Commit | Line | Data |
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fd7b231f AK |
1 | /* |
2 | * Kernel Probes (KProbes) | |
3 | * arch/ia64/kernel/kprobes.c | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
18 | * | |
19 | * Copyright (C) IBM Corporation, 2002, 2004 | |
20 | * Copyright (C) Intel Corporation, 2005 | |
21 | * | |
22 | * 2005-Apr Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy | |
23 | * <anil.s.keshavamurthy@intel.com> adapted from i386 | |
24 | */ | |
25 | ||
26 | #include <linux/config.h> | |
27 | #include <linux/kprobes.h> | |
28 | #include <linux/ptrace.h> | |
29 | #include <linux/spinlock.h> | |
30 | #include <linux/string.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/preempt.h> | |
33 | #include <linux/moduleloader.h> | |
34 | ||
35 | #include <asm/pgtable.h> | |
36 | #include <asm/kdebug.h> | |
c7b645f9 | 37 | #include <asm/sections.h> |
fd7b231f | 38 | |
b2761dc2 AK |
39 | extern void jprobe_inst_return(void); |
40 | ||
fd7b231f AK |
41 | /* kprobe_status settings */ |
42 | #define KPROBE_HIT_ACTIVE 0x00000001 | |
43 | #define KPROBE_HIT_SS 0x00000002 | |
44 | ||
852caccc AK |
45 | static struct kprobe *current_kprobe, *kprobe_prev; |
46 | static unsigned long kprobe_status, kprobe_status_prev; | |
b2761dc2 | 47 | static struct pt_regs jprobe_saved_regs; |
fd7b231f AK |
48 | |
49 | enum instruction_type {A, I, M, F, B, L, X, u}; | |
50 | static enum instruction_type bundle_encoding[32][3] = { | |
51 | { M, I, I }, /* 00 */ | |
52 | { M, I, I }, /* 01 */ | |
53 | { M, I, I }, /* 02 */ | |
54 | { M, I, I }, /* 03 */ | |
55 | { M, L, X }, /* 04 */ | |
56 | { M, L, X }, /* 05 */ | |
57 | { u, u, u }, /* 06 */ | |
58 | { u, u, u }, /* 07 */ | |
59 | { M, M, I }, /* 08 */ | |
60 | { M, M, I }, /* 09 */ | |
61 | { M, M, I }, /* 0A */ | |
62 | { M, M, I }, /* 0B */ | |
63 | { M, F, I }, /* 0C */ | |
64 | { M, F, I }, /* 0D */ | |
65 | { M, M, F }, /* 0E */ | |
66 | { M, M, F }, /* 0F */ | |
67 | { M, I, B }, /* 10 */ | |
68 | { M, I, B }, /* 11 */ | |
69 | { M, B, B }, /* 12 */ | |
70 | { M, B, B }, /* 13 */ | |
71 | { u, u, u }, /* 14 */ | |
72 | { u, u, u }, /* 15 */ | |
73 | { B, B, B }, /* 16 */ | |
74 | { B, B, B }, /* 17 */ | |
75 | { M, M, B }, /* 18 */ | |
76 | { M, M, B }, /* 19 */ | |
77 | { u, u, u }, /* 1A */ | |
78 | { u, u, u }, /* 1B */ | |
79 | { M, F, B }, /* 1C */ | |
80 | { M, F, B }, /* 1D */ | |
81 | { u, u, u }, /* 1E */ | |
82 | { u, u, u }, /* 1F */ | |
83 | }; | |
84 | ||
a5403183 AK |
85 | /* |
86 | * In this function we check to see if the instruction | |
87 | * is IP relative instruction and update the kprobe | |
88 | * inst flag accordingly | |
89 | */ | |
1f7ad57b PP |
90 | static void __kprobes update_kprobe_inst_flag(uint template, uint slot, |
91 | uint major_opcode, | |
92 | unsigned long kprobe_inst, | |
93 | struct kprobe *p) | |
fd7b231f | 94 | { |
8bc76772 RL |
95 | p->ainsn.inst_flag = 0; |
96 | p->ainsn.target_br_reg = 0; | |
fd7b231f | 97 | |
a5403183 AK |
98 | if (bundle_encoding[template][slot] == B) { |
99 | switch (major_opcode) { | |
100 | case INDIRECT_CALL_OPCODE: | |
101 | p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; | |
