ptrace.h> |
17 | #include <linux/user.h> | |
18 | #include <linux/security.h> | |
19 | #include <linux/init.h> | |
7ed20e1a | 20 | #include <linux/signal.h> |
33fa9b13 | 21 | #include <linux/uaccess.h> |
1da177e4 | 22 | |
1da177e4 LT |
23 | #include <asm/pgtable.h> |
24 | #include <asm/system.h> | |
25 | #include <asm/traps.h> | |
26 | ||
27 | #include "ptrace.h" | |
28 | ||
29 | #define REG_PC 15 | |
30 | #define REG_PSR 16 | |
31 | /* | |
32 | * does not yet catch signals sent when the child dies. | |
33 | * in exit.c or in signal.c. | |
34 | */ | |
35 | ||
36 | #if 0 | |
37 | /* | |
38 | * Breakpoint SWI instruction: SWI &9F0001 | |
39 | */ | |
40 | #define BREAKINST_ARM 0xef9f0001 | |
41 | #define BREAKINST_THUMB 0xdf00 /* fill this in later */ | |
42 | #else | |
43 | /* | |
44 | * New breakpoints - use an undefined instruction. The ARM architecture | |
45 | * reference manual guarantees that the following instruction space | |
46 | * will produce an undefined instruction exception on all CPUs: | |
47 | * | |
48 | * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx | |
49 | * Thumb: 1101 1110 xxxx xxxx | |
50 | */ | |
51 | #define BREAKINST_ARM 0xe7f001f0 | |
52 | #define BREAKINST_THUMB 0xde01 | |
53 | #endif | |
54 | ||
e513f8bf WD |
55 | struct pt_regs_offset { |
56 | const char *name; | |
57 | int offset; | |
58 | }; | |
59 | ||
60 | #define REG_OFFSET_NAME(r) \ | |
61 | {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)} | |
62 | #define REG_OFFSET_END {.name = NULL, .offset = 0} | |
63 | ||
64 | static const struct pt_regs_offset regoffset_table[] = { | |
65 | REG_OFFSET_NAME(r0), | |
66 | REG_OFFSET_NAME(r1), | |
67 | REG_OFFSET_NAME(r2), | |
68 | REG_OFFSET_NAME(r3), | |
69 | REG_OFFSET_NAME(r4), | |
70 | REG_OFFSET_NAME(r5), | |
71 | REG_OFFSET_NAME(r6), | |
72 | REG_OFFSET_NAME(r7), | |
73 | REG_OFFSET_NAME(r8), | |
74 | REG_OFFSET_NAME(r9), | |
75 | REG_OFFSET_NAME(r10), | |
76 | REG_OFFSET_NAME(fp), | |
77 | REG_OFFSET_NAME(ip), | |
78 | REG_OFFSET_NAME(sp), | |
79 | REG_OFFSET_NAME(lr), | |
80 | REG_OFFSET_NAME(pc), | |
81 | REG_OFFSET_NAME(cpsr), | |
82 | REG_OFFSET_NAME(ORIG_r0), | |
83 | REG_OFFSET_END, | |
84 | }; | |
85 | ||
86 | /** | |
87 | * regs_query_register_offset() - query register offset from its name | |
88 | * @name: the name of a register | |
89 | * | |
90 | * regs_query_register_offset() returns the offset of a register in struct | |
91 | * pt_regs from its name. If the name is invalid, this returns -EINVAL; | |
92 | */ | |
93 | int regs_query_register_offset(const char *name) | |
94 | { | |
95 | const struct pt_regs_offset *roff; | |
96 | for (roff = regoffset_table; roff->name != NULL; roff++) | |
97 | if (!strcmp(roff->name, name)) | |
98 | return roff->offset; | |
99 | return -EINVAL; | |
100 | } | |
101 | ||
102 | /** | |
103 | * regs_query_register_name() - query register name from its offset | |
104 | * @offset: the offset of a register in struct pt_regs. | |
105 | * | |
106 | * regs_query_register_name() returns the name of a register from its | |
107 | * offset in struct pt_regs. If the @offset is invalid, this returns NULL; | |
108 | */ | |
109 | const char *regs_query_register_name(unsigned int offset) | |
110 | { | |
111 | const struct pt_regs_offset *roff; | |
112 | for (roff = regoffset_table; roff->name != NULL; roff++) | |
113 | if (roff->offset == offset) | |
114 | return roff->name; | |
115 | return NULL; | |
116 | } | |
117 | ||
118 | /** | |
119 | * regs_within_kernel_stack() - check the address in the stack | |
120 | * @regs: pt_regs which contains kernel stack pointer. | |
121 | * @addr: address which is checked. | |
122 | * | |
123 | * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). | |
124 | * If @addr is within the kernel stack, it returns true. If not, returns false. | |
