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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> | |
fd7b231f AK |
29 | #include <linux/string.h> |
30 | #include <linux/slab.h> | |
31 | #include <linux/preempt.h> | |
32 | #include <linux/moduleloader.h> | |
33 | ||
34 | #include <asm/pgtable.h> | |
35 | #include <asm/kdebug.h> | |
c7b645f9 | 36 | #include <asm/sections.h> |
fd7b231f | 37 | |
b2761dc2 AK |
38 | extern void jprobe_inst_return(void); |
39 | ||
8a5c4dc5 AM |
40 | DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; |
41 | DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
fd7b231f AK |
42 | |
43 | enum instruction_type {A, I, M, F, B, L, X, u}; | |
44 | static enum instruction_type bundle_encoding[32][3] = { | |
45 | { M, I, I }, /* 00 */ | |
46 | { M, I, I }, /* 01 */ | |
47 | { M, I, I }, /* 02 */ | |
48 | { M, I, I }, /* 03 */ | |
49 | { M, L, X }, /* 04 */ | |
50 | { M, L, X }, /* 05 */ | |
51 | { u, u, u }, /* 06 */ | |
52 | { u, u, u }, /* 07 */ | |
53 | { M, M, I }, /* 08 */ | |
54 | { M, M, I }, /* 09 */ | |
55 | { M, M, I }, /* 0A */ | |
56 | { M, M, I }, /* 0B */ | |
57 | { M, F, I }, /* 0C */ | |
58 | { M, F, I }, /* 0D */ | |
59 | { M, M, F }, /* 0E */ | |
60 | { M, M, F }, /* 0F */ | |
61 | { M, I, B }, /* 10 */ | |
62 | { M, I, B }, /* 11 */ | |
63 | { M, B, B }, /* 12 */ | |
64 | { M, B, B }, /* 13 */ | |
65 | { u, u, u }, /* 14 */ | |
66 | { u, u, u }, /* 15 */ | |
67 | { B, B, B }, /* 16 */ | |
68 | { B, B, B }, /* 17 */ | |
69 | { M, M, B }, /* 18 */ | |
70 | { M, M, B }, /* 19 */ | |
71 | { u, u, u }, /* 1A */ | |
72 | { u, u, u }, /* 1B */ | |
73 | { M, F, B }, /* 1C */ | |
74 | { M, F, B }, /* 1D */ | |
75 | { u, u, u }, /* 1E */ | |
76 | { u, u, u }, /* 1F */ | |
77 | }; | |
78 | ||
a5403183 AK |
79 | /* |
80 | * In this function we check to see if the instruction | |
81 | * is IP relative instruction and update the kprobe | |
82 | * inst flag accordingly | |
83 | */ | |
1f7ad57b PP |
84 | static void __kprobes update_kprobe_inst_flag(uint template, uint slot, |
85 | uint major_opcode, | |
86 | unsigned long kprobe_inst, | |
87 | struct kprobe *p) | |
fd7b231f | 88 | { |
8bc76772 RL |
89 | p->ainsn.inst_flag = 0; |
90 | p->ainsn.target_br_reg = 0; | |
fd7b231f | 91 | |
deac66ae KA |
92 | /* Check for Break instruction |
93 | * Bits 37:40 Major opcode to be zero | |
94 | * Bits 27:32 X6 to be zero | |
95 | * Bits 32:35 X3 to be zero | |
96 | */ | |
97 | if ((!major_opcode) && (!((kprobe_inst >> 27) & 0x1FF)) ) { | |
98 | /* is a break instruction */ | |
99 | p->ainsn.inst_flag |= INST_FLAG_BREAK_INST; | |
100 | return; | |
101 | } | |
102 | ||
a5403183 AK |
103 | if (bundle_encoding[template][slot] == B) { |
104 | switch (major_opcode) { | |
105 | case INDIRECT_CALL_OPCODE: | |
106 | p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; | |
107 | p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); | |
108 | break; | |
109 | case IP_RELATIVE_PREDICT_OPCODE: | |
110 | case IP_RELATIVE_BRANCH_OPCODE: | |
111 | p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR; | |
112 | break; | |
113 | case IP_RELATIVE_CALL_OPCODE: | |
114 | p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR; | |
115 | p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; | |
116 | p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); | |
117 | break; | |
118 | } | |
119 | } else if (bundle_encoding[template][slot] == X) { | |
120 | switch (major_opcode) { | |
121 | case LONG_CALL_OPCODE: | |
122 | p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; | |
123 | p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); | |
