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)