| Message ID | 58708252.p9ogO3naVQ@wuerfel (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
I'd prefer to fix gcc, but I understand. This change is probably better in general, anyway. Queued for 3.18. Thanks. -corey On 08/23/2014 02:04 PM, Arnd Bergmann wrote: > Building ipmi on arm with gcc-4.9 results in this warning > for an allmodconfig build: > > drivers/char/ipmi/ipmi_si_intf.c: In function 'ipmi_thread': > include/linux/time.h:28:5: warning: 'busy_until.tv_sec' may be used uninitialized in this function [-Wmaybe-uninitialized] > if (lhs->tv_sec > rhs->tv_sec) > ^ > drivers/char/ipmi/ipmi_si_intf.c:1007:18: note: 'busy_until.tv_sec' was declared here > struct timespec busy_until; > ^ > > The warning is bogus and this case can not occur. Apparently > this is a false positive resulting from gcc getting a little > smarter about tracking assignments but not smart enough. Marking > the ipmi_thread_busy_wait function as inline gives the gcc > optimization logic enough information to figure out for itself > that the case cannot happen, which gets rid of the warning > without adding any fake initialization. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c > index 5d665680ae33..539ff0db52fc 100644 > --- a/drivers/char/ipmi/ipmi_si_intf.c > +++ b/drivers/char/ipmi/ipmi_si_intf.c > @@ -965,9 +965,9 @@ static inline int ipmi_si_is_busy(struct timespec *ts) > return ts->tv_nsec != -1; > } > > -static int ipmi_thread_busy_wait(enum si_sm_result smi_result, > - const struct smi_info *smi_info, > - struct timespec *busy_until) > +static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result, > + const struct smi_info *smi_info, > + struct timespec *busy_until) > { > unsigned int max_busy_us = 0; > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 5d665680ae33..539ff0db52fc 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -965,9 +965,9 @@ static inline int ipmi_si_is_busy(struct timespec *ts) return ts->tv_nsec != -1; } -static int ipmi_thread_busy_wait(enum si_sm_result smi_result, - const struct smi_info *smi_info, - struct timespec *busy_until) +static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result, + const struct smi_info *smi_info, + struct timespec *busy_until) { unsigned int max_busy_us = 0;
Building ipmi on arm with gcc-4.9 results in this warning for an allmodconfig build: drivers/char/ipmi/ipmi_si_intf.c: In function 'ipmi_thread': include/linux/time.h:28:5: warning: 'busy_until.tv_sec' may be used uninitialized in this function [-Wmaybe-uninitialized] if (lhs->tv_sec > rhs->tv_sec) ^ drivers/char/ipmi/ipmi_si_intf.c:1007:18: note: 'busy_until.tv_sec' was declared here struct timespec busy_until; ^ The warning is bogus and this case can not occur. Apparently this is a false positive resulting from gcc getting a little smarter about tracking assignments but not smart enough. Marking the ipmi_thread_busy_wait function as inline gives the gcc optimization logic enough information to figure out for itself that the case cannot happen, which gets rid of the warning without adding any fake initialization. Signed-off-by: Arnd Bergmann <arnd@arndb.de>