2 * Kernel Probes (KProbes)
3 * arch/i386/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
21 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
22 * Probes initial implementation ( includes contributions from
24 * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
25 * interface to access function arguments.
26 * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston
27 * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
28 * <prasanna@in.ibm.com> added function-return probes.
31 #include <linux/kprobes.h>
32 #include <linux/ptrace.h>
33 #include <linux/preempt.h>
34 #include <linux/kdebug.h>
35 #include <asm/cacheflush.h>
37 #include <asm/uaccess.h>
38 #include <asm/alternative.h>
40 void jprobe_return_end(void);
42 DEFINE_PER_CPU(struct kprobe
*, current_kprobe
) = NULL
;
43 DEFINE_PER_CPU(struct kprobe_ctlblk
, kprobe_ctlblk
);
45 /* insert a jmp code */
46 static __always_inline
void set_jmp_op(void *from
, void *to
)
48 struct __arch_jmp_op
{
51 } __attribute__((packed
)) *jop
;
52 jop
= (struct __arch_jmp_op
*)from
;
53 jop
->raddr
= (long)(to
) - ((long)(from
) + 5);
54 jop
->op
= RELATIVEJUMP_INSTRUCTION
;
58 * returns non-zero if opcodes can be boosted.
60 static __always_inline
int can_boost(kprobe_opcode_t
*opcodes
)
62 #define W(row,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,ba,bb,bc,bd,be,bf) \
63 (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
64 (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
65 (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
66 (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
69 * Undefined/reserved opcodes, conditional jump, Opcode Extension
70 * Groups, and some special opcodes can not be boost.
72 static const unsigned long twobyte_is_boostable
[256 / 32] = {
73 /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
74 /* ------------------------------- */
75 W(0x00, 0,0,1,1,0,0,1,0,1,1,0,0,0,0,0,0)| /* 00 */
76 W(0x10, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 10 */
77 W(0x20, 1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0)| /* 20 */
78 W(0x30, 0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 30 */
79 W(0x40, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 40 */
80 W(0x50, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 50 */
81 W(0x60, 1,1,1,1,1,1,1,1,1,1,1,1,0,0,1,1)| /* 60 */
82 W(0x70, 0,0,0,0,1,1,1,1,0,0,0,0,0,0,1,1), /* 70 */
83 W(0x80, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 80 */
84 W(0x90, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1), /* 90 */
85 W(0xa0, 1,1,0,1,1,1,0,0,1,1,0,1,1,1,0,1)| /* a0 */
86 W(0xb0, 1,1,1,1,1,1,1,1,0,0,0,1,1,1,1,1), /* b0 */
87 W(0xc0, 1,1,0,0,0,0,0,0,1,1,1,1,1,1,1,1)| /* c0 */
88 W(0xd0, 0,1,1,1,0,1,0,0,1,1,0,1,1,1,0,1), /* d0 */
89 W(0xe0, 0,1,1,0,0,1,0,0,1,1,0,1,1,1,0,1)| /* e0 */
90 W(0xf0, 0,1,1,1,0,1,0,0,1,1,1,0,1,1,1,0) /* f0 */
91 /* ------------------------------- */
92 /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
95 kprobe_opcode_t opcode
;
96 kprobe_opcode_t
*orig_opcodes
= opcodes
;
98 if (opcodes
- orig_opcodes
> MAX_INSN_SIZE
- 1)
100 opcode
= *(opcodes
++);
102 /* 2nd-byte opcode */
103 if (opcode
== 0x0f) {
104 if (opcodes
- orig_opcodes
> MAX_INSN_SIZE
- 1)
106 return test_bit(*opcodes
, twobyte_is_boostable
);
109 switch (opcode
& 0xf0) {
111 if (0x63 < opcode
&& opcode
< 0x67)
112 goto retry
; /* prefixes */
113 /* can't boost Address-size override and bound */
114 return (opcode
!= 0x62 && opcode
!= 0x67);
116 return 0; /* can't boost conditional jump */
118 /* can't boost software-interruptions */
119 return (0xc1 < opcode
&& opcode
< 0xcc) || opcode
== 0xcf;
121 /* can boost AA* and XLAT */
122 return (opcode
== 0xd4 || opcode
== 0xd5 || opcode
== 0xd7);
124 /* can boost in/out and absolute jmps */
125 return ((opcode
& 0x04) || opcode
== 0xea);
127 if ((opcode
& 0x0c) == 0 && opcode
!= 0xf1)
128 goto retry
; /* lock/rep(ne) prefix */
129 /* clear and set flags can be boost */
130 return (opcode
== 0xf5 || (0xf7 < opcode
&& opcode
< 0xfe));
132 if (opcode
== 0x26 || opcode
== 0x36 || opcode
== 0x3e)
133 goto retry
; /* prefixes */
134 /* can't boost CS override and call */
135 return (opcode
!= 0x2e && opcode
!= 0x9a);
140 * returns non-zero if opcode modifies the interrupt flag.
