linux-kernel - [PATCH] coccinelle: deref_null: avoid useless computation

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-next>] [day] [month] [year] [list]

Date:   Sat,  3 Feb 2018 08:44:58 +0100
From:   Julia Lawall <Julia.Lawall@...6.fr>
To:     Masahiro Yamada <yamada.masahiro@...ionext.com>
Cc:     kernel-janitors@...r.kernel.org,
        Gilles Muller <Gilles.Muller@...6.fr>,
        Nicolas Palix <nicolas.palix@...g.fr>,
        Michal Marek <michal.lkml@...kovi.net>, cocci@...teme.lip6.fr,
        linux-kernel@...r.kernel.org
Subject: [PATCH] coccinelle: deref_null: avoid useless computation

The effect of the rules ifm1, pr11, and pr12 is only used in the final rule,
which depends on context && !org && !report.  Thus these rules should only
be performed in those circumstances.

Signed-off-by: Julia Lawall <Julia.Lawall@...6.fr>

---
 scripts/coccinelle/null/deref_null.cocci |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/scripts/coccinelle/null/deref_null.cocci b/scripts/coccinelle/null/deref_null.cocci
index f192d60..b16ccb7 100644
--- a/scripts/coccinelle/null/deref_null.cocci
+++ b/scripts/coccinelle/null/deref_null.cocci
@@ -212,7 +212,7 @@ else S3
 // The following three rules are duplicates of ifm, pr1 and pr2 respectively.
 // It is need because the previous rule as already made a "change".
 
-@...1@
+@...1 depends on context && !org && !report@
 expression *E;
 statement S1,S2;
 position p1;
@@ -220,7 +220,7 @@ position p1;
 
 if@p1 ((E == NULL && ...) || ...) S1 else S2
 
-@...1 expression@
+@...1 depends on context && !org && !report expression@
 expression *ifm1.E;
 identifier f;
 position p1;
@@ -228,7 +228,7 @@ position p1;
 
  (E != NULL && ...) ? <+...E->f@.....+> : ...
 
-@...2 expression@
+@...2 depends on context && !org && !report expression@
 expression *ifm1.E;
 identifier f;
 position p2;