102 | p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); | |
103 | break; | |
104 | case IP_RELATIVE_PREDICT_OPCODE: | |
105 | case IP_RELATIVE_BRANCH_OPCODE: | |
106 | p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR; | |
107 | break; | |
108 | case IP_RELATIVE_CALL_OPCODE: | |
109 | p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR; | |
110 | p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; | |
111 | p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); | |
112 | break; | |
113 | } | |
114 | } else if (bundle_encoding[template][slot] == X) { | |
115 | switch (major_opcode) { | |
116 | case LONG_CALL_OPCODE: | |
117 | p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; | |
118 | p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); | |
119 | break; | |
120 | } | |
121 | } | |
122 | return; | |
123 | } | |
fd7b231f | 124 | |
708de8f1 AK |
125 | /* |
126 | * In this function we check to see if the instruction | |
127 | * on which we are inserting kprobe is supported. | |
128 | * Returns 0 if supported | |
129 | * Returns -EINVAL if unsupported | |
130 | */ | |
1f7ad57b PP |
131 | static int __kprobes unsupported_inst(uint template, uint slot, |
132 | uint major_opcode, | |
133 | unsigned long kprobe_inst, | |
134 | struct kprobe *p) | |
708de8f1 AK |
135 | { |
136 | unsigned long addr = (unsigned long)p->addr; | |
137 | ||
138 | if (bundle_encoding[template][slot] == I) { | |
139 | switch (major_opcode) { | |
140 | case 0x0: //I_UNIT_MISC_OPCODE: | |
141 | /* | |
142 | * Check for Integer speculation instruction | |
143 | * - Bit 33-35 to be equal to 0x1 | |
144 | */ | |
145 | if (((kprobe_inst >> 33) & 0x7) == 1) { | |
146 | printk(KERN_WARNING | |
147 | "Kprobes on speculation inst at <0x%lx> not supported\n", | |
148 | addr); | |
149 | return -EINVAL; | |
150 | } | |
151 | ||
152 | /* | |
153 | * IP relative mov instruction | |
154 | * - Bit 27-35 to be equal to 0x30 | |
155 | */ | |
156 | if (((kprobe_inst >> 27) & 0x1FF) == 0x30) { | |
157 | printk(KERN_WARNING | |
158 | "Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n", | |
159 | addr); | |
160 | return -EINVAL; | |
161 | ||
162 | } | |
163 | } | |
164 | } | |
165 | return 0; | |
166 | } | |
167 | ||
168 | ||
1674eafc AK |
169 | /* |
170 | * In this function we check to see if the instruction | |
171 | * (qp) cmpx.crel.ctype p1,p2=r2,r3 | |
172 | * on which we are inserting kprobe is cmp instruction | |
173 | * with ctype as unc. | |
174 | */ | |
1f7ad57b PP |
175 | static uint __kprobes is_cmp_ctype_unc_inst(uint template, uint slot, |
176 | uint major_opcode, | |
177 | unsigned long kprobe_inst) | |
1674eafc AK |
178 | { |
179 | cmp_inst_t cmp_inst; | |
180 | uint ctype_unc = 0; | |
181 | ||
182 | if (!((bundle_encoding[template][slot] == I) || | |
183 | (bundle_encoding[template][slot] == M))) | |
184 | goto out; | |
185 | ||
186 | if (!((major_opcode == 0xC) || (major_opcode == 0xD) || | |
187 | (major_opcode == 0xE))) | |
188 | goto out; | |
189 | ||
190 | cmp_inst.l = kprobe_inst; | |
191 | if ((cmp_inst.f.x2 == 0) || (cmp_inst.f.x2 == 1)) { | |
192 | /* Integere compare - Register Register (A6 type)*/ | |
193 | if ((cmp_inst.f.tb == 0) && (cmp_inst.f.ta == 0) | |
