Messages in this thread | | | Subject | Re: [PATCH] irqchip/gic: check return value of of_address_to_resource | From | Bo Yan <> | Date | Thu, 5 Jul 2018 12:18:36 -0700 |
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Marc,
I'm also wondering if of_address_to_resource can really fail in this particular case?
What if we just explicitly discard the return value like this:
(void)of_address_to_resource(node, 1, &cpuif_res);
This suppresses Coverity warning by explicitly stating we are 100% sure the function call will always return success.
On 07/05/2018 12:13 PM, Marc Zyngier wrote: > Hi Bo, > > On Thu, 5 Jul 2018 11:20:59 -0700 > Bo Yan <byan@nvidia.com> wrote: > >> The of_address_to_resource returns 0 if successful. gic_check_eoimode >> calls it without checking the return value. This induces Coverity >> warning: "Unchecked return value". >> >> Return false from gic_check_eoimode if of_address_to_resource returns >> non-0 value. >> >> Signed-off-by: Bo Yan <byan@nvidia.com> >> --- >> drivers/irqchip/irq-gic.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c >> index ced10c4..0bceb10 100644 >> --- a/drivers/irqchip/irq-gic.c >> +++ b/drivers/irqchip/irq-gic.c >> @@ -1284,7 +1284,8 @@ static bool gic_check_eoimode(struct device_node *node, void __iomem **base) >> { >> struct resource cpuif_res; >> >> - of_address_to_resource(node, 1, &cpuif_res); >> + if (of_address_to_resource(node, 1, &cpuif_res)) >> + return false; > > We've just done an of_iomap() on this resource, which succeeded. How > can the same thing now fail? It would mean that the device tree has > been pulled from under our feet... > > And if it could happen, why is returning false the right thing to do? > Why would we say we want EOImode==0 instead of 1? > >> >> if (!is_hyp_mode_available()) >> return false; > > As it stands, I'm not taking such a patch. It either papers over a > bigger problem, or just keeps a warning quiet for the sake of it. > > Thanks, > > M. >
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