[PATCH V2 2/2] checkpatch: Add a couple new alloc functions to alloc with multiplies check

From: Joe Perches
Date: Wed Sep 13 2023 - 21:41:55 EST


vmalloc() and vzalloc() functions have now 2-factor multiplication
argument forms vmalloc_array() and vcalloc(), correspondingly.

Add alloc-with-multiplies checks for these new functions.

Simplify the original codes repeated else to use a hash.

Link: https://github.com/KSPP/linux/issues/342

Original-patch-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Co-developed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Link: https://lore.kernel.org/lkml/ZQCaO+tYycDxVLy7@work/
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---

v2: Fix search because vmalloc functions don't take a 3rd argument

scripts/checkpatch.pl | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 617f9e53bacdf..4cb248985eefc 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -834,6 +834,16 @@ our %deprecated_apis = (
#Create a search pattern for all these strings to speed up a loop below
our $deprecated_apis_search = '(?:' . join('|', keys %deprecated_apis) . ')';

+our %alloc_with_multiply_apis = (
+ "kmalloc" => "kmalloc_array",
+ "kvmalloc" => "kvmalloc_array",
+ "vmalloc" => "vmalloc_array",
+ "kvzalloc" => "kvcalloc",
+ "kzalloc" => "kcalloc",
+ "vzalloc" => "vcalloc",
+);
+our $alloc_with_multiply_search = '(?:' . join('|', keys %alloc_with_multiply_apis) . ')';
+
our $mode_perms_world_writable = qr{
S_IWUGO |
S_IWOTH |
@@ -7187,17 +7197,14 @@ sub process {
"Prefer $3(sizeof(*$1)...) over $3($4...)\n" . $herecurr);
}

-# check for (kv|k)[mz]alloc with multiplies that could be kmalloc_array/kvmalloc_array/kvcalloc/kcalloc
+# check for various allocs with multiplies that should use safer functions
if ($perl_version_ok &&
defined $stat &&
- $stat =~ /^\+\s*($Lval)\s*\=\s*(?:$balanced_parens)?\s*((?:kv|k)[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)\s*,/) {
+ $stat =~ /^\+\s*($Lval)\s*\=\s*(?:$balanced_parens)?\s*($alloc_with_multiply_search)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/) {
my $oldfunc = $3;
+ my $newfunc = $alloc_with_multiply_apis{$oldfunc};
my $a1 = $4;
my $a2 = $10;
- my $newfunc = "kmalloc_array";
- $newfunc = "kvmalloc_array" if ($oldfunc eq "kvmalloc");
- $newfunc = "kvcalloc" if ($oldfunc eq "kvzalloc");
- $newfunc = "kcalloc" if ($oldfunc eq "kzalloc");
my $r1 = $a1;
my $r2 = $a2;
if ($a1 =~ /^sizeof\s*\S/) {
@@ -7213,7 +7220,7 @@ sub process {
"Prefer $newfunc over $oldfunc with multiply\n" . $herectx) &&
$cnt == 1 &&
$fix) {
- $fixed[$fixlinenr] =~ s/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*((?:kv|k)[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/$1 . ' = ' . "$newfunc(" . trim($r1) . ', ' . trim($r2)/e;
+ $fixed[$fixlinenr] =~ s/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*($oldfunc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/$1 . ' = ' . "$newfunc(" . trim($r1) . ', ' . trim($r2)/e;
}
}
}
--
2.41.0