194 | &&(cmp_inst.f.c == 1)) | |
195 | ctype_unc = 1; | |
196 | } else if ((cmp_inst.f.x2 == 2)||(cmp_inst.f.x2 == 3)) { | |
197 | /* Integere compare - Immediate Register (A8 type)*/ | |
198 | if ((cmp_inst.f.ta == 0) &&(cmp_inst.f.c == 1)) | |
199 | ctype_unc = 1; | |
200 | } | |
201 | out: | |
202 | return ctype_unc; | |
203 | } | |
204 | ||
a5403183 AK |
205 | /* |
206 | * In this function we override the bundle with | |
207 | * the break instruction at the given slot. | |
208 | */ | |
1f7ad57b PP |
209 | static void __kprobes prepare_break_inst(uint template, uint slot, |
210 | uint major_opcode, | |
211 | unsigned long kprobe_inst, | |
212 | struct kprobe *p) | |
a5403183 AK |
213 | { |
214 | unsigned long break_inst = BREAK_INST; | |
215 | bundle_t *bundle = &p->ainsn.insn.bundle; | |
216 | ||
217 | /* | |
218 | * Copy the original kprobe_inst qualifying predicate(qp) | |
1674eafc AK |
219 | * to the break instruction iff !is_cmp_ctype_unc_inst |
220 | * because for cmp instruction with ctype equal to unc, | |
221 | * which is a special instruction always needs to be | |
222 | * executed regradless of qp | |
a5403183 | 223 | */ |
1674eafc AK |
224 | if (!is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst)) |
225 | break_inst |= (0x3f & kprobe_inst); | |
a5403183 AK |
226 | |
227 | switch (slot) { | |
228 | case 0: | |
229 | bundle->quad0.slot0 = break_inst; | |
230 | break; | |
231 | case 1: | |
232 | bundle->quad0.slot1_p0 = break_inst; | |
233 | bundle->quad1.slot1_p1 = break_inst >> (64-46); | |
234 | break; | |
235 | case 2: | |
236 | bundle->quad1.slot2 = break_inst; | |
237 | break; | |
8bc76772 | 238 | } |
cd2675bf | 239 | |
a5403183 AK |
240 | /* |
241 | * Update the instruction flag, so that we can | |
242 | * emulate the instruction properly after we | |
243 | * single step on original instruction | |
244 | */ | |
245 | update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p); | |
246 | } | |
247 | ||
248 | static inline void get_kprobe_inst(bundle_t *bundle, uint slot, | |
249 | unsigned long *kprobe_inst, uint *major_opcode) | |
250 | { | |
251 | unsigned long kprobe_inst_p0, kprobe_inst_p1; | |
252 | unsigned int template; | |
253 | ||
254 | template = bundle->quad0.template; | |
fd7b231f | 255 | |
fd7b231f | 256 | switch (slot) { |
a5403183 AK |
257 | case 0: |
258 | *major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT); | |
259 | *kprobe_inst = bundle->quad0.slot0; | |
fd7b231f | 260 | break; |
a5403183 AK |
261 | case 1: |
262 | *major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT); | |
263 | kprobe_inst_p0 = bundle->quad0.slot1_p0; | |
264 | kprobe_inst_p1 = bundle->quad1.slot1_p1; | |
265 | *kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46)); | |
fd7b231f | 266 | break; |
a5403183 AK |
267 | case 2: |
268 | *major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT); | |
269 | *kprobe_inst = bundle->quad1.slot2; | |
fd7b231f AK |
270 | break; |
271 | } | |
a5403183 | 272 | } |
fd7b231f | 273 | |
c7b645f9 KA |
274 | /* Returns non-zero if the addr is in the Interrupt Vector Table */ |
275 | static inline int in_ivt_functions(unsigned long addr) | |
276 | { | |
