Re: [PATCH 1/1] scripts/checkpatch.pl: update kmalloc_array/kcalloc conversion warning

From: Fabian Frederick
Date: Tue Jul 01 2014 - 16:07:15 EST




> On 29 June 2014 at 11:33 Joe Perches <joe@xxxxxxxxxxx> wrote:
>
>
> On Sun, 2014-06-29 at 11:21 +0200, Fabian Frederick wrote:
> > On Fri, 27 Jun 2014 14:37:04 -0700 Joe Perches <joe@xxxxxxxxxxx> wrote:
> []
> > > I'm not sure of the value of this as I think at some point
> > > if not already today, the compiler will optimize the multiply
> > > away.
> > >
> > > But it's probably better to look at the non-sizeof variable
> > > and emit the warning only when it's not $Constant or some
> > > upper-case only macro #define like "\b[A-Z_]+\b" is used.
> []
> > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> []
> > > +Â Â Â Â Â Â Â Â Â}
> > > +Â Â Â Â Â Â Â Â Âif ($r1 !~ /^sizeof\b/ && $r2 =~ /^sizeof\s*\S/ &&
> > > +Â Â Â Â Â Â Â Â Â Â Â!($r1 =~ /^$Constant$/ || $r1 =~ /^[A-Z_]+$/)) {
>
> This last test should be
>
> /^[A-Z_][A-Z0-9_]*$/
>
> to allow upper case macros with digits too
>
> > Already tested ? If not I can do it and give you some feedback ...
>
> Lightly. Test away.

Tested on rc3: 766 warnings against 976 with original version.

No more warnings for things like:

mm/huge_memory.c
pages = kmalloc(sizeof(struct page *) * HPAGE_PMD_NR, GFP_KERNEL);

net/ipv6/ip6_fib.c
mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);

lib/sort.c
a = kmalloc(1000 * sizeof(int), GFP_KERNEL);

Looks good.

Fabian

>
>
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