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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 | ||
fd7b231f AK |
26 | #include <linux/kprobes.h> |
27 | #include <linux/ptrace.h> | |
fd7b231f AK |
28 | #include <linux/string.h> |
29 | #include <linux/slab.h> | |
30 | #include <linux/preempt.h> | |
31 | #include <linux/moduleloader.h> | |
32 | ||
33 | #include <asm/pgtable.h> | |
34 | #include <asm/kdebug.h> | |
c7b645f9 | 35 | #include <asm/sections.h> |
c04c1c81 | 36 | #include <asm/uaccess.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 | ||
3ca269d8 | 253 | static void __kprobes get_kprobe_inst(bundle_t *bundle, uint slot, |
a5403183 AK |
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 | 279 | /* Returns non-zero if the addr is in the Interrupt Vector Table */ |
3ca269d8 | 280 | static int __kprobes in_ivt_functions(unsigned long addr) |
c7b645f9 KA |
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 | ||
3ca269d8 | 310 | static void __kprobes 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 | ||
3ca269d8 | 316 | static void __kprobes 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 | ||
3ca269d8 | 322 | static void __kprobes set_current_kprobe(struct kprobe *p, |
8a5c4dc5 | 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 | ||
a9ad965e | 451 | void __kprobes flush_insn_slot(struct kprobe *p) |
452 | { | |
453 | unsigned long arm_addr; | |
454 | ||
455 | arm_addr = ((unsigned long)&p->opcode.bundle) & ~0xFULL; | |
456 | flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); | |
457 | } | |
458 | ||
1f7ad57b | 459 | void __kprobes arch_arm_kprobe(struct kprobe *p) |
8bc76772 RL |
460 | { |
461 | unsigned long addr = (unsigned long)p->addr; | |
462 | unsigned long arm_addr = addr & ~0xFULL; | |
463 | ||
a9ad965e | 464 | flush_insn_slot(p); |
8bc76772 | 465 | memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t)); |
fd7b231f AK |
466 | flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); |
467 | } | |
468 | ||
1f7ad57b | 469 | void __kprobes arch_disarm_kprobe(struct kprobe *p) |
fd7b231f AK |
470 | { |
471 | unsigned long addr = (unsigned long)p->addr; | |
472 | unsigned long arm_addr = addr & ~0xFULL; | |
473 | ||
474 | /* p->opcode contains the original unaltered bundle */ | |
475 | memcpy((char *) arm_addr, (char *) &p->opcode.bundle, sizeof(bundle_t)); | |
476 | flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); | |
477 | } | |
478 | ||
fd7b231f AK |
479 | /* |
480 | * We are resuming execution after a single step fault, so the pt_regs | |
481 | * structure reflects the register state after we executed the instruction | |
482 | * located in the kprobe (p->ainsn.insn.bundle). We still need to adjust | |
cd2675bf AK |
483 | * the ip to point back to the original stack address. To set the IP address |
484 | * to original stack address, handle the case where we need to fixup the | |
485 | * relative IP address and/or fixup branch register. | |
fd7b231f | 486 | */ |
1f7ad57b | 487 | static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 488 | { |
8bc76772 | 489 | unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL; |
cd2675bf AK |
490 | unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL; |
491 | unsigned long template; | |
492 | int slot = ((unsigned long)p->addr & 0xf); | |
fd7b231f | 493 | |
cd2675bf AK |
494 | template = p->opcode.bundle.quad0.template; |
495 | ||
496 | if (slot == 1 && bundle_encoding[template][1] == L) | |
497 | slot = 2; | |
498 | ||
499 | if (p->ainsn.inst_flag) { | |
500 | ||
501 | if (p->ainsn.inst_flag & INST_FLAG_FIX_RELATIVE_IP_ADDR) { | |
502 | /* Fix relative IP address */ | |
