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-rw-r--r--arch/ppc64/kernel/kprobes.c459
1 files changed, 0 insertions, 459 deletions
diff --git a/arch/ppc64/kernel/kprobes.c b/arch/ppc64/kernel/kprobes.c
deleted file mode 100644
index 511af54e623..00000000000
--- a/arch/ppc64/kernel/kprobes.c
+++ /dev/null
@@ -1,459 +0,0 @@
-/*
- * Kernel Probes (KProbes)
- * arch/ppc64/kernel/kprobes.c
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright (C) IBM Corporation, 2002, 2004
- *
- * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
- * Probes initial implementation ( includes contributions from
- * Rusty Russell).
- * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
- * interface to access function arguments.
- * 2004-Nov Ananth N Mavinakayanahalli <ananth@in.ibm.com> kprobes port
- * for PPC64
- */
-
-#include <linux/config.h>
-#include <linux/kprobes.h>
-#include <linux/ptrace.h>
-#include <linux/preempt.h>
-#include <asm/cacheflush.h>
-#include <asm/kdebug.h>
-#include <asm/sstep.h>
-
-static DECLARE_MUTEX(kprobe_mutex);
-DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
-DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
-
-int __kprobes arch_prepare_kprobe(struct kprobe *p)
-{
- int ret = 0;
- kprobe_opcode_t insn = *p->addr;
-
- if ((unsigned long)p->addr & 0x03) {
- printk("Attempt to register kprobe at an unaligned address\n");
- ret = -EINVAL;
- } else if (IS_MTMSRD(insn) || IS_RFID(insn)) {
- printk("Cannot register a kprobe on rfid or mtmsrd\n");
- ret = -EINVAL;
- }
-
- /* insn must be on a special executable page on ppc64 */
- if (!ret) {
- down(&kprobe_mutex);
- p->ainsn.insn = get_insn_slot();
- up(&kprobe_mutex);
- if (!p->ainsn.insn)
- ret = -ENOMEM;
- }
- return ret;
-}
-
-void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
- memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
- p->opcode = *p->addr;
-}
-
-void __kprobes arch_arm_kprobe(struct kprobe *p)
-{
- *p->addr = BREAKPOINT_INSTRUCTION;
- flush_icache_range((unsigned long) p->addr,
- (unsigned long) p->addr + sizeof(kprobe_opcode_t));
-}
-
-void __kprobes arch_disarm_kprobe(struct kprobe *p)
-{
- *p->addr = p->opcode;
- flush_icache_range((unsigned long) p->addr,
- (unsigned long) p->addr + sizeof(kprobe_opcode_t));
-}
-
-void __kprobes arch_remove_kprobe(struct kprobe *p)
-{
- down(&kprobe_mutex);
- free_insn_slot(p->ainsn.insn);
- up(&kprobe_mutex);
-}
-
-static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
-{
- kprobe_opcode_t insn = *p->ainsn.insn;
-
- regs->msr |= MSR_SE;
-
- /* single step inline if it is a trap variant */
- if (is_trap(insn))
- regs->nip = (unsigned long)p->addr;
- else
- regs->nip = (unsigned long)p->ainsn.insn;
-}
-
-static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
-{
- kcb->prev_kprobe.kp = kprobe_running();
- kcb->prev_kprobe.status = kcb->kprobe_status;
- kcb->prev_kprobe.saved_msr = kcb->kprobe_saved_msr;
-}
-
-static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
-{
- __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
- kcb->kprobe_status = kcb->prev_kprobe.status;
- kcb->kprobe_saved_msr = kcb->prev_kprobe.saved_msr;
-}
-
-static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- __get_cpu_var(current_kprobe) = p;
- kcb->kprobe_saved_msr = regs->msr;
-}
-
-/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
- struct pt_regs *regs)
-{
- struct kretprobe_instance *ri;
-
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *)regs->link;
-
- /* Replace the return addr with trampoline addr */
- regs->link = (unsigned long)kretprobe_trampoline;
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
- }
-}
-
-static inline int kprobe_handler(struct pt_regs *regs)
-{
- struct kprobe *p;
- int ret = 0;
- unsigned int *addr = (unsigned int *)regs->nip;
- struct kprobe_ctlblk *kcb;
-
- /*
- * We don't want to be preempted for the entire
- * duration of kprobe processing
- */
- preempt_disable();
- kcb = get_kprobe_ctlblk();
-
- /* Check we're not actually recursing */
- if (kprobe_running()) {
- p = get_kprobe(addr);
- if (p) {
- kprobe_opcode_t insn = *p->ainsn.insn;
- if (kcb->kprobe_status == KPROBE_HIT_SS &&
- is_trap(insn)) {
- regs->msr &= ~MSR_SE;
- regs->msr |= kcb->kprobe_saved_msr;
- goto no_kprobe;
- }
- /* We have reentered the kprobe_handler(), since
- * another probe was hit while within the handler.
