checkpatch: prefer ether_addr_copy to memcpy(foo, bar, ETH_ALEN)

ether_addr_copy was added for kernel version 3.14.  It's slightly
smaller/faster for some arches.  Encourage its use.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 05c99c0b7e6c..1dbd6d1cd1b5 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4087,6 +4087,16 @@ sub process {
                         }
                 }
 
+# Check for memcpy(foo, bar, ETH_ALEN) that could be ether_addr_copy(foo, bar)
+                if ($^V && $^V ge 5.10.0 &&
+                    $line =~ /^\+(?:.*?)\bmemcpy\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/s) {
+                        if (WARN("PREFER_ETHER_ADDR_COPY",
+                                 "Prefer ether_addr_copy() over memcpy() if the Ethernet addresses are __aligned(2)\n" . $herecurr) &&
+                            $fix) {
+                                $fixed[$linenr - 1] =~ s/\bmemcpy\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/ether_addr_copy($2, $7)/;
+                        }
+                }
+
 # typecasts on min/max could be min_t/max_t
                 if ($^V && $^V ge 5.10.0 &&
                     defined $stat &&