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 enum instruction_type
{A
, I
, M
, F
, B
, L
, X
, u
};
44 static enum instruction_type bundle_encoding
[32][3] = {
80 * In this function we check to see if the instruction
81 * is IP relative instruction and update the kprobe
82 * inst flag accordingly
84 static void __kprobes
update_kprobe_inst_flag(uint
template, uint slot
,
86 unsigned long kprobe_inst
,
89 p
->ainsn
.inst_flag
= 0;
90 p
->ainsn
.target_br_reg
= 0;
93 /* Check for Break instruction
94 * Bits 37:40 Major opcode to be zero
95 * Bits 27:32 X6 to be zero
96 * Bits 32:35 X3 to be zero
98 if ((!major_opcode
) && (!((kprobe_inst
>> 27) & 0x1FF)) ) {
99 /* is a break instruction */
100 p
->ainsn
.inst_flag
|= INST_FLAG_BREAK_INST
;
104 if (bundle_encoding
[template][slot
] == B
) {
105 switch (major_opcode
) {
106 case INDIRECT_CALL_OPCODE
:
107 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_BRANCH_REG
;
108 p
->ainsn
.target_br_reg
= ((kprobe_inst
>> 6) & 0x7);
110 case IP_RELATIVE_PREDICT_OPCODE
:
111 case IP_RELATIVE_BRANCH_OPCODE
:
112 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_RELATIVE_IP_ADDR
;
114 case IP_RELATIVE_CALL_OPCODE
:
115 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_RELATIVE_IP_ADDR
;
116 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_BRANCH_REG
;
117 p
->ainsn
.target_br_reg
= ((kprobe_inst
>> 6) & 0x7);
120 } else if (bundle_encoding
[template][slot
] == X
) {
121 switch (major_opcode
) {
122 case LONG_CALL_OPCODE
:
123 p
->ainsn
.inst_flag
|= INST_FLAG_FIX_BRANCH_REG
;
124 p
->ainsn
.target_br_reg
= ((kprobe_inst
>> 6) & 0x7);
132 * In this function we check to see if the instruction
133 * (qp) cmpx.crel.ctype p1,p2=r2,r3
134 * on which we are inserting kprobe is cmp instruction
137 static uint __kprobes
is_cmp_ctype_unc_inst(uint
template, uint slot
,
139 unsigned long kprobe_inst
)
144 if (!((bundle_encoding
[template][slot
] == I
) ||
145 (bundle_encoding
[template][slot
] == M
)))
148 if (!((major_opcode
== 0xC) || (major_opcode
== 0xD) ||
149 (major_opcode
== 0xE)))
152 cmp_inst
.l
= kprobe_inst
;
153 if ((cmp_inst
.f
.x2
== 0) || (cmp_inst
.f
.x2
== 1)) {
154 /* Integere compare - Register Register (A6 type)*/
155 if ((cmp_inst
.f
.tb
== 0) && (cmp_inst
.f
.ta
== 0)
156 &&(cmp_inst
.f
.c
== 1))
158 } else if ((cmp_inst
.f
.x2
== 2)||(cmp_inst
.f
.x2
== 3)) {
159 /* Integere compare - Immediate Register (A8 type)*/
160 if ((cmp_inst
.f
.ta
== 0) &&(cmp_inst
.f
.c
== 1))
168 * In this function we check to see if the instruction
169 * on which we are inserting kprobe is supported.
