nand: davinci: add support for timing configuration
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / mn10300 / kernel / kprobes.c
blob67e6389d625a43a7cf62d4d1f5358233b5fef3d7
1 /* MN10300 Kernel probes implementation
3 * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
4 * Written by Mark Salter (msalter@redhat.com)
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public Licence as published by
8 * the Free Software Foundation; either version 2 of the Licence, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public Licence for more details.
16 * You should have received a copy of the GNU General Public Licence
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 #include <linux/kprobes.h>
21 #include <linux/ptrace.h>
22 #include <linux/spinlock.h>
23 #include <linux/preempt.h>
24 #include <linux/kdebug.h>
25 #include <asm/cacheflush.h>
27 struct kretprobe_blackpoint kretprobe_blacklist[] = { { NULL, NULL } };
28 const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
30 /* kprobe_status settings */
31 #define KPROBE_HIT_ACTIVE 0x00000001
32 #define KPROBE_HIT_SS 0x00000002
34 static struct kprobe *cur_kprobe;
35 static unsigned long cur_kprobe_orig_pc;
36 static unsigned long cur_kprobe_next_pc;
37 static int cur_kprobe_ss_flags;
38 static unsigned long kprobe_status;
39 static kprobe_opcode_t cur_kprobe_ss_buf[MAX_INSN_SIZE + 2];
40 static unsigned long cur_kprobe_bp_addr;
42 DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
45 /* singlestep flag bits */
46 #define SINGLESTEP_BRANCH 1
47 #define SINGLESTEP_PCREL 2
49 #define READ_BYTE(p, valp) \
50 do { *(u8 *)(valp) = *(u8 *)(p); } while (0)
52 #define READ_WORD16(p, valp) \
53 do { \
54 READ_BYTE((p), (valp)); \
55 READ_BYTE((u8 *)(p) + 1, (u8 *)(valp) + 1); \
56 } while (0)
58 #define READ_WORD32(p, valp) \
59 do { \
60 READ_BYTE((p), (valp)); \
61 READ_BYTE((u8 *)(p) + 1, (u8 *)(valp) + 1); \
62 READ_BYTE((u8 *)(p) + 2, (u8 *)(valp) + 2); \
63 READ_BYTE((u8 *)(p) + 3, (u8 *)(valp) + 3); \
64 } while (0)
67 static const u8 mn10300_insn_sizes[256] =
69 /* 1 2 3 4 5 6 7 8 9 a b c d e f */
70 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, /* 0 */
71 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 1 */
72 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, /* 2 */
73 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, /* 3 */
74 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, /* 4 */
75 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, /* 5 */
76 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6 */
77 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 7 */
78 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 8 */
79 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 9 */
80 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* a */
81 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* b */
82 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, /* c */
83 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* d */
84 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* e */
85 0, 2, 2, 2, 2, 2, 2, 4, 0, 3, 0, 4, 0, 6, 7, 1 /* f */