125 | */ | |
126 | bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) | |
127 | { | |
128 | return ((addr & ~(THREAD_SIZE - 1)) == | |
129 | (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); | |
130 | } | |
131 | ||
132 | /** | |
133 | * regs_get_kernel_stack_nth() - get Nth entry of the stack | |
134 | * @regs: pt_regs which contains kernel stack pointer. | |
135 | * @n: stack entry number. | |
136 | * | |
137 | * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which | |
138 | * is specified by @regs. If the @n th entry is NOT in the kernel stack, | |
139 | * this returns 0. | |
140 | */ | |
141 | unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) | |
142 | { | |
143 | unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); | |
144 | addr += n; | |
145 | if (regs_within_kernel_stack(regs, (unsigned long)addr)) | |
146 | return *addr; | |
147 | else | |
148 | return 0; | |
149 | } | |
150 | ||
1da177e4 LT |
151 | /* |
152 | * this routine will get a word off of the processes privileged stack. | |
153 | * the offset is how far from the base addr as stored in the THREAD. | |
154 | * this routine assumes that all the privileged stacks are in our | |
155 | * data space. | |
156 | */ | |
157 | static inline long get_user_reg(struct task_struct *task, int offset) | |
158 | { | |
815d5ec8 | 159 | return task_pt_regs(task)->uregs[offset]; |
1da177e4 LT |
160 | } |
161 | ||
162 | /* | |
163 | * this routine will put a word on the processes privileged stack. | |
164 | * the offset is how far from the base addr as stored in the THREAD. | |
165 | * this routine assumes that all the privileged stacks are in our | |
166 | * data space. | |
167 | */ | |
168 | static inline int | |
169 | put_user_reg(struct task_struct *task, int offset, long data) | |
170 | { | |
815d5ec8 | 171 | struct pt_regs newregs, *regs = task_pt_regs(task); |
1da177e4 LT |
172 | int ret = -EINVAL; |
173 | ||
174 | newregs = *regs; | |
175 | newregs.uregs[offset] = data; | |
176 | ||
177 | if (valid_user_regs(&newregs)) { | |
178 | regs->uregs[offset] = data; | |
179 | ret = 0; | |
180 | } | |
181 | ||
182 | return ret; | |
183 | } | |
184 | ||
185 | static inline int | |
186 | read_u32(struct task_struct *task, unsigned long addr, u32 *res) | |
187 | { | |
188 | int ret; | |
189 | ||
190 | ret = access_process_vm(task, addr, res, sizeof(*res), 0); | |
191 | ||
192 | return ret == sizeof(*res) ? 0 : -EIO; | |
193 | } | |
194 | ||
195 | static inline int | |
196 | read_instr(struct task_struct *task, unsigned long addr, u32 *res) | |
197 | { | |
198 | int ret; | |
199 | ||
200 | if (addr & 1) { | |
201 | u16 val; | |
202 | ret = access_process_vm(task, addr & ~1, &val, sizeof(val), 0); | |
203 | ret = ret == sizeof(val) ? 0 : -EIO; | |
204 | *res = val; | |
205 | } else { | |
206 | u32 val; | |
207 | ret = access_process_vm(task, addr & ~3, &val, sizeof(val), 0); | |
208 | ret = ret == sizeof(val) ? 0 : -EIO; | |
209 | *res = val; | |
210 | } | |
211 | return ret; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Get value of register `rn' (in the instruction) | |
216 | */ | |
217 | static unsigned long | |
218 | ptrace_getrn(struct task_struct *child, unsigned long insn) | |
219 | { | |
220 | unsigned int reg = (insn >> 16) & 15; | |
221 | unsigned long val; | |
222 | ||
223 | val = get_user_reg(child, reg); | |
224 | if (reg == 15) | |
1de765c1 | 225 | val += 8; |
1da177e4 LT |
226 | |
227 | return val; | |
228 | } | |
229 | ||
230 | /* | |
231 | * Get value of operand 2 (in an ALU instruction) | |
232 | */ | |
233 | static unsigned long | |
234 | ptrace_getaluop2(struct task_struct *child, unsigned long insn) | |
235 | { | |
236 | unsigned long val; | |
237 | int shift; | |
238 | int type; | |
239 | ||
240 | if (insn & 1 << 25) { | |
