RE: [PATCH] checkpatch: add warning on %pk instead of %pK usage

[Roberts, William C]

> -----Original Message-----
> From: Joe Perches [mailto:joe@xxxxxxxxxxx]
> Sent: Friday, February 10, 2017 12:12 PM
> To: Roberts, William C <william.c.roberts@xxxxxxxxx>; linux-
> kernel@xxxxxxxxxxxxxxx; apw@xxxxxxxxxxxxx; Andew Morton <akpm@linux-
> foundation.org>
> Cc: keescook@xxxxxxxxxxxx; kernel-hardening@xxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] checkpatch: add warning on %pk instead of %pK usage
> 
> On Fri, 2017-02-10 at 11:37 -0800, william.c.roberts@xxxxxxxxx wrote:
> > From: William Roberts <william.c.roberts@xxxxxxxxx>
> >
> > Sample output:
> > WARNING: %pk is close to %pK, did you mean %pK?.
> > \#20: FILE: drivers/char/applicom.c:230:
> > +			printk(KERN_INFO "Could not allocate IRQ %d for PCI
> Applicom
> > +device. %pk\n", dev->irq, pci_get_class);
> 
> There isn't a single instance of this in the kernel tree.
> 
> Maybe if this is really useful, then all the %p<foo> extensions should be
> enumerated and all unknown uses should have warnings.

I was thinking of doing that, but I figured I would start with the bare minimum patch.

> 
> Something like:
> 
> ---
>  scripts/checkpatch.pl | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index
> ad5ea5c545b2..8a90b457e8b5 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -5305,6 +5305,15 @@ sub process {
>  			}
>  		}
> 
> +# check for vsprintf extension %p<foo> misuses
> +		if ($line =~ /\b$logFunctions\s*\(.*$String/) {
> +			my $format = get_quoted_string($line, $rawline);
> +			if ($format =~
> /(\%[\*\d\.]*p(?![\WFfSsBKRraEhMmIiUDdgVCbGN]).)/) {
> +				WARN("VSPRINTF_POINTER_EXTENSION",
> +				     "Invalid vsprintf pointer extension '$1'\n" .
> $herecurr);
> +			}
> +		}
> +
>  # check for logging continuations
>  		if ($line =~ /\bprintk\s*\(\s*KERN_CONT\b|\bpr_cont\s*\(/) {
>  			WARN("LOGGING_CONTINUATION",