88 #define LT (1 << 0)
89 #define GT (1 << 1)
90 #define GE (1 << 2)
91 #define LE (1 << 3)
92 #define CS (1 << 4)
93 #define HI (1 << 5)
94 #define CC (1 << 6)
95 #define LS (1 << 7)
96 #define EQ (1 << 8)
97 #define NE (1 << 9)
98 #define RA (1 << 10)
99 #define VC (1 << 11)
100 #define VS (1 << 12)
101 #define NC (1 << 13)
102 #define NS (1 << 14)
104 static const u16 cond_table[] = {
105 /* V C N Z */
106 /* 0 0 0 0 */ (NE | NC | CC | VC | GE | GT | HI),
107 /* 0 0 0 1 */ (EQ | NC | CC | VC | GE | LE | LS),
108 /* 0 0 1 0 */ (NE | NS | CC | VC | LT | LE | HI),
109 /* 0 0 1 1 */ (EQ | NS | CC | VC | LT | LE | LS),
110 /* 0 1 0 0 */ (NE | NC | CS | VC | GE | GT | LS),
111 /* 0 1 0 1 */ (EQ | NC | CS | VC | GE | LE | LS),
112 /* 0 1 1 0 */ (NE | NS | CS | VC | LT | LE | LS),
113 /* 0 1 1 1 */ (EQ | NS | CS | VC | LT | LE | LS),
114 /* 1 0 0 0 */ (NE | NC | CC | VS | LT | LE | HI),
115 /* 1 0 0 1 */ (EQ | NC | CC | VS | LT | LE | LS),
116 /* 1 0 1 0 */ (NE | NS | CC | VS | GE | GT | HI),
117 /* 1 0 1 1 */ (EQ | NS | CC | VS | GE | LE | LS),
118 /* 1 1 0 0 */ (NE | NC | CS | VS | LT | LE | LS),
119 /* 1 1 0 1 */ (EQ | NC | CS | VS | LT | LE | LS),
120 /* 1 1 1 0 */ (NE | NS | CS | VS | GE | GT | LS),
121 /* 1 1 1 1 */ (EQ | NS | CS | VS | GE | LE | LS),
125 * Calculate what the PC will be after executing next instruction
127 static unsigned find_nextpc(struct pt_regs *regs, int *flags)
129 unsigned size;
130 s8 x8;
131 s16 x16;
132 s32 x32;
133 u8 opc, *pc, *sp, *next;
135 next = 0;
136 *flags = SINGLESTEP_PCREL;
138 pc = (u8 *) regs->pc;
139 sp = (u8 *) (regs + 1);
140 opc = *pc;
142 size = mn10300_insn_sizes[opc];
143 if (size > 0) {
144 next = pc + size;
145 } else {
146 switch (opc) {
147 /* Bxx (d8,PC) */
148 case 0xc0 ... 0xca:
149 x8 = 2;
150 if (cond_table[regs->epsw & 0xf] & (1 << (opc & 0xf)))
151 x8 = (s8)pc[1];
152 next = pc + x8;
153 *flags |= SINGLESTEP_BRANCH;
154 break;
156 /* JMP (d16,PC) or CALL (d16,PC) */
157 case 0xcc:
158 case 0xcd:
159 READ_WORD16(pc + 1, &x16);
160 next = pc + x16;
161 *flags |= SINGLESTEP_BRANCH;
162 break;
164 /* JMP (d32,PC) or CALL (d32,PC) */
165 case 0xdc:
166 case 0xdd:
167 READ_WORD32(pc + 1, &x32);
168 next = pc + x32;
169 *flags |= SINGLESTEP_BRANCH;
170 break;
172 /* RETF */
173 case 0xde:
174 next = (u8 *)regs->mdr;
175 *flags &= ~SINGLESTEP_PCREL;
176 *flags |= SINGLESTEP_BRANCH;
177 break;
179 /* RET */
180 case 0xdf:
181 sp += pc[2];
182 READ_WORD32(sp, &x32);
183 next = (u8 *)x32;
184 *flags &= ~SINGLESTEP_PCREL;
185 *flags |= SINGLESTEP_BRANCH;
186 break;
188 case 0xf0:
189 next = pc + 2;
190 opc = pc[1];
191 if (opc >= 0xf0 && opc <= 0xf7) {
192 /* JMP (An) / CALLS (An) */
193 switch (opc & 3) {
194 case 0:
195 next = (u8 *)regs->a0;
196 break;
197 case 1:
198 next = (u8 *)regs->a1;
199 break;
200 case 2:
201 next = (u8 *)regs->a2;
202 break;
203 case 3:
204 next = (u8 *)regs->a3;
205 break;
207 *flags &= ~SINGLESTEP_PCREL;
208 *flags |= SINGLESTEP_BRANCH;
209 } else if (opc == 0xfc) {
210 /* RETS */
211 READ_WORD32(sp, &x32);
212 next = (u8 *)x32;
213 *flags &= ~SINGLESTEP_PCREL;
214 *flags |= SINGLESTEP_BRANCH;
