* Re: [linux-next:master 14680/14811] mm/filemap.c:4250:1: sparse: sparse: Using plain integer as NULL pointer
[not found] <202305070840.X0G3ofjl-lkp@intel.com>
@ 2023-05-08 16:45 ` Nhat Pham
2023-05-08 16:57 ` Heiko Carstens
0 siblings, 1 reply; 3+ messages in thread
From: Nhat Pham @ 2023-05-08 16:45 UTC (permalink / raw)
To: kernel test robot
Cc: oe-kbuild-all, Linux Memory Management List, Andrew Morton, hca,
gor, agordeev, borntraeger, svens, linux-s390
On Sat, May 6, 2023 at 5:28 PM kernel test robot <lkp@intel.com> wrote:
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head: 83e5775d7afda68f6d7576d21f7a080fbfeecc4f
> commit: d39c65bc7fcb1dad22dc1585fc669b5bfe5d3108 [14680/14811] cachestat: implement cachestat syscall
> config: s390-randconfig-s041-20230507 (https://download.01.org/0day-ci/archive/20230507/202305070840.X0G3ofjl-lkp@intel.com/config)
> compiler: s390-linux-gcc (GCC) 12.1.0
> 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: v0.6.4-39-gce1a6720-dirty
> # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=d39c65bc7fcb1dad22dc1585fc669b5bfe5d3108
> git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> git fetch --no-tags linux-next master
> git checkout d39c65bc7fcb1dad22dc1585fc669b5bfe5d3108
> # save the config file
> mkdir build_dir && cp config build_dir/.config
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=s390 olddefconfig
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=s390 SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@intel.com>
> | Link: https://lore.kernel.org/oe-kbuild-all/202305070840.X0G3ofjl-lkp@intel.com/
>
> sparse warnings: (new ones prefixed by >>)
> mm/filemap.c:1416:17: sparse: sparse: context imbalance in 'migration_entry_wait_on_locked' - unexpected unlock
> >> mm/filemap.c:4250:1: sparse: sparse: Using plain integer as NULL pointer
> >> mm/filemap.c:4250:1: sparse: sparse: Using plain integer as NULL pointer
> >> mm/filemap.c:4250:1: sparse: sparse: Using plain integer as NULL pointer
> >> mm/filemap.c:4250:1: sparse: sparse: Using plain integer as NULL pointer
>
> vim +4250 mm/filemap.c
>
> 4215
> 4216 /*
> 4217 * The cachestat(2) system call.
> 4218 *
> 4219 * cachestat() returns the page cache statistics of a file in the
> 4220 * bytes range specified by `off` and `len`: number of cached pages,
> 4221 * number of dirty pages, number of pages marked for writeback,
> 4222 * number of evicted pages, and number of recently evicted pages.
> 4223 *
> 4224 * An evicted page is a page that is previously in the page cache
> 4225 * but has been evicted since. A page is recently evicted if its last
> 4226 * eviction was recent enough that its reentry to the cache would
> 4227 * indicate that it is actively being used by the system, and that
> 4228 * there is memory pressure on the system.
> 4229 *
> 4230 * `off` and `len` must be non-negative integers. If `len` > 0,
> 4231 * the queried range is [`off`, `off` + `len`]. If `len` == 0,
> 4232 * we will query in the range from `off` to the end of the file.
> 4233 *
> 4234 * The `flags` argument is unused for now, but is included for future
> 4235 * extensibility. User should pass 0 (i.e no flag specified).
> 4236 *
> 4237 * Currently, hugetlbfs is not supported.
> 4238 *
> 4239 * Because the status of a page can change after cachestat() checks it
> 4240 * but before it returns to the application, the returned values may
> 4241 * contain stale information.
> 4242 *
> 4243 * return values:
> 4244 * zero - success
> 4245 * -EFAULT - cstat or cstat_range points to an illegal address
> 4246 * -EINVAL - invalid flags
> 4247 * -EBADF - invalid file descriptor
> 4248 * -EOPNOTSUPP - file descriptor is of a hugetlbfs file
> 4249 */
> > 4250 SYSCALL_DEFINE4(cachestat, unsigned int, fd,
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests
Hmm I couldn't see where I used 0 as the null pointer. Maybe
this is a false positive or a result of not wiring up the syscall
for s390? Especially since this is pointed toward the macro
line (SYSCALL_DEFINE).
cc-ing this to s390 maintainers and the s390 mailing list...
Could you help me debug this? Thanks!
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