scripts: checkpatch.pl: add 2 new checks on memset

calls
Reply-To:

Add 2 new checks on memset calls in the file checkpatch.pl as follows:

replace memset by eth_zero_addr if the second argument is an address of zeros (0x00). eth_zero_addr is a wrapper function for memset that takes an address array to set as zero. The size address has to be ETH_ALEN.

replace memset by eth_broadcast_addr if the second argument is the broadcast address (0xff). eth_broadcast_addr is a wrapper function for memset that sets the passed array the broadcast address. The size of the address has to be ETH_ALEN.

In addition, the regex assigned to the variable $stat has been restricted to handle memset function calls of the form:
[<identifer> =]* memset(<arg1>, <arg2>, <arg3>)

Cc Julia Lawall <[email protected]>

Signed-off-by Aya Mahfouz <[email protected]>

Signed-off-by Joe Perches <[email protected]>

---
v2: adjusted all checks on memset calls to be in one body
v3: adjusted all regular expressions per Joe Perches suggestions. Added a Signed-off-by tag for Joe since all the important regular expressions are written by him.

 scripts/checkpatch.pl | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

scripts/checkpatch.pl +15 -2

index d124359..cbe973e 100755
@@ -4890,10 +4890,11 @@ sub process {
 			}
 		}
 
-# Check for misused memsets
+# Check for misused memsets then check for memset(foo, 0x00|0xff, ETH_ALEN)
+# calls that could be eth_zero_addr(foo)|eth_broadcast_addr(foo)
 		if ($^V && $^V ge 5.10.0 &&
 		    defined $stat &&
-		    $stat =~ /^\+(?:.*?)\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {
+		    $stat =~ /^\+(?:\s*$Ident\s*=)?\s*memset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {
 
 			my $ms_addr = $2;
 			my $ms_val = $7;

@@ -4905,6 +4906,18 @@ sub process {
 			} elsif ($ms_size =~ /^(0x|)1$/i) {
 				WARN("MEMSET",
 				     "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$stat\n");
+			} elsif ($ms_val =~ /^(?:0x)?0+$/i &&
+				 $ms_size =~ /^ETH_ALEN$/ &&
+				 WARN("PREFER_ETH_ADDR",
+				     "Prefer eth_zero_addr() over memset() if the second address is 0\n" . $herecurr) &&
+				 $fix) {
+				$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*\Q$ms_addr\E\s*,\s*\Q$ms_val\E\s*,\s*ETH_ALEN\s*\)/eth_zero_addr($ms_addr)/;
+			} elsif ($ms_val =~ /^(?:0xff|255)$/i &&
+				 $ms_size =~ /^ETH_ALEN$/ &&
+				 WARN("PREFER_ETH_ADDR",
+				      "Prefer eth_broadcast_addr() over memset() if the second address is 0xff\n" . $herecurr) &&
+				 $fix) {
+				$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*\Q$ms_addr\E\s*,\s*\Q$ms_val\E\s*,\s*ETH_ALEN\s*\)/eth_broadcast_addr($ms_addr)/;
 			}
 		}
 

Signature · 1 line

1.9.3

Quoted 3 lines · Aya Mahfouz

calls
Reply-To:

Quoted 1 line

Add 2 new checks on memset calls in the file checkpatch.pl as follows:

Hi again Aya

The initial 3 lines here aren't necessary.

I think it'd be a better subject line with something like "checkpatch: prefer eth_<foo>_addr over memset(,,ETH_ALEN)"

Please cc Andrew Morton <[email protected]> And please also don't add Signed-off-by: lines for anyone other than yourself.

Other than those things:

Acked-by Joe Perches <[email protected]>

Quoted 67 lines

replace memset by eth_zero_addr if the second argument is an address of zeros (0x00). eth_zero_addr is a wrapper function for memset that takes an address array to set as zero. The size address has to be ETH_ALEN.

replace memset by eth_broadcast_addr if the second argument is the broadcast address (0xff). eth_broadcast_addr is a wrapper function for memset that sets the passed array the broadcast address. The size of the address has to be ETH_ALEN.

In addition, the regex assigned to the variable $stat has been restricted to handle memset function calls of the form:
[<identifer> =]* memset(<arg1>, <arg2>, <arg3>)

Cc Julia Lawall <[email protected]>

Signed-off-by Aya Mahfouz <[email protected]>

Signed-off-by Joe Perches <[email protected]>

---
v2: adjusted all checks on memset calls to be in one body
v3: adjusted all regular expressions per Joe Perches suggestions. Added a Signed-off-by tag for Joe since all the important regular expressions are written by him.

 scripts/checkpatch.pl | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

scripts/checkpatch.pl +15 -2

index d124359..cbe973e 100755
@@ -4890,10 +4890,11 @@ sub process {
 			}
 		}
 
-# Check for misused memsets
+# Check for misused memsets then check for memset(foo, 0x00|0xff, ETH_ALEN)
+# calls that could be eth_zero_addr(foo)|eth_broadcast_addr(foo)
 		if ($^V && $^V ge 5.10.0 &&
 		    defined $stat &&
-		    $stat =~ /^\+(?:.*?)\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {
+		    $stat =~ /^\+(?:\s*$Ident\s*=)?\s*memset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {
 
 			my $ms_addr = $2;
 			my $ms_val = $7;

@@ -4905,6 +4906,18 @@ sub process {
 			} elsif ($ms_size =~ /^(0x|)1$/i) {
 				WARN("MEMSET",
 				     "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$stat\n");
+			} elsif ($ms_val =~ /^(?:0x)?0+$/i &&
+				 $ms_size =~ /^ETH_ALEN$/ &&
+				 WARN("PREFER_ETH_ADDR",
+				     "Prefer eth_zero_addr() over memset() if the second address is 0\n" . $herecurr) &&
+				 $fix) {
+				$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*\Q$ms_addr\E\s*,\s*\Q$ms_val\E\s*,\s*ETH_ALEN\s*\)/eth_zero_addr($ms_addr)/;
+			} elsif ($ms_val =~ /^(?:0xff|255)$/i &&
+				 $ms_size =~ /^ETH_ALEN$/ &&
+				 WARN("PREFER_ETH_ADDR",
+				      "Prefer eth_broadcast_addr() over memset() if the second address is 0xff\n" . $herecurr) &&
+				 $fix) {
+				$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*\Q$ms_addr\E\s*,\s*\Q$ms_val\E\s*,\s*ETH_ALEN\s*\)/eth_broadcast_addr($ms_addr)/;
 			}
 		}
 

Signature · 1 line

1.9.3

Quoted 8 lines · Joe Perches

Quoted 4 lines · Aya Mahfouz

calls
Reply-To:

Add 2 new checks on memset calls in the file checkpatch.pl as follows:

Hi again Aya

Quoted 5 lines

The initial 3 lines here aren't necessary.

I think it'd be a better subject line with something like "checkpatch: prefer eth_<foo>_addr over memset(,,ETH_ALEN)"

ok, should I resend it as a fresh patch or send the patch with a new subject line and state that it is v4?

Quoted 4 lines

Please cc Andrew Morton <[email protected]> And please also don't add Signed-off-by: lines for anyone other than yourself.

ok, I will cc Andrew. As for your tag, I couldn't take credit for the regex that I did not write. Will not do it in the future again unless the other side agrees to it.