[PATCH v2] scripts: checkpatch.pl: add 2 new checks on memset calls

From: Aya Mahfouz
Date: Tue Feb 24 2015 - 21:41:39 EST


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@xxxxxxx>
Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@xxxxxxxxx>
---
v2: adjusted all checks on memset calls to be in one body

scripts/checkpatch.pl | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d124359..ab43d1b 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4890,10 +4890,10 @@ 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) {
+ $line =~ /^\+(?:.*?)\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {

my $ms_addr = $2;
my $ms_val = $7;
@@ -4901,10 +4901,22 @@ sub process {

if ($ms_size =~ /^(0x|)0$/i) {
ERROR("MEMSET",
- "memset to 0's uses 0 as the 2nd argument, not the 3rd\n" . "$here\n$stat\n");
+ "memset to 0's uses 0 as the 2nd argument, not the 3rd\n" . "$here\n$line\n");
} elsif ($ms_size =~ /^(0x|)1$/i) {
WARN("MEMSET",
- "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$stat\n");
+ "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$line\n");
+ } elsif ($ms_size =~ /^ETH_ALEN/i) {
+ if ($ms_val =~ /^0x00/i && 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($ms_addr)/;
+ } elsif ($ms_val =~ /^0xff/i && 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($ms_addr)/;
+ }
}
}

--
1.9.3

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