277 | return (addr >= (unsigned long)__start_ivt_text | |
278 | && addr < (unsigned long)__end_ivt_text); | |
279 | } | |
280 | ||
1f7ad57b PP |
281 | static int __kprobes valid_kprobe_addr(int template, int slot, |
282 | unsigned long addr) | |
a5403183 AK |
283 | { |
284 | if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) { | |
c7b645f9 KA |
285 | printk(KERN_WARNING "Attempting to insert unaligned kprobe " |
286 | "at 0x%lx\n", addr); | |
a5403183 | 287 | return -EINVAL; |
8bc76772 | 288 | } |
a528e21c | 289 | |
c7b645f9 KA |
290 | if (in_ivt_functions(addr)) { |
291 | printk(KERN_WARNING "Kprobes can't be inserted inside " | |
292 | "IVT functions at 0x%lx\n", addr); | |
293 | return -EINVAL; | |
294 | } | |
295 | ||
a528e21c RL |
296 | if (slot == 1 && bundle_encoding[template][1] != L) { |
297 | printk(KERN_WARNING "Inserting kprobes on slot #1 " | |
298 | "is not supported\n"); | |
299 | return -EINVAL; | |
300 | } | |
301 | ||
a5403183 AK |
302 | return 0; |
303 | } | |
304 | ||
852caccc AK |
305 | static inline void save_previous_kprobe(void) |
306 | { | |
307 | kprobe_prev = current_kprobe; | |
308 | kprobe_status_prev = kprobe_status; | |
309 | } | |
310 | ||
311 | static inline void restore_previous_kprobe(void) | |
312 | { | |
313 | current_kprobe = kprobe_prev; | |
314 | kprobe_status = kprobe_status_prev; | |
315 | } | |
316 | ||
317 | static inline void set_current_kprobe(struct kprobe *p) | |
318 | { | |
319 | current_kprobe = p; | |
320 | } | |
321 | ||
9508dbfe RL |
322 | static void kretprobe_trampoline(void) |
323 | { | |
324 | } | |
325 | ||
326 | /* | |
327 | * At this point the target function has been tricked into | |
328 | * returning into our trampoline. Lookup the associated instance | |
329 | * and then: | |
330 | * - call the handler function | |
331 | * - cleanup by marking the instance as unused | |
332 | * - long jump back to the original return address | |
333 | */ | |
1f7ad57b | 334 | int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) |
9508dbfe RL |
335 | { |
336 | struct kretprobe_instance *ri = NULL; | |
337 | struct hlist_head *head; | |
338 | struct hlist_node *node, *tmp; | |
339 | unsigned long orig_ret_address = 0; | |
340 | unsigned long trampoline_address = | |
341 | ((struct fnptr *)kretprobe_trampoline)->ip; | |
342 | ||
343 | head = kretprobe_inst_table_head(current); | |
344 | ||
345 | /* | |
346 | * It is possible to have multiple instances associated with a given | |
347 | * task either because an multiple functions in the call path | |
348 | * have a return probe installed on them, and/or more then one return | |
349 | * return probe was registered for a target function. | |
350 | * | |
351 | * We can handle this because: | |
352 | * - instances are always inserted at the head of the list | |
353 | * - when multiple return probes are registered for the same | |
354 | * function, the first instance's ret_addr will point to the | |
355 | * real return address, and all the rest will point to | |
356 | * kretprobe_trampoline | |
357 | */ | |
358 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { | |
359 | if (ri->task != current) | |
360 | /* another task is sharing our hash bucket */ | |