142 static int __kprobes
is_IF_modifier(kprobe_opcode_t opcode
)
147 case 0xcf: /* iret/iretd */
148 case 0x9d: /* popf/popfd */
154 int __kprobes
arch_prepare_kprobe(struct kprobe
*p
)
156 /* insn: must be on special executable page on i386. */
157 p
->ainsn
.insn
= get_insn_slot();
161 memcpy(p
->ainsn
.insn
, p
->addr
, MAX_INSN_SIZE
* sizeof(kprobe_opcode_t
));
162 p
->opcode
= *p
->addr
;
163 if (can_boost(p
->addr
)) {
164 p
->ainsn
.boostable
= 0;
166 p
->ainsn
.boostable
= -1;
171 void __kprobes
arch_arm_kprobe(struct kprobe
*p
)
173 text_poke(p
->addr
, ((unsigned char []){BREAKPOINT_INSTRUCTION
}), 1);
176 void __kprobes
arch_disarm_kprobe(struct kprobe
*p
)
178 text_poke(p
->addr
, &p
->opcode
, 1);
181 void __kprobes
arch_remove_kprobe(struct kprobe
*p
)
183 mutex_lock(&kprobe_mutex
);
184 free_insn_slot(p
->ainsn
.insn
, (p
->ainsn
.boostable
== 1));
185 mutex_unlock(&kprobe_mutex
);
188 static void __kprobes
save_previous_kprobe(struct kprobe_ctlblk
*kcb
)
190 kcb
->prev_kprobe
.kp
= kprobe_running();
191 kcb
->prev_kprobe
.status
= kcb
->kprobe_status
;
192 kcb
->prev_kprobe
.old_eflags
= kcb
->kprobe_old_eflags
;
193 kcb
->prev_kprobe
.saved_eflags
= kcb
->kprobe_saved_eflags
;
196 static void __kprobes
restore_previous_kprobe(struct kprobe_ctlblk
*kcb
)
198 __get_cpu_var(current_kprobe
) = kcb
->prev_kprobe
.kp
;
199 kcb
->kprobe_status
= kcb
->prev_kprobe
.status
;
200 kcb
->kprobe_old_eflags
= kcb
->prev_kprobe
.old_eflags
;
201 kcb
->kprobe_saved_eflags
= kcb
->prev_kprobe
.saved_eflags
;
204 static void __kprobes
set_current_kprobe(struct kprobe
*p
, struct pt_regs
*regs
,
205 struct kprobe_ctlblk
*kcb
)
207 __get_cpu_var(current_kprobe
) = p
;
208 kcb
->kprobe_saved_eflags
= kcb
->kprobe_old_eflags
209 = (regs
->eflags
& (TF_MASK
| IF_MASK
));
210 if (is_IF_modifier(p
->opcode
))
211 kcb
->kprobe_saved_eflags
&= ~IF_MASK
;
214 static void __kprobes
prepare_singlestep(struct kprobe
*p
, struct pt_regs
*regs
)
216 regs
->eflags
|= TF_MASK
;
217 regs
->eflags
&= ~IF_MASK
;
218 /*single step inline if the instruction is an int3*/
219 if (p
->opcode
== BREAKPOINT_INSTRUCTION
)
220 regs
->eip
= (unsigned long)p
->addr
;
222 regs
->eip
= (unsigned long)p
->ainsn
.insn
;
225 /* Called with kretprobe_lock held */
226 void __kprobes
arch_prepare_kretprobe(struct kretprobe_instance
*ri
,
227 struct pt_regs
*regs
)
229 unsigned long *sara
= (unsigned long *)®s
->esp
;
231 ri
->ret_addr
= (kprobe_opcode_t
*) *sara
;
233 /* Replace the return addr with trampoline addr */
234 *sara
= (unsigned long) &kretprobe_trampoline
;
238 * Interrupts are disabled on entry as trap3 is an interrupt gate and they
239 * remain disabled thorough out this function.