503 | regs->cr_iip = (regs->cr_iip - bundle_addr) + resume_addr; | |
504 | } | |
505 | ||
506 | if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) { | |
507 | /* | |
508 | * Fix target branch register, software convention is | |
509 | * to use either b0 or b6 or b7, so just checking | |
510 | * only those registers | |
511 | */ | |
512 | switch (p->ainsn.target_br_reg) { | |
513 | case 0: | |
514 | if ((regs->b0 == bundle_addr) || | |
515 | (regs->b0 == bundle_addr + 0x10)) { | |
516 | regs->b0 = (regs->b0 - bundle_addr) + | |
517 | resume_addr; | |
518 | } | |
519 | break; | |
520 | case 6: | |
521 | if ((regs->b6 == bundle_addr) || | |
522 | (regs->b6 == bundle_addr + 0x10)) { | |
523 | regs->b6 = (regs->b6 - bundle_addr) + | |
524 | resume_addr; | |
525 | } | |
526 | break; | |
527 | case 7: | |
528 | if ((regs->b7 == bundle_addr) || | |
529 | (regs->b7 == bundle_addr + 0x10)) { | |
530 | regs->b7 = (regs->b7 - bundle_addr) + | |
531 | resume_addr; | |
532 | } | |
533 | break; | |
534 | } /* end switch */ | |
535 | } | |
536 | goto turn_ss_off; | |
537 | } | |
fd7b231f | 538 | |
cd2675bf AK |
539 | if (slot == 2) { |
540 | if (regs->cr_iip == bundle_addr + 0x10) { | |
541 | regs->cr_iip = resume_addr + 0x10; | |
542 | } | |
543 | } else { | |
544 | if (regs->cr_iip == bundle_addr) { | |
545 | regs->cr_iip = resume_addr; | |
546 | } | |
a5403183 | 547 | } |
fd7b231f | 548 | |
cd2675bf AK |
549 | turn_ss_off: |
550 | /* Turn off Single Step bit */ | |
551 | ia64_psr(regs)->ss = 0; | |
fd7b231f AK |
552 | } |
553 | ||
1f7ad57b | 554 | static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 555 | { |
8bc76772 | 556 | unsigned long bundle_addr = (unsigned long) &p->opcode.bundle; |
fd7b231f AK |
557 | unsigned long slot = (unsigned long)p->addr & 0xf; |
558 | ||
deac66ae KA |
559 | /* single step inline if break instruction */ |
560 | if (p->ainsn.inst_flag == INST_FLAG_BREAK_INST) | |
561 | regs->cr_iip = (unsigned long)p->addr & ~0xFULL; | |
562 | else | |
563 | regs->cr_iip = bundle_addr & ~0xFULL; | |
fd7b231f AK |
564 | |
565 | if (slot > 2) | |
566 | slot = 0; | |
567 | ||
568 | ia64_psr(regs)->ri = slot; | |
569 | ||
570 | /* turn on single stepping */ | |
571 | ia64_psr(regs)->ss = 1; | |
572 | } | |
573 | ||
661e5a3d KA |
574 | static int __kprobes is_ia64_break_inst(struct pt_regs *regs) |
575 | { | |
576 | unsigned int slot = ia64_psr(regs)->ri; | |
577 | unsigned int template, major_opcode; | |
578 | unsigned long kprobe_inst; | |
579 | unsigned long *kprobe_addr = (unsigned long *)regs->cr_iip; | |
580 | bundle_t bundle; | |
581 | ||
582 | memcpy(&bundle, kprobe_addr, sizeof(bundle_t)); | |
583 | template = bundle.quad0.template; | |
584 | ||
585 | /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */ | |
586 | if (slot == 1 && bundle_encoding[template][1] == L) | |
587 | slot++; | |
588 | ||
589 | /* Get Kprobe probe instruction at given slot*/ | |
590 | get_kprobe_inst(&bundle, slot, &kprobe_inst, &major_opcode); | |
591 | ||
592 | /* For break instruction, | |
593 | * Bits 37:40 Major opcode to be zero | |
594 | * Bits 27:32 X6 to be zero | |
595 | * Bits 32:35 X3 to be zero | |
596 | */ | |
597 | if (major_opcode || ((kprobe_inst >> 27) & 0x1FF) ) { | |
598 | /* Not a break instruction */ | |
599 | return 0; | |
600 | } | |
601 | ||
602 | /* Is a break instruction */ | |
603 | return 1; | |
604 | } | |
605 | ||
1f7ad57b | 606 | static int __kprobes pre_kprobes_handler(struct die_args *args) |
fd7b231f AK |
607 | { |
608 | struct kprobe *p; | |
609 | int ret = 0; | |
89cb14c0 | 610 | struct pt_regs *regs = args->regs; |
fd7b231f | 611 | kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs); |
