Re: [PATCH 3/4] block: fix error return code

From: Julia Lawall
Date: Fri Aug 08 2014 - 00:58:51 EST




On Thu, 7 Aug 2014, Jeff Moyer wrote:

> Julia Lawall <Julia.Lawall@xxxxxxx> writes:
>
> > diff --git a/drivers/block/rsxx/core.c b/drivers/block/rsxx/core.c
> > index a8de2ee..fa8077a 100644
> > --- a/drivers/block/rsxx/core.c
> > +++ b/drivers/block/rsxx/core.c
> > @@ -942,6 +942,7 @@ static int rsxx_pci_probe(struct pci_dev *dev,
> > card->event_wq = create_singlethread_workqueue(DRIVER_NAME"_event");
> > if (!card->event_wq) {
> > dev_err(CARD_TO_DEV(card), "Failed card event setup.\n");
> > + st = -ENOMEM;
> > goto failed_event_handler;
> > }
>
> Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
>
> BTW, just above this there is questionable code:
>
> st = rsxx_get_num_targets(card, &card->n_targets);
> if (st)
> dev_info(CARD_TO_DEV(card),
> "Failed reading the number of DMA targets\n");
>
> card->ctrl = kzalloc(card->n_targets * sizeof(*card->ctrl), GFP_KERNEL);
> if (!card->ctrl) {
> st = -ENOMEM;
> goto failed_dma_setup;
> }
>
> From my reading of the kzalloc code, ZERO_SIZE_PTR (which is 16 cast to
> a void *) would be returned from that kzalloc call if the
> rsxx_get_num_targets call failed (since you'd be kzalloc-ing 0 bytes).
> That would lead to the !card->ctrl check not working, right?
>
> I'd suggest not continuing after rsxx_get_num_targets fails.

Good point. I'll fix it up.

julia
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