361 | continue; | |
362 | ||
363 | if (ri->rp && ri->rp->handler) | |
364 | ri->rp->handler(ri, regs); | |
365 | ||
366 | orig_ret_address = (unsigned long)ri->ret_addr; | |
367 | recycle_rp_inst(ri); | |
368 | ||
369 | if (orig_ret_address != trampoline_address) | |
370 | /* | |
371 | * This is the real return address. Any other | |
372 | * instances associated with this task are for | |
373 | * other calls deeper on the call stack | |
374 | */ | |
375 | break; | |
376 | } | |
377 | ||
378 | BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address)); | |
379 | regs->cr_iip = orig_ret_address; | |
380 | ||
381 | unlock_kprobes(); | |
382 | preempt_enable_no_resched(); | |
383 | ||
384 | /* | |
385 | * By returning a non-zero value, we are telling | |
386 | * kprobe_handler() that we have handled unlocking | |
387 | * and re-enabling preemption. | |
388 | */ | |
389 | return 1; | |
390 | } | |
391 | ||
1f7ad57b PP |
392 | void __kprobes arch_prepare_kretprobe(struct kretprobe *rp, |
393 | struct pt_regs *regs) | |
9508dbfe RL |
394 | { |
395 | struct kretprobe_instance *ri; | |
396 | ||
397 | if ((ri = get_free_rp_inst(rp)) != NULL) { | |
398 | ri->rp = rp; | |
399 | ri->task = current; | |
400 | ri->ret_addr = (kprobe_opcode_t *)regs->b0; | |
401 | ||
402 | /* Replace the return addr with trampoline addr */ | |
403 | regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip; | |
404 | ||
405 | add_rp_inst(ri); | |
406 | } else { | |
407 | rp->nmissed++; | |
408 | } | |
409 | } | |
410 | ||
1f7ad57b | 411 | int __kprobes arch_prepare_kprobe(struct kprobe *p) |
a5403183 AK |
412 | { |
413 | unsigned long addr = (unsigned long) p->addr; | |
414 | unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL); | |
415 | unsigned long kprobe_inst=0; | |
416 | unsigned int slot = addr & 0xf, template, major_opcode = 0; | |
417 | bundle_t *bundle = &p->ainsn.insn.bundle; | |
418 | ||
419 | memcpy(&p->opcode.bundle, kprobe_addr, sizeof(bundle_t)); | |
420 | memcpy(&p->ainsn.insn.bundle, kprobe_addr, sizeof(bundle_t)); | |
421 | ||
422 | template = bundle->quad0.template; | |
423 | ||
424 | if(valid_kprobe_addr(template, slot, addr)) | |
425 | return -EINVAL; | |
426 | ||
427 | /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */ | |
428 | if (slot == 1 && bundle_encoding[template][1] == L) | |
429 | slot++; | |
430 | ||
431 | /* Get kprobe_inst and major_opcode from the bundle */ | |
432 | get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode); | |
433 | ||
708de8f1 AK |
434 | if (unsupported_inst(template, slot, major_opcode, kprobe_inst, p)) |
435 | return -EINVAL; | |
436 | ||
a5403183 | 437 | prepare_break_inst(template, slot, major_opcode, kprobe_inst, p); |
8bc76772 RL |
438 | |
439 | return 0; | |
440 | } | |
441 | ||
1f7ad57b | 442 | void __kprobes arch_arm_kprobe(struct kprobe *p) |
8bc76772 RL |
443 | { |
444 | unsigned long addr = (unsigned long)p->addr; | |
445 | unsigned long arm_addr = addr & ~0xFULL; | |
446 | ||
447 | memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t)); | |
fd7b231f AK |
448 | flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); |
449 | } | |
450 | ||
1f7ad57b | 451 | void __kprobes arch_disarm_kprobe(struct kprobe *p) |
