Hi David: Thanks for your feedback. "regmap_write()" could also fail and cause influence on the caller. If patches for "regmap_write()" are needed, then the title could be changed from "uninitialized use" to "miss return check".
On Wed, Oct 2, 2019 at 2:22 PM David Miller <[email protected]> wrote: > > From: Yizhuo <[email protected]> > Date: Tue, 1 Oct 2019 13:24:39 -0700 > > > In function mdio_sc_cfg_reg_write(), variable "reg_value" could be > > uninitialized if regmap_read() fails. However, "reg_value" is used > > to decide the control flow later in the if statement, which is > > potentially unsafe. > > > > Signed-off-by: Yizhuo <[email protected]> > > Applied, but really this is such a pervasive problem. > > So much code doesn't check the return value from either regmap_read > or regmap_write. > > _EVEN_ in the code you are editing, the patch context shows an unchecked > regmap_write() call. > > > @@ -148,11 +148,15 @@ static int mdio_sc_cfg_reg_write(struct > > hns_mdio_device *mdio_dev, > > { > > u32 time_cnt; > > u32 reg_value; > > + int ret; > > > > regmap_write(mdio_dev->subctrl_vbase, cfg_reg, set_val); > ^^^^^^^^^^^^ > > Grepping for regmap_{read,write}() shows how big an issue this is. > > I don't know what to do, maybe we can work over time to add checks to > all calls and then force warnings on unchecked return values so that > the problem is not introduced in the future. -- Kind Regards, Yizhuo Zhai Computer Science, Graduate Student University of California, Riverside
