Re: question about drivers/rtc/rtc-cmos.c

[Andrew Morton]

On Wed, 25 Dec 2013 20:32:12 +0100 (CET) Julia Lawall <julia.lawall@xxxxxxx> wrote:

> The function cmos_do_probe contains the code:
> 
> 		if (is_hpet_enabled()) {
>                         int err;
> 
>                         rtc_cmos_int_handler = hpet_rtc_interrupt;
> 			err = hpet_register_irq_handler(cmos_interrupt);
>                         if (err != 0) {
>                                 dev_warn(dev, "hpet_register_irq_handler "
>                                                 " failed in rtc_init().");
>                                 goto cleanup1;
>                         }
>                 }
> 
> Is it intentional that the error code returned by 
> hpet_register_irq_handler is put ina local variable that will not be seen 
> at label cleanup1?  The return value is retval, which is 0 at this point.

No, I'd say that's a bug.  How does this look?


From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: drivers/rtc/rtc-cmos.c: propagate hpet_register_irq_handler() failure

If hpet_register_irq_handler() fails, cmos_do_probe() will incorrectly
return 0.

Reported-by: Julia Lawall <julia.lawall@xxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 drivers/rtc/rtc-cmos.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff -puN drivers/rtc/rtc-cmos.c~drivers-rtc-rtc-cmosc-propagate-hpet_register_irq_handler-failure drivers/rtc/rtc-cmos.c
--- a/drivers/rtc/rtc-cmos.c~drivers-rtc-rtc-cmosc-propagate-hpet_register_irq_handler-failure
+++ a/drivers/rtc/rtc-cmos.c
@@ -708,11 +708,9 @@ cmos_do_probe(struct device *dev, struct
 		irq_handler_t rtc_cmos_int_handler;
 
 		if (is_hpet_enabled()) {
-			int err;
-
 			rtc_cmos_int_handler = hpet_rtc_interrupt;
-			err = hpet_register_irq_handler(cmos_interrupt);
-			if (err != 0) {
+			retval = hpet_register_irq_handler(cmos_interrupt);
+			if (retval) {
 				dev_warn(dev, "hpet_register_irq_handler "
 						" failed in rtc_init().");
 				goto cleanup1;
_

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