d217d545 AM |
612 | struct kprobe_ctlblk *kcb; |
613 | ||
614 | /* | |
615 | * We don't want to be preempted for the entire | |
616 | * duration of kprobe processing | |
617 | */ | |
618 | preempt_disable(); | |
619 | kcb = get_kprobe_ctlblk(); | |
fd7b231f | 620 | |
fd7b231f AK |
621 | /* Handle recursion cases */ |
622 | if (kprobe_running()) { | |
623 | p = get_kprobe(addr); | |
624 | if (p) { | |
8a5c4dc5 | 625 | if ((kcb->kprobe_status == KPROBE_HIT_SS) && |
deac66ae KA |
626 | (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) { |
627 | ia64_psr(regs)->ss = 0; | |
fd7b231f AK |
628 | goto no_kprobe; |
629 | } | |
852caccc AK |
630 | /* We have reentered the pre_kprobe_handler(), since |
631 | * another probe was hit while within the handler. | |
632 | * We here save the original kprobes variables and | |
633 | * just single step on the instruction of the new probe | |
634 | * without calling any user handlers. | |
635 | */ | |
8a5c4dc5 AM |
636 | save_previous_kprobe(kcb); |
637 | set_current_kprobe(p, kcb); | |
bf8d5c52 | 638 | kprobes_inc_nmissed_count(p); |
852caccc | 639 | prepare_ss(p, regs); |
8a5c4dc5 | 640 | kcb->kprobe_status = KPROBE_REENTER; |
852caccc | 641 | return 1; |
89cb14c0 | 642 | } else if (args->err == __IA64_BREAK_JPROBE) { |
fd7b231f AK |
643 | /* |
644 | * jprobe instrumented function just completed | |
645 | */ | |
8a5c4dc5 | 646 | p = __get_cpu_var(current_kprobe); |
fd7b231f AK |
647 | if (p->break_handler && p->break_handler(p, regs)) { |
648 | goto ss_probe; | |
649 | } | |
eb3a7292 KA |
650 | } else if (!is_ia64_break_inst(regs)) { |
651 | /* The breakpoint instruction was removed by | |
652 | * another cpu right after we hit, no further | |
653 | * handling of this interrupt is appropriate | |
654 | */ | |
655 | ret = 1; | |
656 | goto no_kprobe; | |
89cb14c0 KA |
657 | } else { |
658 | /* Not our break */ | |
659 | goto no_kprobe; | |
fd7b231f AK |
660 | } |
661 | } | |
662 | ||
fd7b231f AK |
663 | p = get_kprobe(addr); |
664 | if (!p) { | |
661e5a3d KA |
665 | if (!is_ia64_break_inst(regs)) { |
666 | /* | |
667 | * The breakpoint instruction was removed right | |
668 | * after we hit it. Another cpu has removed | |
669 | * either a probepoint or a debugger breakpoint | |
670 | * at this address. In either case, no further | |
671 | * handling of this interrupt is appropriate. | |
672 | */ | |
673 | ret = 1; | |
674 | ||
675 | } | |
676 | ||
677 | /* Not one of our break, let kernel handle it */ | |
fd7b231f AK |
678 | goto no_kprobe; |
679 | } | |
680 | ||
8a5c4dc5 AM |
681 | set_current_kprobe(p, kcb); |
682 | kcb->kprobe_status = KPROBE_HIT_ACTIVE; | |
fd7b231f AK |
683 | |
684 | if (p->pre_handler && p->pre_handler(p, regs)) | |
685 | /* | |
686 | * Our pre-handler is specifically requesting that we just | |
9508dbfe RL |
687 | * do a return. This is used for both the jprobe pre-handler |
688 | * and the kretprobe trampoline | |
fd7b231f AK |
689 | */ |
690 | return 1; | |
691 | ||
692 | ss_probe: | |
693 | prepare_ss(p, regs); | |
8a5c4dc5 | 694 | kcb->kprobe_status = KPROBE_HIT_SS; |
fd7b231f AK |
695 | return 1; |
696 | ||
697 | no_kprobe: | |
d217d545 | 698 | preempt_enable_no_resched(); |
fd7b231f AK |
699 | return ret; |
700 | } | |
701 | ||
1f7ad57b | 702 | static int __kprobes post_kprobes_handler(struct pt_regs *regs) |
fd7b231f | 703 | { |
8a5c4dc5 AM |
704 | struct kprobe *cur = kprobe_running(); |
705 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
706 | ||
707 | if (!cur) | |
fd7b231f AK |
708 | return 0; |
709 | ||
8a5c4dc5 AM |
710 | if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { |
711 | kcb->kprobe_status = KPROBE_HIT_SSDONE; | |
