2 * Kernel Probes (KProbes)
3 * arch/ia64/kernel/kprobes.c
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.
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.
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.
19 * Copyright (C) IBM Corporation, 2002, 2004
20 * Copyright (C) Intel Corporation, 2005
22 * 2005-Apr Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy
23 * <anil.s.keshavamurthy@intel.com> adapted from i386
26 #include <linux/kprobes.h>
27 #include <linux/ptrace.h>
28 #include <linux/string.h>
29 #include <linux/slab.h>
30 #include <linux/preempt.h>
31 #include <linux/moduleloader.h>
32 #include <linux/kdebug.h>
34 #include <asm/pgtable.h>
35 #include <asm/sections.h>
36 #include <asm/uaccess.h>
38 extern void jprobe_inst_return(void);
40 DEFINE_PER_CPU(struct kprobe
*, current_kprobe
) = NULL
;
41 DEFINE_PER_CPU(struct kprobe_ctlblk
, kprobe_ctlblk
);
43 struct kretprobe_blackpoint kretprobe_blacklist
[] = {{NULL
, NULL
}};
45 enum instruction_type
{A
, I
, M
, F
, B
, L
, X
, u
};
46 static enum instruction_type bundle_encoding
[32][3] = {
81 /* Insert a long branch code */
82 static void __kprobes
set_brl_inst(void *from
, void *to
)
84 s64 rel
= ((s64
) to
- (s64
) from
) >> 4;
86 brl
= (bundle_t
*) ((u64
) from
& ~0xf);
87 brl
->quad0
.template = 0x05; /* [MLX](stop) */
88 brl
->quad0
.slot0
= NOP_M_INST
; /* nop.m 0x0 */
89 brl
->quad0
.slot1_p0
= ((rel
>> 20) & 0x7fffffffff) << 2;
90 brl
->quad1
.slot1_p1
= (((rel
>> 20) & 0x7fffffffff) << 2) >> (64 - 46);
91 /* brl.cond.sptk.many.clr rel<<4 (qp=0) */
92 brl
->quad1
.slot2
= BRL_INST(rel
>> 59, rel
& 0xfffff);
96 * In this function we check to see if the instruction
97 * is IP relative instruction and update the kprobe
98 * inst flag accordingly
100 static void __kprobes
update_kprobe_inst_flag(uint
template, uint slot
,
102 unsigned long kprobe_inst
,
105 p
->ainsn
.inst_flag
= 0;
106 p
->ainsn
.target_br_reg
= 0;
107 p
->ainsn
.slot
= slot
;
109 /* Check for Break instruction
110 * Bits 37:40 Major opcode to be zero
111 * Bits 27:32 X6 to be zero
112 * Bits 32:35 X3 to be zero
114 if ((!major_opcode
) && (!((kprobe_inst
>> 27) & 0x1FF)) ) {
115 /* is a break instruction */
116 p
->ainsn
.inst_flag
|= INST_FLAG_BREAK_INST
;
120 if (bundle_encoding
[template][slot
] == B
) {
121 switch (major_opcode
) {
122 case INDIRECT_CALL_OPCODE
:
123 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_BRANCH_REG
;
124 p
->ainsn
.target_br_reg
= ((kprobe_inst
>> 6) & 0x7);
126 case IP_RELATIVE_PREDICT_OPCODE
:
127 case IP_RELATIVE_BRANCH_OPCODE
:
128 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_RELATIVE_IP_ADDR
;
130 case IP_RELATIVE_CALL_OPCODE
:
131 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_RELATIVE_IP_ADDR
;
132 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_BRANCH_REG
;
133 p
->ainsn
.target_br_reg
= ((kprobe_inst
>> 6) & 0x7);
136 } else if (bundle_encoding
[template][slot
] == X
) {
137 switch (major_opcode
) {
138 case LONG_CALL_OPCODE
:
139 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_BRANCH_REG
;
140 p
->ainsn
.target_br_reg
= ((kprobe_inst
>> 6) & 0x7);
148 * In this function we check to see if the instruction
149 * (qp) cmpx.crel.ctype p1,p2=r2,r3
150 * on which we are inserting kprobe is cmp instruction
153 static uint __kprobes
is_cmp_ctype_unc_inst(uint
template, uint slot
,
155 unsigned long kprobe_inst
)
160 if (!((bundle_encoding
[template][slot
] == I
) ||
161 (bundle_encoding
[template][slot
] == M
)))
164 if (!((major_opcode
== 0xC) || (major_opcode
== 0xD) ||
165 (major_opcode
== 0xE)))
168 cmp_inst
.l
= kprobe_inst
;
169 if ((cmp_inst
.f
.x2
== 0) || (cmp_inst
.f
.x2
== 1)) {
170 /* Integer compare - Register Register (A6 type)*/
171 if ((cmp_inst
.f
.tb
== 0) && (cmp_inst
.f
.ta
== 0)
172 &&(cmp_inst
.f
.c
== 1))
174 } else if ((cmp_inst
.f
.x2
== 2)||(cmp_inst
.f
.x2
== 3)) {
175 /* Integer compare - Immediate Register (A8 type)*/
176 if ((cmp_inst
.f
.ta
== 0) &&(cmp_inst
.f
.c
== 1))
184 * In this function we check to see if the instruction
185 * on which we are inserting kprobe is supported.