124 | break; | |
125 | } | |
126 | } | |
127 | return; | |
128 | } | |
fd7b231f | 129 | |
708de8f1 AK |
130 | /* |
131 | * In this function we check to see if the instruction | |
132 | * on which we are inserting kprobe is supported. | |
133 | * Returns 0 if supported | |
134 | * Returns -EINVAL if unsupported | |
135 | */ | |
1f7ad57b PP |
136 | static int __kprobes unsupported_inst(uint template, uint slot, |
137 | uint major_opcode, | |
138 | unsigned long kprobe_inst, | |
139 | struct kprobe *p) | |
708de8f1 AK |
140 | { |
141 | unsigned long addr = (unsigned long)p->addr; | |
142 | ||
143 | if (bundle_encoding[template][slot] == I) { | |
144 | switch (major_opcode) { | |
145 | case 0x0: //I_UNIT_MISC_OPCODE: | |
146 | /* | |
147 | * Check for Integer speculation instruction | |
148 | * - Bit 33-35 to be equal to 0x1 | |
149 | */ | |
150 | if (((kprobe_inst >> 33) & 0x7) == 1) { | |
151 | printk(KERN_WARNING | |
152 | "Kprobes on speculation inst at <0x%lx> not supported\n", | |
153 | addr); | |
154 | return -EINVAL; | |
155 | } | |
156 | ||
157 | /* | |
158 | * IP relative mov instruction | |
159 | * - Bit 27-35 to be equal to 0x30 | |
160 | */ | |
161 | if (((kprobe_inst >> 27) & 0x1FF) == 0x30) { | |
162 | printk(KERN_WARNING | |
163 | "Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n", | |
164 | addr); | |
165 | return -EINVAL; | |
166 | ||
167 | } | |
168 | } | |
169 | } | |
170 | return 0; | |
171 | } | |
172 | ||
173 | ||
1674eafc AK |
174 | /* |
175 | * In this function we check to see if the instruction | |
176 | * (qp) cmpx.crel.ctype p1,p2=r2,r3 | |
177 | * on which we are inserting kprobe is cmp instruction | |
178 | * with ctype as unc. | |
179 | */ | |
1f7ad57b PP |
180 | static uint __kprobes is_cmp_ctype_unc_inst(uint template, uint slot, |
181 | uint major_opcode, | |
182 | unsigned long kprobe_inst) | |
1674eafc AK |
183 | { |
184 | cmp_inst_t cmp_inst; | |
185 | uint ctype_unc = 0; | |
186 | ||
187 | if (!((bundle_encoding[template][slot] == I) || | |
188 | (bundle_encoding[template][slot] == M))) | |
189 | goto out; | |
190 | ||
191 | if (!((major_opcode == 0xC) || (major_opcode == 0xD) || | |
192 | (major_opcode == 0xE))) | |
193 | goto out; | |
194 | ||
195 | cmp_inst.l = kprobe_inst; | |
196 | if ((cmp_inst.f.x2 == 0) || (cmp_inst.f.x2 == 1)) { | |
197 | /* Integere compare - Register Register (A6 type)*/ | |
198 | if ((cmp_inst.f.tb == 0) && (cmp_inst.f.ta == 0) | |
199 | &&(cmp_inst.f.c == 1)) | |
200 | ctype_unc = 1; | |
201 | } else if ((cmp_inst.f.x2 == 2)||(cmp_inst.f.x2 == 3)) { | |
202 | /* Integere compare - Immediate Register (A8 type)*/ | |
203 | if ((cmp_inst.f.ta == 0) &&(cmp_inst.f.c == 1)) | |
204 | ctype_unc = 1; | |
205 | } | |
206 | out: | |
207 | return ctype_unc; | |
208 | } | |
209 | ||
a5403183 AK |
210 | /* |
211 | * In this function we override the bundle with | |
212 | * the break instruction at the given slot. | |
213 | */ | |
1f7ad57b PP |
214 | static void __kprobes prepare_break_inst(uint template, uint slot, |
215 | uint major_opcode, | |
216 | unsigned long kprobe_inst, | |
217 | struct kprobe *p) | |
a5403183 AK |
218 | { |
219 | unsigned long break_inst = BREAK_INST; | |
220 | bundle_t *bundle = &p->ainsn.insn.bundle; | |
221 | ||
222 | /* | |
223 | * Copy the original kprobe_inst qualifying predicate(qp) | |
1674eafc AK |
224 | * to the break instruction iff !is_cmp_ctype_unc_inst |
225 | * because for cmp instruction with ctype equal to unc, | |
226 | * which is a special instruction always needs to be | |
227 | * executed regradless of qp | |
a5403183 | 228 | */ |
1674eafc AK |
