Re: next: x86: clang: mm/khugepaged.c:1428:45: error: variable 'pmd' is uninitialized when used here
From: Andrew Morton
Date: Thu Nov 24 2022 - 14:33:25 EST
On Thu, 24 Nov 2022 21:07:48 +0530 Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote:
> LKFT CI system noticed clang-15 build failures on x86_64 and i386.
>
> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
>
> make --silent --keep-going --jobs=8
> O=/home/tuxbuild/.cache/tuxmake/builds/1/build LLVM=1 LLVM_IAS=1
> ARCH=x86_64 SRCARCH=x86 CROSS_COMPILE=x86_64-linux-gnu-
> 'HOSTCC=sccache clang' 'CC=sccache clang'
> mm/khugepaged.c:1428:45: error: variable 'pmd' is uninitialized when
> used here [-Werror,-Wuninitialized]
> page_table_check_pte_clear_range(mm, addr, pmd);
> ^~~
> mm/khugepaged.c:1415:2: note: variable 'pmd' is declared here
> pmd_t pmd;
> ^
Thanks. Due to "mm/khugepaged: fix GUP-fast interaction by freeing
ptes via mmu_gather".
Jann, I'll just do this for now:
--- a/mm/khugepaged.c~mm-khugepaged-fix-gup-fast-interaction-by-freeing-ptes-via-mmu_gather-fix
+++ a/mm/khugepaged.c
@@ -1431,7 +1431,6 @@ static void collapse_and_free_pmd(struct
*/
if (vma->anon_vma)
lockdep_assert_held_write(&vma->anon_vma->root->rwsem);
- page_table_check_pte_clear_range(mm, addr, pmd);
tlb_gather_mmu(&tlb, mm);
pmd = READ_ONCE(*pmdp);
_
please check.