712 | cur->post_handler(cur, regs, 0); | |
852caccc | 713 | } |
fd7b231f | 714 | |
8a5c4dc5 | 715 | resume_execution(cur, regs); |
fd7b231f | 716 | |
852caccc | 717 | /*Restore back the original saved kprobes variables and continue. */ |
8a5c4dc5 AM |
718 | if (kcb->kprobe_status == KPROBE_REENTER) { |
719 | restore_previous_kprobe(kcb); | |
852caccc AK |
720 | goto out; |
721 | } | |
8a5c4dc5 | 722 | reset_current_kprobe(); |
852caccc AK |
723 | |
724 | out: | |
fd7b231f AK |
725 | preempt_enable_no_resched(); |
726 | return 1; | |
727 | } | |
728 | ||
1f7ad57b | 729 | static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr) |
fd7b231f | 730 | { |
8a5c4dc5 AM |
731 | struct kprobe *cur = kprobe_running(); |
732 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | |
733 | ||
fd7b231f | 734 | |
c04c1c81 PP |
735 | switch(kcb->kprobe_status) { |
736 | case KPROBE_HIT_SS: | |
737 | case KPROBE_REENTER: | |
738 | /* | |
739 | * We are here because the instruction being single | |
740 | * stepped caused a page fault. We reset the current | |
741 | * kprobe and the instruction pointer points back to | |
742 | * the probe address and allow the page fault handler | |
743 | * to continue as a normal page fault. | |
744 | */ | |
745 | regs->cr_iip = ((unsigned long)cur->addr) & ~0xFULL; | |
746 | ia64_psr(regs)->ri = ((unsigned long)cur->addr) & 0xf; | |
747 | if (kcb->kprobe_status == KPROBE_REENTER) | |
748 | restore_previous_kprobe(kcb); | |
749 | else | |
750 | reset_current_kprobe(); | |
fd7b231f | 751 | preempt_enable_no_resched(); |
c04c1c81 PP |
752 | break; |
753 | case KPROBE_HIT_ACTIVE: | |
754 | case KPROBE_HIT_SSDONE: | |
755 | /* | |
756 | * We increment the nmissed count for accounting, | |
757 | * we can also use npre/npostfault count for accouting | |
758 | * these specific fault cases. | |
759 | */ | |
760 | kprobes_inc_nmissed_count(cur); | |
761 | ||
762 | /* | |
763 | * We come here because instructions in the pre/post | |
764 | * handler caused the page_fault, this could happen | |
765 | * if handler tries to access user space by | |
766 | * copy_from_user(), get_user() etc. Let the | |
767 | * user-specified handler try to fix it first. | |
768 | */ | |
769 | if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) | |
770 | return 1; | |
771 | ||
772 | /* | |
773 | * Let ia64_do_page_fault() fix it. | |
774 | */ | |
775 | break; | |
776 | default: | |
777 | break; | |
fd7b231f AK |
778 | } |
779 | ||
780 | return 0; | |
781 | } | |
782 | ||
1f7ad57b PP |
783 | int __kprobes kprobe_exceptions_notify(struct notifier_block *self, |
784 | unsigned long val, void *data) | |
fd7b231f AK |
785 | { |
786 | struct die_args *args = (struct die_args *)data; | |
66ff2d06 AM |
787 | int ret = NOTIFY_DONE; |
788 | ||
2326c770 | 789 | if (args->regs && user_mode(args->regs)) |
790 | return ret; | |
791 | ||
fd7b231f AK |
792 | switch(val) { |
793 | case DIE_BREAK: | |
9138d581 | 794 | /* err is break number from ia64_bad_break() */ |
5a94bcfd | 795 | if (args->err == 0x80200 || args->err == 0x80300 || args->err == 0) |
9138d581 KO |
796 | if (pre_kprobes_handler(args)) |
797 | ret = NOTIFY_STOP; | |
fd7b231f | 798 | break; |
9138d581 KO |
799 | case DIE_FAULT: |
800 | /* err is vector number from ia64_fault() */ | |
801 | if (args->err == 36) | |
802 | if (post_kprobes_handler(args->regs)) | |
803 | ret = NOTIFY_STOP; | |
fd7b231f AK |
804 | break; |
805 | case DIE_PAGE_FAULT: | |
d217d545 AM |
806 | /* kprobe_running() needs smp_processor_id() */ |
807 | preempt_disable(); | |
808 | if (kprobe_running() && | |
809 | kprobes_fault_handler(args->regs, args->trapnr)) | |