215 } else if (opc == 0xfd) {
216 /* RTI */
217 READ_WORD32(sp + 4, &x32);
218 next = (u8 *)x32;
219 *flags &= ~SINGLESTEP_PCREL;
220 *flags |= SINGLESTEP_BRANCH;
222 break;
224 /* potential 3-byte conditional branches */
225 case 0xf8:
226 next = pc + 3;
227 opc = pc[1];
228 if (opc >= 0xe8 && opc <= 0xeb &&
229 (cond_table[regs->epsw & 0xf] &
230 (1 << ((opc & 0xf) + 3)))
232 READ_BYTE(pc+2, &x8);
233 next = pc + x8;
234 *flags |= SINGLESTEP_BRANCH;
236 break;
238 case 0xfa:
239 if (pc[1] == 0xff) {
240 /* CALLS (d16,PC) */
241 READ_WORD16(pc + 2, &x16);
242 next = pc + x16;
243 } else
244 next = pc + 4;
245 *flags |= SINGLESTEP_BRANCH;
246 break;
248 case 0xfc:
249 x32 = 6;
250 if (pc[1] == 0xff) {
251 /* CALLS (d32,PC) */
252 READ_WORD32(pc + 2, &x32);
254 next = pc + x32;
255 *flags |= SINGLESTEP_BRANCH;
256 break;
257 /* LXX (d8,PC) */
258 /* SETLB - loads the next four bytes into the LIR reg */
259 case 0xd0 ... 0xda:
260 case 0xdb:
261 panic("Can't singlestep Lxx/SETLB\n");
262 break;
265 return (unsigned)next;
270 * set up out of place singlestep of some branching instructions
272 static unsigned __kprobes singlestep_branch_setup(struct pt_regs *regs)
274 u8 opc, *pc, *sp, *next;
276 next = NULL;
277 pc = (u8 *) regs->pc;
278 sp = (u8 *) (regs + 1);
280 switch (pc[0]) {
281 case 0xc0 ... 0xca: /* Bxx (d8,PC) */
282 case 0xcc: /* JMP (d16,PC) */
283 case 0xdc: /* JMP (d32,PC) */
284 case 0xf8: /* Bxx (d8,PC) 3-byte version */
285 /* don't really need to do anything except cause trap */
286 next = pc;
287 break;
289 case 0xcd: /* CALL (d16,PC) */
290 pc[1] = 5;
291 pc[2] = 0;
292 next = pc + 5;
293 break;
295 case 0xdd: /* CALL (d32,PC) */
296 pc[1] = 7;
297 pc[2] = 0;
298 pc[3] = 0;
299 pc[4] = 0;
300 next = pc + 7;
301 break;
303 case 0xde: /* RETF */
304 next = pc + 3;
305 regs->mdr = (unsigned) next;
306 break;
308 case 0xdf: /* RET */
309 sp += pc[2];
310 next = pc + 3;
311 *(unsigned *)sp = (unsigned) next;
312 break;
314 case 0xf0:
315 next = pc + 2;
316 opc = pc[1];
317 if (opc >= 0xf0 && opc <= 0xf3) {
318 /* CALLS (An) */
319 /* use CALLS (d16,PC) to avoid mucking with An */
320 pc[0] = 0xfa;
321 pc[1] = 0xff;
322 pc[2] = 4;
323 pc[3] = 0;
324 next = pc + 4;
325 } else if (opc >= 0xf4 && opc <= 0xf7) {
326 /* JMP (An) */
327 next = pc;
328 } else if (opc == 0xfc) {
329 /* RETS */
330 next = pc + 2;
331 *(unsigned *) sp = (unsigned) next;
332 } else if (opc == 0xfd) {
333 /* RTI */
334 next = pc + 2;
335 *(unsigned *)(sp + 4) = (unsigned) next;
337 break;
339 case 0xfa: /* CALLS (d16,PC) */
340 pc[2] = 4;
341 pc[3] = 0;
342 next = pc + 4;
343 break;
345 case 0xfc: /* CALLS (d32,PC) */
346 pc[2] = 6;
347 pc[3] = 0;
348 pc[4] = 0;
349 pc[5] = 0;
350 next = pc + 6;
351 break;
353 case 0xd0 ... 0xda: /* LXX (d8,PC) */
354 case 0xdb: /* SETLB */
355 panic("Can't singlestep Lxx/SETLB\n");
358 return (unsigned) next;
361 int __kprobes arch_prepare_kprobe(struct kprobe *p)
363 return 0;
366 void __kprobes arch_copy_kprobe(struct kprobe *p)
368 memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
371 void __kprobes arch_arm_kprobe(struct kprobe *p)
