lkml.org 
[lkml]   [2021]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [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
Date


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

\
 
 \ /
  Last update: 2021-07-06 02:12    [W:0.051 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site