From 791dfeb49519f18a6efea4619f5678457f1532ff Mon Sep 17 00:00:00 2001 From: Fabian Frederick Date: Fri, 8 Aug 2014 14:23:29 -0700 Subject: [PATCH] scripts/coccinelle/free: add NULL test before freeing functions Warns or generates patch for NULL check before the following functions: kfree usb_free_urb debugfs_remove debugfs_remove_recursive Signed-off-by: Fabian Frederick Acked-by: Julia Lawall Cc: Gilles Muller Cc: Joe Perches Cc: Markus Elfring Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/coccinelle/free/ifnullfree.cocci | 52 ++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 scripts/coccinelle/free/ifnullfree.cocci diff --git a/scripts/coccinelle/free/ifnullfree.cocci b/scripts/coccinelle/free/ifnullfree.cocci new file mode 100644 index 000000000000..77ab43f30b8d --- /dev/null +++ b/scripts/coccinelle/free/ifnullfree.cocci @@ -0,0 +1,52 @@ +/// NULL check before some freeing functions is not needed. +/// +/// Based on checkpatch warning +/// "kfree(NULL) is safe this check is probably not required" +/// and kfreeaddr.cocci by Julia Lawall. +/// +/// Comments: - +/// Options: --no-includes --include-headers + +virtual patch +virtual org +virtual report +virtual context + +@r2 depends on patch@ +expression E; +@@ +- if (E) +( +- kfree(E); ++ kfree(E); +| +- debugfs_remove(E); ++ debugfs_remove(E); +| +- debugfs_remove_recursive(E); ++ debugfs_remove_recursive(E); +| +- usb_free_urb(E); ++ usb_free_urb(E); +) + +@r depends on context || report || org @ +expression E; +position p; +@@ + +* if (E) +* \(kfree@p\|debugfs_remove@p\|debugfs_remove_recursive@p\|usb_free_urb\)(E); + +@script:python depends on org@ +p << r.p; +@@ + +cocci.print_main("NULL check before that freeing function is not needed", p) + +@script:python depends on report@ +p << r.p; +@@ + +msg = "WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values." +coccilib.report.print_report(p[0], msg) -- 2.20.1