checkpatch: Suggest kmalloc_obj family for sizeof allocations

To support shifting away from sized allocation towards typed
allocations, suggest the kmalloc_obj family of macros when a sizeof() is
present in the argument lists.

Link: https://patch.msgid.link/20251203233036.3212363-2-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index c0250244cf7a3cb5e289b04fa4a9f644692dc278..4ab5ebbbb061894c776fca6b7654cd472789c244 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -7258,17 +7258,42 @@ 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 (kv|k)[mz]alloc that could be kmalloc_obj/kvmalloc_obj/kzalloc_obj/kvzalloc_obj
+               if ($perl_version_ok &&
+                   defined $stat &&
+                   $stat =~ /^\+\s*($Lval)\s*\=\s*(?:$balanced_parens)?\s*((?:kv|k)[mz]alloc)\s*\(\s*($FuncArg)\s*,/) {
+                       my $oldfunc = $3;
+                       my $a1 = $4;
+                       my $newfunc = "kmalloc_obj";
+                       $newfunc = "kvmalloc_obj" if ($oldfunc eq "kvmalloc");
+                       $newfunc = "kvzalloc_obj" if ($oldfunc eq "kvzalloc");
+                       $newfunc = "kzalloc_obj" if ($oldfunc eq "kzalloc");
+
+                       if ($a1 =~ s/^sizeof\s*\S\(?([^\)]*)\)?$/$1/) {
+                               my $cnt = statement_rawlines($stat);
+                               my $herectx = get_stat_here($linenr, $cnt, $here);
+
+                               if (WARN("ALLOC_WITH_SIZEOF",
+                                        "Prefer $newfunc over $oldfunc with sizeof\n" . $herectx) &&
+                                   $cnt == 1 &&
+                                   $fix) {
+                                       $fixed[$fixlinenr] =~ s/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*((?:kv|k)[mz]alloc)\s*\(\s*($FuncArg)\s*,/$1 = $newfunc($a1,/;
+                               }
+                       }
+               }
+
+
+# check for (kv|k)[mz]alloc with multiplies that could be kmalloc_objs/kvmalloc_objs/kzalloc_objs/kvzalloc_objs
                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*,/) {
                        my $oldfunc = $3;
                        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 $newfunc = "kmalloc_objs";
+                       $newfunc = "kvmalloc_objs" if ($oldfunc eq "kvmalloc");
+                       $newfunc = "kvzalloc_objs" if ($oldfunc eq "kvzalloc");
+                       $newfunc = "kzalloc_objs" if ($oldfunc eq "kzalloc");
                        my $r1 = $a1;
                        my $r2 = $a2;
                        if ($a1 =~ /^sizeof\s*\S/) {
@@ -7284,7 +7309,9 @@ 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;
+                                       my $sized = trim($r2);
+                                       $sized =~ s/^sizeof\s*\S\(?([^\)]*)\)?$/$1/;
+                                       $fixed[$fixlinenr] =~ s/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*((?:kv|k)[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/$1 . ' = ' . "$newfunc(" . $sized . ', ' . trim($r1)/e;
                                }
                        }
                }