linux-kernel - Re: [PATCH] livepatch: Skip livepatch tests if ftrace cannot be configured

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Message-ID: <20220204204303.scyxvt4yh2gjftce@dev0025.ash9.facebook.com>
Date:   Fri, 4 Feb 2022 12:43:03 -0800
From:   David Vernet <void@...ifault.com>
To:     Joe Lawrence <joe.lawrence@...hat.com>
Cc:     live-patching@...r.kernel.org, linux-kernel@...r.kernel.org,
        jpoimboe@...hat.com, pmladek@...e.com, jikos@...nel.org,
        mbenes@...e.cz, corbet@....net, kernel-team@...com
Subject: Re: [PATCH] livepatch: Skip livepatch tests if ftrace cannot be
 configured

On Fri, Feb 04, 2022 at 03:30:02PM -0500, Joe Lawrence wrote:

Hi Joe,

Thanks for the review.

> sp: s/permament/permanent
> 

Ack, thanks for catching that.

> > +	if [[ "$result" == *"Device or resource busy"* ]]; then
> > +		skip "failed to set kernel.ftrace_enabled=$1"
> > +	fi
> > +
> 
> style nit: move the blank line from here to just before the new # Skip
> comment

Ack.

> Can we be more paranoid and just look for the exact result that we expect:
> 
> if [[ "$result" != "kernel.ftrace_enabled = 1" ]]; then
> 	skip "failed to set kernel.ftrace_enabled=$1"
> fi

Agreed, this is cleaner and less brittle.

I'll follow-up with a v2 patch shortly. Thanks!

- David