66ff2d06 | 810 | ret = NOTIFY_STOP; |
d217d545 | 811 | preempt_enable(); |
fd7b231f AK |
812 | default: |
813 | break; | |
814 | } | |
66ff2d06 | 815 | return ret; |
fd7b231f AK |
816 | } |
817 | ||
d3ef1f5a ZY |
818 | struct param_bsp_cfm { |
819 | unsigned long ip; | |
820 | unsigned long *bsp; | |
821 | unsigned long cfm; | |
822 | }; | |
823 | ||
824 | static void ia64_get_bsp_cfm(struct unw_frame_info *info, void *arg) | |
825 | { | |
826 | unsigned long ip; | |
827 | struct param_bsp_cfm *lp = arg; | |
828 | ||
829 | do { | |
830 | unw_get_ip(info, &ip); | |
831 | if (ip == 0) | |
832 | break; | |
833 | if (ip == lp->ip) { | |
834 | unw_get_bsp(info, (unsigned long*)&lp->bsp); | |
835 | unw_get_cfm(info, (unsigned long*)&lp->cfm); | |
836 | return; | |
837 | } | |
838 | } while (unw_unwind(info) >= 0); | |
839 | lp->bsp = 0; | |
840 | lp->cfm = 0; | |
841 | return; | |
842 | } | |
843 | ||
1f7ad57b | 844 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 845 | { |
b2761dc2 AK |
846 | struct jprobe *jp = container_of(p, struct jprobe, kp); |
847 | unsigned long addr = ((struct fnptr *)(jp->entry))->ip; | |
8a5c4dc5 | 848 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
d3ef1f5a ZY |
849 | struct param_bsp_cfm pa; |
850 | int bytes; | |
851 | ||
852 | /* | |
853 | * Callee owns the argument space and could overwrite it, eg | |
854 | * tail call optimization. So to be absolutely safe | |
855 | * we save the argument space before transfering the control | |
856 | * to instrumented jprobe function which runs in | |
857 | * the process context | |
858 | */ | |
859 | pa.ip = regs->cr_iip; | |
860 | unw_init_running(ia64_get_bsp_cfm, &pa); | |
861 | bytes = (char *)ia64_rse_skip_regs(pa.bsp, pa.cfm & 0x3f) | |
862 | - (char *)pa.bsp; | |
863 | memcpy( kcb->jprobes_saved_stacked_regs, | |
864 | pa.bsp, | |
865 | bytes ); | |
866 | kcb->bsp = pa.bsp; | |
867 | kcb->cfm = pa.cfm; | |
fd7b231f | 868 | |
b2761dc2 | 869 | /* save architectural state */ |
8a5c4dc5 | 870 | kcb->jprobe_saved_regs = *regs; |
b2761dc2 AK |
871 | |
872 | /* after rfi, execute the jprobe instrumented function */ | |
873 | regs->cr_iip = addr & ~0xFULL; | |
874 | ia64_psr(regs)->ri = addr & 0xf; | |
875 | regs->r1 = ((struct fnptr *)(jp->entry))->gp; | |
876 | ||
877 | /* | |
878 | * fix the return address to our jprobe_inst_return() function | |
879 | * in the jprobes.S file | |
880 | */ | |
881 | regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip; | |
882 | ||
883 | return 1; | |
fd7b231f AK |
884 | } |
885 | ||
1f7ad57b | 886 | int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) |
fd7b231f | 887 | { |
8a5c4dc5 | 888 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
d3ef1f5a | 889 | int bytes; |
8a5c4dc5 | 890 | |
d3ef1f5a | 891 | /* restoring architectural state */ |
8a5c4dc5 | 892 | *regs = kcb->jprobe_saved_regs; |
d3ef1f5a ZY |
893 | |
894 | /* restoring the original argument space */ | |
895 | flush_register_stack(); | |
896 | bytes = (char *)ia64_rse_skip_regs(kcb->bsp, kcb->cfm & 0x3f) | |
897 | - (char *)kcb->bsp; | |
898 | memcpy( kcb->bsp, | |
899 | kcb->jprobes_saved_stacked_regs, | |
900 | bytes ); | |
901 | invalidate_stacked_regs(); | |
902 | ||
d217d545 | 903 | preempt_enable_no_resched(); |
b2761dc2 | 904 | return 1; |
fd7b231f | 905 | } |
9508dbfe RL |
906 | |
907 | static struct kprobe trampoline_p = { | |
908 | .pre_handler = trampoline_probe_handler | |
909 | }; | |
910 | ||
6772926b | 911 | int __init arch_init_kprobes(void) |
9508dbfe RL |
912 | { |
913 | trampoline_p.addr = | |
914 | (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip; | |
915 | return register_kprobe(&trampoline_p); | |
916 | } |