241 | val = insn & 255; | |
242 | shift = (insn >> 8) & 15; | |
243 | type = 3; | |
244 | } else { | |
245 | val = get_user_reg (child, insn & 15); | |
246 | ||
247 | if (insn & (1 << 4)) | |
248 | shift = (int)get_user_reg (child, (insn >> 8) & 15); | |
249 | else | |
250 | shift = (insn >> 7) & 31; | |
251 | ||
252 | type = (insn >> 5) & 3; | |
253 | } | |
254 | ||
255 | switch (type) { | |
256 | case 0: val <<= shift; break; | |
257 | case 1: val >>= shift; break; | |
258 | case 2: | |
259 | val = (((signed long)val) >> shift); | |
260 | break; | |
261 | case 3: | |
262 | val = (val >> shift) | (val << (32 - shift)); | |
263 | break; | |
264 | } | |
265 | return val; | |
266 | } | |
267 | ||
268 | /* | |
269 | * Get value of operand 2 (in a LDR instruction) | |
270 | */ | |
271 | static unsigned long | |
272 | ptrace_getldrop2(struct task_struct *child, unsigned long insn) | |
273 | { | |
274 | unsigned long val; | |
275 | int shift; | |
276 | int type; | |
277 | ||
278 | val = get_user_reg(child, insn & 15); | |
279 | shift = (insn >> 7) & 31; | |
280 | type = (insn >> 5) & 3; | |
281 | ||
282 | switch (type) { | |
283 | case 0: val <<= shift; break; | |
284 | case 1: val >>= shift; break; | |
285 | case 2: | |
286 | val = (((signed long)val) >> shift); | |
287 | break; | |
288 | case 3: | |
289 | val = (val >> shift) | (val << (32 - shift)); | |
290 | break; | |
291 | } | |
292 | return val; | |
293 | } | |
294 | ||
295 | #define OP_MASK 0x01e00000 | |
296 | #define OP_AND 0x00000000 | |
297 | #define OP_EOR 0x00200000 | |
298 | #define OP_SUB 0x00400000 | |
299 | #define OP_RSB 0x00600000 | |
300 | #define OP_ADD 0x00800000 | |
301 | #define OP_ADC 0x00a00000 | |
302 | #define OP_SBC 0x00c00000 | |
303 | #define OP_RSC 0x00e00000 | |
304 | #define OP_ORR 0x01800000 | |
305 | #define OP_MOV 0x01a00000 | |
306 | #define OP_BIC 0x01c00000 | |
307 | #define OP_MVN 0x01e00000 | |
308 | ||
309 | static unsigned long | |
310 | get_branch_address(struct task_struct *child, unsigned long pc, unsigned long insn) | |
311 | { | |
312 | u32 alt = 0; | |
313 | ||
314 | switch (insn & 0x0e000000) { | |
315 | case 0x00000000: | |
316 | case 0x02000000: { | |
317 | /* | |
318 | * data processing | |
319 | */ | |
320 | long aluop1, aluop2, ccbit; | |
321 | ||
22f975f4 NV |
322 | if ((insn & 0x0fffffd0) == 0x012fff10) { |
323 | /* | |
324 | * bx or blx | |
325 | */ | |
326 | alt = get_user_reg(child, insn & 15); | |
327 | break; | |
328 | } | |
329 | ||
330 | ||
1da177e4 LT |
331 | if ((insn & 0xf000) != 0xf000) |
332 | break; | |
333 | ||
334 | aluop1 = ptrace_getrn(child, insn); | |
335 | aluop2 = ptrace_getaluop2(child, insn); | |
336 | ccbit = get_user_reg(child, REG_PSR) & PSR_C_BIT ? 1 : 0; | |
337 | ||
338 | switch (insn & OP_MASK) { | |
339 | case OP_AND: alt = aluop1 & aluop2; break; | |
340 | case OP_EOR: alt = aluop1 ^ aluop2; break; | |
341 | case OP_SUB: alt = aluop1 - aluop2; break; | |
342 | case OP_RSB: alt = aluop2 - aluop1; break; | |
343 | case OP_ADD: alt = aluop1 + aluop2; break; | |
344 | case OP_ADC: alt = aluop1 + aluop2 + ccbit; break; | |
345 | case OP_SBC: alt = aluop1 - aluop2 + ccbit; break; | |
346 | case OP_RSC: alt = aluop2 - aluop1 + ccbit; break; | |
347 | case OP_ORR: alt = aluop1 | aluop2; break; | |
348 | case OP_MOV: alt = aluop2; break; | |
349 | case OP_BIC: alt = aluop1 & ~aluop2; break; | |
350 | case OP_MVN: alt = ~aluop2; break; | |
351 | } | |
352 | break; | |
353 | } | |
354 | ||
355 | case 0x04000000: | |
356 | case 0x06000000: | |
357 | /* | |
358 | * ldr | |
359 | */ | |
360 | if ((insn & 0x0010f000) == 0x0010f000) { | |
361 | unsigned long base; | |
362 | ||
363 | base = ptrace_getrn(child, insn); | |
364 | if (insn & 1 << 24) { | |
365 | long aluop2; | |
366 | ||
367 | if (insn & 0x02000000) | |
