Commit 070580b0 authored by Kees Cook's avatar Kees Cook
Browse files

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: default avatarKees Cook <kees@kernel.org>
parent 2932ba8d

scripts/checkpatch.pl

+33 −6
Original line number Diff line number Diff line
@@ -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;

				}

			}

		}