[PATCH] checkpatch: add vmalloc() and vzalloc() to alloc with multiplies check

[Iurii Trukhin]

vmalloc() and vzalloc() have 2-factor multiplication argument forms
vmalloc_array() and vcalloc() in <linux/vmalloc.h> that protect against
integer overflow during size calculation.

Commit 070580b0b174 ("checkpatch: Suggest kmalloc_obj family for sizeof
allocations") updated ALLOC_WITH_MULTIPLY for the (kv|k)[mz]alloc()
family to suggest kmalloc_objs(type, count, gfp), while vmalloc_array()
and vcalloc() retain the (count, size) signature.

Extend ALLOC_WITH_MULTIPLY to warn when vmalloc() or vzalloc() is called
with a 2-factor sizeof() multiplication and suggest vmalloc_array() or
vcalloc() respectively, including --fix support. Also include the 'v'
prefix in ALLOC_ARRAY_ARGS so swapped sizeof() first arguments to
vmalloc_array() and vcalloc() are flagged.

Link: https://github.com/KSPP/linux/issues/342
Signed-off-by: Iurii Trukhin <y...@trukhin.com>
---
 scripts/checkpatch.pl | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 8a7787d228a6..651a46f1fc40 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -7355,10 +7355,11 @@ sub process {
                }


-# check for (kv|k)[mz]alloc with multiplies that could be
kmalloc_objs/kvmalloc_objs/kzalloc_objs/kvzalloc_objs
+# check for (kv|k|v)[mz]alloc with multiplies that could be
+# kmalloc_objs/kvmalloc_objs/kzalloc_objs/kvzalloc_objs/vmalloc_array/vcalloc
                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*((?:kv|k|v)[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)\s*(?:,|\))/)
{
                        my $oldfunc = $3;
                        my $a1 = $4;
                        my $a2 = $10;
@@ -7366,6 +7367,8 @@ sub process {
                        $newfunc = "kvmalloc_objs" if ($oldfunc eq "kvmalloc");
                        $newfunc = "kvzalloc_objs" if ($oldfunc eq "kvzalloc");
                        $newfunc = "kzalloc_objs" if ($oldfunc eq "kzalloc");
+                       $newfunc = "vmalloc_array" if ($oldfunc eq "vmalloc");
+                       $newfunc = "vcalloc" if ($oldfunc eq "vzalloc");
                        my $r1 = $a1;
                        my $r2 = $a2;
                        if ($a1 =~ /^sizeof\s*\S/) {
@@ -7381,9 +7384,13 @@ sub process {
                                         "Prefer $newfunc over $oldfunc with 
multiply\n" . $herectx) &&
                                    $cnt == 1 &&
                                    $fix) {
-                                       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;
+                                       if ($oldfunc =~ /^v/) {
+                                               $fixed[$fixlinenr] =~
s/\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(v[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/$1
. ' = ' . "$newfunc(" . trim($r1) . ', ' . trim($r2)/e;
+                                       } else {
+                                               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;
+                                       }
                                }
                        }
                }
@@ -7397,7 +7404,7 @@ sub process {
                }

 # check for alloc argument mismatch
-               if ($line =~
/\b((?:devm_)?((?:k|kv)?(calloc|malloc_array)(?:_node)?))\s*\(\s*sizeof\b/)
{
+               if ($line =~
/\b((?:devm_)?((?:k|kv|v)?(calloc|malloc_array)(?:_node)?))\s*\(\s*sizeof\b/)
{
                        WARN("ALLOC_ARRAY_ARGS",
                             "$1 uses number as first arg, sizeof is generally 
wrong\n" .
$herecurr);
                }
-- 
2.56.0