170 * Returns qp value if supported
171 * Returns -EINVAL if unsupported
173 static int __kprobes
unsupported_inst(uint
template, uint slot
,
175 unsigned long kprobe_inst
,
180 qp
= kprobe_inst
& 0x3f;
181 if (is_cmp_ctype_unc_inst(template, slot
, major_opcode
, kprobe_inst
)) {
182 if (slot
== 1 && qp
) {
183 printk(KERN_WARNING
"Kprobes on cmp unc"
184 "instruction on slot 1 at <0x%lx>"
185 "is not supported\n", addr
);
191 else if (bundle_encoding
[template][slot
] == I
) {
192 if (major_opcode
== 0) {
194 * Check for Integer speculation instruction
195 * - Bit 33-35 to be equal to 0x1
197 if (((kprobe_inst
>> 33) & 0x7) == 1) {
199 "Kprobes on speculation inst at <0x%lx> not supported\n",
204 * IP relative mov instruction
205 * - Bit 27-35 to be equal to 0x30
207 if (((kprobe_inst
>> 27) & 0x1FF) == 0x30) {
209 "Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n",
215 else if ((major_opcode
== 5) && !(kprobe_inst
& (0xFUl
<< 33)) &&
216 (kprobe_inst
& (0x1UL
<< 12))) {
217 /* test bit instructions, tbit,tnat,tf
218 * bit 33-36 to be equal to 0
219 * bit 12 to be equal to 1
221 if (slot
== 1 && qp
) {
222 printk(KERN_WARNING
"Kprobes on test bit"
223 "instruction on slot at <0x%lx>"
224 "is not supported\n", addr
);
230 else if (bundle_encoding
[template][slot
] == B
) {
231 if (major_opcode
== 7) {
232 /* IP-Relative Predict major code is 7 */
233 printk(KERN_WARNING
"Kprobes on IP-Relative"
234 "Predict is not supported\n");
237 else if (major_opcode
== 2) {
238 /* Indirect Predict, major code is 2
239 * bit 27-32 to be equal to 10 or 11
241 int x6
=(kprobe_inst
>> 27) & 0x3F;
242 if ((x6
== 0x10) || (x6
== 0x11)) {
243 printk(KERN_WARNING
"Kprobes on"
244 "Indirect Predict is not supported\n");
249 /* kernel does not use float instruction, here for safety kprobe
250 * will judge whether it is fcmp/flass/float approximation instruction
252 else if (unlikely(bundle_encoding
[template][slot
] == F
)) {
253 if ((major_opcode
== 4 || major_opcode
== 5) &&
254 (kprobe_inst
& (0x1 << 12))) {
255 /* fcmp/fclass unc instruction */
256 if (slot
== 1 && qp
) {
257 printk(KERN_WARNING
"Kprobes on fcmp/fclass "
258 "instruction on slot at <0x%lx> "
259 "is not supported\n", addr
);
265 if ((major_opcode
== 0 || major_opcode
== 1) &&
266 (kprobe_inst
& (0x1UL
<< 33))) {
267 /* float Approximation instruction */
268 if (slot
== 1 && qp
) {
269 printk(KERN_WARNING
"Kprobes on float Approx "
270 "instr at <0x%lx> is not supported\n",
281 * In this function we override the bundle with
282 * the break instruction at the given slot.
284 static void __kprobes
prepare_break_inst(uint
template, uint slot
,
286 unsigned long kprobe_inst
,
290 unsigned long break_inst
= BREAK_INST
;
291 bundle_t
*bundle
= &p
->opcode
.bundle
;
294 * Copy the original kprobe_inst qualifying predicate(qp)
295 * to the break instruction
301 bundle
->quad0
.slot0
= break_inst
;
304 bundle
->quad0
.slot1_p0
= break_inst
;
305 bundle
->quad1
.slot1_p1
= break_inst
>> (64-46);
308 bundle
->quad1
.slot2
= break_inst
;
313 * Update the instruction flag, so that we can
314 * emulate the instruction properly after we
315 * single step on original instruction
317 update_kprobe_inst_flag(template, slot
, major_opcode
, kprobe_inst
, p
);
320 static void __kprobes
get_kprobe_inst(bundle_t
*bundle
, uint slot
,
321 unsigned long *kprobe_inst
, uint
*major_opcode
)
323 unsigned long kprobe_inst_p0
, kprobe_inst_p1
;
324 unsigned int template;
326 template = bundle
->quad0
.template;
