From: Catalin Marinas <catalin.marinas@arm.com>
To: Ionela Voinescu <ionela.voinescu@arm.com>
Cc: kernel test robot <lkp@intel.com>,
kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
Sudeep Holla <sudeep.holla@arm.com>
Subject: Re: arch/arm64/kernel/topology.c:367:22: sparse: sparse: dereference of noderef expression
Date: Wed, 6 Jan 2021 15:21:19 +0000 [thread overview]
Message-ID: <20210106152118.GA23403@gaia> (raw)
In-Reply-To: <20210106150724.GA16591@arm.com>
On Wed, Jan 06, 2021 at 03:07:24PM +0000, Ionela Voinescu wrote:
> On Friday 18 Dec 2020 at 10:44:10 (+0000), Catalin Marinas wrote:
> > On Fri, Dec 18, 2020 at 05:00:16AM +0800, kernel test robot wrote:
> > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > > head: 74f602dc96dd854c7b2034947798c1e2a6b84066
> > > commit: 68c5debcc06d6d24f15dbf978780fc5efc147d5e arm64: implement CPPC FFH support using AMUs
> > > date: 5 weeks ago
> > > config: arm64-randconfig-s032-20201217 (attached as .config)
> > > compiler: aarch64-linux-gcc (GCC) 9.3.0
> > > reproduce:
> > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > > chmod +x ~/bin/make.cross
> > > # apt-get install sparse
> > > # sparse version: v0.6.3-184-g1b896707-dirty
> > > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=68c5debcc06d6d24f15dbf978780fc5efc147d5e
> > > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > > git fetch --no-tags linus master
> > > git checkout 68c5debcc06d6d24f15dbf978780fc5efc147d5e
> > > # save the attached .config to linux build tree
> > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=arm64
> > >
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <lkp@intel.com>
> > >
> > >
> > > "sparse warnings: (new ones prefixed by >>)"
> > > >> arch/arm64/kernel/topology.c:367:22: sparse: sparse: dereference of noderef expression
> > >
> > > vim +367 arch/arm64/kernel/topology.c
> > >
> > > 362
> > > 363 int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val)
> > > 364 {
> > > 365 int ret = -EOPNOTSUPP;
> > > 366
> > > > 367 switch ((u64)reg->address) {
> >
> > That's not a dereference but I guess sparse complains of dropping the
> > __iomem. We could change the cast to (__force u64) to silence sparse.
> >
> > Thanks for the report.
> >
>
> Nothing I've tried seemed to silence sparse here, including casting to
> (__force u64).
Would it work if we changed the case lines to (u64 __iomem)0x0?
--
Catalin
next prev parent reply other threads:[~2021-01-06 15:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-17 21:00 arch/arm64/kernel/topology.c:367:22: sparse: sparse: dereference of noderef expression kernel test robot
2020-12-18 10:44 ` Catalin Marinas
2021-01-06 15:07 ` Ionela Voinescu
2021-01-06 15:21 ` Catalin Marinas [this message]
2021-01-06 15:52 ` Ionela Voinescu
2021-01-06 16:13 ` Al Viro
2021-01-06 16:47 ` Ionela Voinescu
2021-01-06 17:47 ` Al Viro
2021-01-06 20:12 ` Ionela Voinescu
2021-01-06 20:46 ` Al Viro
-- strict thread matches above, loose matches on Subject: below --
2021-01-06 5:50 kernel test robot
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