368 | aluop2 = ptrace_getldrop2(child, insn); | |
369 | else | |
370 | aluop2 = insn & 0xfff; | |
371 | ||
372 | if (insn & 1 << 23) | |
373 | base += aluop2; | |
374 | else | |
375 | base -= aluop2; | |
376 | } | |
1de765c1 | 377 | read_u32(child, base, &alt); |
1da177e4 LT |
378 | } |
379 | break; | |
380 | ||
381 | case 0x08000000: | |
382 | /* | |
383 | * ldm | |
384 | */ | |
385 | if ((insn & 0x00108000) == 0x00108000) { | |
386 | unsigned long base; | |
387 | unsigned int nr_regs; | |
388 | ||
389 | if (insn & (1 << 23)) { | |
390 | nr_regs = hweight16(insn & 65535) << 2; | |
391 | ||
392 | if (!(insn & (1 << 24))) | |
393 | nr_regs -= 4; | |
394 | } else { | |
395 | if (insn & (1 << 24)) | |
396 | nr_regs = -4; | |
397 | else | |
398 | nr_regs = 0; | |
399 | } | |
400 | ||
401 | base = ptrace_getrn(child, insn); | |
402 | ||
1de765c1 | 403 | read_u32(child, base + nr_regs, &alt); |
1da177e4 LT |
404 | break; |
405 | } | |
406 | break; | |
407 | ||
408 | case 0x0a000000: { | |
409 | /* | |
410 | * bl or b | |
411 | */ | |
412 | signed long displ; | |
413 | /* It's a branch/branch link: instead of trying to | |
414 | * figure out whether the branch will be taken or not, | |
415 | * we'll put a breakpoint at both locations. This is | |
416 | * simpler, more reliable, and probably not a whole lot | |
417 | * slower than the alternative approach of emulating the | |
418 | * branch. | |
419 | */ | |
420 | displ = (insn & 0x00ffffff) << 8; | |
421 | displ = (displ >> 6) + 8; | |
422 | if (displ != 0 && displ != 4) | |
423 | alt = pc + displ; | |
424 | } | |
425 | break; | |
426 | } | |
427 | ||
428 | return alt; | |
429 | } | |
430 | ||
431 | static int | |
432 | swap_insn(struct task_struct *task, unsigned long addr, | |
433 | void *old_insn, void *new_insn, int size) | |
434 | { | |
435 | int ret; | |
436 | ||
437 | ret = access_process_vm(task, addr, old_insn, size, 0); | |
438 | if (ret == size) | |
439 | ret = access_process_vm(task, addr, new_insn, size, 1); | |
440 | return ret; | |
441 | } | |
442 | ||
443 | static void | |
444 | add_breakpoint(struct task_struct *task, struct debug_info *dbg, unsigned long addr) | |
445 | { | |
446 | int nr = dbg->nsaved; | |
447 | ||
448 | if (nr < 2) { | |
449 | u32 new_insn = BREAKINST_ARM; | |
450 | int res; | |
451 | ||
452 | res = swap_insn(task, addr, &dbg->bp[nr].insn, &new_insn, 4); | |
453 | ||
454 | if (res == 4) { | |
455 | dbg->bp[nr].address = addr; | |
456 | dbg->nsaved += 1; | |
457 | } | |
458 | } else | |
459 | printk(KERN_ERR "ptrace: too many breakpoints\n"); | |
460 | } | |
461 | ||
462 | /* | |
463 | * Clear one breakpoint in the user program. We copy what the hardware | |
464 | * does and use bit 0 of the address to indicate whether this is a Thumb | |
465 | * breakpoint or an ARM breakpoint. | |
466 | */ | |
467 | static void clear_breakpoint(struct task_struct *task, struct debug_entry *bp) | |
468 | { | |
469 | unsigned long addr = bp->address; | |
470 | union debug_insn old_insn; | |
471 | int ret; | |
472 | ||
473 | if (addr & 1) { | |
474 | ret = swap_insn(task, addr & ~1, &old_insn.thumb, | |
475 | &bp->insn.thumb, 2); | |
476 | ||
477 | if (ret != 2 || old_insn.thumb != BREAKINST_THUMB) | |
478 | printk(KERN_ERR "%s:%d: corrupted Thumb breakpoint at " | |
19c5870c AD |
479 | "0x%08lx (0x%04x)\n", task->comm, |
480 | task_pid_nr(task), addr, old_insn.thumb); | |
1da177e4 LT |
481 | } else { |
482 | ret = swap_insn(task, addr & ~3, &old_insn.arm, | |
483 | &bp->insn.arm, 4); | |
484 | ||
485 | if (ret != 4 || old_insn.arm != BREAKINST_ARM) | |
486 | printk(KERN_ERR "%s:%d: corrupted ARM breakpoint at " | |
19c5870c AD |
487 | "0x%08lx (0x%08x)\n", task->comm, |
488 | task_pid_nr(task), addr, old_insn.arm); | |
1da177e4 LT |
489 | } |
490 | } | |
491 | ||
