[frederic-dynticks:cpuset/nocb 1/4] include/linux/cpumask.h:636:26: warning: passing argument 1 of 'rcu_nocb_cpumask_update' discards 'const' qualifier from pointer target type

From: kernel test robot
Date: Wed May 25 2022 - 18:53:28 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git cpuset/nocb
head: ad895c0b6a5e3c41d46f184900d193e70bfc90d3
commit: 25db09cc1131b612d5dbb474ea1640b90b2518ca [1/4] rcu/nocb: Pass a cpumask instead of a single CPU to offload/deoffload
config: mips-allyesconfig (https://download.01.org/0day-ci/archive/20220526/202205260631.a3Mk6u8a-lkp@xxxxxxxxx/config)
compiler: mips-linux-gcc (GCC) 11.3.0
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
# https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git/commit/?id=25db09cc1131b612d5dbb474ea1640b90b2518ca
git remote add frederic-dynticks https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
git fetch --no-tags frederic-dynticks cpuset/nocb
git checkout 25db09cc1131b612d5dbb474ea1640b90b2518ca
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash kernel/rcu/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

In file included from include/linux/smp.h:13,
from arch/mips/include/asm/cpu-type.h:12,
from arch/mips/include/asm/timex.h:19,
from include/linux/timex.h:65,
from include/linux/time32.h:13,
from include/linux/time.h:60,
from include/linux/stat.h:19,
from include/linux/module.h:13,
from kernel/rcu/rcutorture.c:18:
kernel/rcu/rcutorture.c: In function 'rcu_nocb_toggle':
>> include/linux/cpumask.h:636:26: warning: passing argument 1 of 'rcu_nocb_cpumask_update' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
636 | #define cpumask_of(cpu) (get_cpu_mask(cpu))
| ~^~~~~~~~~~~~~~~~~~
kernel/rcu/rcutorture.c:1890:49: note: in expansion of macro 'cpumask_of'
1890 | rcu_nocb_cpumask_update(cpumask_of(cpu), true);
| ^~~~~~~~~~
In file included from include/linux/rbtree.h:24,
from include/linux/mm_types.h:11,
from include/linux/buildid.h:5,
from include/linux/module.h:14,
from kernel/rcu/rcutorture.c:18:
include/linux/rcupdate.h:117:45: note: expected 'struct cpumask *' but argument is of type 'const struct cpumask *'
117 | int rcu_nocb_cpumask_update(struct cpumask *cpumask, bool offload);
| ~~~~~~~~~~~~~~~~^~~~~~~
In file included from include/linux/smp.h:13,
from arch/mips/include/asm/cpu-type.h:12,
from arch/mips/include/asm/timex.h:19,
from include/linux/timex.h:65,
from include/linux/time32.h:13,
from include/linux/time.h:60,
from include/linux/stat.h:19,
from include/linux/module.h:13,
from kernel/rcu/rcutorture.c:18:
>> include/linux/cpumask.h:636:26: warning: passing argument 1 of 'rcu_nocb_cpumask_update' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
636 | #define cpumask_of(cpu) (get_cpu_mask(cpu))
| ~^~~~~~~~~~~~~~~~~~
kernel/rcu/rcutorture.c:1893:49: note: in expansion of macro 'cpumask_of'
1893 | rcu_nocb_cpumask_update(cpumask_of(cpu), false);
| ^~~~~~~~~~
In file included from include/linux/rbtree.h:24,
from include/linux/mm_types.h:11,
from include/linux/buildid.h:5,
from include/linux/module.h:14,
from kernel/rcu/rcutorture.c:18:
include/linux/rcupdate.h:117:45: note: expected 'struct cpumask *' but argument is of type 'const struct cpumask *'
117 | int rcu_nocb_cpumask_update(struct cpumask *cpumask, bool offload);
| ~~~~~~~~~~~~~~~~^~~~~~~


vim +636 include/linux/cpumask.h

2d3854a37e8b767 Rusty Russell 2008-11-05 631
cd83e42c6b0413d Rusty Russell 2008-11-07 632 /**
cd83e42c6b0413d Rusty Russell 2008-11-07 633 * cpumask_of - the cpumask containing just a given cpu
cd83e42c6b0413d Rusty Russell 2008-11-07 634 * @cpu: the cpu (<= nr_cpu_ids)
cd83e42c6b0413d Rusty Russell 2008-11-07 635 */
cd83e42c6b0413d Rusty Russell 2008-11-07 @636 #define cpumask_of(cpu) (get_cpu_mask(cpu))
cd83e42c6b0413d Rusty Russell 2008-11-07 637

:::::: The code at line 636 was first introduced by commit
:::::: cd83e42c6b0413dcbb548c2ead799111ff7e6a13 cpumask: new API, v2

:::::: TO: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
:::::: CC: Ingo Molnar <mingo@xxxxxxx>

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