Re: [PATCH V2 14/15] ARM: bpf: cleanup cppcheck shifting error

Russell King - ARM Linux admin
2019-06-24T14:01:01Z

On Mon, Jun 24, 2019 at 08:51:04PM +0700, Phong Tran wrote:
> [arch/arm/net/bpf_jit_32.c:618]: (error) Shifting signed 32-bit value by
> 31 bits is undefined behaviour
>
> Signed-off-by: Phong Tran <tranmanphong@gmail.com>
> ---
> arch/arm/net/bpf_jit_32.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
> index adff54c312bf..4e8ad26305ca 100644
> --- a/arch/arm/net/bpf_jit_32.c
> +++ b/arch/arm/net/bpf_jit_32.c
> @@ -612,7 +612,7 @@ static inline void emit_a32_mov_se_i64(const bool is64, const s8 dst[],
> const u32 val, struct jit_ctx *ctx) {
> u64 val64 = val;
>
> - if (is64 && (val & (1<<31)))
> + if (is64 && (val & (BIT(31))))

Extra parens are not necessary, please remove.

> val64 |= 0xffffffff00000000ULL;
> emit_a32_mov_i64(dst, val64, ctx);
> }
> --
> 2.11.0
>
>

--
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