- * We here save the original kprobes variables and
- * just single step on the instruction of the new probe
- * without calling any user handlers.
- */
- save_previous_kprobe(kcb);
- set_current_kprobe(p, regs, kcb);
- kcb->kprobe_saved_msr = regs->msr;
- p->nmissed++;
- prepare_singlestep(p, regs);
- kcb->kprobe_status = KPROBE_REENTER;
- return 1;
- } else {
- p = __get_cpu_var(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- goto ss_probe;
- }
- }
- goto no_kprobe;
- }
-
- p = get_kprobe(addr);
- if (!p) {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /*
- * PowerPC has multiple variants of the "trap"
- * instruction. If the current instruction is a
- * trap variant, it could belong to someone else
- */
- kprobe_opcode_t cur_insn = *addr;
- if (is_trap(cur_insn))
- goto no_kprobe;
- /*
- * The breakpoint instruction was removed right
- * after we hit it. Another cpu has removed
- * either a probepoint or a debugger breakpoint
- * at this address. In either case, no further
- * handling of this interrupt is appropriate.
- */
- ret = 1;
- }
- /* Not one of ours: let kernel handle it */
- goto no_kprobe;
- }
-
- kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- set_current_kprobe(p, regs, kcb);
- if (p->pre_handler && p->pre_handler(p, regs))
- /* handler has already set things up, so skip ss setup */
- return 1;
-
-ss_probe:
- prepare_singlestep(p, regs);
- kcb->kprobe_status = KPROBE_HIT_SS;
- return 1;
-
-no_kprobe:
- preempt_enable_no_resched();
- return ret;
-}
-
-/*
- * Function return probe trampoline:
- * - init_kprobes() establishes a probepoint here
- * - When the probed function returns, this probe
- * causes the handlers to fire
- */
-void kretprobe_trampoline_holder(void)
-{
- asm volatile(".global kretprobe_trampoline\n"
- "kretprobe_trampoline:\n"
- "nop\n");
-}
-
-/*
- * Called when the probe at kretprobe trampoline is hit
- */
-int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kretprobe_instance *ri = NULL;
- struct hlist_head *head;
- struct hlist_node *node, *tmp;
- unsigned long flags, orig_ret_address = 0;
- unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline;
-
- spin_lock_irqsave(&kretprobe_lock, flags);
- head = kretprobe_inst_table_head(current);
-
- /*
- * It is possible to have multiple instances associated with a given
- * task either because an multiple functions in the call path
- * have a return probe installed on them, and/or more then one return
- * return probe was registered for a target function.