186 * Returns qp value if supported
187 * Returns -EINVAL if unsupported
189 static int __kprobes
unsupported_inst(uint
template, uint slot
,
191 unsigned long kprobe_inst
,
196 qp
= kprobe_inst
& 0x3f;
197 if (is_cmp_ctype_unc_inst(template, slot
, major_opcode
, kprobe_inst
)) {
198 if (slot
== 1 && qp
) {
199 printk(KERN_WARNING
"Kprobes on cmp unc "
200 "instruction on slot 1 at <0x%lx> "
201 "is not supported\n", addr
);
207 else if (bundle_encoding
[template][slot
] == I
) {
208 if (major_opcode
== 0) {
210 * Check for Integer speculation instruction
211 * - Bit 33-35 to be equal to 0x1
213 if (((kprobe_inst
>> 33) & 0x7) == 1) {
215 "Kprobes on speculation inst at <0x%lx> not supported\n",
220 * IP relative mov instruction
221 * - Bit 27-35 to be equal to 0x30
223 if (((kprobe_inst
>> 27) & 0x1FF) == 0x30) {
225 "Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n",
231 else if ((major_opcode
== 5) && !(kprobe_inst
& (0xFUl
<< 33)) &&
232 (kprobe_inst
& (0x1UL
<< 12))) {
233 /* test bit instructions, tbit,tnat,tf
234 * bit 33-36 to be equal to 0
235 * bit 12 to be equal to 1
237 if (slot
== 1 && qp
) {
238 printk(KERN_WARNING
"Kprobes on test bit "
239 "instruction on slot at <0x%lx> "
240 "is not supported\n", addr
);
246 else if (bundle_encoding
[template][slot
] == B
) {
247 if (major_opcode
== 7) {
248 /* IP-Relative Predict major code is 7 */
249 printk(KERN_WARNING
"Kprobes on IP-Relative"
250 "Predict is not supported\n");
253 else if (major_opcode
== 2) {
254 /* Indirect Predict, major code is 2
255 * bit 27-32 to be equal to 10 or 11
257 int x6
=(kprobe_inst
>> 27) & 0x3F;
258 if ((x6
== 0x10) || (x6
== 0x11)) {
259 printk(KERN_WARNING
"Kprobes on "
260 "Indirect Predict is not supported\n");
265 /* kernel does not use float instruction, here for safety kprobe
266 * will judge whether it is fcmp/flass/float approximation instruction
268 else if (unlikely(bundle_encoding
[template][slot
] == F
)) {
269 if ((major_opcode
== 4 || major_opcode
== 5) &&
270 (kprobe_inst
& (0x1 << 12))) {
271 /* fcmp/fclass unc instruction */
272 if (slot
== 1 && qp
) {
273 printk(KERN_WARNING
"Kprobes on fcmp/fclass "
274 "instruction on slot at <0x%lx> "
275 "is not supported\n", addr
);
281 if ((major_opcode
== 0 || major_opcode
== 1) &&
282 (kprobe_inst
& (0x1UL
<< 33))) {
283 /* float Approximation instruction */
284 if (slot
== 1 && qp
) {
285 printk(KERN_WARNING
"Kprobes on float Approx "
286 "instr at <0x%lx> is not supported\n",
297 * In this function we override the bundle with
298 * the break instruction at the given slot.