330 *major_opcode
= (bundle
->quad0
.slot0
>> SLOT0_OPCODE_SHIFT
);
331 *kprobe_inst
= bundle
->quad0
.slot0
;
334 *major_opcode
= (bundle
->quad1
.slot1_p1
>> SLOT1_p1_OPCODE_SHIFT
);
335 kprobe_inst_p0
= bundle
->quad0
.slot1_p0
;
336 kprobe_inst_p1
= bundle
->quad1
.slot1_p1
;
337 *kprobe_inst
= kprobe_inst_p0
| (kprobe_inst_p1
<< (64-46));
340 *major_opcode
= (bundle
->quad1
.slot2
>> SLOT2_OPCODE_SHIFT
);
341 *kprobe_inst
= bundle
->quad1
.slot2
;
346 /* Returns non-zero if the addr is in the Interrupt Vector Table */
347 static int __kprobes
in_ivt_functions(unsigned long addr
)
349 return (addr
>= (unsigned long)__start_ivt_text
350 && addr
< (unsigned long)__end_ivt_text
);
353 static int __kprobes
valid_kprobe_addr(int template, int slot
,
356 if ((slot
> 2) || ((bundle_encoding
[template][1] == L
) && slot
> 1)) {
357 printk(KERN_WARNING
"Attempting to insert unaligned kprobe "
362 if (in_ivt_functions(addr
)) {
363 printk(KERN_WARNING
"Kprobes can't be inserted inside "
364 "IVT functions at 0x%lx\n", addr
);
371 static void __kprobes
save_previous_kprobe(struct kprobe_ctlblk
*kcb
)
373 kcb
->prev_kprobe
.kp
= kprobe_running();
374 kcb
->prev_kprobe
.status
= kcb
->kprobe_status
;
377 static void __kprobes
restore_previous_kprobe(struct kprobe_ctlblk
*kcb
)
379 __get_cpu_var(current_kprobe
) = kcb
->prev_kprobe
.kp
;
380 kcb
->kprobe_status
= kcb
->prev_kprobe
.status
;
383 static void __kprobes
set_current_kprobe(struct kprobe
*p
,
384 struct kprobe_ctlblk
*kcb
)
386 __get_cpu_var(current_kprobe
) = p
;
389 static void kretprobe_trampoline(void)
394 * At this point the target function has been tricked into
395 * returning into our trampoline. Lookup the associated instance
397 * - call the handler function
398 * - cleanup by marking the instance as unused
399 * - long jump back to the original return address
401 int __kprobes
trampoline_probe_handler(struct kprobe
*p
, struct pt_regs
*regs
)
403 struct kretprobe_instance
*ri
= NULL
;
404 struct hlist_head
*head
, empty_rp
;
405 struct hlist_node
*node
, *tmp
;
406 unsigned long flags
, orig_ret_address
= 0;
407 unsigned long trampoline_address
=
408 ((struct fnptr
*)kretprobe_trampoline
)->ip
;
410 INIT_HLIST_HEAD(&empty_rp
);
411 spin_lock_irqsave(&kretprobe_lock
, flags
);
412 head
= kretprobe_inst_table_head(current
);
415 * It is possible to have multiple instances associated with a given
416 * task either because an multiple functions in the call path
417 * have a return probe installed on them, and/or more then one return
418 * return probe was registered for a target function.
420 * We can handle this because:
421 * - instances are always inserted at the head of the list
422 * - when multiple return probes are registered for the same
423 * function, the first instance's ret_addr will point to the
424 * real return address, and all the rest will point to
425 * kretprobe_trampoline
427 hlist_for_each_entry_safe(ri
, node
, tmp
, head
, hlist
) {
428 if (ri
->task
!= current
)
429 /* another task is sharing our hash bucket */
432 if (ri
->rp
&& ri
->rp
->handler
)
433 ri
->rp
->handler(ri
, regs
);
435 orig_ret_address
= (unsigned long)ri
->ret_addr
;
436 recycle_rp_inst(ri
, &empty_rp
);
438 if (orig_ret_address
!= trampoline_address
)
440 * This is the real return address. Any other
441 * instances associated with this task are for
442 * other calls deeper on the call stack
447 kretprobe_assert(ri
, orig_ret_address
, trampoline_address
);
449 regs
->cr_iip
= orig_ret_address
