please pick 552546366a30 to 5.4.y

please pick 552546366a30 to 5.4.y

[Nick Desaulniers]

Dear stable kernel maintainers,
Please consider cherry-picking
commit 552546366a30 ("hugetlbfs: hugetlb_fault_mutex_hash() cleanup")
to linux-5.4.y.  It first landed in v5.5-rc1 and fixes an instance of
the warning -Wsizeof-array-div.

It cherry picks cleanly, I verified that I can build
CONFIG_USERFAULTFD=y
CONFIG_HUGETLBFS=y
with it applied, and that none of the call sites of
hugetlb_fault_mutex_hash have an issue with the signature change once
applied to 5.4.y.

-- 
Thanks,
~Nick Desaulniers

Re: please pick 552546366a30 to 5.4.y

[Greg KH]

On Wed, Mar 24, 2021 at 09:47:49AM -0700, Nick Desaulniers wrote:
> Dear stable kernel maintainers,
> Please consider cherry-picking
> commit 552546366a30 ("hugetlbfs: hugetlb_fault_mutex_hash() cleanup")
> to linux-5.4.y.  It first landed in v5.5-rc1 and fixes an instance of
> the warning -Wsizeof-array-div.

What shows that warning?  I don't see it here with my gcc builds :)

thanks,

greg k-h

Re: please pick 552546366a30 to 5.4.y

[Nick Desaulniers]

On Wed, Mar 24, 2021 at 10:06 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Wed, Mar 24, 2021 at 09:47:49AM -0700, Nick Desaulniers wrote:
> > Dear stable kernel maintainers,
> > Please consider cherry-picking
> > commit 552546366a30 ("hugetlbfs: hugetlb_fault_mutex_hash() cleanup")
> > to linux-5.4.y.  It first landed in v5.5-rc1 and fixes an instance of
> > the warning -Wsizeof-array-div.
>
> What shows that warning?  I don't see it here with my gcc builds :)

$ make LLVM=1 -j72 defconfig
$ ./scripts/config -e CONFIG_HUGETLBFS
$ make LLVM=1 -j72 mm/hugetlb.o
...
  CC      mm/hugetlb.o
mm/hugetlb.c:4159:40: warning: expression does not compute the number
of elements in this array; element type is 'unsigned long', not 'u32'
(aka 'unsigned int') [-Wsizeof-array-div]
        hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
                                          ~~~ ^
mm/hugetlb.c:4153:16: note: array 'key' declared here
        unsigned long key[2];
                      ^
mm/hugetlb.c:4159:40: note: place parentheses around the 'sizeof(u32)'
expression to silence this warning
        hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
                                              ^
-- 
Thanks,
~Nick Desaulniers

Re: please pick 552546366a30 to 5.4.y

[Greg KH]

On Wed, Mar 24, 2021 at 10:09:08AM -0700, Nick Desaulniers wrote:
> On Wed, Mar 24, 2021 at 10:06 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Wed, Mar 24, 2021 at 09:47:49AM -0700, Nick Desaulniers wrote:
> > > Dear stable kernel maintainers,
> > > Please consider cherry-picking
> > > commit 552546366a30 ("hugetlbfs: hugetlb_fault_mutex_hash() cleanup")
> > > to linux-5.4.y.  It first landed in v5.5-rc1 and fixes an instance of
> > > the warning -Wsizeof-array-div.
> >
> > What shows that warning?  I don't see it here with my gcc builds :)
> 
> $ make LLVM=1 -j72 defconfig
> $ ./scripts/config -e CONFIG_HUGETLBFS
> $ make LLVM=1 -j72 mm/hugetlb.o
> ...
>   CC      mm/hugetlb.o
> mm/hugetlb.c:4159:40: warning: expression does not compute the number
> of elements in this array; element type is 'unsigned long', not 'u32'
> (aka 'unsigned int') [-Wsizeof-array-div]
>         hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
>                                           ~~~ ^
> mm/hugetlb.c:4153:16: note: array 'key' declared here
>         unsigned long key[2];
>                       ^
> mm/hugetlb.c:4159:40: note: place parentheses around the 'sizeof(u32)'
> expression to silence this warning
>         hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
>                                               ^

Ok, will queue it up, thanks.

greg k-h