300 static void __kprobes
prepare_break_inst(uint
template, uint slot
,
302 unsigned long kprobe_inst
,
306 unsigned long break_inst
= BREAK_INST
;
307 bundle_t
*bundle
= &p
->opcode
.bundle
;
310 * Copy the original kprobe_inst qualifying predicate(qp)
311 * to the break instruction
317 bundle
->quad0
.slot0
= break_inst
;
320 bundle
->quad0
.slot1_p0
= break_inst
;
321 bundle
->quad1
.slot1_p1
= break_inst
>> (64-46);
324 bundle
->quad1
.slot2
= break_inst
;
329 * Update the instruction flag, so that we can
330 * emulate the instruction properly after we
331 * single step on original instruction
333 update_kprobe_inst_flag(template, slot
, major_opcode
, kprobe_inst
, p
);
336 static void __kprobes
get_kprobe_inst(bundle_t
*bundle
, uint slot
,
337 unsigned long *kprobe_inst
, uint
*major_opcode
)
339 unsigned long kprobe_inst_p0
, kprobe_inst_p1
;
340 unsigned int template;
342 template = bundle
->quad0
.template;
346 *major_opcode
= (bundle
->quad0
.slot0
>> SLOT0_OPCODE_SHIFT
);
347 *kprobe_inst
= bundle
->quad0
.slot0
;
350 *major_opcode
= (bundle
->quad1
.slot1_p1
>> SLOT1_p1_OPCODE_SHIFT
);
351 kprobe_inst_p0
= bundle
->quad0
.slot1_p0
;
352 kprobe_inst_p1
= bundle
->quad1
.slot1_p1
;
353 *kprobe_inst
= kprobe_inst_p0
| (kprobe_inst_p1
<< (64-46));
356 *major_opcode
= (bundle
->quad1
.slot2
>> SLOT2_OPCODE_SHIFT
);
357 *kprobe_inst
= bundle
->quad1
.slot2
;
362 /* Returns non-zero if the addr is in the Interrupt Vector Table */
363 static int __kprobes
in_ivt_functions(unsigned long addr
)
365 return (addr
>= (unsigned long)__start_ivt_text
366 && addr
< (unsigned long)__end_ivt_text
);
369 static int __kprobes
valid_kprobe_addr(int template, int slot
,
372 if ((slot
> 2) || ((bundle_encoding
[template][1] == L
) && slot
> 1)) {
373 printk(KERN_WARNING
"Attempting to insert unaligned kprobe "
378 if (in_ivt_functions(addr
)) {
379 printk(KERN_WARNING
"Kprobes can't be inserted inside "
380 "IVT functions at 0x%lx\n", addr
);
387 static void __kprobes
save_previous_kprobe(struct kprobe_ctlblk
*kcb
)
390 i
= atomic_add_return(1, &kcb
->prev_kprobe_index
);
391 kcb
->prev_kprobe
[i
-1].kp
= kprobe_running();
392 kcb
->prev_kprobe
[i
-1].status
= kcb
->kprobe_status
;
395 static void __kprobes
restore_previous_kprobe(struct kprobe_ctlblk
*kcb
)
398 i
= atomic_read(&kcb
->prev_kprobe_index
);
399 __get_cpu_var(current_kprobe
) = kcb
->prev_kprobe
[i
-1].kp
;
400 kcb
->kprobe_status
= kcb
->prev_kprobe
[i
-1].status
;
401 atomic_sub(1, &kcb
->prev_kprobe_index
);
404 static void __kprobes
set_current_kprobe(struct kprobe
*p
,
405 struct kprobe_ctlblk
*kcb
)
407 __get_cpu_var(current_kprobe
) = p
;
410 static void kretprobe_trampoline(void)
415 * At this point the target function has been tricked into
416 * returning into our trampoline. Lookup the associated instance
418 * - call the handler function
419 * - cleanup by marking the instance as unused
420 * - long jump back to the original return address
422 int __kprobes
trampoline_probe_handler(struct kprobe
*p
, struct pt_regs
*regs
)
424 struct kretprobe_instance
*ri
= NULL
;
425 struct hlist_head
*head
, empty_rp
;
426 struct hlist_node
*node
, *tmp
;
427 unsigned long flags
, orig_ret_address
= 0;
428 unsigned long trampoline_address
=
429 ((struct fnptr
*)kretprobe_trampoline
)->ip
;
431 INIT_HLIST_HEAD(&empty_rp
);
432 kretprobe_hash_lock(current
, &head
, &flags
);
435 * It is possible to have multiple instances associated with a given
436 * task either because an multiple functions in the call path
437 * have a return probe installed on them, and/or more then one return
438 * return probe was registered for a target function.
