linux-kernel - Re: [PATCH] drm/msm/dp: Add a missing semi-colon

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8943f0acd2944144b21b5796c07e79ff5e707aaf.camel@perches.com>
Date:   Sat, 06 Feb 2021 21:06:54 -0800
From:   Joe Perches <joe@...ches.com>
To:     Stephen Boyd <swboyd@...omium.org>,
        Rob Clark <robdclark@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     linux-kernel@...r.kernel.org, Sean Paul <sean@...rly.run>,
        Kuogee Hsieh <khsieh@...eaurora.org>,
        linux-arm-msm@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        freedreno@...ts.freedesktop.org, Lee Jones <lee.jones@...aro.org>
Subject: Re: [PATCH] drm/msm/dp: Add a missing semi-colon

On Sat, 2021-02-06 at 20:18 -0800, Stephen Boyd wrote:
> A missing semicolon here causes my external display to stop working.
> Indeed, missing the semicolon on the return statement leads to
> dp_panel_update_tu_timings() not existing because the compiler thinks
> it's part of the return statement of a void function, so it must not be
> important.
> 
>   $ ./scripts/bloat-o-meter before.o after.o
>   add/remove: 1/1 grow/shrink: 0/1 up/down: 7400/-7540 (-140)
>   Function                                     old     new   delta
>   dp_panel_update_tu_timings                     -    7400   +7400
>   _dp_ctrl_calc_tu.constprop                 18024   17900    -124
>   dp_panel_update_tu_timings.constprop        7416       -   -7416
>   Total: Before=54440, After=54300, chg -0.26%
> 
> Add a semicolon so this function works like it used to.
[]
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
[]
> @@ -631,7 +631,7 @@ static void _dp_ctrl_calc_tu(struct dp_tu_calc_input *in,
>  
> 
>  	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
>  	if (!tu)
> -		return
> +		return;
>  
> 
>  	dp_panel_update_tu_timings(in, tu);

Wow, that's really unfortunate that dp_panel_update_tu_timings
is also void.

Perhaps this as YA checkpatch warning:

---
 scripts/checkpatch.pl | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 9a549b009d2f..6df13e5a1557 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3674,6 +3674,12 @@ sub process {
 			}
 		}
 
+# check only a c90 keyword on the line (except else)
+		if ($sline =~ /^\+\s*($c90_Keywords)\s*$/ && $1 ne 'else') {
+			WARN("BARE_KEYWORD",
+				 "'$1' as the only word on a line is not good style\n" . $herecurr);
+		}
+
 # check multi-line statement indentation matches previous line
 		if ($perl_version_ok &&
 		    $prevline =~ /^\+([ \t]*)((?:$c90_Keywords(?:\s+if)\s*)|(?:$Declare\s*)?(?:$Ident|\(\s*\*\s*$Ident\s*\))\s*|(?:\*\s*)*$Lval\s*=\s*$Ident\s*)\(.*(\&\&|\|\||,)\s*$/) {