Re: [PATCH v11 5/9] arm64: Kprobes with single stepping support

From: Li Bin
Date: Tue Apr 19 2016 - 21:30:20 EST


Hi David,

on 2016/3/9 13:32, David Long wrote:
> +int __kprobes arch_prepare_kprobe(struct kprobe *p)
> +{
> + unsigned long probe_addr = (unsigned long)p->addr;

Here should verify the addr alignment:

if (probe_addr & 0x3)
return -EINVAL;

Thanks,
Li Bin

> +
> + /* copy instruction */
> + p->opcode = le32_to_cpu(*p->addr);
> +
> + if (in_exception_text(probe_addr))
> + return -EINVAL;
> +
> + /* decode instruction */
> + switch (arm_kprobe_decode_insn(p->addr, &p->ainsn)) {
> + case INSN_REJECTED: /* insn not supported */
> + return -EINVAL;
> +
> + case INSN_GOOD_NO_SLOT: /* insn need simulation */
> + return -EINVAL;
> +
> + case INSN_GOOD: /* instruction uses slot */
> + p->ainsn.insn = get_insn_slot();
> + if (!p->ainsn.insn)
> + return -ENOMEM;
> + break;
> + };
> +
> + /* prepare the instruction */
> + arch_prepare_ss_slot(p);
> +
> + return 0;
> +}
> +