440 * We can handle this because:
441 * - instances are always inserted at the head of the list
442 * - when multiple return probes are registered for the same
443 * function, the first instance's ret_addr will point to the
444 * real return address, and all the rest will point to
445 * kretprobe_trampoline
447 hlist_for_each_entry_safe(ri
, node
, tmp
, head
, hlist
) {
448 if (ri
->task
!= current
)
449 /* another task is sharing our hash bucket */
452 orig_ret_address
= (unsigned long)ri
->ret_addr
;
453 if (orig_ret_address
!= trampoline_address
)
455 * This is the real return address. Any other
456 * instances associated with this task are for
457 * other calls deeper on the call stack
462 regs
->cr_iip
= orig_ret_address
;
464 hlist_for_each_entry_safe(ri
, node
, tmp
, head
, hlist
) {
465 if (ri
->task
!= current
)
466 /* another task is sharing our hash bucket */
469 if (ri
->rp
&& ri
->rp
->handler
)
470 ri
->rp
->handler(ri
, regs
);
472 orig_ret_address
= (unsigned long)ri
->ret_addr
;
473 recycle_rp_inst(ri
, &empty_rp
);
475 if (orig_ret_address
!= trampoline_address
)
477 * This is the real return address. Any other
478 * instances associated with this task are for
479 * other calls deeper on the call stack
484 kretprobe_assert(ri
, orig_ret_address
, trampoline_address
);
486 reset_current_kprobe();
487 kretprobe_hash_unlock(current
, &flags
);
488 preempt_enable_no_resched();
490 hlist_for_each_entry_safe(ri
, node
, tmp
, &empty_rp
, hlist
) {
491 hlist_del(&ri
->hlist
);
495 * By returning a non-zero value, we are telling
496 * kprobe_handler() that we don't want the post_handler
497 * to run (and have re-enabled preemption)
502 void __kprobes
arch_prepare_kretprobe(struct kretprobe_instance
*ri
,
503 struct pt_regs
*regs
)
505 ri
->ret_addr
= (kprobe_opcode_t
*)regs
->b0
;
507 /* Replace the return addr with trampoline addr */
508 regs
->b0
= ((struct fnptr
*)kretprobe_trampoline
)->ip
;
511 /* Check the instruction in the slot is break */
512 static int __kprobes
__is_ia64_break_inst(bundle_t
*bundle
, uint slot
)
514 unsigned int major_opcode
;
515 unsigned int template = bundle
->quad0
.template;
516 unsigned long kprobe_inst
;
518 /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
519 if (slot
== 1 && bundle_encoding
[template][1] == L
)
522 /* Get Kprobe probe instruction at given slot*/
523 get_kprobe_inst(bundle
, slot
, &kprobe_inst
, &major_opcode
);
525 /* For break instruction,
526 * Bits 37:40 Major opcode to be zero
527 * Bits 27:32 X6 to be zero
528 * Bits 32:35 X3 to be zero
530 if (major_opcode
|| ((kprobe_inst
>> 27) & 0x1FF)) {
531 /* Not a break instruction */
535 /* Is a break instruction */
540 * In this function, we check whether the target bundle modifies IP or
541 * it triggers an exception. If so, it cannot be boostable.