229 | if (!is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst)) |
230 | break_inst |= (0x3f & kprobe_inst); | |
a5403183 AK |
231 | |
232 | switch (slot) { | |
233 | case 0: | |
234 | bundle->quad0.slot0 = break_inst; | |
235 | break; | |
236 | case 1: | |
237 | bundle->quad0.slot1_p0 = break_inst; | |
238 | bundle->quad1.slot1_p1 = break_inst >> (64-46); | |
239 | break; | |
240 | case 2: | |
241 | bundle->quad1.slot2 = break_inst; | |
242 | break; | |
8bc76772 | 243 | } |
cd2675bf | 244 | |
a5403183 AK |
245 | /* |
246 | * Update the instruction flag, so that we can | |
247 | * emulate the instruction properly after we | |
248 | * single step on original instruction | |
249 | */ | |
250 | update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p); | |
251 | } | |
252 | ||
253 | static inline void get_kprobe_inst(bundle_t *bundle, uint slot, | |
254 | unsigned long *kprobe_inst, uint *major_opcode) | |
255 | { | |
256 | unsigned long kprobe_inst_p0, kprobe_inst_p1; | |
257 | unsigned int template; | |
258 | ||
259 | template = bundle->quad0.template; | |
fd7b231f | 260 | |
fd7b231f | 261 | switch (slot) { |
a5403183 AK |
262 | case 0: |
263 | *major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT); | |
264 | *kprobe_inst = bundle->quad0.slot0; | |
fd7b231f | 265 | break; |
a5403183 AK |
266 | case 1: |
267 | *major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT); | |
268 | kprobe_inst_p0 = bundle->quad0.slot1_p0; | |
269 | kprobe_inst_p1 = bundle->quad1.slot1_p1; | |
270 | *kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46)); | |
fd7b231f | 271 | break; |
a5403183 AK |
272 | case 2: |
273 | *major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT); | |
274 | *kprobe_inst = bundle->quad1.slot2; | |
fd7b231f AK |
275 | break; |
276 | } | |
a5403183 | 277 | } |
fd7b231f | 278 | |
c7b645f9 KA |
279 | /* Returns non-zero if the addr is in the Interrupt Vector Table */ |
280 | static inline int in_ivt_functions(unsigned long addr) | |
281 | { | |
282 | return (addr >= (unsigned long)__start_ivt_text | |
283 | && addr < (unsigned long)__end_ivt_text); | |
284 | } | |
285 | ||
1f7ad57b PP |
286 | static int __kprobes valid_kprobe_addr(int template, int slot, |
287 | unsigned long addr) | |
a5403183 AK |
288 | { |
289 | if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) { | |
c7b645f9 KA |
290 | printk(KERN_WARNING "Attempting to insert unaligned kprobe " |
291 | "at 0x%lx\n", addr); | |
a5403183 | 292 | return -EINVAL; |
8bc76772 | 293 | } |
a528e21c | 294 | |
c7b645f9 KA |
295 | if (in_ivt_functions(addr)) { |
296 | printk(KERN_WARNING "Kprobes can't be inserted inside " | |
297 | "IVT functions at 0x%lx\n", addr); | |
298 | return -EINVAL; | |
299 | } | |
300 | ||
a528e21c RL |
301 | if (slot == 1 && bundle_encoding[template][1] != L) { |
302 | printk(KERN_WARNING "Inserting kprobes on slot #1 " | |
303 | "is not supported\n"); | |
304 | return -EINVAL; | |
305 | } | |
306 | ||
a5403183 AK |
307 | return 0; |
308 | } | |
309 | ||
8a5c4dc5 | 310 | static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) |
852caccc | 311 | { |
8a5c4dc5 AM |
312 | kcb->prev_kprobe.kp = kprobe_running(); |
313 | kcb->prev_kprobe.status = kcb->kprobe_status; | |
852caccc AK |
314 | } |
315 | ||
8a5c4dc5 | 316 | static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb) |
852caccc | 317 | { |
8a5c4dc5 AM |
318 | __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; |
319 | kcb->kprobe_status = kcb->prev_kprobe.status; | |
852caccc AK |
320 | } |
321 | ||
8a5c4dc5 AM |
322 | static inline void set_current_kprobe(struct kprobe *p, |
