Re: [PATCH] checkpatch: Fix use of uninitialized value

[Greg Kurz]

On Thu, 8 Apr 2021 10:49:13 -0700
Isaku Yamahata <isaku.yamahata@gmail.com> wrote:

> 
> How about initializing them explicitly as follows?
> ($realfile ne '') prevents the case realfile eq '' && acpi_testexpted eq ''.
> Anyway your patch also should fix it. So
> Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 8f7053ec9b..2eb894a628 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -1325,8 +1325,8 @@ sub process {
>       my %suppress_whiletrailers;
>       my %suppress_export;
>  
> -        my $acpi_testexpected;
> -        my $acpi_nontestexpected;
> +        my $acpi_testexpected = '';
> +        my $acpi_nontestexpected = '';
>  

Hmm... I haven't tried but I believe this will break when these are
passed to checkfilename() :

sub checkfilename {
        my ($name, $acpi_testexpected, $acpi_nontestexpected) = @_;
[...]
        if (defined $$acpi_testexpected and defined $$acpi_nontestexpected) {
                ERROR("Do not add expected files together with tests, " .


>       # Pre-scan the patch sanitizing the lines.
>  
> 
> On Thu, Apr 08, 2021 at 08:51:19AM +0200,
> Greg Kurz <groug@kaod.org> wrote:
> 
> > checkfilename() doesn't always set $acpi_testexpected. Fix the following
> > warning:
> > 
> > Use of uninitialized value $acpi_testexpected in string eq at
> >  ./scripts/checkpatch.pl line 1529.
> > 
> > Fixes: d2f1af0e4120 ("checkpatch: don't emit warning on newly created acpi 
> > data files")
> > Cc: isaku.yamahata@intel.com
> > Signed-off-by: Greg Kurz <groug@kaod.org>
> > ---
> >  scripts/checkpatch.pl |    1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > index 8f7053ec9b26..3d185cceac94 100755
> > --- a/scripts/checkpatch.pl
> > +++ b/scripts/checkpatch.pl
> > @@ -1532,6 +1532,7 @@ sub process {
> >                  ($line =~ /\{\s*([\w\/\.\-]*)\s*\=\>\s*([\w\/\.\-]*)\s*\}/ 
> > &&
> >                   (defined($1) || defined($2)))) &&
> >                        !(($realfile ne '') &&
> > +                        defined($acpi_testexpected) &&
> >                          ($realfile eq $acpi_testexpected))) {
> >                     $reported_maintainer_file = 1;
> >                     WARN("added, moved or deleted file(s), does MAINTAINERS 
> > need updating?\n" . $herecurr);
> > 
> > 
> > 
>