543 static int __kprobes
can_boost(bundle_t
*bundle
, uint slot
,
544 unsigned long bundle_addr
)
546 unsigned int template = bundle
->quad0
.template;
549 if (search_exception_tables(bundle_addr
+ slot
) ||
550 __is_ia64_break_inst(bundle
, slot
))
551 return 0; /* exception may occur in this bundle*/
552 } while ((++slot
) < 3);
554 if (template >= 0x10 /* including B unit */ ||
555 template == 0x04 /* including X unit */ ||
556 template == 0x06) /* undefined */
562 /* Prepare long jump bundle and disables other boosters if need */
563 static void __kprobes
prepare_booster(struct kprobe
*p
)
565 unsigned long addr
= (unsigned long)p
->addr
& ~0xFULL
;
566 unsigned int slot
= (unsigned long)p
->addr
& 0xf;
567 struct kprobe
*other_kp
;
569 if (can_boost(&p
->ainsn
.insn
[0].bundle
, slot
, addr
)) {
570 set_brl_inst(&p
->ainsn
.insn
[1].bundle
, (bundle_t
*)addr
+ 1);
571 p
->ainsn
.inst_flag
|= INST_FLAG_BOOSTABLE
;
574 /* disables boosters in previous slots */
575 for (; addr
< (unsigned long)p
->addr
; addr
++) {
576 other_kp
= get_kprobe((void *)addr
);
578 other_kp
->ainsn
.inst_flag
&= ~INST_FLAG_BOOSTABLE
;
582 int __kprobes
arch_prepare_kprobe(struct kprobe
*p
)
584 unsigned long addr
= (unsigned long) p
->addr
;
585 unsigned long *kprobe_addr
= (unsigned long *)(addr
& ~0xFULL
);
586 unsigned long kprobe_inst
=0;
587 unsigned int slot
= addr
& 0xf, template, major_opcode
= 0;
591 bundle
= &((kprobe_opcode_t
*)kprobe_addr
)->bundle
;
592 template = bundle
->quad0
.template;
594 if(valid_kprobe_addr(template, slot
, addr
))
597 /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
598 if (slot
== 1 && bundle_encoding
[template][1] == L
)
601 /* Get kprobe_inst and major_opcode from the bundle */
602 get_kprobe_inst(bundle
, slot
, &kprobe_inst
, &major_opcode
);
604 qp
= unsupported_inst(template, slot
, major_opcode
, kprobe_inst
, addr
);
608 p
->ainsn
.insn
= get_insn_slot();
611 memcpy(&p
->opcode
, kprobe_addr
, sizeof(kprobe_opcode_t
));
612 memcpy(p
->ainsn
.insn
, kprobe_addr
, sizeof(kprobe_opcode_t
));
614 prepare_break_inst(template, slot
, major_opcode
, kprobe_inst
, p
, qp
);
621 void __kprobes
arch_arm_kprobe(struct kprobe
*p
)
623 unsigned long arm_addr
;
624 bundle_t
*src
, *dest
;
626 arm_addr
= ((unsigned long)p
->addr
) & ~0xFUL
;
627 dest
= &((kprobe_opcode_t
*)arm_addr
)->bundle
;
628 src
= &p
->opcode
.bundle
;
630 flush_icache_range((unsigned long)p
->ainsn
.insn
,
631 (unsigned long)p
->ainsn
.insn
+
632 sizeof(kprobe_opcode_t
) * MAX_INSN_SIZE
);
634 switch (p
->ainsn
.slot
) {
636 dest
->quad0
.slot0
= src
->quad0
.slot0
;
639 dest
->quad1
.slot1_p1
= src
->quad1
.slot1_p1
;
642 dest
->quad1
.slot2
= src
->quad1
.slot2
;
645 flush_icache_range(arm_addr
, arm_addr
+ sizeof(kprobe_opcode_t
));
648 void __kprobes
arch_disarm_kprobe(struct kprobe
*p
)
650 unsigned long arm_addr
;
651 bundle_t
*src
, *dest
;
653 arm_addr
= ((unsigned long)p
->addr
) & ~0xFUL
;
654 dest
= &((kprobe_opcode_t
*)arm_addr
)->bundle
;
655 /* p->ainsn.insn contains the original unaltered kprobe_opcode_t */
656 src
= &p
->ainsn
.insn
->bundle
;
657 switch (p
->ainsn
.slot
) {
659 dest
->quad0
.slot0
= src
->quad0
.slot0
;
662 dest
->quad1
.slot1_p1
= src
->quad1
.slot1_p1
;
665 dest
->quad1
.slot2
= src
->quad1
.slot2
;
668 flush_icache_range(arm_addr
, arm_addr
+ sizeof(kprobe_opcode_t
));
671 void __kprobes
arch_remove_kprobe(struct kprobe
*p
)
673 mutex_lock(&kprobe_mutex
);
674 free_insn_slot(p
->ainsn
.insn
, p
->ainsn
.inst_flag
& INST_FLAG_BOOSTABLE
);
675 mutex_unlock(&kprobe_mutex
);
678 * We are resuming execution after a single step fault, so the pt_regs
679 * structure reflects the register state after we executed the instruction
680 * located in the kprobe (p->ainsn.insn->bundle). We still need to adjust
681 * the ip to point back to the original stack address. To set the IP address
682 * to original stack address, handle the case where we need to fixup the
683 * relative IP address and/or fixup branch register.