241 static int __kprobes
kprobe_handler(struct pt_regs
*regs
)
245 kprobe_opcode_t
*addr
;
246 struct kprobe_ctlblk
*kcb
;
248 addr
= (kprobe_opcode_t
*)(regs
->eip
- sizeof(kprobe_opcode_t
));
251 * We don't want to be preempted for the entire
252 * duration of kprobe processing
255 kcb
= get_kprobe_ctlblk();
257 /* Check we're not actually recursing */
258 if (kprobe_running()) {
259 p
= get_kprobe(addr
);
261 if (kcb
->kprobe_status
== KPROBE_HIT_SS
&&
262 *p
->ainsn
.insn
== BREAKPOINT_INSTRUCTION
) {
263 regs
->eflags
&= ~TF_MASK
;
264 regs
->eflags
|= kcb
->kprobe_saved_eflags
;
267 /* We have reentered the kprobe_handler(), since
268 * another probe was hit while within the handler.
269 * We here save the original kprobes variables and
270 * just single step on the instruction of the new probe
271 * without calling any user handlers.
273 save_previous_kprobe(kcb
);
274 set_current_kprobe(p
, regs
, kcb
);
275 kprobes_inc_nmissed_count(p
);
276 prepare_singlestep(p
, regs
);
277 kcb
->kprobe_status
= KPROBE_REENTER
;
280 if (*addr
!= BREAKPOINT_INSTRUCTION
) {
281 /* The breakpoint instruction was removed by
282 * another cpu right after we hit, no further
283 * handling of this interrupt is appropriate
285 regs
->eip
-= sizeof(kprobe_opcode_t
);
289 p
= __get_cpu_var(current_kprobe
);
290 if (p
->break_handler
&& p
->break_handler(p
, regs
)) {
297 p
= get_kprobe(addr
);
299 if (*addr
!= BREAKPOINT_INSTRUCTION
) {
301 * The breakpoint instruction was removed right
302 * after we hit it. Another cpu has removed
303 * either a probepoint or a debugger breakpoint
304 * at this address. In either case, no further
305 * handling of this interrupt is appropriate.
306 * Back up over the (now missing) int3 and run
307 * the original instruction.
309 regs
->eip
-= sizeof(kprobe_opcode_t
);
312 /* Not one of ours: let kernel handle it */
316 set_current_kprobe(p
, regs
, kcb
);
317 kcb
->kprobe_status
= KPROBE_HIT_ACTIVE
;
319 if (p
->pre_handler
&& p
->pre_handler(p
, regs
))
320 /* handler has already set things up, so skip ss setup */
324 #if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
325 if (p
->ainsn
.boostable
== 1 && !p
->post_handler
){
326 /* Boost up -- we can execute copied instructions directly */
327 reset_current_kprobe();
328 regs
->eip
= (unsigned long)p
->ainsn
.insn
;
329 preempt_enable_no_resched();
333 prepare_singlestep(p
, regs
);
334 kcb
->kprobe_status
= KPROBE_HIT_SS
;
338 preempt_enable_no_resched();
343 * For function-return probes, init_kprobes() establishes a probepoint
344 * here. When a retprobed function returns, this probe is hit and
345 * trampoline_probe_handler() runs, calling the kretprobe's handler.