;
451 reset_current_kprobe();
452 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
453 preempt_enable_no_resched();
455 hlist_for_each_entry_safe(ri
, node
, tmp
, &empty_rp
, hlist
) {
456 hlist_del(&ri
->hlist
);
460 * By returning a non-zero value, we are telling
461 * kprobe_handler() that we don't want the post_handler
462 * to run (and have re-enabled preemption)
467 /* Called with kretprobe_lock held */
468 void __kprobes
arch_prepare_kretprobe(struct kretprobe_instance
*ri
,
469 struct pt_regs
*regs
)
471 ri
->ret_addr
= (kprobe_opcode_t
*)regs
->b0
;
473 /* Replace the return addr with trampoline addr */
474 regs
->b0
= ((struct fnptr
*)kretprobe_trampoline
)->ip
;
477 int __kprobes
arch_prepare_kprobe(struct kprobe
*p
)
479 unsigned long addr
= (unsigned long) p
->addr
;
480 unsigned long *kprobe_addr
= (unsigned long *)(addr
& ~0xFULL
);
481 unsigned long kprobe_inst
=0;
482 unsigned int slot
= addr
& 0xf, template, major_opcode
= 0;
486 bundle
= &((kprobe_opcode_t
*)kprobe_addr
)->bundle
;
487 template = bundle
->quad0
.template;
489 if(valid_kprobe_addr(template, slot
, addr
))
492 /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
493 if (slot
== 1 && bundle_encoding
[template][1] == L
)
496 /* Get kprobe_inst and major_opcode from the bundle */
497 get_kprobe_inst(bundle
, slot
, &kprobe_inst
, &major_opcode
);
499 qp
= unsupported_inst(template, slot
, major_opcode
, kprobe_inst
, addr
);
503 p
->ainsn
.insn
= get_insn_slot();
506 memcpy(&p
->opcode
, kprobe_addr
, sizeof(kprobe_opcode_t
));
507 memcpy(p
->ainsn
.insn
, kprobe_addr
, sizeof(kprobe_opcode_t
));
509 prepare_break_inst(template, slot
, major_opcode
, kprobe_inst
, p
, qp
);
514 void __kprobes
arch_arm_kprobe(struct kprobe
*p
)
516 unsigned long arm_addr
;
517 bundle_t
*src
, *dest
;
519 arm_addr
= ((unsigned long)p
->addr
) & ~0xFUL
;
520 dest
= &((kprobe_opcode_t
*)arm_addr
)->bundle
;
521 src
= &p
->opcode
.bundle
;
523 flush_icache_range((unsigned long)p
->ainsn
.insn
,
524 (unsigned long)p
->ainsn
.insn
+ sizeof(kprobe_opcode_t
));
525 switch (p
->ainsn
.slot
) {
527 dest
->quad0
.slot0
= src
->quad0
.slot0
;
530 dest
->quad1
.slot1_p1
= src
->quad1
.slot1_p1
;
533 dest
->quad1
.slot2
= src
->quad1
.slot2
;
536 flush_icache_range(arm_addr
, arm_addr
+ sizeof(kprobe_opcode_t
));
539 void __kprobes
arch_disarm_kprobe(struct kprobe
*p
)
541 unsigned long arm_addr
;
542 bundle_t
*src
, *dest
;
544 arm_addr
= ((unsigned long)p
->addr
) & ~0xFUL
;
545 dest
= &((kprobe_opcode_t
*)arm_addr
)->bundle
;
546 /* p->ainsn.insn contains the original unaltered kprobe_opcode_t */
547 src
= &p
->ainsn
.insn
->bundle
;
548 switch (p
->ainsn
.slot
) {
550 dest
->quad0
.slot0
= src
->quad0
.slot0
;
553 dest
->quad1
.slot1_p1
= src
->quad1
.slot1_p1
;
556 dest
->quad1
.slot2
= src
->quad1
.slot2
;
559 flush_icache_range(arm_addr
, arm_addr
+ sizeof(kprobe_opcode_t
));
562 void __kprobes
arch_remove_kprobe(struct kprobe
*p
)
564 mutex_lock(&kprobe_mutex
);
565 free_insn_slot(p
->ainsn
.insn
, 0);
566 mutex_unlock(&kprobe_mutex
);
569 * We are resuming execution after a single step fault, so the pt_regs
570 * structure reflects the register state after we executed the instruction
571 * located in the kprobe (p->ainsn.insn.bundle). We still need to adjust
572 * the ip to point back to the original stack address. To set the IP address
573 * to original stack address, handle the case where we need to fixup the
574 * relative IP address and/or fixup branch register.