323 | struct kprobe_ctlblk *kcb) | |
852caccc | 324 | { |
8a5c4dc5 | 325 | __get_cpu_var(current_kprobe) = p; |
852caccc AK |
326 | } |
327 | ||
9508dbfe RL |
328 | static void kretprobe_trampoline(void) |
329 | { | |
330 | } | |
331 | ||
332 | /* | |
333 | * At this point the target function has been tricked into | |
334 | * returning into our trampoline. Lookup the associated instance | |
335 | * and then: | |
336 | * - call the handler function | |
337 | * - cleanup by marking the instance as unused | |
338 | * - long jump back to the original return address | |
339 | */ | |
1f7ad57b | 340 | int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) |
9508dbfe RL |
341 | { |
342 | struct kretprobe_instance *ri = NULL; | |
343 | struct hlist_head *head; | |
344 | struct hlist_node *node, *tmp; | |
991a51d8 | 345 | unsigned long flags, orig_ret_address = 0; |
9508dbfe RL |
346 | unsigned long trampoline_address = |
347 | ((struct fnptr *)kretprobe_trampoline)->ip; | |
348 | ||
991a51d8 | 349 | spin_lock_irqsave(&kretprobe_lock, flags); |
9138d581 | 350 | head = kretprobe_inst_table_head(current); |
9508dbfe RL |
351 | |
352 | /* | |
353 | * It is possible to have multiple instances associated with a given | |
354 | * task either because an multiple functions in the call path | |
355 | * have a return probe installed on them, and/or more then one return | |
356 | * return probe was registered for a target function. | |
357 | * | |
358 | * We can handle this because: | |
359 | * - instances are always inserted at the head of the list | |
360 | * - when multiple return probes are registered for the same | |
361 | * function, the first instance's ret_addr will point to the | |
362 | * real return address, and all the rest will point to | |
363 | * kretprobe_trampoline | |
364 | */ | |
365 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { | |
9138d581 | 366 | if (ri->task != current) |
9508dbfe | 367 | /* another task is sharing our hash bucket */ |
9138d581 | 368 | continue; |
9508dbfe RL |
369 | |
370 | if (ri->rp && ri->rp->handler) | |
371 | ri->rp->handler(ri, regs); | |
372 | ||
373 | orig_ret_address = (unsigned long)ri->ret_addr; | |
374 | recycle_rp_inst(ri); | |
375 | ||
376 | if (orig_ret_address != trampoline_address) | |
377 | /* | |
378 | * This is the real return address. Any other | |
379 | * instances associated with this task are for | |
380 | * other calls deeper on the call stack | |
381 | */ | |
382 | break; | |
383 | } | |
384 | ||
385 | BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address)); | |
386 | regs->cr_iip = orig_ret_address; | |
387 | ||
8a5c4dc5 | 388 | reset_current_kprobe(); |
991a51d8 | 389 | spin_unlock_irqrestore(&kretprobe_lock, flags); |
9508dbfe RL |
390 | preempt_enable_no_resched(); |
391 | ||
d217d545 AM |
392 | /* |
393 | * By returning a non-zero value, we are telling | |
394 | * kprobe_handler() that we don't want the post_handler | |
395 | * to run (and have re-enabled preemption) | |
396 | */ | |
9138d581 | 397 | return 1; |
9508dbfe RL |
398 | } |
399 | ||
991a51d8 | 400 | /* Called with kretprobe_lock held */ |
1f7ad57b PP |
401 | void __kprobes arch_prepare_kretprobe(struct kretprobe *rp, |
402 | struct pt_regs *regs) | |
9508dbfe RL |
403 | { |
404 | struct kretprobe_instance *ri; | |
405 | ||
406 | if ((ri = get_free_rp_inst(rp)) != NULL) { | |
407 | ri->rp = rp; | |
408 | ri->task = current; | |
409 | ri->ret_addr = (kprobe_opcode_t *)regs->b0; | |
410 | ||
411 | /* Replace the return addr with trampoline addr */ | |
412 | regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip; | |