347 void __kprobes
kretprobe_trampoline_holder(void)
349 asm volatile ( ".global kretprobe_trampoline\n"
350 "kretprobe_trampoline: \n"
352 /* skip cs, eip, orig_eax */
365 " call trampoline_handler\n"
366 /* move eflags to cs */
367 " movl 52(%esp), %edx\n"
368 " movl %edx, 48(%esp)\n"
369 /* save true return address on eflags */
370 " movl %eax, 52(%esp)\n"
378 /* skip eip, orig_eax, es, ds, fs */
385 * Called from kretprobe_trampoline
387 fastcall
void *__kprobes
trampoline_handler(struct pt_regs
*regs
)
389 struct kretprobe_instance
*ri
= NULL
;
390 struct hlist_head
*head
, empty_rp
;
391 struct hlist_node
*node
, *tmp
;
392 unsigned long flags
, orig_ret_address
= 0;
393 unsigned long trampoline_address
=(unsigned long)&kretprobe_trampoline
;
395 INIT_HLIST_HEAD(&empty_rp
);
396 spin_lock_irqsave(&kretprobe_lock
, flags
);
397 head
= kretprobe_inst_table_head(current
);
398 /* fixup registers */
399 regs
->xcs
= __KERNEL_CS
| get_kernel_rpl();
400 regs
->eip
= trampoline_address
;
401 regs
->orig_eax
= 0xffffffff;
404 * It is possible to have multiple instances associated with a given
405 * task either because an multiple functions in the call path
406 * have a return probe installed on them, and/or more then one return
407 * return probe was registered for a target function.
409 * We can handle this because:
410 * - instances are always inserted at the head of the list
411 * - when multiple return probes are registered for the same
412 * function, the first instance's ret_addr will point to the
413 * real return address, and all the rest will point to
414 * kretprobe_trampoline
416 hlist_for_each_entry_safe(ri
, node
, tmp
, head
, hlist
) {
417 if (ri
->task
!= current
)
418 /* another task is sharing our hash bucket */
421 if (ri
->rp
&& ri
->rp
->handler
){
422 __get_cpu_var(current_kprobe
) = &ri
->rp
->kp
;
423 get_kprobe_ctlblk()->kprobe_status
= KPROBE_HIT_ACTIVE
;
424 ri
->rp
->handler(ri
, regs
);
425 __get_cpu_var(current_kprobe
) = NULL
;
428 orig_ret_address
= (unsigned long)ri
->ret_addr
;
429 recycle_rp_inst(ri
, &empty_rp
);
431 if (orig_ret_address
!= trampoline_address
)
433 * This is the real return address. Any other
434 * instances associated with this task are for
435 * other calls deeper on the call stack
440 kretprobe_assert(ri
, orig_ret_address
, trampoline_address
);
441 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
443 hlist_for_each_entry_safe(ri
, node
, tmp
, &empty_rp
, hlist
) {
444 hlist_del(&ri
->hlist
);
447 return (void*)orig_ret_address
;
451 * Called after single-stepping. p->addr is the address of the
452 * instruction whose first byte has been replaced by the "int 3"
453 * instruction. To avoid the SMP problems that can occur when we
454 * temporarily put back the original opcode to single-step, we
455 * single-stepped a copy of the instruction. The address of this
456 * copy is p->ainsn.insn.
458 * This function prepares to return from the post-single-step
459 * interrupt. We have to fix up the stack as follows:
461 * 0) Except in the case of absolute or indirect jump or call instructions,
462 * the new eip is relative to the copied instruction. We need to make
463 * it relative to the original instruction.
465 * 1) If the single-stepped instruction was pushfl, then the TF and IF
466 * flags are set in the just-pushed eflags, and may need to be cleared.
468 * 2) If the single-stepped instruction was a call, the return address
469 * that is atop the stack is the address following the copied instruction.
470 * We need to make it the address following the original instruction.
472 * This function also checks instruction size for preparing direct execution.