685 static void __kprobes
resume_execution(struct kprobe
*p
, struct pt_regs
*regs
)
687 unsigned long bundle_addr
= (unsigned long) (&p
->ainsn
.insn
->bundle
);
688 unsigned long resume_addr
= (unsigned long)p
->addr
& ~0xFULL
;
689 unsigned long template;
690 int slot
= ((unsigned long)p
->addr
& 0xf);
692 template = p
->ainsn
.insn
->bundle
.quad0
.template;
694 if (slot
== 1 && bundle_encoding
[template][1] == L
)
697 if (p
->ainsn
.inst_flag
& ~INST_FLAG_BOOSTABLE
) {
699 if (p
->ainsn
.inst_flag
& INST_FLAG_FIX_RELATIVE_IP_ADDR
) {
700 /* Fix relative IP address */
701 regs
->cr_iip
= (regs
->cr_iip
- bundle_addr
) +
705 if (p
->ainsn
.inst_flag
& INST_FLAG_FIX_BRANCH_REG
) {
707 * Fix target branch register, software convention is
708 * to use either b0 or b6 or b7, so just checking
709 * only those registers
711 switch (p
->ainsn
.target_br_reg
) {
713 if ((regs
->b0
== bundle_addr
) ||
714 (regs
->b0
== bundle_addr
+ 0x10)) {
715 regs
->b0
= (regs
->b0
- bundle_addr
) +
720 if ((regs
->b6
== bundle_addr
) ||
721 (regs
->b6
== bundle_addr
+ 0x10)) {
722 regs
->b6
= (regs
->b6
- bundle_addr
) +
727 if ((regs
->b7
== bundle_addr
) ||
728 (regs
->b7
== bundle_addr
+ 0x10)) {
729 regs
->b7
= (regs
->b7
- bundle_addr
) +
739 if (regs
->cr_iip
== bundle_addr
+ 0x10) {
740 regs
->cr_iip
= resume_addr
+ 0x10;
743 if (regs
->cr_iip
== bundle_addr
) {
744 regs
->cr_iip
= resume_addr
;
749 /* Turn off Single Step bit */
750 ia64_psr(regs
)->ss
= 0;
753 static void __kprobes
prepare_ss(struct kprobe
*p
, struct pt_regs
*regs
)
755 unsigned long bundle_addr
= (unsigned long) &p
->ainsn
.insn
->bundle
;
756 unsigned long slot
= (unsigned long)p
->addr
& 0xf;
758 /* single step inline if break instruction */
759 if (p
->ainsn
.inst_flag
== INST_FLAG_BREAK_INST
)
760 regs
->cr_iip
= (unsigned long)p
->addr
& ~0xFULL
;
762 regs
->cr_iip
= bundle_addr
& ~0xFULL
;
767 ia64_psr(regs
)->ri
= slot
;
769 /* turn on single stepping */
770 ia64_psr(regs
)->ss
= 1;
773 static int __kprobes
is_ia64_break_inst(struct pt_regs
*regs
)
775 unsigned int slot
= ia64_psr(regs
)->ri
;
776 unsigned long *kprobe_addr
= (unsigned long *)regs
->cr_iip
;
779 memcpy(&bundle
, kprobe_addr
, sizeof(bundle_t
));
781 return __is_ia64_break_inst(&bundle
, slot
);
784 static int __kprobes
pre_kprobes_handler(struct die_args
*args
)
788 struct pt_regs
*regs
= args
->regs
;
789 kprobe_opcode_t
*addr
= (kprobe_opcode_t
*)instruction_pointer(regs
);
790 struct kprobe_ctlblk
*kcb
;
793 * We don't want to be preempted for the entire
794 * duration of kprobe processing
797 kcb
= get_kprobe_ctlblk();
799 /* Handle recursion cases */
800 if (kprobe_running()) {
801 p
= get_kprobe(addr
);
803 if ((kcb
->kprobe_status
== KPROBE_HIT_SS
) &&
804 (p
->ainsn
.inst_flag
== INST_FLAG_BREAK_INST
)) {
805 ia64_psr(regs
)->ss
= 0;
808 /* We have reentered the pre_kprobe_handler(), since
809 * another probe was hit while within the handler.
