On Wed. 10 Mar 2021 at 03:11, Vincent MAILHOL <mailhol.vincent@xxxxxxxxxx> wrote: > > On Wed. 10 Mar 2021 at 02:27, Jimmy Assarsson <jimmyassarsson@xxxxxxxxx> wrote: > > > > Hi Vincent, > > > > On 2021-03-09 13:09, Vincent Mailhol wrote: > > > This driver supports the ES581.4, ES582.1 and ES584.1 interfaces from > > > ETAS GmbH (https://www.etas.com/en/products/es58x.php). > > ... > > > diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c > > > new file mode 100644 > > > index 000000000000..31f907a7b75f > > > --- /dev/null > > > +++ b/drivers/net/can/usb/etas_es58x/es58x_core.c > > ... > > > +/** > > > + * es58x_add_skb_idx() - Increment an index of the loopback FIFO. > > > + * @priv: ES58X private parameters related to the network device. > > > + * @idx: address of the index to be incremented. > > > + * @a: the increment. Must be positive and less or equal to > > > + * @priv->can.echo_skb_max. > > > + * > > > + * Do a modulus addition: set *@idx to (*@idx + @a) % > > > + * @priv->can.echo_skb_max. > > > + * > > > + * Rationale: the modulus operator % takes a decent amount of CPU > > > + * cycles (c.f. other division functions such as > > > + * include/linux/math64.h:iter_div_u64_rem()). > > > + */ > > > +static __always_inline void es58x_add_skb_idx(struct es58x_priv *priv, > > > + u16 *idx, u16 a) > > > > Never used? > > Indeed, this is a leftover. Should have been removed in v11 when I > made the device FIFO size a power of two. > I was not warned by the compiler, probably because this is an inline function. > > > ... > > > +/** > > > + * es58x_get_product_info() - Get the product information and print them. > > > + * @es58x_dev: ES58X device. > > > + * > > > + * Do a synchronous call to get the product information. > > > + * > > > + * Return: zero on success, errno when any error occurs. > > > + */ > > > +static int es58x_get_product_info(struct es58x_device *es58x_dev) > > > +{ > > > + struct usb_device *udev = es58x_dev->udev; > > > + const int es58x_prod_info_idx = 6; > > > + /* Empirical tests show a prod_info length of maximum 83, > > > + * below should be more than enough. > > > + */ > > > + const size_t prod_info_len = 127; > > > + char *prod_info; > > > + int ret; > > > + > > > + prod_info = kmalloc(prod_info_len, GFP_KERNEL); > > > + if (!prod_info) > > > + return -ENOMEM; > > > + > > > + ret = usb_string(udev, es58x_prod_info_idx, prod_info, prod_info_len); > > > + if (ret < 0) { > > > + dev_err(es58x_dev->dev, > > > + "%s: Could not read the product info: %pe\n", > > > + __func__, ERR_PTR(ret)); > > > > Missing free > > Absolutely! > > > > + return ret; > > > + } else if (ret >= prod_info_len - 1) { > > > + dev_warn(es58x_dev->dev, > > > + "%s: Buffer is too small, result might be truncated\n", > > > + __func__); > > > + } > > > + dev_info(es58x_dev->dev, "Product info: %s\n", prod_info); > > > + kfree(prod_info); > > > + > > > + return 0; > > > +} > > Thanks for the two findings, both will be fixed in v13. Out of curiosity, did you find the two issues throughout a code review or did you use any kind of static analysis tool?