492 | void ptrace_set_bpt(struct task_struct *child) | |
493 | { | |
494 | struct pt_regs *regs; | |
495 | unsigned long pc; | |
496 | u32 insn; | |
497 | int res; | |
498 | ||
815d5ec8 | 499 | regs = task_pt_regs(child); |
1da177e4 LT |
500 | pc = instruction_pointer(regs); |
501 | ||
502 | if (thumb_mode(regs)) { | |
503 | printk(KERN_WARNING "ptrace: can't handle thumb mode\n"); | |
504 | return; | |
505 | } | |
506 | ||
507 | res = read_instr(child, pc, &insn); | |
508 | if (!res) { | |
509 | struct debug_info *dbg = &child->thread.debug; | |
510 | unsigned long alt; | |
511 | ||
512 | dbg->nsaved = 0; | |
513 | ||
514 | alt = get_branch_address(child, pc, insn); | |
515 | if (alt) | |
516 | add_breakpoint(child, dbg, alt); | |
517 | ||
518 | /* | |
519 | * Note that we ignore the result of setting the above | |
520 | * breakpoint since it may fail. When it does, this is | |
521 | * not so much an error, but a forewarning that we may | |
522 | * be receiving a prefetch abort shortly. | |
523 | * | |
524 | * If we don't set this breakpoint here, then we can | |
525 | * lose control of the thread during single stepping. | |
526 | */ | |
527 | if (!alt || predicate(insn) != PREDICATE_ALWAYS) | |
528 | add_breakpoint(child, dbg, pc + 4); | |
529 | } | |
530 | } | |
531 | ||
532 | /* | |
533 | * Ensure no single-step breakpoint is pending. Returns non-zero | |
534 | * value if child was being single-stepped. | |
535 | */ | |
536 | void ptrace_cancel_bpt(struct task_struct *child) | |
537 | { | |
538 | int i, nsaved = child->thread.debug.nsaved; | |
539 | ||
540 | child->thread.debug.nsaved = 0; | |
541 | ||
542 | if (nsaved > 2) { | |
543 | printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved); | |
544 | nsaved = 2; | |
545 | } | |
546 | ||
547 | for (i = 0; i < nsaved; i++) | |
548 | clear_breakpoint(child, &child->thread.debug.bp[i]); | |
549 | } | |
550 | ||
440e6ca7 CH |
551 | void user_disable_single_step(struct task_struct *task) |
552 | { | |
553 | task->ptrace &= ~PT_SINGLESTEP; | |
554 | ptrace_cancel_bpt(task); | |
555 | } | |
556 | ||
557 | void user_enable_single_step(struct task_struct *task) | |
558 | { | |
559 | task->ptrace |= PT_SINGLESTEP; | |
560 | } | |
561 | ||
1da177e4 LT |
562 | /* |
563 | * Called by kernel/ptrace.c when detaching.. | |
1da177e4 LT |
564 | */ |
565 | void ptrace_disable(struct task_struct *child) | |
566 | { | |
440e6ca7 | 567 | user_disable_single_step(child); |
1da177e4 LT |
568 | } |
569 | ||
570 | /* | |
571 | * Handle hitting a breakpoint. | |
572 | */ | |
573 | void ptrace_break(struct task_struct *tsk, struct pt_regs *regs) | |
574 | { | |
575 | siginfo_t info; | |
576 | ||
577 | ptrace_cancel_bpt(tsk); | |
578 | ||
579 | info.si_signo = SIGTRAP; | |
580 | info.si_errno = 0; | |
581 | info.si_code = TRAP_BRKPT; | |
582 | info.si_addr = (void __user *)instruction_pointer(regs); | |
583 | ||
584 | force_sig_info(SIGTRAP, &info, tsk); | |
585 | } | |
586 | ||
587 | static int break_trap(struct pt_regs *regs, unsigned int instr) | |
588 | { | |
589 | ptrace_break(current, regs); | |
590 | return 0; | |
591 | } | |
592 | ||
593 | static struct undef_hook arm_break_hook = { | |
594 | .instr_mask = 0x0fffffff, | |
595 | .instr_val = 0x07f001f0, | |
596 | .cpsr_mask = PSR_T_BIT, | |
597 | .cpsr_val = 0, | |
598 | .fn = break_trap, | |
599 | }; | |
600 | ||
601 | static struct undef_hook thumb_break_hook = { | |
602 | .instr_mask = 0xffff, | |
603 | .instr_val = 0xde01, | |
604 | .cpsr_mask = PSR_T_BIT, | |
605 | .cpsr_val = PSR_T_BIT, | |
606 | .fn = break_trap, | |
607 | }; | |
608 | ||
d23bc1b3 DJ |
609 | static int thumb2_break_trap(struct pt_regs *regs, unsigned int instr) |
610 | { | |
611 | unsigned int instr2; | |
612 | void __user *pc; | |
613 | ||
614 | /* Check the second half of the instruction. */ | |