810 * We here save the original kprobes variables and
811 * just single step on the instruction of the new probe
812 * without calling any user handlers.
814 save_previous_kprobe(kcb
);
815 set_current_kprobe(p
, kcb
);
816 kprobes_inc_nmissed_count(p
);
818 kcb
->kprobe_status
= KPROBE_REENTER
;
820 } else if (args
->err
== __IA64_BREAK_JPROBE
) {
822 * jprobe instrumented function just completed
824 p
= __get_cpu_var(current_kprobe
);
825 if (p
->break_handler
&& p
->break_handler(p
, regs
)) {
828 } else if (!is_ia64_break_inst(regs
)) {
829 /* The breakpoint instruction was removed by
830 * another cpu right after we hit, no further
831 * handling of this interrupt is appropriate
841 p
= get_kprobe(addr
);
843 if (!is_ia64_break_inst(regs
)) {
845 * The breakpoint instruction was removed right
846 * after we hit it. Another cpu has removed
847 * either a probepoint or a debugger breakpoint
848 * at this address. In either case, no further
849 * handling of this interrupt is appropriate.
855 /* Not one of our break, let kernel handle it */
859 set_current_kprobe(p
, kcb
);
860 kcb
->kprobe_status
= KPROBE_HIT_ACTIVE
;
862 if (p
->pre_handler
&& p
->pre_handler(p
, regs
))
864 * Our pre-handler is specifically requesting that we just
865 * do a return. This is used for both the jprobe pre-handler
866 * and the kretprobe trampoline
871 #if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
872 if (p
->ainsn
.inst_flag
== INST_FLAG_BOOSTABLE
&& !p
->post_handler
) {
873 /* Boost up -- we can execute copied instructions directly */
874 ia64_psr(regs
)->ri
= p
->ainsn
.slot
;
875 regs
->cr_iip
= (unsigned long)&p
->ainsn
.insn
->bundle
& ~0xFULL
;
876 /* turn single stepping off */
877 ia64_psr(regs
)->ss
= 0;
879 reset_current_kprobe();
880 preempt_enable_no_resched();
885 kcb
->kprobe_status
= KPROBE_HIT_SS
;
889 preempt_enable_no_resched();
893 static int __kprobes
post_kprobes_handler(struct pt_regs
*regs
)
895 struct kprobe
*cur
= kprobe_running();
896 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
901 if ((kcb
->kprobe_status
!= KPROBE_REENTER
) && cur
->post_handler
) {
902 kcb
->kprobe_status
= KPROBE_HIT_SSDONE
;
903 cur
->post_handler(cur
, regs
, 0);
906 resume_execution(cur
, regs
);
908 /*Restore back the original saved kprobes variables and continue. */
909 if (kcb
->kprobe_status
== KPROBE_REENTER
) {
910 restore_previous_kprobe(kcb
);
913 reset_current_kprobe();
916 preempt_enable_no_resched();
920 int __kprobes
kprobe_fault_handler(struct pt_regs
*regs
, int trapnr
)
922 struct kprobe
*cur
= kprobe_running();
923 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
926 switch(kcb
->kprobe_status
) {
930 * We are here because the instruction being single
931 * stepped caused a page fault. We reset the current
932 * kprobe and the instruction pointer points back to
933 * the probe address and allow the page fault handler
934 * to continue as a normal page fault.
936 regs
->cr_iip
= ((unsigned long)cur
->addr
) & ~0xFULL
;
937 ia64_psr(regs
)->ri
= ((unsigned long)cur
->addr
) & 0xf;
938 if (kcb
->kprobe_status
== KPROBE_REENTER
)
939 restore_previous_kprobe(kcb
);
941 reset_current_kprobe();
942 preempt_enable_no_resched();
944 case KPROBE_HIT_ACTIVE
:
945 case KPROBE_HIT_SSDONE
:
947 * We increment the nmissed count for accounting,
948 * we can also use npre/npostfault count for accouting
949 * these specific fault cases.
951 kprobes_inc_nmissed_count(cur
);
954 * We come here because instructions in the pre/post
955 * handler caused the page_fault, this could happen
956 * if handler tries to access user space by
957 * copy_from_user(), get_user() etc. Let the
958 * user-specified handler try to fix it first.
