[linux-next:master 2203/5042] WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

[linux-next:master 2203/5042] WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   6ebf211bb11dfc004a2ff73a9de5386fa309c430
commit: 991e5583647d33ee3a9c89248974ef98b9f539a8 [2203/5042] lib/test_bitmap: add tests for bitmap_{read,write}()
config: xtensa-randconfig-r012-20230725 (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/config)
compiler: xtensa-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202404102353.Cv1gUjk3-lkp@intel.com/

All warnings (new ones prefixed by >>, old ones prefixed by <<):

WARNING: modpost: missing MODULE_DESCRIPTION() in vmlinux.o
>> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
WARNING: modpost: vmlinux: section mismatch in reference: bitmap_allocate_region+0xb4 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [linux-next:master 2203/5042] WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

[Andy Shevchenko]

On Wed, Apr 10, 2024 at 11:22:16PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   6ebf211bb11dfc004a2ff73a9de5386fa309c430
> commit: 991e5583647d33ee3a9c89248974ef98b9f539a8 [2203/5042] lib/test_bitmap: add tests for bitmap_{read,write}()
> config: xtensa-randconfig-r012-20230725 (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/config)
> compiler: xtensa-linux-gcc (GCC) 13.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202404102353.Cv1gUjk3-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
> 
> WARNING: modpost: missing MODULE_DESCRIPTION() in vmlinux.o
> >> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_allocate_region+0xb4 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

As pointed out earlier, this is unconfirmed bug in GCC (GCC developers
point a finger at kernel code and vice versa). Can you reproduce this
with clang?

-- 
With Best Regards,
Andy Shevchenko

Re: [linux-next:master 2203/5042] WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

[Alexander Lobakin]

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Wed, 10 Apr 2024 18:27:50 +0300

> On Wed, Apr 10, 2024 at 11:22:16PM +0800, kernel test robot wrote:
>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
>> head:   6ebf211bb11dfc004a2ff73a9de5386fa309c430
>> commit: 991e5583647d33ee3a9c89248974ef98b9f539a8 [2203/5042] lib/test_bitmap: add tests for bitmap_{read,write}()
>> config: xtensa-randconfig-r012-20230725 (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/config)
>> compiler: xtensa-linux-gcc (GCC) 13.2.0
>> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/reproduce)
>>
>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>> the same patch/commit), kindly add following tags
>> | Reported-by: kernel test robot <lkp@intel.com>
>> | Closes: https://lore.kernel.org/oe-kbuild-all/202404102353.Cv1gUjk3-lkp@intel.com/
>>
>> All warnings (new ones prefixed by >>, old ones prefixed by <<):
>>
>> WARNING: modpost: missing MODULE_DESCRIPTION() in vmlinux.o
>>>> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
>> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_allocate_region+0xb4 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
> 
> As pointed out earlier, this is unconfirmed bug in GCC (GCC developers
> point a finger at kernel code and vice versa). Can you reproduce this
> with clang?

I'm unable to reproduce it on clang-trunk (19).

Thanks,
Olek

Re: [linux-next:master 2203/5042] WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

[Andy Shevchenko]

On Thu, Apr 11, 2024 at 11:08:40AM +0200, Alexander Lobakin wrote:
> From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Date: Wed, 10 Apr 2024 18:27:50 +0300
> 
> > On Wed, Apr 10, 2024 at 11:22:16PM +0800, kernel test robot wrote:
> >> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> >> head:   6ebf211bb11dfc004a2ff73a9de5386fa309c430
> >> commit: 991e5583647d33ee3a9c89248974ef98b9f539a8 [2203/5042] lib/test_bitmap: add tests for bitmap_{read,write}()
> >> config: xtensa-randconfig-r012-20230725 (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/config)
> >> compiler: xtensa-linux-gcc (GCC) 13.2.0
> >> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/reproduce)
> >>
> >> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> >> the same patch/commit), kindly add following tags
> >> | Reported-by: kernel test robot <lkp@intel.com>
> >> | Closes: https://lore.kernel.org/oe-kbuild-all/202404102353.Cv1gUjk3-lkp@intel.com/
> >>
> >> All warnings (new ones prefixed by >>, old ones prefixed by <<):
> >>
> >> WARNING: modpost: missing MODULE_DESCRIPTION() in vmlinux.o
> >>>> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
> >> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_allocate_region+0xb4 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
> > 
> > As pointed out earlier, this is unconfirmed bug in GCC (GCC developers
> > point a finger at kernel code and vice versa). Can you reproduce this
> > with clang?
> 
> I'm unable to reproduce it on clang-trunk (19).

For xtensa? Because it's particular to very that architecture (GCC backend).

-- 
With Best Regards,
Andy Shevchenko

Re: [linux-next:master 2203/5042] WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)

[Liu, Yujie]

Hi Andy,

On Wed, 2024-04-10 at 18:27 +0300, Andy Shevchenko wrote:
> On Wed, Apr 10, 2024 at 11:22:16PM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > head:   6ebf211bb11dfc004a2ff73a9de5386fa309c430
> > commit: 991e5583647d33ee3a9c89248974ef98b9f539a8 [2203/5042] lib/test_bitmap: add tests for bitmap_{read,write}()
> > config: xtensa-randconfig-r012-20230725 (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/config)
> > compiler: xtensa-linux-gcc (GCC) 13.2.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404102353.Cv1gUjk3-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202404102353.Cv1gUjk3-lkp@intel.com/
> > 
> > All warnings (new ones prefixed by >>, old ones prefixed by <<):
> > 
> > WARNING: modpost: missing MODULE_DESCRIPTION() in vmlinux.o
> > > > WARNING: modpost: vmlinux: section mismatch in reference: bitmap_read+0x128 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
> > WARNING: modpost: vmlinux: section mismatch in reference: bitmap_allocate_region+0xb4 (section: .text.unlikely) -> __setup_str_initcall_blacklist (section: .init.rodata)
> 
> As pointed out earlier, this is unconfirmed bug in GCC (GCC developers
> point a finger at kernel code and vice versa). Can you reproduce this
> with clang?

Thanks for the reminder of the previous comment in [1].

[1] https://lore.kernel.org/all/202403121032.WDY8ftKq-lkp@intel.com/

This warning was captured in a randconfig cross compilation for xtensa
architecture. Seems clang doesn't support xtensa backend yet. We tried
some randconfig build for x86_64 with clang, but cannot reproduce
this. 

We only observed this warning on xtensa, but not on other
architectures, so we don't have other configs at hand that can be used
to reproduce with clang. Sorry for this.

--
Best Regards,
Yujie