Re: [PATCH] checkpatch.pl: Add warning for new __packed additions

[josh@joshtriplett.org]

On Mon, Feb 24, 2014 at 03:38:16PM -0500, Tom Rini wrote:
> While there are valid reasons to use __packed, often the answer is that
> you should be doing something else here instead.
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Joe Perches <joe@perches.com>
> Cc: Josh Triplett <josh@joshtriplett.org>
> Signed-off-by: Tom Rini <trini@ti.com>
> ---
>  scripts/checkpatch.pl |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 0ea2a1e..fef3b13 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -4010,6 +4010,11 @@ sub process {
>  			WARN("PREFER_PACKED",
>  			     "__packed is preferred over __attribute__((packed))\n" . $herecurr);
>  		}
> +# Check for new packed usage, warn to use care
> +		if ($line =~ /\b(__attribute__\s*\(\s*\(.*\bpacked|__packed)\b/) {
> +			WARN("NEW_PACKED",
> +			     "Adding new packed members is to be done with care\n" . $herecurr);
> +		}

This seems wrong; "is to be done with care" is the very definition of a
false positive.  At *best* this should always be CHK, and even then it
seems excessive.

- Josh Triplett