576 static void __kprobes
resume_execution(struct kprobe
*p
, struct pt_regs
*regs
)
578 unsigned long bundle_addr
= (unsigned long) (&p
->ainsn
.insn
->bundle
);
579 unsigned long resume_addr
= (unsigned long)p
->addr
& ~0xFULL
;
580 unsigned long template;
581 int slot
= ((unsigned long)p
->addr
& 0xf);
583 template = p
->ainsn
.insn
->bundle
.quad0
.template;
585 if (slot
== 1 && bundle_encoding
[template][1] == L
)
588 if (p
->ainsn
.inst_flag
) {
590 if (p
->ainsn
.inst_flag
& INST_FLAG_FIX_RELATIVE_IP_ADDR
) {
591 /* Fix relative IP address */
592 regs
->cr_iip
= (regs
->cr_iip
- bundle_addr
) +
596 if (p
->ainsn
.inst_flag
& INST_FLAG_FIX_BRANCH_REG
) {
598 * Fix target branch register, software convention is
599 * to use either b0 or b6 or b7, so just checking
600 * only those registers
602 switch (p
->ainsn
.target_br_reg
) {
604 if ((regs
->b0
== bundle_addr
) ||
605 (regs
->b0
== bundle_addr
+ 0x10)) {
606 regs
->b0
= (regs
->b0
- bundle_addr
) +
611 if ((regs
->b6
== bundle_addr
) ||
612 (regs
->b6
== bundle_addr
+ 0x10)) {
613 regs
->b6
= (regs
->b6
- bundle_addr
) +
618 if ((regs
->b7
== bundle_addr
) ||
619 (regs
->b7
== bundle_addr
+ 0x10)) {
620 regs
->b7
= (regs
->b7
- bundle_addr
) +
630 if (regs
->cr_iip
== bundle_addr
+ 0x10) {
631 regs
->cr_iip
= resume_addr
+ 0x10;
634 if (regs
->cr_iip
== bundle_addr
) {
635 regs
->cr_iip
= resume_addr
;
640 /* Turn off Single Step bit */
641 ia64_psr(regs
)->ss
= 0;
644 static void __kprobes
prepare_ss(struct kprobe
*p
, struct pt_regs
*regs
)
646 unsigned long bundle_addr
= (unsigned long) &p
->ainsn
.insn
->bundle
;
647 unsigned long slot
= (unsigned long)p
->addr
& 0xf;
649 /* single step inline if break instruction */
650 if (p
->ainsn
.inst_flag
== INST_FLAG_BREAK_INST
)
651 regs
->cr_iip
= (unsigned long)p
->addr
& ~0xFULL
;
653 regs
->cr_iip
= bundle_addr
& ~0xFULL
;
658 ia64_psr(regs
)->ri
= slot
;
660 /* turn on single stepping */
661 ia64_psr(regs
)->ss
= 1;
664 static int __kprobes
is_ia64_break_inst(struct pt_regs
*regs
)
666 unsigned int slot
= ia64_psr(regs
)->ri
;
667 unsigned int template, major_opcode
;
668 unsigned long kprobe_inst
;
669 unsigned long *kprobe_addr
= (unsigned long *)regs
->cr_iip
;
672 memcpy(&bundle
, kprobe_addr
, sizeof(bundle_t
));
673 template = bundle
.quad0
.template;
675 /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
676 if (slot
== 1 && bundle_encoding
[template][1] == L
)
679 /* Get Kprobe probe instruction at given slot*/
680 get_kprobe_inst(&bundle
, slot
, &kprobe_inst
, &major_opcode
);
682 /* For break instruction,
683 * Bits 37:40 Major opcode to be zero
684 * Bits 27:32 X6 to be zero
685 * Bits 32:35 X3 to be zero
687 if (major_opcode
|| ((kprobe_inst
>> 27) & 0x1FF) ) {
688 /* Not a break instruction */
692 /* Is a break instruction */
696 static int __kprobes
pre_kprobes_handler(struct die_args
*args
)
700 struct pt_regs
*regs
= args
->regs
;
701 kprobe_opcode_t
*addr
= (kprobe_opcode_t
*)instruction_pointer(regs
);
702 struct kprobe_ctlblk
*kcb
;
705 * We don't want to be preempted for the entire
706 * duration of kprobe processing
709 kcb
= get_kprobe_ctlblk();
711 /* Handle recursion cases */
712 if (kprobe_running()) {
713 p
= get_kprobe(addr
);
715 if ((kcb
->kprobe_status
== KPROBE_HIT_SS
) &&
716 (p
->ainsn
.inst_flag
== INST_FLAG_BREAK_INST
)) {
717 ia64_psr(regs
)->ss
= 0;
720 /* We have reentered the pre_kprobe_handler(), since
721 * another probe was hit while within the handler.
