Re: [PATCH 0001/0001] format idle IP output func+offset/length

From: Liu, Changcheng
Date: Mon Nov 06 2017 - 11:48:50 EST


Thx Josh. I'll refine the patch.
Answer question as below.

On 07:11 Mon 06 Nov, Josh Poimboeuf wrote:
> On Mon, Nov 06, 2017 at 06:52:03PM +0800, Liu, Changcheng wrote:
> > kaslr feature is enabled in kernel.
> > Remove kernel text address when dumping idle IP info
> >
> > Signed-off-by: Liu Changcheng <changcheng.liu@xxxxxxxxx>
> > Signed-off-by: Jerry Liu <primerlink@xxxxxxxxx>
> >
> > diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
> > index 0bc0a35..9cc4178 100644
> > --- a/lib/nmi_backtrace.c
> > +++ b/lib/nmi_backtrace.c
> > @@ -92,7 +92,7 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
> > if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
> > arch_spin_lock(&lock);
> > if (regs && cpu_in_idle(instruction_pointer(regs))) {
> > - pr_warn("NMI backtrace for cpu %d skipped: idling at pc %#lx\n",
> > + pr_warn("NMI backtrace for cpu %d skipped: idling at %pS\n",
> > cpu, instruction_pointer(regs));
> > } else {
> > pr_warn("NMI backtrace for cpu %d\n", cpu);
>
> 1) The patch introduces a compile warning.
I've got the point because the conversion between pointer and unsigned long.
>
> 2) When posting a new version of the patch, it should have a new version
> in the subject, e.g. "PATCH v2".
Thx for your guide. I'm on the way to work with community.
>
> 3) The subject is missing a prefix, like "lib_backtrace: "
>
> 4) The subject isn't very clear, how about something like:
>
> lib_backtrace: fix kernel text address leak
I'll use this subject.
>
> 5) The description isn't correct. KASLR isn't always enabled, it
> depends on the user's config. But even without KASLR, we don't want
> to leak kernel text addresses.
That's fine.
>
> 6) The description should use complete sentences.
Yes.
>
> 7) I'm not sure the "Signed-off-by:" chain is correct. Was Jerry Liu
> the original author of the patch?
This is my personal bad habit. I'll correct it.
>
> --
> Josh