615 | pc = (void __user *)(instruction_pointer(regs) + 2); | |
616 | ||
617 | if (processor_mode(regs) == SVC_MODE) { | |
618 | instr2 = *(u16 *) pc; | |
619 | } else { | |
620 | get_user(instr2, (u16 __user *)pc); | |
621 | } | |
622 | ||
623 | if (instr2 == 0xa000) { | |
624 | ptrace_break(current, regs); | |
625 | return 0; | |
626 | } else { | |
627 | return 1; | |
628 | } | |
629 | } | |
630 | ||
631 | static struct undef_hook thumb2_break_hook = { | |
632 | .instr_mask = 0xffff, | |
633 | .instr_val = 0xf7f0, | |
634 | .cpsr_mask = PSR_T_BIT, | |
635 | .cpsr_val = PSR_T_BIT, | |
636 | .fn = thumb2_break_trap, | |
637 | }; | |
638 | ||
1da177e4 LT |
639 | static int __init ptrace_break_init(void) |
640 | { | |
641 | register_undef_hook(&arm_break_hook); | |
642 | register_undef_hook(&thumb_break_hook); | |
d23bc1b3 | 643 | register_undef_hook(&thumb2_break_hook); |
1da177e4 LT |
644 | return 0; |
645 | } | |
646 | ||
647 | core_initcall(ptrace_break_init); | |
648 | ||
649 | /* | |
650 | * Read the word at offset "off" into the "struct user". We | |
651 | * actually access the pt_regs stored on the kernel stack. | |
652 | */ | |
653 | static int ptrace_read_user(struct task_struct *tsk, unsigned long off, | |
654 | unsigned long __user *ret) | |
655 | { | |
656 | unsigned long tmp; | |
657 | ||
658 | if (off & 3 || off >= sizeof(struct user)) | |
659 | return -EIO; | |
660 | ||
661 | tmp = 0; | |
68b7f715 PB |
662 | if (off == PT_TEXT_ADDR) |
663 | tmp = tsk->mm->start_code; | |
664 | else if (off == PT_DATA_ADDR) | |
665 | tmp = tsk->mm->start_data; | |
666 | else if (off == PT_TEXT_END_ADDR) | |
667 | tmp = tsk->mm->end_code; | |
668 | else if (off < sizeof(struct pt_regs)) | |
1da177e4 LT |
669 | tmp = get_user_reg(tsk, off >> 2); |
670 | ||
671 | return put_user(tmp, ret); | |
672 | } | |
673 | ||
674 | /* | |
675 | * Write the word at offset "off" into "struct user". We | |
676 | * actually access the pt_regs stored on the kernel stack. | |
677 | */ | |
678 | static int ptrace_write_user(struct task_struct *tsk, unsigned long off, | |
679 | unsigned long val) | |
680 | { | |
681 | if (off & 3 || off >= sizeof(struct user)) | |
682 | return -EIO; | |
683 | ||
684 | if (off >= sizeof(struct pt_regs)) | |
685 | return 0; | |
686 | ||
687 | return put_user_reg(tsk, off >> 2, val); | |
688 | } | |
689 | ||
690 | /* | |
691 | * Get all user integer registers. | |
692 | */ | |
693 | static int ptrace_getregs(struct task_struct *tsk, void __user *uregs) | |
694 | { | |
815d5ec8 | 695 | struct pt_regs *regs = task_pt_regs(tsk); |
1da177e4 LT |
696 | |
697 | return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0; | |
698 | } | |
699 | ||
700 | /* | |
701 | * Set all user integer registers. | |
702 | */ | |
703 | static int ptrace_setregs(struct task_struct *tsk, void __user *uregs) | |
704 | { | |
705 | struct pt_regs newregs; | |
706 | int ret; | |
707 | ||
708 | ret = -EFAULT; | |
709 | if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) { | |
815d5ec8 | 710 | struct pt_regs *regs = task_pt_regs(tsk); |
1da177e4 LT |
711 | |
712 | ret = -EINVAL; | |
713 | if (valid_user_regs(&newregs)) { | |
714 | *regs = newregs; | |
715 | ret = 0; | |
716 | } | |
717 | } | |
718 | ||
719 | return ret; | |
720 | } | |
721 | ||
722 | /* | |
723 | * Get the child FPU state. | |
724 | */ | |
725 | static int ptrace_getfpregs(struct task_struct *tsk, void __user *ufp) | |
726 | { | |
e7c1b32f | 727 | return copy_to_user(ufp, &task_thread_info(tsk)->fpstate, |
1da177e4 LT |
728 | sizeof(struct user_fp)) ? -EFAULT : 0; |
729 | } | |
730 | ||
731 | /* | |
732 | * Set the child FPU state. | |
733 | */ | |
734 | static int ptrace_setfpregs(struct task_struct *tsk, void __user *ufp) | |
735 | { | |
