Re: [PATCH -tip v3 6/7] kprobes/x86: Remove disable_irq from ftrace-based/optimized kprobe

Ingo Molnar
2017-09-28T07:25:47Z

* Masami Hiramatsu <mhiramat@kernel.org> wrote:

> Actually kprobes doesn't need to disable irq if it is
> called from ftrace/jump trampoline code because
> Documentation/kprobes.txt says
>
> -----
> Probe handlers are run with preemption disabled. Depending on the
> architecture and optimization state, handlers may also run with
> interrupts disabled (e.g., kretprobe handlers and optimized kprobe
> handlers run without interrupt disabled on x86/x86-64).
> -----
>
> So let's remove irq disabling from those handlers.

> - local_irq_save(flags);

The title is talking about disable_irq():

kprobes/x86: Remove disable_irq from ftrace-based/optimized kprobe

... but the patch is actually using local_irq_save(), which is an entirely
different thing! You probably wanted to say:

kprobes/x86: Remove irq disabling from ftrace-based/optimized kprobes

Also note the plural of 'kprobes' when we refer to them as a generic thing.

I fixed the title, but _please_ read changelogs more carefully before sending
them.

Thanks,

Ingo