Le 28/01/2022 à 11:08, Anders Roxell a écrit :
> Clang warns:
>
> arch/powerpc/mm/book3s64/radix_tlb.c:1191:23: error: variable 'hstart' is
> uninitialized when used here [-Werror,-Wuninitialized]
> __tlbiel_va_range(hstart, hend, pid,
> ^~~~~~
> arch/powerpc/mm/book3s64/radix_tlb.c:1175:23: note: initialize the variable
> 'hstart' to silence this warning
> unsigned long hstart, hend;
> ^
> = 0
> arch/powerpc/mm/book3s64/radix_tlb.c:1191:31: error: variable 'hend' is
> uninitialized when used here [-Werror,-Wuninitialized]
> __tlbiel_va_range(hstart, hend, pid,
> ^~~~
> arch/powerpc/mm/book3s64/radix_tlb.c:1175:29: note: initialize the variable
> 'hend' to silence this warning
> unsigned long hstart, hend;
> ^
> = 0
> 2 errors generated.
>
> Rework the 'if (IS_ENABLE(CONFIG_TRANSPARENT_HUGEPAGE))' so hstart/hend
> always gets initialized, this will silence the warnings. That will also
> simplify the 'else' path. Clang is getting confused with these warnings,
> but the warnings is a false-positive.
>
> Suggested-by: Arnd Bergmann <a...@arndb.de>
> Suggested-by: Nathan Chancellor <nat...@kernel.org>
> Signed-off-by: Anders Roxell <anders.rox...@linaro.org>
> ---
> arch/powerpc/mm/book3s64/radix_tlb.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c
> b/arch/powerpc/mm/book3s64/radix_tlb.c
> index 7724af19ed7e..7d65965a0688 100644
> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
> @@ -1174,12 +1174,9 @@ static inline void __radix__flush_tlb_range(struct
> mm_struct *mm,
> bool hflush = false;
You should then remove the default initialisation of hflush to false
which has become pointless.
With that fixed,
Reviewed-by: Christophe Leroy <christophe.le...@csgroup.eu>
> unsigned long hstart, hend;
>
> - if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
> - hstart = (start + PMD_SIZE - 1) & PMD_MASK;
> - hend = end & PMD_MASK;
> - if (hstart < hend)
> - hflush = true;
> - }
> + hstart = (start + PMD_SIZE - 1) & PMD_MASK;
> + hend = end & PMD_MASK;
> + hflush = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hstart <
> hend;
>
> if (type == FLUSH_TYPE_LOCAL) {
> asm volatile("ptesync": : :"memory");