413 | ||
414 | add_rp_inst(ri); | |
415 | } else { | |
416 | rp->nmissed++; | |
417 | } | |
418 | } | |
419 | ||
1f7ad57b | 420 | int __kprobes arch_prepare_kprobe(struct kprobe *p) |
a5403183 AK |
421 | { |
422 | unsigned long addr = (unsigned long) p->addr; | |
423 | unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL); | |
424 | unsigned long kprobe_inst=0; | |
425 | unsigned int slot = addr & 0xf, template, major_opcode = 0; | |
426 | bundle_t *bundle = &p->ainsn.insn.bundle; | |
427 | ||
428 | memcpy(&p->opcode.bundle, kprobe_addr, sizeof(bundle_t)); | |
429 | memcpy(&p->ainsn.insn.bundle, kprobe_addr, sizeof(bundle_t)); | |
430 | ||
431 | template = bundle->quad0.template; | |
432 | ||
433 | if(valid_kprobe_addr(template, slot, addr)) | |
434 | return -EINVAL; | |
435 | ||
436 | /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */ | |
437 | if (slot == 1 && bundle_encoding[template][1] == L) | |
438 | slot++; | |
439 | ||
440 | /* Get kprobe_inst and major_opcode from the bundle */ | |
441 | get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode); | |
442 | ||
708de8f1 AK |
443 | if (unsupported_inst(template, slot, major_opcode, kprobe_inst, p)) |
444 | return -EINVAL; | |
445 | ||
a5403183 | 446 | prepare_break_inst(template, slot, major_opcode, kprobe_inst, p); |
8bc76772 RL |
447 | |
448 | return 0; | |
449 | } | |
450 | ||
1f7ad57b | 451 | void __kprobes arch_arm_kprobe(struct kprobe *p) |
8bc76772 RL |
452 | { |
453 | unsigned long addr = (unsigned long)p->addr; | |
454 | unsigned long arm_addr = addr & ~0xFULL; | |
455 | ||
456 | memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t)); | |
fd7b231f AK |
457 | flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); |
458 | } | |
459 | ||
1f7ad57b | 460 | void __kprobes arch_disarm_kprobe(struct kprobe *p) |
fd7b231f AK |
461 | { |
462 | unsigned long addr = (unsigned long)p->addr; | |
463 | unsigned long arm_addr = addr & ~0xFULL; | |
464 | ||
465 | /* p->opcode contains the original unaltered bundle */ | |
466 | memcpy((char *) arm_addr, (char *) &p->opcode.bundle, sizeof(bundle_t)); | |
467 | flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); | |
468 | } | |
469 | ||
fd7b231f AK |
470 | /* |
471 | * We are resuming execution after a single step fault, so the pt_regs | |
472 | * structure reflects the register state after we executed the instruction | |
473 | * located in the kprobe (p->ainsn.insn.bundle). We still need to adjust | |
cd2675bf AK |
474 | * the ip to point back to the original stack address. To set the IP address |
475 | * to original stack address, handle the case where we need to fixup the | |
476 | * relative IP address and/or fixup branch register. | |
fd7b231f | 477 | */ |
1f7ad57b | 478 | static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 479 | { |
8bc76772 | 480 | unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL; |
cd2675bf AK |
481 | unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL; |
482 | unsigned long template; | |
483 | int slot = ((unsigned long)p->addr & 0xf); | |
fd7b231f | 484 | |
cd2675bf AK |
485 | template = p->opcode.bundle.quad0.template; |
486 | ||
487 | if (slot == 1 && bundle_encoding[template][1] == L) | |
488 | slot = 2; | |
489 | ||
490 | if (p->ainsn.inst_flag) { | |
491 | ||
492 | if (p->ainsn.inst_flag & INST_FLAG_FIX_RELATIVE_IP_ADDR) { | |
493 | /* Fix relative IP address */ | |
494 | regs->cr_iip = (regs->cr_iip - bundle_addr) + resume_addr; | |
495 | } | |
496 | ||
497 | if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) { | |
498 | /* | |
499 | * Fix target branch register, software convention is | |