- *
- * We can handle this because:
- * - instances are always inserted at the head of the list
- * - when multiple return probes are registered for the same
- * function, the first instance's ret_addr will point to the
- * real return address, and all the rest will point to
- * kretprobe_trampoline
- */
- hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
-
- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
-
- orig_ret_address = (unsigned long)ri->ret_addr;
- recycle_rp_inst(ri);
-
- if (orig_ret_address != trampoline_address)
- /*
- * This is the real return address. Any other
- * instances associated with this task are for
- * other calls deeper on the call stack
- */
- break;
- }
-
- BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
- regs->nip = orig_ret_address;
-
- reset_current_kprobe();
- spin_unlock_irqrestore(&kretprobe_lock, flags);
- preempt_enable_no_resched();
-
- /*
- * By returning a non-zero value, we are telling
- * kprobe_handler() that we don't want the post_handler
- * to run (and have re-enabled preemption)
- */
- return 1;
-}
-
-/*
- * Called after single-stepping. p->addr is the address of the
- * instruction whose first byte has been replaced by the "breakpoint"
- * instruction. To avoid the SMP problems that can occur when we
- * temporarily put back the original opcode to single-step, we
- * single-stepped a copy of the instruction. The address of this
- * copy is p->ainsn.insn.
- */
-static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
-{
- int ret;
- unsigned int insn = *p->ainsn.insn;
-
- regs->nip = (unsigned long)p->addr;
- ret = emulate_step(regs, insn);
- if (ret == 0)
- regs->nip = (unsigned long)p->addr + 4;
-}
-
-static inline int post_kprobe_handler(struct pt_regs *regs)
-{
- struct kprobe *cur = kprobe_running();
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (!cur)
- return 0;
-
- if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- cur->post_handler(cur, regs, 0);
- }
-
- resume_execution(cur, regs);
- regs->msr |= kcb->kprobe_saved_msr;
-
- /*Restore back the original saved kprobes variables and continue. */
- if (kcb->kprobe_status == KPROBE_REENTER) {
- restore_previous_kprobe(kcb);
- goto out;
- }
- reset_current_kprobe();
-out:
- preempt_enable_no_resched();
-
- /*
- * if somebody else is singlestepping across a probe point, msr
- * will have SE set, in which case, continue the remaining processing
- * of do_debug, as if this is not a probe hit.
- */
- if (regs->msr & MSR_SE)
- return 0;
-
- return 1;
-}
-
-static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
-{
- struct kprobe *cur = kprobe_running();
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
- return 1;
-
- if (kcb->kprobe_status & KPROBE_HIT_SS) {
- resume_execution(cur, regs);
- regs->msr &= ~MSR_SE;
- regs->msr |= kcb->kprobe_saved_msr;
-
- reset_current_kprobe();
- preempt_enable_no_resched();
- }
- return 0;
-}
-
-/*
- * Wrapper routine to for handling exceptions.
- */
-int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- struct die_args *args = (struct die_args *)data;
- int ret = NOTIFY_DONE;
-
- switch (val) {
- case DIE_BPT:
- if (kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_SSTEP:
- if (post_kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_PAGE_FAULT:
- /* kprobe_running() needs smp_processor_id() */
- preempt_disable();
- if (kprobe_running() &&
- kprobe_fault_handler(args->regs, args->trapnr))
- ret = NOTIFY_STOP;
- preempt_enable();
- break;
- default:
- break;
- }
- return ret;
-}
-
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct jprobe *jp = container_of(p, struct jprobe, kp);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
-
- /* setup return addr to the jprobe handler routine */
- regs->nip = (unsigned long)(((func_descr_t *)jp->entry)->entry);
- regs->gpr[2] = (unsigned long)(((func_descr_t *)jp->entry)->toc);
-
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- asm volatile("trap" ::: "memory");
-}
-
-void __kprobes jprobe_return_end(void)
-{
-};
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
- /*
- * FIXME - we should ideally be validating that we got here 'cos
- * of the "trap" in jprobe_return() above, before restoring the
- * saved regs...
- */
- memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
- preempt_enable_no_resched();
- return 1;
-}
-
-static struct kprobe trampoline_p = {
- .addr = (kprobe_opcode_t *) &kretprobe_trampoline,
- .pre_handler = trampoline_probe_handler
-};
-
-int __init arch_init_kprobes(void)
-{
- return register_kprobe(&trampoline_p);
-}
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