Re: [PATCH 3/3] checkpatch: add ethtool_sprintf rules

From: Przemek Kitszel <przemyslaw.kitszel@intel.com>
To: Justin Stitt <justinstitt@google.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Shay Agroskin <shayagr@amazon.com>,
	Arthur Kiyanovski <akiyano@amazon.com>,
	David Arinzon <darinzon@amazon.com>,
	Noam Dagan <ndagan@amazon.com>, Saeed Bishara <saeedb@amazon.com>,
	Rasesh Mody <rmody@marvell.com>,
	Sudarsana Kalluru <skalluru@marvell.com>,
	<GR-Linux-NIC-Dev@marvell.com>,
	Dimitris Michailidis <dmichail@fungible.com>,
	Yisen Zhuang <yisen.zhuang@huawei.com>,
	Salil Mehta <salil.mehta@huawei.com>,
	Jesse Brandeburg <jesse.brandeburg@intel.com>,
	Tony Nguyen <anthony.l.nguyen@intel.com>,
	Louis Peens <louis.peens@corigine.com>,
	Shannon Nelson <shannon.nelson@amd.com>,
	"Brett Creeley" <brett.creeley@amd.com>, <drivers@pensando.io>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
	Ronak Doshi <doshir@vmware.com>,
	VMware PV-Drivers Reviewers <pv-drivers@vmware.com>,
	Andy Whitcroft <apw@canonical.com>, Joe Perches <joe@perches.com>,
	"Dwaipayan Ray" <dwaipayanray1@gmail.com>,
	Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Nathan Chancellor <nathan@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	<intel-wired-lan@lists.osuosl.org>, <oss-drivers@corigine.com>,
	<linux-hyperv@vger.kernel.org>
Subject: Re: [PATCH 3/3] checkpatch: add ethtool_sprintf rules
Date: Thu, 26 Oct 2023 11:29:47 +0200	[thread overview]
Message-ID: <cb83107f-f022-86c6-b463-a1eee4936967@intel.com> (raw)
In-Reply-To: <20231025-ethtool_puts_impl-v1-3-6a53a93d3b72@google.com>

On 10/26/23 01:40, Justin Stitt wrote:
> Add some warnings for using ethtool_sprintf() where a simple
> ethtool_puts() would suffice.
> 
> The two cases are:
> 
> 1) Use ethtool_sprintf() with just two arguments:
> |       ethtool_sprintf(&data, driver[i].name);
> or
> 2) Use ethtool_sprintf() with a standalone "%s" fmt string:
> |       ethtool_sprintf(&data, "%s", driver[i].name);
> 
> The former may cause -Wformat-security warnings while the latter is just
> not preferred. Both are safely in the category of warnings, not errors.
> 
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> ---
>   scripts/checkpatch.pl | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 7d16f863edf1..1ba9ce778746 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -7020,6 +7020,19 @@ sub process {
>   			     "Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90\n" . $herecurr);
>   		}
>   
> +# ethtool_sprintf uses that should likely be ethtool_puts
> +		if (   $line =~ /\bethtool_sprintf\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\)/   ) {

no need for whitespace right after opening parenthesis, same at the end

Does it work for ethtool_sprintf(calls broken
				 into multiple lines)?

BTW, I really like this series!

> +			WARN("ETHTOOL_SPRINTF",
> +			     "Prefer ethtool_puts over ethtool_sprintf with only two arguments" . $herecurr);
> +		}
> +
> +		# use $rawline because $line loses %s via sanitization and thus we can't match against it.
> +		if (   $rawline =~ /\bethtool_sprintf\s*\(\s*$FuncArg\s*,\s*\"\%s\"\s*,\s*$FuncArg\s*\)/   ) {
> +			WARN("ETHTOOL_SPRINTF2",
> +			     "Prefer ethtool_puts over ethtool_sprintf with standalone \"%s\" specifier" . $herecurr);
> +		}
> +
> +
>   # typecasts on min/max could be min_t/max_t
>   		if ($perl_version_ok &&
>   		    defined $stat &&
> 