e7c1b32f | 736 | struct thread_info *thread = task_thread_info(tsk); |
1da177e4 LT |
737 | thread->used_cp[1] = thread->used_cp[2] = 1; |
738 | return copy_from_user(&thread->fpstate, ufp, | |
739 | sizeof(struct user_fp)) ? -EFAULT : 0; | |
740 | } | |
741 | ||
742 | #ifdef CONFIG_IWMMXT | |
743 | ||
744 | /* | |
745 | * Get the child iWMMXt state. | |
746 | */ | |
747 | static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp) | |
748 | { | |
e7c1b32f | 749 | struct thread_info *thread = task_thread_info(tsk); |
1da177e4 LT |
750 | |
751 | if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) | |
752 | return -ENODATA; | |
753 | iwmmxt_task_disable(thread); /* force it to ram */ | |
cdaabbd7 RK |
754 | return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE) |
755 | ? -EFAULT : 0; | |
1da177e4 LT |
756 | } |
757 | ||
758 | /* | |
759 | * Set the child iWMMXt state. | |
760 | */ | |
761 | static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp) | |
762 | { | |
e7c1b32f | 763 | struct thread_info *thread = task_thread_info(tsk); |
1da177e4 LT |
764 | |
765 | if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) | |
766 | return -EACCES; | |
767 | iwmmxt_task_release(thread); /* force a reload */ | |
17320a96 | 768 | return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE) |
cdaabbd7 | 769 | ? -EFAULT : 0; |
1da177e4 LT |
770 | } |
771 | ||
772 | #endif | |
773 | ||
5429b060 LB |
774 | #ifdef CONFIG_CRUNCH |
775 | /* | |
776 | * Get the child Crunch state. | |
777 | */ | |
778 | static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp) | |
779 | { | |
780 | struct thread_info *thread = task_thread_info(tsk); | |
781 | ||
782 | crunch_task_disable(thread); /* force it to ram */ | |
783 | return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE) | |
784 | ? -EFAULT : 0; | |
785 | } | |
786 | ||
787 | /* | |
788 | * Set the child Crunch state. | |
789 | */ | |
790 | static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp) | |
791 | { | |
792 | struct thread_info *thread = task_thread_info(tsk); | |
793 | ||
794 | crunch_task_release(thread); /* force a reload */ | |
795 | return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE) | |
796 | ? -EFAULT : 0; | |
797 | } | |
798 | #endif | |
799 | ||
3d1228ea CM |
800 | #ifdef CONFIG_VFP |
801 | /* | |
802 | * Get the child VFP state. | |
803 | */ | |
804 | static int ptrace_getvfpregs(struct task_struct *tsk, void __user *data) | |
805 | { | |
806 | struct thread_info *thread = task_thread_info(tsk); | |
807 | union vfp_state *vfp = &thread->vfpstate; | |
808 | struct user_vfp __user *ufp = data; | |
809 | ||
ad187f95 | 810 | vfp_sync_hwstate(thread); |
3d1228ea CM |
811 | |
812 | /* copy the floating point registers */ | |
813 | if (copy_to_user(&ufp->fpregs, &vfp->hard.fpregs, | |
814 | sizeof(vfp->hard.fpregs))) | |
815 | return -EFAULT; | |
816 | ||
817 | /* copy the status and control register */ | |
818 | if (put_user(vfp->hard.fpscr, &ufp->fpscr)) | |
819 | return -EFAULT; | |
820 | ||
821 | return 0; | |
822 | } | |
823 | ||
824 | /* | |
825 | * Set the child VFP state. | |
826 | */ | |
827 | static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data) | |
828 | { | |
829 | struct thread_info *thread = task_thread_info(tsk); | |
830 | union vfp_state *vfp = &thread->vfpstate; | |
831 | struct user_vfp __user *ufp = data; | |
832 | ||
ad187f95 | 833 | vfp_sync_hwstate(thread); |
3d1228ea CM |
834 | |
835 | /* copy the floating point registers */ | |
836 | if (copy_from_user(&vfp->hard.fpregs, &ufp->fpregs, | |
837 | sizeof(vfp->hard.fpregs))) | |
838 | return -EFAULT; | |
839 | ||
840 | /* copy the status and control register */ | |
841 | if (get_user(vfp->hard.fpscr, &ufp->fpscr)) | |
842 | return -EFAULT; | |
843 | ||
ad187f95 RK |
844 | vfp_flush_hwstate(thread); |
