Re: [BUGFIX PATCH bpf-next] error-injection: Fix to prohibit jump optimization

[Daniel Borkmann]

On 03/12/2018 03:06 PM, Masami Hiramatsu wrote:
> On Mon, 12 Mar 2018 11:44:21 +0100
> Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote:
>> On 03/12/2018 11:27 AM, Masami Hiramatsu wrote:
>>> On Mon, 12 Mar 2018 19:00:49 +0900
>>> Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
>>>
>>>> Since the kprobe which was optimized by jump can not change
>>>> the execution path, the kprobe for error-injection must not
>>>> be optimized. To prohibit it, set a dummy post-handler as
>>>> officially stated in Documentation/kprobes.txt.
>>>
>>> Note that trace-probe based BPF is not affected, because it
>>> ensures the trace-probe is based on ftrace, which is not
>>> jump optimized.
>>
>> Thanks for the fix! I presume this should go via bpf instead of bpf-next
>> tree since 4b1a29a7f542 ("error-injection: Support fault injection framework")
>> is in Linus' tree as well. Unless there are objection I would rather route
>> it that way so it would be for 4.16.
> 
> Ah, right! It should go into 4.16. It should be applicable cleanly either tree
> since there is only the above commit on kernel/fail_function.c :)

Applied to bpf tree, thanks Masami!