722 * We here save the original kprobes variables and
723 * just single step on the instruction of the new probe
724 * without calling any user handlers.
726 save_previous_kprobe(kcb
);
727 set_current_kprobe(p
, kcb
);
728 kprobes_inc_nmissed_count(p
);
730 kcb
->kprobe_status
= KPROBE_REENTER
;
732 } else if (args
->err
== __IA64_BREAK_JPROBE
) {
734 * jprobe instrumented function just completed
736 p
= __get_cpu_var(current_kprobe
);
737 if (p
->break_handler
&& p
->break_handler(p
, regs
)) {
740 } else if (!is_ia64_break_inst(regs
)) {
741 /* The breakpoint instruction was removed by
742 * another cpu right after we hit, no further
743 * handling of this interrupt is appropriate
753 p
= get_kprobe(addr
);
755 if (!is_ia64_break_inst(regs
)) {
757 * The breakpoint instruction was removed right
758 * after we hit it. Another cpu has removed
759 * either a probepoint or a debugger breakpoint
760 * at this address. In either case, no further
761 * handling of this interrupt is appropriate.
767 /* Not one of our break, let kernel handle it */
771 set_current_kprobe(p
, kcb
);
772 kcb
->kprobe_status
= KPROBE_HIT_ACTIVE
;
774 if (p
->pre_handler
&& p
->pre_handler(p
, regs
))
776 * Our pre-handler is specifically requesting that we just
777 * do a return. This is used for both the jprobe pre-handler
778 * and the kretprobe trampoline
784 kcb
->kprobe_status
= KPROBE_HIT_SS
;
788 preempt_enable_no_resched();
792 static int __kprobes
post_kprobes_handler(struct pt_regs
*regs
)
794 struct kprobe
*cur
= kprobe_running();
795 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
800 if ((kcb
->kprobe_status
!= KPROBE_REENTER
) && cur
->post_handler
) {
801 kcb
->kprobe_status
= KPROBE_HIT_SSDONE
;
802 cur
->post_handler(cur
, regs
, 0);
805 resume_execution(cur
, regs
);
807 /*Restore back the original saved kprobes variables and continue. */
808 if (kcb
->kprobe_status
== KPROBE_REENTER
) {
809 restore_previous_kprobe(kcb
);
812 reset_current_kprobe();
815 preempt_enable_no_resched();
819 static int __kprobes
kprobes_fault_handler(struct pt_regs
*regs
, int trapnr
)
821 struct kprobe
*cur
= kprobe_running();
822 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
825 switch(kcb
->kprobe_status
) {
829 * We are here because the instruction being single
830 * stepped caused a page fault. We reset the current
831 * kprobe and the instruction pointer points back to
832 * the probe address and allow the page fault handler
833 * to continue as a normal page fault.
835 regs
->cr_iip
= ((unsigned long)cur
->addr
) & ~0xFULL
;
836 ia64_psr(regs
)->ri
= ((unsigned long)cur
->addr
) & 0xf;
837 if (kcb
->kprobe_status
== KPROBE_REENTER
)
838 restore_previous_kprobe(kcb
);
840 reset_current_kprobe();
841 preempt_enable_no_resched();
843 case KPROBE_HIT_ACTIVE
:
844 case KPROBE_HIT_SSDONE
:
846 * We increment the nmissed count for accounting,
847 * we can also use npre/npostfault count for accouting
848 * these specific fault cases.
