From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 19 Mar 2018 15:38:51 +0100 From: Lukas Wunner Subject: Re: [PATCHv2 2/4] gpio: Remove VLA from MAX3191X driver Message-ID: <20180319143851.GA24209@wunner.de> References: <20180315180030.20001-1-labbott@redhat.com> <20180315180030.20001-3-labbott@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180315180030.20001-3-labbott@redhat.com> To: Laura Abbott Cc: Linus Walleij , Kees Cook , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Mathias Duckeck List-ID: On Thu, Mar 15, 2018 at 11:00:28AM -0700, Laura Abbott wrote: > > The new challenge is to remove VLAs from the kernel > (see https://lkml.org/lkml/2018/3/7/621) > > This patch replaces several a VLA with an appropriate call to > kmalloc_array. > > Signed-off-by: Laura Abbott Reviewed-and-tested-by: Lukas Wunner This one isn't a hotpath, so the kmalloc overhead is negligible. Did a quick test on a single-chip MAX31913 with no apparent issues. > --- > v2: No changes > --- > drivers/gpio/gpio-max3191x.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpio/gpio-max3191x.c b/drivers/gpio/gpio-max3191x.c > index f74b1072e84b..b5b9cb1fda50 100644 > --- a/drivers/gpio/gpio-max3191x.c > +++ b/drivers/gpio/gpio-max3191x.c > @@ -315,12 +315,17 @@ static void gpiod_set_array_single_value_cansleep(unsigned int ndescs, > struct gpio_desc **desc, > int value) > { > - int i, values[ndescs]; > + int i, *values; > + > + values = kmalloc_array(ndescs, sizeof(*values), GFP_KERNEL); > + if (!values) > + return; > > for (i = 0; i < ndescs; i++) > values[i] = value; > > gpiod_set_array_value_cansleep(ndescs, desc, values); > + kfree(values); > } > > static struct gpio_descs *devm_gpiod_get_array_optional_count( > -- > 2.14.3 >