500 | * to use either b0 or b6 or b7, so just checking | |
501 | * only those registers | |
502 | */ | |
503 | switch (p->ainsn.target_br_reg) { | |
504 | case 0: | |
505 | if ((regs->b0 == bundle_addr) || | |
506 | (regs->b0 == bundle_addr + 0x10)) { | |
507 | regs->b0 = (regs->b0 - bundle_addr) + | |
508 | resume_addr; | |
509 | } | |
510 | break; | |
511 | case 6: | |
512 | if ((regs->b6 == bundle_addr) || | |
513 | (regs->b6 == bundle_addr + 0x10)) { | |
514 | regs->b6 = (regs->b6 - bundle_addr) + | |
515 | resume_addr; | |
516 | } | |
517 | break; | |
518 | case 7: | |
519 | if ((regs->b7 == bundle_addr) || | |
520 | (regs->b7 == bundle_addr + 0x10)) { | |
521 | regs->b7 = (regs->b7 - bundle_addr) + | |
522 | resume_addr; | |
523 | } | |
524 | break; | |
525 | } /* end switch */ | |
526 | } | |
527 | goto turn_ss_off; | |
528 | } | |
fd7b231f | 529 | |
cd2675bf AK |
530 | if (slot == 2) { |
531 | if (regs->cr_iip == bundle_addr + 0x10) { | |
532 | regs->cr_iip = resume_addr + 0x10; | |
533 | } | |
534 | } else { | |
535 | if (regs->cr_iip == bundle_addr) { | |
536 | regs->cr_iip = resume_addr; | |
537 | } | |
a5403183 | 538 | } |
fd7b231f | 539 | |
cd2675bf AK |
540 | turn_ss_off: |
541 | /* Turn off Single Step bit */ | |
542 | ia64_psr(regs)->ss = 0; | |
fd7b231f AK |
543 | } |
544 | ||
1f7ad57b | 545 | static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 546 | { |
8bc76772 | 547 | unsigned long bundle_addr = (unsigned long) &p->opcode.bundle; |
fd7b231f AK |
548 | unsigned long slot = (unsigned long)p->addr & 0xf; |
549 | ||
deac66ae KA |
550 | /* single step inline if break instruction */ |
551 | if (p->ainsn.inst_flag == INST_FLAG_BREAK_INST) | |
552 | regs->cr_iip = (unsigned long)p->addr & ~0xFULL; | |
553 | else | |
554 | regs->cr_iip = bundle_addr & ~0xFULL; | |
fd7b231f AK |
555 | |
556 | if (slot > 2) | |
557 | slot = 0; | |
558 | ||
559 | ia64_psr(regs)->ri = slot; | |
560 | ||
561 | /* turn on single stepping */ | |
562 | ia64_psr(regs)->ss = 1; | |
563 | } | |
564 | ||
661e5a3d KA |
565 | static int __kprobes is_ia64_break_inst(struct pt_regs *regs) |
566 | { | |
567 | unsigned int slot = ia64_psr(regs)->ri; | |
568 | unsigned int template, major_opcode; | |
569 | unsigned long kprobe_inst; | |
570 | unsigned long *kprobe_addr = (unsigned long *)regs->cr_iip; | |
571 | bundle_t bundle; | |
572 | ||
573 | memcpy(&bundle, kprobe_addr, sizeof(bundle_t)); | |
574 | template = bundle.quad0.template; | |
575 | ||
576 | /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */ | |
577 | if (slot == 1 && bundle_encoding[template][1] == L) | |
578 | slot++; | |
579 | ||
580 | /* Get Kprobe probe instruction at given slot*/ | |
581 | get_kprobe_inst(&bundle, slot, &kprobe_inst, &major_opcode); | |
582 | ||
583 | /* For break instruction, | |
584 | * Bits 37:40 Major opcode to be zero | |
585 | * Bits 27:32 X6 to be zero | |
586 | * Bits 32:35 X3 to be zero | |
587 | */ | |
588 | if (major_opcode || ((kprobe_inst >> 27) & 0x1FF) ) { | |
589 | /* Not a break instruction */ | |
590 | return 0; | |
591 | } | |
592 | ||
593 | /* Is a break instruction */ | |
594 | return 1; | |
595 | } | |
596 | ||
1f7ad57b | 597 | static int __kprobes pre_kprobes_handler(struct die_args *args) |
fd7b231f AK |
598 | { |
599 | struct kprobe *p; | |
600 | int ret = 0; | |
89cb14c0 | 601 | struct pt_regs *regs = args->regs; |
fd7b231f | 602 | kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs); |
d217d545 AM |
603 | struct kprobe_ctlblk *kcb; |
604 | ||
605 | /* | |
606 | * We don't want to be preempted for the entire | |
