Hi all, Friendly ping: who can take this, please? Thanks -- Gustavo On Mon, Jun 29, 2020 at 09:43:26AM +0300, Peter Ujfalusi wrote: > > > On 26/06/2020 16.29, Gustavo A. R. Silva wrote: > > Hi Peter, > > > > Please, see my comments below... > > > > On Fri, Jun 26, 2020 at 10:30:37AM +0300, Peter Ujfalusi wrote: > >> > >> > >> On 24/06/2020 20.12, Gustavo A. R. Silva wrote: > >>> Hi Vinod, > >>> > >>> On 6/24/20 00:55, Vinod Koul wrote: > >>>> On 19-06-20, 17:43, Gustavo A. R. Silva wrote: > >>>>> Make use of the struct_size() helper instead of an open-coded version > >>>>> in order to avoid any potential type mistakes. > >>>>> > >>>>> This code was detected with the help of Coccinelle and, audited and > >>>>> fixed manually. > >>>>> > >>>>> Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83 > >>>>> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> > >>>>> --- > >>>>> drivers/dma/ti/k3-udma.c | 4 ++-- > >>>>> 1 file changed, 2 insertions(+), 2 deletions(-) > >>>>> > >>>>> diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c > >>>>> index 0d5fb154b8e2..411c54b86ba8 100644 > >>>>> --- a/drivers/dma/ti/k3-udma.c > >>>>> +++ b/drivers/dma/ti/k3-udma.c > >>>>> @@ -2209,7 +2209,7 @@ udma_prep_slave_sg_pkt(struct udma_chan *uc, struct scatterlist *sgl, > >>>>> u32 ring_id; > >>>>> unsigned int i; > >>>>> > >>>>> - d = kzalloc(sizeof(*d) + sglen * sizeof(d->hwdesc[0]), GFP_NOWAIT); > >>>>> + d = kzalloc(struct_size(d, hwdesc, sglen), GFP_NOWAIT); > >>>> > >>>> struct_size() is a * b + c but here we need, a + b * c.. the trailing > >>>> struct is N times here.. > >>>> > >>> > >>> struct_size() works exactly as expected in this case. :) > >>> Please, see: > >>> > >>> include/linux/overflow.h:314: > >>> 314 #define struct_size(p, member, count) \ > >>> 315 __ab_c_size(count, \ > >>> 316 sizeof(*(p)->member) + __must_be_array((p)->member),\ > >>> 317 sizeof(*(p))) > >> > >> True, struct_size is for this sort of things. > >> > >> Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> > >> > >> While looking it up in include/linux/overflow.h I have noticed your > >> commit in linux-next, which adds flex_array_size() > >> > >> The example in the commit message contradicts with what the helper > > > > There is no contradiction here. > > > >> does imho. To be correct it should have been: > >> > >> struct something { > >> size_t count; > >> struct foo items[]; > >> }; > >> > >> - struct something *instance; > >> + struct something instance; > >> > >> - instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL); > >> + instance.items = kmalloc(struct_size(instance, items, count), GFP_KERNEL); > >> instance->count = count; > >> memcpy(instance->items, src, flex_array_size(instance, items, instance->count)); > >> > > > > This is all wrong. Please, double check how struct_size() works. > > Yes, I got it mixed up, I know how struct_size works... For some reason > I just overlooked it's use in the kmalloc(). > > > > > Thanks > > -- > > Gustavo > > > >>>>> if (!d) > >>>>> return NULL; > >>>>> > >>>>> @@ -2525,7 +2525,7 @@ udma_prep_dma_cyclic_pkt(struct udma_chan *uc, dma_addr_t buf_addr, > >>>>> if (period_len >= SZ_4M) > >>>>> return NULL; > >>>>> > >>>>> - d = kzalloc(sizeof(*d) + periods * sizeof(d->hwdesc[0]), GFP_NOWAIT); > >>>>> + d = kzalloc(struct_size(d, hwdesc, periods), GFP_NOWAIT); > >>>>> if (!d) > >>>>> return NULL; > >>>>> > >>>>> -- > >>>>> 2.27.0 > >>>> > >> > >> - Péter > >> > >> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki > >> > > - Péter > > Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. > Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki >
