/*
* 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
* for PPC64
*/
+#include <linux/config.h>
#include <linux/kprobes.h>
#include <linux/ptrace.h>
#include <linux/preempt.h>
-#include <linux/module.h>
#include <asm/cacheflush.h>
#include <asm/kdebug.h>
#include <asm/sstep.h>
-#include <asm/uaccess.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
if (!ret) {
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
p->opcode = *p->addr;
- flush_icache_range((unsigned long)p->ainsn.insn,
- (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));
}
return ret;
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
- mutex_lock(&kprobe_mutex);
+ down(&kprobe_mutex);
free_insn_slot(p->ainsn.insn);
- mutex_unlock(&kprobe_mutex);
+ up(&kprobe_mutex);
}
-static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
+static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
{
+ kprobe_opcode_t insn = *p->ainsn.insn;
+
regs->msr |= MSR_SE;
- /*
- * On powerpc we should single step on the original
- * instruction even if the probed insn is a trap
- * variant as values in regs could play a part in
- * if the trap is taken or not
- */
- regs->nip = (unsigned long)p->ainsn.insn;
+ /* 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 void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
+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 void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+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 void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
+static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
__get_cpu_var(current_kprobe) = p;
}
}
-static int __kprobes kprobe_handler(struct pt_regs *regs)
+static inline int kprobe_handler(struct pt_regs *regs)
{
struct kprobe *p;
int ret = 0;
regs->nip = (unsigned long)p->addr + 4;
}
-static int __kprobes post_kprobe_handler(struct pt_regs *regs)
+static inline int post_kprobe_handler(struct pt_regs *regs)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
return 1;
}
-static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- const struct exception_table_entry *entry;
-
- switch(kcb->kprobe_status) {
- case KPROBE_HIT_SS:
- case KPROBE_REENTER:
- /*
- * We are here because the instruction being single
- * stepped caused a page fault. We reset the current
- * kprobe and the nip points back to the probe address
- * and allow the page fault handler to continue as a
- * normal page fault.
- */
- regs->nip = (unsigned long)cur->addr;
+
+ 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;
- if (kcb->kprobe_status == KPROBE_REENTER)
- restore_previous_kprobe(kcb);
- else
- reset_current_kprobe();
- preempt_enable_no_resched();
- break;
- case KPROBE_HIT_ACTIVE:
- case KPROBE_HIT_SSDONE:
- /*
- * We increment the nmissed count for accounting,
- * we can also use npre/npostfault count for accouting
- * these specific fault cases.
- */
- kprobes_inc_nmissed_count(cur);
-
- /*
- * We come here because instructions in the pre/post
- * handler caused the page_fault, this could happen
- * if handler tries to access user space by
- * copy_from_user(), get_user() etc. Let the
- * user-specified handler try to fix it first.
- */
- if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
- return 1;
- /*
- * In case the user-specified fault handler returned
- * zero, try to fix up.
- */
- if ((entry = search_exception_tables(regs->nip)) != NULL) {
- regs->nip = entry->fixup;
- return 1;
- }
-
- /*
- * fixup_exception() could not handle it,
- * Let do_page_fault() fix it.
- */
- break;
- default:
- break;
+ reset_current_kprobe();
+ preempt_enable_no_resched();
}
return 0;
}
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
- if (args->regs && user_mode(args->regs))
- return ret;
-
switch (val) {
case DIE_BPT:
if (kprobe_handler(args->regs))
git://git.onelab.eu / linux-2.6.git / blobdiff