fd7b231f AK |
452 | { |
453 | unsigned long addr = (unsigned long)p->addr; | |
454 | unsigned long arm_addr = addr & ~0xFULL; | |
455 | ||
456 | /* p->opcode contains the original unaltered bundle */ | |
457 | memcpy((char *) arm_addr, (char *) &p->opcode.bundle, sizeof(bundle_t)); | |
458 | flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); | |
459 | } | |
460 | ||
1f7ad57b | 461 | void __kprobes arch_remove_kprobe(struct kprobe *p) |
fd7b231f AK |
462 | { |
463 | } | |
464 | ||
465 | /* | |
466 | * We are resuming execution after a single step fault, so the pt_regs | |
467 | * structure reflects the register state after we executed the instruction | |
468 | * located in the kprobe (p->ainsn.insn.bundle). We still need to adjust | |
cd2675bf AK |
469 | * the ip to point back to the original stack address. To set the IP address |
470 | * to original stack address, handle the case where we need to fixup the | |
471 | * relative IP address and/or fixup branch register. | |
fd7b231f | 472 | */ |
1f7ad57b | 473 | static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 474 | { |
8bc76772 | 475 | unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL; |
cd2675bf AK |
476 | unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL; |
477 | unsigned long template; | |
478 | int slot = ((unsigned long)p->addr & 0xf); | |
fd7b231f | 479 | |
cd2675bf AK |
480 | template = p->opcode.bundle.quad0.template; |
481 | ||
482 | if (slot == 1 && bundle_encoding[template][1] == L) | |
483 | slot = 2; | |
484 | ||
485 | if (p->ainsn.inst_flag) { | |
486 | ||
487 | if (p->ainsn.inst_flag & INST_FLAG_FIX_RELATIVE_IP_ADDR) { | |
488 | /* Fix relative IP address */ | |
489 | regs->cr_iip = (regs->cr_iip - bundle_addr) + resume_addr; | |
490 | } | |
491 | ||
492 | if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) { | |
493 | /* | |
494 | * Fix target branch register, software convention is | |
495 | * to use either b0 or b6 or b7, so just checking | |
496 | * only those registers | |
497 | */ | |
498 | switch (p->ainsn.target_br_reg) { | |
499 | case 0: | |
500 | if ((regs->b0 == bundle_addr) || | |
501 | (regs->b0 == bundle_addr + 0x10)) { | |
502 | regs->b0 = (regs->b0 - bundle_addr) + | |
503 | resume_addr; | |
504 | } | |
505 | break; | |
506 | case 6: | |
507 | if ((regs->b6 == bundle_addr) || | |
508 | (regs->b6 == bundle_addr + 0x10)) { | |
509 | regs->b6 = (regs->b6 - bundle_addr) + | |
510 | resume_addr; | |
511 | } | |
512 | break; | |
513 | case 7: | |
514 | if ((regs->b7 == bundle_addr) || | |
515 | (regs->b7 == bundle_addr + 0x10)) { | |
516 | regs->b7 = (regs->b7 - bundle_addr) + | |
517 | resume_addr; | |
518 | } | |
519 | break; | |
520 | } /* end switch */ | |
521 | } | |
522 | goto turn_ss_off; | |
523 | } | |
fd7b231f | 524 | |
cd2675bf AK |
525 | if (slot == 2) { |
526 | if (regs->cr_iip == bundle_addr + 0x10) { | |
527 | regs->cr_iip = resume_addr + 0x10; | |
528 | } | |
529 | } else { | |
530 | if (regs->cr_iip == bundle_addr) { | |
531 | regs->cr_iip = resume_addr; | |
532 | } | |
a5403183 | 533 | } |
fd7b231f | 534 | |
cd2675bf AK |
535 | turn_ss_off: |
536 | /* Turn off Single Step bit */ | |