960 if (cur
->fault_handler
&& cur
->fault_handler(cur
, regs
, trapnr
))
963 * In case the user-specified fault handler returned
964 * zero, try to fix up.
966 if (ia64_done_with_exception(regs
))
970 * Let ia64_do_page_fault() fix it.
980 int __kprobes
kprobe_exceptions_notify(struct notifier_block
*self
,
981 unsigned long val
, void *data
)
983 struct die_args
*args
= (struct die_args
*)data
;
984 int ret
= NOTIFY_DONE
;
986 if (args
->regs
&& user_mode(args
->regs
))
991 /* err is break number from ia64_bad_break() */
992 if ((args
->err
>> 12) == (__IA64_BREAK_KPROBE
>> 12)
993 || args
->err
== __IA64_BREAK_JPROBE
995 if (pre_kprobes_handler(args
))
999 /* err is vector number from ia64_fault() */
1000 if (args
->err
== 36)
1001 if (post_kprobes_handler(args
->regs
))
1010 struct param_bsp_cfm
{
1016 static void ia64_get_bsp_cfm(struct unw_frame_info
*info
, void *arg
)
1019 struct param_bsp_cfm
*lp
= arg
;
1022 unw_get_ip(info
, &ip
);
1026 unw_get_bsp(info
, (unsigned long*)&lp
->bsp
);
1027 unw_get_cfm(info
, (unsigned long*)&lp
->cfm
);
1030 } while (unw_unwind(info
) >= 0);
1036 unsigned long arch_deref_entry_point(void *entry
)
1038 return ((struct fnptr
*)entry
)->ip
;
1041 int __kprobes
setjmp_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
1043 struct jprobe
*jp
= container_of(p
, struct jprobe
, kp
);
1044 unsigned long addr
= arch_deref_entry_point(jp
->entry
);
1045 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
1046 struct param_bsp_cfm pa
;
1050 * Callee owns the argument space and could overwrite it, eg
1051 * tail call optimization. So to be absolutely safe
1052 * we save the argument space before transferring the control
1053 * to instrumented jprobe function which runs in
1054 * the process context
1056 pa
.ip
= regs
->cr_iip
;
1057 unw_init_running(ia64_get_bsp_cfm
, &pa
);
1058 bytes
= (char *)ia64_rse_skip_regs(pa
.bsp
, pa
.cfm
& 0x3f)
1060 memcpy( kcb
->jprobes_saved_stacked_regs
,
1066 /* save architectural state */
1067 kcb
->jprobe_saved_regs
= *regs
;
1069 /* after rfi, execute the jprobe instrumented function */
1070 regs
->cr_iip
= addr
& ~0xFULL
;
1071 ia64_psr(regs
)->ri
= addr
& 0xf;
1072 regs
->r1
= ((struct fnptr
*)(jp
->entry
))->gp
;
1075 * fix the return address to our jprobe_inst_return() function
1076 * in the jprobes.S file
1078 regs
->b0
= ((struct fnptr
*)(jprobe_inst_return
))->ip
;
1083 /* ia64 does not need this */
1084 void __kprobes
jprobe_return(void)
1088 int __kprobes
longjmp_break_handler(struct kprobe
*p
, struct pt_regs
*regs
)
1090 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
1093 /* restoring architectural state */
1094 *regs
= kcb
->jprobe_saved_regs
;
1096 /* restoring the original argument space */
1097 flush_register_stack();
1098 bytes
= (char *)ia64_rse_skip_regs(kcb
->bsp
, kcb
->cfm
& 0x3f)
1101 kcb
->jprobes_saved_stacked_regs
,
1103 invalidate_stacked_regs();
1105 preempt_enable_no_resched();
1109 static struct kprobe trampoline_p
= {
1110 .pre_handler
= trampoline_probe_handler
1113 int __init
arch_init_kprobes(void)
1116 (kprobe_opcode_t
*)((struct fnptr
*)kretprobe_trampoline
)->ip
;
1117 return register_kprobe(&trampoline_p
);
1120 int __kprobes
arch_trampoline_kprobe(struct kprobe
*p
)
1123 (kprobe_opcode_t
*)((struct fnptr
*)kretprobe_trampoline
)->ip
)