int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
+ struct kprobe *prev;
struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr);
+ struct ppc_inst prefix = ppc_inst_read((struct ppc_inst *)(p->addr - 1));
if ((unsigned long)p->addr & 0x03) {
printk("Attempt to register kprobe at an unaligned address\n");
} else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) {
printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n");
ret = -EINVAL;
+ } else if (ppc_inst_prefixed(prefix)) {
+ printk("Cannot register a kprobe on the second word of prefixed instruction\n");
+ ret = -EINVAL;
+ }
+ preempt_disable();
+ prev = get_kprobe(p->addr - 1);
+ preempt_enable_no_resched();
+ if (prev &&
+ ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)prev->ainsn.insn))) {
+ printk("Cannot register a kprobe on the second word of prefixed instruction\n");
+ ret = -EINVAL;
}
/* insn must be on a special executable page on ppc64. This is