850 kprobes_inc_nmissed_count(cur
);
853 * We come here because instructions in the pre/post
854 * handler caused the page_fault, this could happen
855 * if handler tries to access user space by
856 * copy_from_user(), get_user() etc. Let the
857 * user-specified handler try to fix it first.
859 if (cur
->fault_handler
&& cur
->fault_handler(cur
, regs
, trapnr
))
862 * In case the user-specified fault handler returned
863 * zero, try to fix up.
865 if (ia64_done_with_exception(regs
))
869 * Let ia64_do_page_fault() fix it.
879 int __kprobes
kprobe_exceptions_notify(struct notifier_block
*self
,
880 unsigned long val
, void *data
)
882 struct die_args
*args
= (struct die_args
*)data
;
883 int ret
= NOTIFY_DONE
;
885 if (args
->regs
&& user_mode(args
->regs
))
890 /* err is break number from ia64_bad_break() */
891 if ((args
->err
>> 12) == (__IA64_BREAK_KPROBE
>> 12)
892 || args
->err
== __IA64_BREAK_JPROBE
894 if (pre_kprobes_handler(args
))
898 /* err is vector number from ia64_fault() */
900 if (post_kprobes_handler(args
->regs
))
904 /* kprobe_running() needs smp_processor_id() */
906 if (kprobe_running() &&
907 kprobes_fault_handler(args
->regs
, args
->trapnr
))
916 struct param_bsp_cfm
{
922 static void ia64_get_bsp_cfm(struct unw_frame_info
*info
, void *arg
)
925 struct param_bsp_cfm
*lp
= arg
;
928 unw_get_ip(info
, &ip
);
932 unw_get_bsp(info
, (unsigned long*)&lp
->bsp
);
933 unw_get_cfm(info
, (unsigned long*)&lp
->cfm
);
936 } while (unw_unwind(info
) >= 0);
942 int __kprobes
setjmp_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
944 struct jprobe
*jp
= container_of(p
, struct jprobe
, kp
);
945 unsigned long addr
= ((struct fnptr
*)(jp
->entry
))->ip
;
946 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
947 struct param_bsp_cfm pa
;
951 * Callee owns the argument space and could overwrite it, eg
952 * tail call optimization. So to be absolutely safe
953 * we save the argument space before transfering the control
954 * to instrumented jprobe function which runs in
955 * the process context
957 pa
.ip
= regs
->cr_iip
;
958 unw_init_running(ia64_get_bsp_cfm
, &pa
);
959 bytes
= (char *)ia64_rse_skip_regs(pa
.bsp
, pa
.cfm
& 0x3f)
961 memcpy( kcb
->jprobes_saved_stacked_regs
,
967 /* save architectural state */
968 kcb
->jprobe_saved_regs
= *regs
;
970 /* after rfi, execute the jprobe instrumented function */
971 regs
->cr_iip
= addr
& ~0xFULL
;
972 ia64_psr(regs
)->ri
= addr
& 0xf;
973 regs
->r1
= ((struct fnptr
*)(jp
->entry
))->gp
;
976 * fix the return address to our jprobe_inst_return() function
977 * in the jprobes.S file
979 regs
->b0
= ((struct fnptr
*)(jprobe_inst_return
))->ip
;
984 int __kprobes
longjmp_break_handler(struct kprobe
*p
, struct pt_regs
*regs
)
986 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
989 /* restoring architectural state */
990 *regs
= kcb
->jprobe_saved_regs
;
992 /* restoring the original argument space */
993 flush_register_stack();
994 bytes
= (char *)ia64_rse_skip_regs(kcb
->bsp
, kcb
->cfm
& 0x3f)
997 kcb
->jprobes_saved_stacked_regs
,
999 invalidate_stacked_regs();
1001 preempt_enable_no_resched();
1005 static struct kprobe trampoline_p
= {
1006 .pre_handler
= trampoline_probe_handler
1009 int __init
arch_init_kprobes(void)
1012 (kprobe_opcode_t
*)((struct fnptr
*)kretprobe_trampoline
)->ip
;
1013 return register_kprobe(&trampoline_p
);
1016 int __kprobes
arch_trampoline_kprobe(struct kprobe
*p
)
1019 (kprobe_opcode_t
*)((struct fnptr
*)kretprobe_trampoline
)->ip
)