Re: [PATCH] checkpatch: Add --strict test for kmalloc/kzalloc with multiply

From: Joe Perches
Date: Thu May 15 2014 - 19:04:54 EST


On Thu, 2014-05-15 at 15:58 -0700, Andrew Morton wrote:
> On Tue, 13 May 2014 16:48:49 -0700 Joe Perches <joe@xxxxxxxxxxx> wrote:
> > Protect against sizeof overflows by preferring
> > kmalloc_array and kcalloc to kmalloc/kzalloc
> > with a sizeof multiply.
[]
> > +# check for k[mz]alloc with multiplies that could be kmalloc_array/kcalloc
> > + if ($^V && $^V ge 5.10.0 &&
> > + $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*(k[mz]alloc)\s*\(\s*($FuncArg)\s*\*\s*($FuncArg)/) {
> > + my $oldfunc = $3;
> > + my $a1 = $4;
> > + my $a2 = $10;
> > + my $newfunc = "kmalloc_array";
> > + $newfunc = "kcalloc" if ($oldfunc eq "kzalloc");
> > + if ($a1 =~ /^sizeof\s*\S/ || $a2 =~ /^sizeof\s*\S/) {
> > + CHK("ALLOC_WITH_MULTIPLY",
> > + "Prefer $newfunc over $oldfunc with multiply\n" . $herecurr);
> > + }
> > + }
> > +
>
> Why hide this behind --strict?

Non-obvious CHK/--strict tests are less controversial.

The block above it
"prefer foo = alloc(sizeof(*foo)) over foo = alloc(sizeof(struct bar))"
used CHK so I copied it.

I've no objection to making it WARN instead,


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