845 | ||
3d1228ea CM |
846 | return 0; |
847 | } | |
848 | #endif | |
849 | ||
481bed45 | 850 | long arch_ptrace(struct task_struct *child, long request, long addr, long data) |
1da177e4 | 851 | { |
1da177e4 LT |
852 | int ret; |
853 | ||
854 | switch (request) { | |
1da177e4 LT |
855 | case PTRACE_PEEKUSR: |
856 | ret = ptrace_read_user(child, addr, (unsigned long __user *)data); | |
857 | break; | |
858 | ||
1da177e4 LT |
859 | case PTRACE_POKEUSR: |
860 | ret = ptrace_write_user(child, addr, data); | |
861 | break; | |
862 | ||
1da177e4 LT |
863 | case PTRACE_GETREGS: |
864 | ret = ptrace_getregs(child, (void __user *)data); | |
865 | break; | |
866 | ||
867 | case PTRACE_SETREGS: | |
868 | ret = ptrace_setregs(child, (void __user *)data); | |
869 | break; | |
870 | ||
871 | case PTRACE_GETFPREGS: | |
872 | ret = ptrace_getfpregs(child, (void __user *)data); | |
873 | break; | |
874 | ||
875 | case PTRACE_SETFPREGS: | |
876 | ret = ptrace_setfpregs(child, (void __user *)data); | |
877 | break; | |
878 | ||
879 | #ifdef CONFIG_IWMMXT | |
880 | case PTRACE_GETWMMXREGS: | |
881 | ret = ptrace_getwmmxregs(child, (void __user *)data); | |
882 | break; | |
883 | ||
884 | case PTRACE_SETWMMXREGS: | |
885 | ret = ptrace_setwmmxregs(child, (void __user *)data); | |
886 | break; | |
887 | #endif | |
888 | ||
889 | case PTRACE_GET_THREAD_AREA: | |
e7c1b32f | 890 | ret = put_user(task_thread_info(child)->tp_value, |
1da177e4 LT |
891 | (unsigned long __user *) data); |
892 | break; | |
893 | ||
3f471126 | 894 | case PTRACE_SET_SYSCALL: |
5ba6d3fe | 895 | task_thread_info(child)->syscall = data; |
3f471126 | 896 | ret = 0; |
3f471126 NP |
897 | break; |
898 | ||
5429b060 LB |
899 | #ifdef CONFIG_CRUNCH |
900 | case PTRACE_GETCRUNCHREGS: | |
901 | ret = ptrace_getcrunchregs(child, (void __user *)data); | |
902 | break; | |
903 | ||
904 | case PTRACE_SETCRUNCHREGS: | |
905 | ret = ptrace_setcrunchregs(child, (void __user *)data); | |
906 | break; | |
907 | #endif | |
908 | ||
3d1228ea CM |
909 | #ifdef CONFIG_VFP |
910 | case PTRACE_GETVFPREGS: | |
911 | ret = ptrace_getvfpregs(child, (void __user *)data); | |
912 | break; | |
913 | ||
914 | case PTRACE_SETVFPREGS: | |
915 | ret = ptrace_setvfpregs(child, (void __user *)data); | |
916 | break; | |
917 | #endif | |
918 | ||
1da177e4 LT |
919 | default: |
920 | ret = ptrace_request(child, request, addr, data); | |
921 | break; | |
922 | } | |
923 | ||
924 | return ret; | |
925 | } | |
926 | ||
3f471126 | 927 | asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno) |
1da177e4 LT |
928 | { |
929 | unsigned long ip; | |
930 | ||
931 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
3f471126 | 932 | return scno; |
1da177e4 | 933 | if (!(current->ptrace & PT_PTRACED)) |
3f471126 | 934 | return scno; |
1da177e4 LT |
935 | |
936 | /* | |
937 | * Save IP. IP is used to denote syscall entry/exit: | |
938 | * IP = 0 -> entry, = 1 -> exit | |
939 | */ | |
940 | ip = regs->ARM_ip; | |
941 | regs->ARM_ip = why; | |
942 | ||
5ba6d3fe | 943 | current_thread_info()->syscall = scno; |
3f471126 | 944 | |
1da177e4 LT |
945 | /* the 0x80 provides a way for the tracing parent to distinguish |
946 | between a syscall stop and SIGTRAP delivery */ | |
947 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
948 | ? 0x80 : 0)); | |
949 | /* | |
950 | * this isn't the same as continuing with a signal, but it will do | |
951 | * for normal use. strace only continues with a signal if the | |
952 | * stopping signal is not SIGTRAP. -brl | |
953 | */ | |
954 | if (current->exit_code) { | |
955 | send_sig(current->exit_code, current, 1); | |
956 | current->exit_code = 0; | |
957 | } | |
958 | regs->ARM_ip = ip; | |
3f471126 | 959 | |
5ba6d3fe | 960 | return current_thread_info()->syscall; |
1da177e4 | 961 | } |