[PATCH] scripts: checkpatch.pl: add 2 new checks on memset calls

[Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>]

This patch adds 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.

Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
---
 scripts/checkpatch.pl | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d124359..9619882 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4918,6 +4918,25 @@ sub process {
 			}
 		}
 
+# Check for memset(foo, 0x00|0xff, ETH_ALEN) that could be eth_zero_addr(foo)|eth_broadcast_addr(foo)
+		if ($^V && $^V ge 5.10.0 &&
+		    $line =~ /^\+(?:.*?)\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/s) {
+			my $num = $7;
+			if ($num =~ "0x00" && WARN("PREFER_ETH_ZERO_ADDR",
+				 "Prefer eth_zero_addr() over memset() if the second address is 0x00\n" . $herecurr) &&
+			    $fix) {
+
+				$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/eth_zero_addr($2)/;
+			}
+			elsif ($num =~ "0xff" && WARN("PREFER_ETH_BROADCAST_ADDR",
+				 "Prefer eth_broadcast_addr() over memset() if the second address is 0xff\n" . $herecurr) &&
+			    $fix) {
+
+				$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/eth_broadcast_addr($2)/;
+			}
+		}
+
+
 # typecasts on min/max could be min_t/max_t
 		if ($^V && $^V ge 5.10.0 &&
 		    defined $stat &&
-- 
1.9.3