537 | ia64_psr(regs)->ss = 0; | |
fd7b231f AK |
538 | } |
539 | ||
1f7ad57b | 540 | static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 541 | { |
8bc76772 | 542 | unsigned long bundle_addr = (unsigned long) &p->opcode.bundle; |
fd7b231f AK |
543 | unsigned long slot = (unsigned long)p->addr & 0xf; |
544 | ||
545 | /* Update instruction pointer (IIP) and slot number (IPSR.ri) */ | |
546 | regs->cr_iip = bundle_addr & ~0xFULL; | |
547 | ||
548 | if (slot > 2) | |
549 | slot = 0; | |
550 | ||
551 | ia64_psr(regs)->ri = slot; | |
552 | ||
553 | /* turn on single stepping */ | |
554 | ia64_psr(regs)->ss = 1; | |
555 | } | |
556 | ||
1f7ad57b | 557 | static int __kprobes pre_kprobes_handler(struct die_args *args) |
fd7b231f AK |
558 | { |
559 | struct kprobe *p; | |
560 | int ret = 0; | |
89cb14c0 | 561 | struct pt_regs *regs = args->regs; |
fd7b231f AK |
562 | kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs); |
563 | ||
564 | preempt_disable(); | |
565 | ||
566 | /* Handle recursion cases */ | |
567 | if (kprobe_running()) { | |
568 | p = get_kprobe(addr); | |
569 | if (p) { | |
570 | if (kprobe_status == KPROBE_HIT_SS) { | |
571 | unlock_kprobes(); | |
572 | goto no_kprobe; | |
573 | } | |
852caccc AK |
574 | /* We have reentered the pre_kprobe_handler(), since |
575 | * another probe was hit while within the handler. | |
576 | * We here save the original kprobes variables and | |
577 | * just single step on the instruction of the new probe | |
578 | * without calling any user handlers. | |
579 | */ | |
580 | save_previous_kprobe(); | |
581 | set_current_kprobe(p); | |
582 | p->nmissed++; | |
583 | prepare_ss(p, regs); | |
584 | kprobe_status = KPROBE_REENTER; | |
585 | return 1; | |
89cb14c0 | 586 | } else if (args->err == __IA64_BREAK_JPROBE) { |
fd7b231f AK |
587 | /* |
588 | * jprobe instrumented function just completed | |
589 | */ | |
590 | p = current_kprobe; | |
591 | if (p->break_handler && p->break_handler(p, regs)) { | |
592 | goto ss_probe; | |
593 | } | |
89cb14c0 KA |
594 | } else { |
595 | /* Not our break */ | |
596 | goto no_kprobe; | |
fd7b231f AK |
597 | } |
598 | } | |
599 | ||
600 | lock_kprobes(); | |
601 | p = get_kprobe(addr); | |
602 | if (!p) { | |
603 | unlock_kprobes(); | |
604 | goto no_kprobe; | |
605 | } | |
606 | ||
607 | kprobe_status = KPROBE_HIT_ACTIVE; | |
852caccc | 608 | set_current_kprobe(p); |
fd7b231f AK |
609 | |
610 | if (p->pre_handler && p->pre_handler(p, regs)) | |
611 | /* | |
612 | * Our pre-handler is specifically requesting that we just | |
9508dbfe RL |
613 | * do a return. This is used for both the jprobe pre-handler |
614 | * and the kretprobe trampoline | |
fd7b231f AK |
615 | */ |
616 | return 1; | |
617 | ||
618 | ss_probe: | |
619 | prepare_ss(p, regs); | |
620 | kprobe_status = KPROBE_HIT_SS; | |
621 | return 1; | |
622 | ||
623 | no_kprobe: | |
624 | preempt_enable_no_resched(); | |
625 | return ret; | |
626 | } | |
627 | ||
1f7ad57b | 628 | static int __kprobes post_kprobes_handler(struct pt_regs *regs) |
fd7b231f AK |
629 | { |
630 | if (!kprobe_running()) | |
631 | return 0; | |
632 | ||
852caccc AK |
633 | if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) { |
