Messages in this thread | | | Date | Tue, 7 Dec 2021 14:06:47 +0100 | From | Marek Behún <> | Subject | Re: [PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration |
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On Mon, 6 Dec 2021 16:25:10 -0800 Jakub Kicinski <kuba@kernel.org> wrote:
> On Mon, 6 Dec 2021 23:29:53 +0100 Marek Behún wrote: > > On Mon, 6 Dec 2021 14:21:03 +0100 > > Andrew Lunn <andrew@lunn.ch> wrote: > > > > > On Mon, Dec 06, 2021 at 04:32:19PM +0500, Ameer Hamza wrote: > > > > Uninitialized err variable defined in mv88e6393x_serdes_power > > > > function may cause undefined behaviour if it is called from > > > > mv88e6xxx_serdes_power_down context. > > > > > > > > Addresses-Coverity: 1494644 ("Uninitialized scalar variable") > > > > > > > > Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com> > > > > --- > > > > drivers/net/dsa/mv88e6xxx/serdes.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c > > > > index 55273013bfb5..33727439724a 100644 > > > > --- a/drivers/net/dsa/mv88e6xxx/serdes.c > > > > +++ b/drivers/net/dsa/mv88e6xxx/serdes.c > > > > @@ -1507,7 +1507,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane, > > > > bool on) > > > > { > > > > u8 cmode = chip->ports[port].cmode; > > > > - int err; > > > > + int err = 0; > > > > > > > > if (port != 0 && port != 9 && port != 10) > > > > return -EOPNOTSUPP; > > > > > > Hi Marek > > > > > > This warning likely comes from cmode not being a SERDES mode, and that > > > is not handles in the switch statementing. Do we want an > > > > > > default: > > > err = EINVAL; > > > > > > ? > > > > currently all the .serdes_power() methods return 0 for non-serdes ports. > > This is because the way it is written, these methods are not called if > > there is not a serdes lane for a given port. > > > > For this issue with err variable undefined, to fix it we should simply > > set int err=0 at the beginning of mv88e6393x_serdes_power(), to make it > > behave like other serdes_power() methods do in serdes.c. > > Any objections to using a default case in the switch statement, tho? > I agree with Andrew that default statement would make the reasoning > clearer than just setting the variable at the start of the function.
No objection, just that it should be done for all the serdes_power() methods in serdes.c.
Marek
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