Messages in this thread | | | Subject | Re: [kbuild-all] Re: kernel/time/clocksource-wdtest.c:47:22: warning: signed shift result (0x27BC86B00) requires 35 bits to represent, but 'long' only has 32 bits | From | Rong Chen <> | Date | Tue, 6 Jul 2021 08:11:07 +0800 |
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On 7/5/21 11:21 PM, Paul E. McKenney wrote: > On Mon, Jul 05, 2021 at 03:47:09PM +0800, Rong Chen wrote: >> >> On 7/5/21 1:43 AM, Paul E. McKenney wrote: >>> On Sun, Jul 04, 2021 at 05:42:36AM +0800, kernel test robot wrote: >>>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >>>> head: 303392fd5c160822bf778270b28ec5ea50cab2b4 >>>> commit: 1253b9b87e42ab6a3d5c2cb27af2bdd67d7e50ff clocksource: Provide kernel module to test clocksource watchdog >>>> date: 11 days ago >>>> config: mips-randconfig-r015-20210702 (attached as .config) >>>> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9eb613b2de3163686b1a4bd1160f15ac56a4b083) >>>> reproduce (this is a W=1 build): >>>> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross >>>> chmod +x ~/bin/make.cross >>>> # install mips cross compiling tool for clang build >>>> # apt-get install binutils-mips-linux-gnu >>>> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1253b9b87e42ab6a3d5c2cb27af2bdd67d7e50ff >>>> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >>>> git fetch --no-tags linus master >>>> git checkout 1253b9b87e42ab6a3d5c2cb27af2bdd67d7e50ff >>>> # save the attached .config to linux build tree >>>> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips >>>> >>>> If you fix the issue, kindly add following tag as appropriate >>>> Reported-by: kernel test robot <lkp@intel.com> >>>> >>>> All warnings (new ones prefixed by >>): >>>> >>>>>> kernel/time/clocksource-wdtest.c:47:22: warning: signed shift result (0x27BC86B00) requires 35 bits to represent, but 'long' only has 32 bits [-Wshift-overflow] >>>> .mult = TICK_NSEC << JIFFIES_SHIFT, /* details above */ >>>> ~~~~~~~~~ ^ ~~~~~~~~~~~~~ >>>> 1 warning generated. >>> You have CONFIG_HZ_24=y and this test module assumes HZ > 100, as noted >>> just above the excerpt below: >>> >>> /* Assume HZ > 100. */ >>> #define JIFFIES_SHIFT 8 >>> >>> So this is expected behavior. >>> >>> Would it help if I gave that comment some teeth, for example, as >>> shown at the end of this email? >> Hi Paul, >> >> I have confirmed that the below change can avoid the warning. > Very good, and thank you! May I add your Tested-by?
Yes, please.
Best Regards, Rong Chen
> > Thanx, Paul > >> Best Regards, >> Rong Chen >> >>> ------------------------------------------------------------------------ >>> >>> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug >>> index e1856030fa66..8f0ad6e4183c 100644 >>> --- a/lib/Kconfig.debug >>> +++ b/lib/Kconfig.debug >>> @@ -2573,6 +2573,7 @@ config TEST_FPU >>> config TEST_CLOCKSOURCE_WATCHDOG >>> tristate "Test clocksource watchdog in kernel space" >>> depends on CLOCKSOURCE_WATCHDOG >>> + depends on HZ >= 100 >>> help >>> Enable this option to create a kernel module that will trigger >>> a test of the clocksource watchdog. This module may be loaded >>> _______________________________________________ >>> kbuild-all mailing list -- kbuild-all@lists.01.org >>> To unsubscribe send an email to kbuild-all-leave@lists.01.org
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