607 | * duration of kprobe processing | |
608 | */ | |
609 | preempt_disable(); | |
610 | kcb = get_kprobe_ctlblk(); | |
fd7b231f | 611 | |
fd7b231f AK |
612 | /* Handle recursion cases */ |
613 | if (kprobe_running()) { | |
614 | p = get_kprobe(addr); | |
615 | if (p) { | |
8a5c4dc5 | 616 | if ((kcb->kprobe_status == KPROBE_HIT_SS) && |
deac66ae KA |
617 | (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) { |
618 | ia64_psr(regs)->ss = 0; | |
fd7b231f AK |
619 | goto no_kprobe; |
620 | } | |
852caccc AK |
621 | /* We have reentered the pre_kprobe_handler(), since |
622 | * another probe was hit while within the handler. | |
623 | * We here save the original kprobes variables and | |
624 | * just single step on the instruction of the new probe | |
625 | * without calling any user handlers. | |
626 | */ | |
8a5c4dc5 AM |
627 | save_previous_kprobe(kcb); |
628 | set_current_kprobe(p, kcb); | |
bf8d5c52 | 629 | kprobes_inc_nmissed_count(p); |
852caccc | 630 | prepare_ss(p, regs); |
8a5c4dc5 | 631 | kcb->kprobe_status = KPROBE_REENTER; |
852caccc | 632 | return 1; |
89cb14c0 | 633 | } else if (args->err == __IA64_BREAK_JPROBE) { |
fd7b231f AK |
634 | /* |
635 | * jprobe instrumented function just completed | |
636 | */ | |
8a5c4dc5 | 637 | p = __get_cpu_var(current_kprobe); |
fd7b231f AK |
638 | if (p->break_handler && p->break_handler(p, regs)) { |
639 | goto ss_probe; | |
640 | } | |
89cb14c0 KA |
641 | } else { |
642 | /* Not our break */ | |
643 | goto no_kprobe; | |
fd7b231f AK |
644 | } |
645 | } | |
646 | ||
fd7b231f AK |
647 | p = get_kprobe(addr); |
648 | if (!p) { | |
661e5a3d KA |
649 | if (!is_ia64_break_inst(regs)) { |
650 | /* | |
651 | * The breakpoint instruction was removed right | |
652 | * after we hit it. Another cpu has removed | |
653 | * either a probepoint or a debugger breakpoint | |
654 | * at this address. In either case, no further | |
655 | * handling of this interrupt is appropriate. | |
656 | */ | |
657 | ret = 1; | |
658 | ||
659 | } | |
660 | ||
661 | /* Not one of our break, let kernel handle it */ | |
fd7b231f AK |
662 | goto no_kprobe; |
663 | } | |
664 | ||
8a5c4dc5 AM |
665 | set_current_kprobe(p, kcb); |
666 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; | |
fd7b231f AK |
667 | |
668 | if (p->pre_handler && p->pre_handler(p, regs)) | |
669 | /* | |
670 | * Our pre-handler is specifically requesting that we just | |
9508dbfe RL |
671 | * do a return. This is used for both the jprobe pre-handler |
672 | * and the kretprobe trampoline | |
fd7b231f AK |
673 | */ |
674 | return 1; | |
675 | ||
676 | ss_probe: | |
677 | prepare_ss(p, regs); | |
8a5c4dc5 | 678 | kcb->kprobe_status = KPROBE_HIT_SS; |
fd7b231f AK |
679 | return 1; |
680 | ||
681 | no_kprobe: | |
d217d545 | 682 | preempt_enable_no_resched(); |
fd7b231f AK |
683 | return ret; |
684 | } | |
685 | ||
1f7ad57b | 686 | static int __kprobes post_kprobes_handler(struct pt_regs *regs) |
fd7b231f | 687 | { |
8a5c4dc5 AM |
688 | struct kprobe *cur = kprobe_running(); |
689 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
690 | ||
691 | if (!cur) | |
fd7b231f AK |
692 | return 0; |
693 | ||
8a5c4dc5 AM |
694 | if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { |
695 | kcb->kprobe_status = KPROBE_HIT_SSDONE; | |
696 | cur->post_handler(cur, regs, 0); | |
852caccc | 697 | } |
fd7b231f | 698 | |
8a5c4dc5 | 699 | resume_execution(cur, regs); |
fd7b231f | 700 | |
852caccc | 701 | /*Restore back the original saved kprobes variables and continue. */ |
8a5c4dc5 AM |
702 | if (kcb->kprobe_status == KPROBE_REENTER) { |
703 | restore_previous_kprobe(kcb); | |
852caccc AK |
