Re: [linux-next:master 1304/1443] fs/jfs/jfs_dmap.c:196:23: warning: result of comparison of constant 8796093022201 with expression of type 'int' is always false

[Dongliang Mu <mudongliangabcd@gmail.com>]

On Tue, Oct 18, 2022 at 9:39 PM Dave Kleikamp <dave.kleikamp@oracle.com> wrote:
>
> On 10/18/22 3:11AM, Dongliang Mu wrote:
> > On Tue, Oct 18, 2022 at 1:50 PM kernel test robot <lkp@intel.com> wrote:
> >>
> >> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> >> head:   4ca786ae6681b90b0ec3f4c55c89d12f835f8944
> >> commit: 920f4b7e923b35fd9d117fd3cb616b310cd41010 [1304/1443] fs: jfs: fix shift-out-of-bounds in dbAllocAG
> >> config: mips-randconfig-r005-20221017
> >> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 791a7ae1ba3efd6bca96338e10ffde557ba83920)
> >> 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-mipsel-linux-gnu
> >>          # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=920f4b7e923b35fd9d117fd3cb616b310cd41010
> >>          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 920f4b7e923b35fd9d117fd3cb616b310cd41010
> >>          # save the config file
> >>          mkdir build_dir && cp config build_dir/.config
> >>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash fs/jfs/
> >>
> >> If you fix the issue, kindly add following tag where applicable
> >> | Reported-by: kernel test robot <lkp@intel.com>
> >>
> >> All warnings (new ones prefixed by >>):
> >>
> >>>> fs/jfs/jfs_dmap.c:196:23: warning: result of comparison of constant 8796093022201 with expression of type 'int' is always false [-Wtautological-constant-out-of-range-compare]
> >>             if (bmp->db_agl2size > MAXMAPSIZE - L2MAXAG) {
> >>                 ~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~
> >>     1 warning generated.
> >
> > Hi Dave,
> >
> > I did not double check the upper bound of db_agl2size. It seems the
> > upper bound should be L2MAXL2SIZE - L2MAXAG, other than MAXMAPSIZE -
> > L2MAXAG.
> >
> > And L2MAXL2SIZE = L2BPERDMAP + 3 * L2LPERCTL = 13+3*10 = 43.
> >
> > I will send a fixes commit.
>
> Thanks for fixing that correctly. This was my mistake, since that's the
> value I asked you to use.
>
> I'll use your new patch.

It's fine. I should double-check all my changed code in the patch.

>
> Shaggy