diff options
| author | Joe Perches <joe@perches.com> | 2014-08-07 01:10:55 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-07 03:01:28 +0200 |
| commit | e367455a9f25b11e02b7ea7678a7b146bdd6667e (patch) | |
| tree | 40e3868341e7c764930d13adfd7f53ca304f2737 | |
| parent | checkpatch: improve "no space after cast" test (diff) | |
| download | linux-e367455a9f25b11e02b7ea7678a7b146bdd6667e.tar.xz linux-e367455a9f25b11e02b7ea7678a7b146bdd6667e.zip | |
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>
| -rwxr-xr-x | scripts/checkpatch.pl | 17 |
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; } |