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checkpatch: debugfs_remove() can take NULL

PATCH Superseded Constantine Shulyupin 2 participants 2 messages Nov 17, 2012 Checkpatch

v2 of 4 Superseded Latest is v4 →

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Constantine Shulyupin

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#0 lore raw

PATCH v2 1/1 checkpatch: debugfs_remove() can take NULL

From: Constantine Shulyupin <[email protected]>

debugfs_remove() and debugfs_remove_recursive() can take a NULL, so let's check and warn about that.

Channegs since v1:

- added debugfs_remove_recursive
- all tests for pattenrs are "if (a) xxx(a)" are consolidates

Signed-off-by Constantine Shulyupin <[email protected]>
---
 scripts/checkpatch.pl |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)
scripts/checkpatch.pl +12 -4
index f18750e..2339b54 100755
@@ -3213,21 +3213,29 @@ sub process {
 				$herecurr);
 		}
 
-# check for needless kfree() checks
+# check for needless "if"
 		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
 			my $expr = $1;
+# check for needless kfree() checks
 			if ($line =~ /\bkfree\(\Q$expr\E\);/) {
 				WARN("NEEDLESS_KFREE",
 				     "kfree(NULL) is safe this check is probably not required\n" . $hereprev);
 			}
-		}
 # check for needless usb_free_urb() checks
-		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
-			my $expr = $1;
 			if ($line =~ /\busb_free_urb\(\Q$expr\E\);/) {
 				WARN("NEEDLESS_USB_FREE_URB",
 				     "usb_free_urb(NULL) is safe this check is probably not required\n" . $hereprev);
 			}
+# check for needless debugfs_remove() checks
+			if ($line =~ /\bdebugfs_remove\(\Q$expr\E\);/) {
+				WARN("NEEDLESS_DEBUGFS_REMOVE",
+				     "debugfs_remove(NULL) is safe this check is probably not required\n" . $hereprev);
+			}
+# check for needless debugfs_remove_recursive() checks
+			if ($line =~ /\bdebugfs_remove_recursive\(\Q$expr\E\);/) {
+				WARN("NEEDLESS_DEBUGFS_REMOVE",
+				     "debugfs_remove_recursive(NULL) is safe this check is probably not required\n" . $hereprev);
+			}
 		}
 
 # prefer usleep_range over udelay
Signature · 1 line
1.7.9.5
maintainer
#1 lore raw
Quoted 8 lines · Constantine Shulyupin

From: Constantine Shulyupin <[email protected]>

debugfs_remove() and debugfs_remove_recursive() can take a NULL, so let's check and warn about that.

Channegs since v1:

- added debugfs_remove_recursivere
- all tests for pattenrs are "if (a) xxx(a)" are consolidates

Hello Constantine.

Just some trivia and a suggestion:

There are a couple of typos in the commit message
(I do that all the time myself)

Quoted 33 lines
Signed-off-by Constantine Shulyupin <[email protected]>
---
 scripts/checkpatch.pl |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)
scripts/checkpatch.pl +5 -4
index f18750e..2339b54 100755
@@ -3213,21 +3213,29 @@ sub process {
 				$herecurr);
 		}
 
-# check for needless kfree() checks
+# check for needless "if"
 		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
 			my $expr = $1;
+# check for needless kfree() checks
 			if ($line =~ /\bkfree\(\Q$expr\E\);/) {
 				WARN("NEEDLESS_KFREE",
 				     "kfree(NULL) is safe this check is probably not required\n" . $hereprev);
 			}
-		}
 # check for needless usb_free_urb() checks
-		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
-			my $expr = $1;
 			if ($line =~ /\busb_free_urb\(\Q$expr\E\);/) {
 				WARN("NEEDLESS_USB_FREE_URB",
 				     "usb_free_urb(NULL) is safe this check is probably not required\n" . $hereprev);
 			}
+# check for needless debugfs_remove() checks
+			if ($line =~ /\bdebugfs_remove\(\Q$expr\E\);/) {
+				WARN("NEEDLESS_DEBUGFS_REMOVE",

scripts/checkpatch.pl sub process { · line 3241

Quoted 10 lines
scripts/checkpatch.pl +7 -0
+				     "debugfs_remove(NULL) is safe this check is probably not required\n" . $hereprev);
+			}
+# check for needless debugfs_remove_recursive() checks
+			if ($line =~ /\bdebugfs_remove_recursive\(\Q$expr\E\);/) {
+				WARN("NEEDLESS_DEBUGFS_REMOVE",
+				     "debugfs_remove_recursive(NULL) is safe this check is probably not required\n" . $hereprev);
+			}
 		}
 
 # prefer usleep_range over udelay

Perhaps this is better because it allows whitespace around the check value:

Right now this doesn't trigger, with the suggestion, it does.

	if ( foo )
		kfree ( foo );
scripts/checkpatch.pl +11 -7
index d2d5ba1..c037c31 100755
@@ -3198,21 +3200,25 @@ sub process {
 				$herecurr);
 		}
 
+# check for needless "if (<foo>) fn(<foo>)" uses
+		if ($prevline =~ /\bif\s*\(\s*($Lval)\s*\)/) {
+			my $expr = '\s*\(\s*' . quotemeta($1) . '\s*\)\s*;';
+
 # check for needless kfree() checks
-		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
-			my $expr = $1;
-			if ($line =~ /\bkfree\(\Q$expr\E\);/) {
+			if ($line =~ /\bkfree$expr/) {
 				WARN("NEEDLESS_KFREE",
 				     "kfree(NULL) is safe this check is probably not required\n" . $hereprev);
 			}
-		}
 # check for needless usb_free_urb() checks
-		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
-			my $expr = $1;
-			if ($line =~ /\busb_free_urb\(\Q$expr\E\);/) {
+			if ($line =~ /\busb_free_urb$expr/) {
 				WARN("NEEDLESS_USB_FREE_URB",
 				     "usb_free_urb(NULL) is safe this check is probably not required\n" . $hereprev);
 			}
+# check for needless debugfs_remove() and debugfs_remove_recursive*() checks
+			if ($line =~ /\b(debugfs_remove(?:_recursive)?)$expr/) {
+				WARN("NEEDLESS_DEBUGFS_REMOVE",
+				     "$1(NULL) is safe this check is probably not required\n" . $hereprev);
+			}
 		}
 
 # prefer usleep_range over udelay