373 *p->addr = BREAKPOINT_INSTRUCTION;
374 flush_icache_range((unsigned long) p->addr,
375 (unsigned long) p->addr + sizeof(kprobe_opcode_t));
378 void __kprobes arch_disarm_kprobe(struct kprobe *p)
380 mn10300_dcache_flush();
381 mn10300_icache_inv();
384 void arch_remove_kprobe(struct kprobe *p)
388 static inline
389 void __kprobes disarm_kprobe(struct kprobe *p, struct pt_regs *regs)
391 *p->addr = p->opcode;
392 regs->pc = (unsigned long) p->addr;
393 mn10300_dcache_flush();
394 mn10300_icache_inv();
397 static inline
398 void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
400 unsigned long nextpc;
402 cur_kprobe_orig_pc = regs->pc;
403 memcpy(cur_kprobe_ss_buf, &p->ainsn.insn[0], MAX_INSN_SIZE);
404 regs->pc = (unsigned long) cur_kprobe_ss_buf;
406 nextpc = find_nextpc(regs, &cur_kprobe_ss_flags);
407 if (cur_kprobe_ss_flags & SINGLESTEP_PCREL)
408 cur_kprobe_next_pc = cur_kprobe_orig_pc + (nextpc - regs->pc);
409 else
410 cur_kprobe_next_pc = nextpc;
412 /* branching instructions need special handling */
413 if (cur_kprobe_ss_flags & SINGLESTEP_BRANCH)
414 nextpc = singlestep_branch_setup(regs);
416 cur_kprobe_bp_addr = nextpc;
418 *(u8 *) nextpc = BREAKPOINT_INSTRUCTION;
419 mn10300_dcache_flush_range2((unsigned) cur_kprobe_ss_buf,
420 sizeof(cur_kprobe_ss_buf));
421 mn10300_icache_inv();
424 static inline int __kprobes kprobe_handler(struct pt_regs *regs)
426 struct kprobe *p;
427 int ret = 0;
428 unsigned int *addr = (unsigned int *) regs->pc;
430 /* We're in an interrupt, but this is clear and BUG()-safe. */
431 preempt_disable();
433 /* Check we're not actually recursing */
434 if (kprobe_running()) {
435 /* We *are* holding lock here, so this is safe.
436 Disarm the probe we just hit, and ignore it. */
437 p = get_kprobe(addr);
438 if (p) {
439 disarm_kprobe(p, regs);
440 ret = 1;
441 } else {
442 p = cur_kprobe;
443 if (p->break_handler && p->break_handler(p, regs))
444 goto ss_probe;
446 /* If it's not ours, can't be delete race, (we hold lock). */
447 goto no_kprobe;
450 p = get_kprobe(addr);
451 if (!p) {
452 if (*addr != BREAKPOINT_INSTRUCTION) {
453 /* The breakpoint instruction was removed right after
454 * we hit it. Another cpu has removed either a
455 * probepoint or a debugger breakpoint at this address.
456 * In either case, no further handling of this
457 * interrupt is appropriate.
459 ret = 1;
461 /* Not one of ours: let kernel handle it */
462 goto no_kprobe;
465 kprobe_status = KPROBE_HIT_ACTIVE;
466 cur_kprobe = p;
467 if (p->pre_handler(p, regs)) {
468 /* handler has already set things up, so skip ss setup */
469 return 1;
472 ss_probe:
473 prepare_singlestep(p, regs);
474 kprobe_status = KPROBE_HIT_SS;
475 return 1;
477 no_kprobe:
478 preempt_enable_no_resched();
479 return ret;
483 * Called after single-stepping. p->addr is the address of the
484 * instruction whose first byte has been replaced by the "breakpoint"
485 * instruction. To avoid the SMP problems that can occur when we
486 * temporarily put back the original opcode to single-step, we
487 * single-stepped a copy of the instruction. The address of this
488 * copy is p->ainsn.insn.