634 | kprobe_status = KPROBE_HIT_SSDONE; | |
fd7b231f | 635 | current_kprobe->post_handler(current_kprobe, regs, 0); |
852caccc | 636 | } |
fd7b231f AK |
637 | |
638 | resume_execution(current_kprobe, regs); | |
639 | ||
852caccc AK |
640 | /*Restore back the original saved kprobes variables and continue. */ |
641 | if (kprobe_status == KPROBE_REENTER) { | |
642 | restore_previous_kprobe(); | |
643 | goto out; | |
644 | } | |
645 | ||
fd7b231f | 646 | unlock_kprobes(); |
852caccc AK |
647 | |
648 | out: | |
fd7b231f AK |
649 | preempt_enable_no_resched(); |
650 | return 1; | |
651 | } | |
652 | ||
1f7ad57b | 653 | static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr) |
fd7b231f AK |
654 | { |
655 | if (!kprobe_running()) | |
656 | return 0; | |
657 | ||
658 | if (current_kprobe->fault_handler && | |
659 | current_kprobe->fault_handler(current_kprobe, regs, trapnr)) | |
660 | return 1; | |
661 | ||
662 | if (kprobe_status & KPROBE_HIT_SS) { | |
663 | resume_execution(current_kprobe, regs); | |
664 | unlock_kprobes(); | |
665 | preempt_enable_no_resched(); | |
666 | } | |
667 | ||
668 | return 0; | |
669 | } | |
670 | ||
1f7ad57b PP |
671 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, |
672 | unsigned long val, void *data) | |
fd7b231f AK |
673 | { |
674 | struct die_args *args = (struct die_args *)data; | |
675 | switch(val) { | |
676 | case DIE_BREAK: | |
89cb14c0 | 677 | if (pre_kprobes_handler(args)) |
fd7b231f AK |
678 | return NOTIFY_STOP; |
679 | break; | |
680 | case DIE_SS: | |
681 | if (post_kprobes_handler(args->regs)) | |
682 | return NOTIFY_STOP; | |
683 | break; | |
684 | case DIE_PAGE_FAULT: | |
685 | if (kprobes_fault_handler(args->regs, args->trapnr)) | |
686 | return NOTIFY_STOP; | |
687 | default: | |
688 | break; | |
689 | } | |
690 | return NOTIFY_DONE; | |
691 | } | |
692 | ||
1f7ad57b | 693 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 694 | { |
b2761dc2 AK |
695 | struct jprobe *jp = container_of(p, struct jprobe, kp); |
696 | unsigned long addr = ((struct fnptr *)(jp->entry))->ip; | |
fd7b231f | 697 | |
b2761dc2 AK |
698 | /* save architectural state */ |
699 | jprobe_saved_regs = *regs; | |
700 | ||
701 | /* after rfi, execute the jprobe instrumented function */ | |
702 | regs->cr_iip = addr & ~0xFULL; | |
703 | ia64_psr(regs)->ri = addr & 0xf; | |
704 | regs->r1 = ((struct fnptr *)(jp->entry))->gp; | |
705 | ||
706 | /* | |
707 | * fix the return address to our jprobe_inst_return() function | |
708 | * in the jprobes.S file | |
709 | */ | |
710 | regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip; | |
711 | ||
712 | return 1; | |
fd7b231f AK |
713 | } |
714 | ||
1f7ad57b | 715 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 716 | { |
b2761dc2 AK |
717 | *regs = jprobe_saved_regs; |
718 | return 1; | |
fd7b231f | 719 | } |
9508dbfe RL |
720 | |
721 | static struct kprobe trampoline_p = { | |
722 | .pre_handler = trampoline_probe_handler | |
723 | }; | |
724 | ||
6772926b | 725 | int __init arch_init_kprobes(void) |
9508dbfe RL |
726 | { |
727 | trampoline_p.addr = | |
728 | (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip; | |
729 | return register_kprobe(&trampoline_p); | |
730 | } |