474 static void __kprobes
resume_execution(struct kprobe
*p
,
475 struct pt_regs
*regs
, struct kprobe_ctlblk
*kcb
)
477 unsigned long *tos
= (unsigned long *)®s
->esp
;
478 unsigned long copy_eip
= (unsigned long)p
->ainsn
.insn
;
479 unsigned long orig_eip
= (unsigned long)p
->addr
;
481 regs
->eflags
&= ~TF_MASK
;
482 switch (p
->ainsn
.insn
[0]) {
483 case 0x9c: /* pushfl */
484 *tos
&= ~(TF_MASK
| IF_MASK
);
485 *tos
|= kcb
->kprobe_old_eflags
;
487 case 0xc2: /* iret/ret/lret */
492 case 0xea: /* jmp absolute -- eip is correct */
493 /* eip is already adjusted, no more changes required */
494 p
->ainsn
.boostable
= 1;
496 case 0xe8: /* call relative - Fix return addr */
497 *tos
= orig_eip
+ (*tos
- copy_eip
);
499 case 0x9a: /* call absolute -- same as call absolute, indirect */
500 *tos
= orig_eip
+ (*tos
- copy_eip
);
503 if ((p
->ainsn
.insn
[1] & 0x30) == 0x10) {
505 * call absolute, indirect
506 * Fix return addr; eip is correct.
507 * But this is not boostable
509 *tos
= orig_eip
+ (*tos
- copy_eip
);
511 } else if (((p
->ainsn
.insn
[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
512 ((p
->ainsn
.insn
[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
513 /* eip is correct. And this is boostable */
514 p
->ainsn
.boostable
= 1;
521 if (p
->ainsn
.boostable
== 0) {
522 if ((regs
->eip
> copy_eip
) &&
523 (regs
->eip
- copy_eip
) + 5 < MAX_INSN_SIZE
) {
525 * These instructions can be executed directly if it
526 * jumps back to correct address.
528 set_jmp_op((void *)regs
->eip
,
529 (void *)orig_eip
+ (regs
->eip
- copy_eip
));
530 p
->ainsn
.boostable
= 1;
532 p
->ainsn
.boostable
= -1;
536 regs
->eip
= orig_eip
+ (regs
->eip
- copy_eip
);
543 * Interrupts are disabled on entry as trap1 is an interrupt gate and they
544 * remain disabled thoroughout this function.
546 static int __kprobes
post_kprobe_handler(struct pt_regs
*regs
)
548 struct kprobe
*cur
= kprobe_running();
549 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
554 if ((kcb
->kprobe_status
!= KPROBE_REENTER
) && cur
->post_handler
) {
555 kcb
->kprobe_status
= KPROBE_HIT_SSDONE
;
556 cur
->post_handler(cur
, regs
, 0);
559 resume_execution(cur
, regs
, kcb
);
560 regs
->eflags
|= kcb
->kprobe_saved_eflags
;
562 /*Restore back the original saved kprobes variables and continue. */
563 if (kcb
->kprobe_status
== KPROBE_REENTER
) {
564 restore_previous_kprobe(kcb
);
567 reset_current_kprobe();
569 preempt_enable_no_resched();
572 * if somebody else is singlestepping across a probe point, eflags
573 * will have TF set, in which case, continue the remaining processing
574 * of do_debug, as if this is not a probe hit.
576 if (regs
->eflags
& TF_MASK
)
582 static int __kprobes
kprobe_fault_handler(struct pt_regs
*regs
, int trapnr
)
584 struct kprobe
*cur
= kprobe_running();
585 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
587 switch(kcb
->kprobe_status
) {
591 * We are here because the instruction being single
592 * stepped caused a page fault. We reset the current
593 * kprobe and the eip points back to the probe address
594 * and allow the page fault handler to continue as a
597 regs
->eip
= (unsigned long)cur
->addr
;
598 regs
->eflags
|= kcb
->kprobe_old_eflags
;
599 if (kcb
->kprobe_status
== KPROBE_REENTER
)
600 restore_previous_kprobe(kcb
);
602 reset_current_kprobe();
603 preempt_enable_no_resched();
605 case KPROBE_HIT_ACTIVE
:
606 case KPROBE_HIT_SSDONE
:
608 * We increment the nmissed count for accounting,
609 * we can also use npre/npostfault count for accouting
610 * these specific fault cases.