490 static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
492 /* we may need to fixup regs/stack after singlestepping a call insn */
493 if (cur_kprobe_ss_flags & SINGLESTEP_BRANCH) {
494 regs->pc = cur_kprobe_orig_pc;
495 switch (p->ainsn.insn[0]) {
496 case 0xcd: /* CALL (d16,PC) */
497 *(unsigned *) regs->sp = regs->mdr = regs->pc + 5;
498 break;
499 case 0xdd: /* CALL (d32,PC) */
500 /* fixup mdr and return address on stack */
501 *(unsigned *) regs->sp = regs->mdr = regs->pc + 7;
502 break;
503 case 0xf0:
504 if (p->ainsn.insn[1] >= 0xf0 &&
505 p->ainsn.insn[1] <= 0xf3) {
506 /* CALLS (An) */
507 /* fixup MDR and return address on stack */
508 regs->mdr = regs->pc + 2;
509 *(unsigned *) regs->sp = regs->mdr;
511 break;
513 case 0xfa: /* CALLS (d16,PC) */
514 /* fixup MDR and return address on stack */
515 *(unsigned *) regs->sp = regs->mdr = regs->pc + 4;
516 break;
518 case 0xfc: /* CALLS (d32,PC) */
519 /* fixup MDR and return address on stack */
520 *(unsigned *) regs->sp = regs->mdr = regs->pc + 6;
521 break;
525 regs->pc = cur_kprobe_next_pc;
526 cur_kprobe_bp_addr = 0;
529 static inline int __kprobes post_kprobe_handler(struct pt_regs *regs)
531 if (!kprobe_running())
532 return 0;
534 if (cur_kprobe->post_handler)
535 cur_kprobe->post_handler(cur_kprobe, regs, 0);
537 resume_execution(cur_kprobe, regs);
538 reset_current_kprobe();
539 preempt_enable_no_resched();
540 return 1;
543 /* Interrupts disabled, kprobe_lock held. */
544 static inline
545 int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
547 if (cur_kprobe->fault_handler &&
548 cur_kprobe->fault_handler(cur_kprobe, regs, trapnr))
549 return 1;
551 if (kprobe_status & KPROBE_HIT_SS) {
552 resume_execution(cur_kprobe, regs);
553 reset_current_kprobe();
554 preempt_enable_no_resched();
556 return 0;
560 * Wrapper routine to for handling exceptions.
562 int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
563 unsigned long val, void *data)
565 struct die_args *args = data;
567 switch (val) {
568 case DIE_BREAKPOINT:
569 if (cur_kprobe_bp_addr != args->regs->pc) {
570 if (kprobe_handler(args->regs))
571 return NOTIFY_STOP;
572 } else {
573 if (post_kprobe_handler(args->regs))
574 return NOTIFY_STOP;
576 break;
577 case DIE_GPF:
578 if (kprobe_running() &&
579 kprobe_fault_handler(args->regs, args->trapnr))
580 return NOTIFY_STOP;
581 break;
582 default:
583 break;
585 return NOTIFY_DONE;
588 /* Jprobes support. */
589 static struct pt_regs jprobe_saved_regs;
590 static struct pt_regs *jprobe_saved_regs_location;
591 static kprobe_opcode_t jprobe_saved_stack[MAX_STACK_SIZE];
593 int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
595 struct jprobe *jp = container_of(p, struct jprobe, kp);
597 jprobe_saved_regs_location = regs;
598 memcpy(&jprobe_saved_regs, regs, sizeof(struct pt_regs));
600 /* Save a whole stack frame, this gets arguments
601 * pushed onto the stack after using up all the
602 * arg registers.
604 memcpy(&jprobe_saved_stack, regs + 1, sizeof(jprobe_saved_stack));
606 /* setup return addr to the jprobe handler routine */
607 regs->pc = (unsigned long) jp->entry;
608 return 1;
611 void __kprobes jprobe_return(void)
613 void *orig_sp = jprobe_saved_regs_location + 1;
615 preempt_enable_no_resched();
616 asm volatile(" mov %0,sp\n"
617 ".globl jprobe_return_bp_addr\n"
618 "jprobe_return_bp_addr:\n\t"
619 " .byte 0xff\n"
620 : : "d" (orig_sp));
623 extern void jprobe_return_bp_addr(void);
625 int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
627 u8 *addr = (u8 *) regs->pc;
629 if (addr == (u8 *) jprobe_return_bp_addr) {
630 if (jprobe_saved_regs_location != regs) {
631 printk(KERN_ERR"JPROBE:"
632 " Current regs (%p) does not match saved regs"
633 " (%p).\n",
634 regs, jprobe_saved_regs_location);
635 BUG();
638 /* Restore old register state.
640 memcpy(regs, &jprobe_saved_regs, sizeof(struct pt_regs));
642 memcpy(regs + 1, &jprobe_saved_stack,
643 sizeof(jprobe_saved_stack));
644 return 1;
646 return 0;
649 int __init arch_init_kprobes(void)
651 return 0;