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authorJoe Perches <joe@perches.com>2014-08-07 03:10:55 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-07 05:01:28 +0400
commite367455a9f25b11e02b7ea7678a7b146bdd6667e (patch)
tree40e3868341e7c764930d13adfd7f53ca304f2737 /scripts
parentf27c95db1176b41c6c87d9d3480d15efbca8f3ff (diff)
downloadlinux-e367455a9f25b11e02b7ea7678a7b146bdd6667e.tar.xz
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 <joe@perches.com> Reported-by: Theodore Ts'o <tytso@mit.edu> Original-patch-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts')
-rwxr-xr-xscripts/checkpatch.pl17
1 files 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;
}