612 kprobes_inc_nmissed_count(cur
);
615 * We come here because instructions in the pre/post
616 * handler caused the page_fault, this could happen
617 * if handler tries to access user space by
618 * copy_from_user(), get_user() etc. Let the
619 * user-specified handler try to fix it first.
621 if (cur
->fault_handler
&& cur
->fault_handler(cur
, regs
, trapnr
))
625 * In case the user-specified fault handler returned
626 * zero, try to fix up.
628 if (fixup_exception(regs
))
632 * fixup_exception() could not handle it,
633 * Let do_page_fault() fix it.
643 * Wrapper routine to for handling exceptions.
645 int __kprobes
kprobe_exceptions_notify(struct notifier_block
*self
,
646 unsigned long val
, void *data
)
648 struct die_args
*args
= (struct die_args
*)data
;
649 int ret
= NOTIFY_DONE
;
651 if (args
->regs
&& user_mode_vm(args
->regs
))
656 if (kprobe_handler(args
->regs
))
660 if (post_kprobe_handler(args
->regs
))
665 /* kprobe_running() needs smp_processor_id() */
667 if (kprobe_running() &&
668 kprobe_fault_handler(args
->regs
, args
->trapnr
))
678 int __kprobes
setjmp_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
680 struct jprobe
*jp
= container_of(p
, struct jprobe
, kp
);
682 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
684 kcb
->jprobe_saved_regs
= *regs
;
685 kcb
->jprobe_saved_esp
= ®s
->esp
;
686 addr
= (unsigned long)(kcb
->jprobe_saved_esp
);
689 * TBD: As Linus pointed out, gcc assumes that the callee
690 * owns the argument space and could overwrite it, e.g.
691 * tailcall optimization. So, to be absolutely safe
692 * we also save and restore enough stack bytes to cover
695 memcpy(kcb
->jprobes_stack
, (kprobe_opcode_t
*)addr
,
696 MIN_STACK_SIZE(addr
));
697 regs
->eflags
&= ~IF_MASK
;
698 regs
->eip
= (unsigned long)(jp
->entry
);
702 void __kprobes
jprobe_return(void)
704 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
706 asm volatile (" xchgl %%ebx,%%esp \n"
708 " .globl jprobe_return_end \n"
709 " jprobe_return_end: \n"
711 (kcb
->jprobe_saved_esp
):"memory");
714 int __kprobes
longjmp_break_handler(struct kprobe
*p
, struct pt_regs
*regs
)
716 struct kprobe_ctlblk
*kcb
= get_kprobe_ctlblk();
717 u8
*addr
= (u8
*) (regs
->eip
- 1);
718 unsigned long stack_addr
= (unsigned long)(kcb
->jprobe_saved_esp
);
719 struct jprobe
*jp
= container_of(p
, struct jprobe
, kp
);
721 if ((addr
> (u8
*) jprobe_return
) && (addr
< (u8
*) jprobe_return_end
)) {
722 if (®s
->esp
!= kcb
->jprobe_saved_esp
) {
723 struct pt_regs
*saved_regs
=
724 container_of(kcb
->jprobe_saved_esp
,
725 struct pt_regs
, esp
);
726 printk("current esp %p does not match saved esp %p\n",
727 ®s
->esp
, kcb
->jprobe_saved_esp
);
728 printk("Saved registers for jprobe %p\n", jp
);
729 show_registers(saved_regs
);
730 printk("Current registers\n");
731 show_registers(regs
);
734 *regs
= kcb
->jprobe_saved_regs
;
735 memcpy((kprobe_opcode_t
*) stack_addr
, kcb
->jprobes_stack
,
736 MIN_STACK_SIZE(stack_addr
));
737 preempt_enable_no_resched();
743 int __kprobes
arch_trampoline_kprobe(struct kprobe
*p
)
748 int __init
arch_init_kprobes(void)