Re: [PATCH -next v2] checkpatch: Add check for array allocator family argument order

[Joe Perches]

On Fri, 2022-11-04 at 18:08 +0100, Christophe JAILLET wrote:
> Le 04/11/2022 à 08:05, Liao Chang a écrit :
> > These array allocator family are sometimes misused with the first and
> > second arguments switchted.
> > 
> > Same issue with calloc, kvcalloc, kvmalloc_array etc.
> > 
> > Bleat if sizeof is the first argument.
> > 
> > Link: https://lore.kernel.org/lkml/5374345c-7973-6a3c-d559-73bf4ac15079@xxxxxxxxxx/
> > Signed-off-by: Liao Chang <liaochang1@xxxxxxxxxx>
> > Acked-by: Joe Perches <joe@xxxxxxxxxxx>
> > ---
> > v2:
> > 1. Acked-by Joe Perches.
> > 2. Use lore links in Link tag.
> > 
> > ---
> >   scripts/checkpatch.pl | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > index 1e5e66ae5a52..a9a9dc277cff 100755
> > --- a/scripts/checkpatch.pl
> > +++ b/scripts/checkpatch.pl
> > @@ -7128,7 +7128,7 @@ sub process {
> >   		}
> >   
> >   # check for alloc argument mismatch
> > -		if ($line =~ /\b((?:devm_)?(?:kcalloc|kmalloc_array))\s*\(\s*sizeof\b/) {
> > +		if ($line =~ /\b((?:devm_)?((?:k|kv)?(calloc|malloc_array)(?:_node)?))\s*\(\s*sizeof\b/) {
> >   			WARN("ALLOC_ARRAY_ARGS",
> >   			     "$1 uses number as first arg, sizeof is generally wrong\n" . $herecurr);
> >   		}
> 
> Hi,
> 
> Should the devm_ and not devm_ cases be separated?
> 
> In the devm_case, sizeof will never be just after the first '('.

Right.

Likely this works better:
---
 scripts/checkpatch.pl | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 7be93c3df2bcb..7f37976a9f8b5 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -7145,12 +7145,18 @@ sub process {
 			     "Reusing the krealloc arg is almost always a bug\n" . $herecurr);
 		}
 
-# check for alloc argument mismatch
-		if ($line =~ /\b((?:devm_)?(?:kcalloc|kmalloc_array))\s*\(\s*sizeof\b/) {
+# check for alloc argument mismatch in alloc functions
+		if ($line =~ /\b(((?:k|kv)?(calloc|malloc_array)(?:_node)?))\s*\(\s*sizeof\b/) {
 			WARN("ALLOC_ARRAY_ARGS",
 			     "$1 uses number as first arg, sizeof is generally wrong\n" . $herecurr);
 		}
 
+# check for alloc argument mismatch in devm_ alloc functions
+		if ($line =~ /\b(devm_((?:k|kv)?(calloc|malloc_array)(?:_node)?))\s*\(\s*$FuncArg\s*,\s*sizeof\b/) {
+			WARN("ALLOC_ARRAY_ARGS",
+			     "$1 uses number as second arg, sizeof is generally wrong\n" . $herecurr);
+		}
+
 # check for multiple semicolons
 		if ($line =~ /;\s*;\s*$/) {
 			if (WARN("ONE_SEMICOLON",