From e367455a9f25b11e02b7ea7678a7b146bdd6667e Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 6 Aug 2014 16:10:55 -0700 Subject: [PATCH] checkpatch: emit fewer kmalloc_array/kcalloc conversion warnings Avoid matching allocs that appear to be known small multiplications of a sizeof with a constant because gcc as of 4.8 cannot optimize the code in a calloc() exactly the same way as an alloc(). Look for numeric constants or what appear to be upper case only macro #defines. Signed-off-by: Joe Perches Reported-by: Theodore Ts'o Original-patch-by: Fabian Frederick Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/checkpatch.pl | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index b351805149a5..3661ffc7af23 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -4487,22 +4487,23 @@ sub process { # check for k[mz]alloc with multiplies that could be kmalloc_array/kcalloc if ($^V && $^V ge 5.10.0 && - $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(k[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/) { + $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(k[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)\s*,/) { my $oldfunc = $3; my $a1 = $4; my $a2 = $10; my $newfunc = "kmalloc_array"; $newfunc = "kcalloc" if ($oldfunc eq "kzalloc"); - if ($a1 =~ /^sizeof\s*\S/ || $a2 =~ /^sizeof\s*\S/) { + my $r1 = $a1; + my $r2 = $a2; + if ($a1 =~ /^sizeof\s*\S/) { + $r1 = $a2; + $r2 = $a1; + } + if ($r1 !~ /^sizeof\b/ && $r2 =~ /^sizeof\s*\S/ && + !($r1 =~ /^$Constant$/ || $r1 =~ /^[A-Z_][A-Z0-9_]*$/)) { if (WARN("ALLOC_WITH_MULTIPLY", "Prefer $newfunc over $oldfunc with multiply\n" . $herecurr) && $fix) { - my $r1 = $a1; - my $r2 = $a2; - if ($a1 =~ /^sizeof\s*\S/) { - $r1 = $a2; - $r2 = $a1; - } $fixed[$linenr - 1] =~ s/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(k[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/$1 . ' = ' . "$newfunc(" . trim($r1) . ', ' . trim($r2)/e; } -- 2.30.2