704 | goto out; |
705 | } | |
8a5c4dc5 | 706 | reset_current_kprobe(); |
852caccc AK |
707 | |
708 | out: | |
fd7b231f AK |
709 | preempt_enable_no_resched(); |
710 | return 1; | |
711 | } | |
712 | ||
1f7ad57b | 713 | static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr) |
fd7b231f | 714 | { |
8a5c4dc5 AM |
715 | struct kprobe *cur = kprobe_running(); |
716 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
717 | ||
8a5c4dc5 | 718 | if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) |
fd7b231f AK |
719 | return 1; |
720 | ||
8a5c4dc5 AM |
721 | if (kcb->kprobe_status & KPROBE_HIT_SS) { |
722 | resume_execution(cur, regs); | |
723 | reset_current_kprobe(); | |
fd7b231f AK |
724 | preempt_enable_no_resched(); |
725 | } | |
726 | ||
727 | return 0; | |
728 | } | |
729 | ||
1f7ad57b PP |
730 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, |
731 | unsigned long val, void *data) | |
fd7b231f AK |
732 | { |
733 | struct die_args *args = (struct die_args *)data; | |
66ff2d06 AM |
734 | int ret = NOTIFY_DONE; |
735 | ||
fd7b231f AK |
736 | switch(val) { |
737 | case DIE_BREAK: | |
9138d581 | 738 | /* err is break number from ia64_bad_break() */ |
5a94bcfd | 739 | if (args->err == 0x80200 || args->err == 0x80300 || args->err == 0) |
9138d581 KO |
740 | if (pre_kprobes_handler(args)) |
741 | ret = NOTIFY_STOP; | |
fd7b231f | 742 | break; |
9138d581 KO |
743 | case DIE_FAULT: |
744 | /* err is vector number from ia64_fault() */ | |
745 | if (args->err == 36) | |
746 | if (post_kprobes_handler(args->regs)) | |
747 | ret = NOTIFY_STOP; | |
fd7b231f AK |
748 | break; |
749 | case DIE_PAGE_FAULT: | |
d217d545 AM |
750 | /* kprobe_running() needs smp_processor_id() */ |
751 | preempt_disable(); | |
752 | if (kprobe_running() && | |
753 | kprobes_fault_handler(args->regs, args->trapnr)) | |
66ff2d06 | 754 | ret = NOTIFY_STOP; |
d217d545 | 755 | preempt_enable(); |
fd7b231f AK |
756 | default: |
757 | break; | |
758 | } | |
66ff2d06 | 759 | return ret; |
fd7b231f AK |
760 | } |
761 | ||
1f7ad57b | 762 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 763 | { |
b2761dc2 AK |
764 | struct jprobe *jp = container_of(p, struct jprobe, kp); |
765 | unsigned long addr = ((struct fnptr *)(jp->entry))->ip; | |
8a5c4dc5 | 766 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
fd7b231f | 767 | |
b2761dc2 | 768 | /* save architectural state */ |
8a5c4dc5 | 769 | kcb->jprobe_saved_regs = *regs; |
b2761dc2 AK |
770 | |
771 | /* after rfi, execute the jprobe instrumented function */ | |
772 | regs->cr_iip = addr & ~0xFULL; | |
773 | ia64_psr(regs)->ri = addr & 0xf; | |
774 | regs->r1 = ((struct fnptr *)(jp->entry))->gp; | |
775 | ||
776 | /* | |
777 | * fix the return address to our jprobe_inst_return() function | |
778 | * in the jprobes.S file | |
779 | */ | |
780 | regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip; | |
781 | ||
782 | return 1; | |
fd7b231f AK |
783 | } |
784 | ||
1f7ad57b | 785 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 786 | { |
8a5c4dc5 AM |
787 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
788 | ||
789 | *regs = kcb->jprobe_saved_regs; | |
d217d545 | 790 | preempt_enable_no_resched(); |
b2761dc2 | 791 | return 1; |
fd7b231f | 792 | } |
9508dbfe RL |
793 | |
794 | static struct kprobe trampoline_p = { | |
795 | .pre_handler = trampoline_probe_handler | |
796 | }; | |
797 | ||
6772926b | 798 | int __init arch_init_kprobes(void) |
9508dbfe RL |
799 | { |
800 | trampoline_p.addr = | |
801 | (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip; | |
802 | return register_kprobe(&trampoline_p); | |
803 | } |