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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 24 Jun 2019 15:00:35 +0100
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Phong Tran <tranmanphong@...il.com>
Cc:     acme@...nel.org, alexander.shishkin@...ux.intel.com,
        alexander.sverdlin@...il.com, allison@...utok.net, andrew@...n.ch,
        ast@...nel.org, bgolaszewski@...libre.com, bpf@...r.kernel.org,
        daniel@...earbox.net, daniel@...que.org, dmg@...ingmachine.org,
        festevam@...il.com, gerg@...inux.org, gregkh@...uxfoundation.org,
        gregory.clement@...tlin.com, haojian.zhuang@...il.com,
        hsweeten@...ionengravers.com, illusionist.neo@...il.com,
        info@...ux.net, jason@...edaemon.net, jolsa@...hat.com,
        kafai@...com, kernel@...gutronix.de, kgene@...nel.org,
        krzk@...nel.org, kstewart@...uxfoundation.org,
        linux-arm-kernel@...ts.infradead.org, linux-imx@....com,
        linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org,
        linux-samsung-soc@...r.kernel.org, liviu.dudau@....com,
        lkundrak@...sk, lorenzo.pieralisi@....com, mark.rutland@....com,
        mingo@...hat.com, namhyung@...nel.org, netdev@...r.kernel.org,
        nsekhar@...com, peterz@...radead.org, robert.jarzmik@...e.fr,
        s.hauer@...gutronix.de, sebastian.hesselbarth@...il.com,
        shawnguo@...nel.org, songliubraving@...com, sudeep.holla@....com,
        swinslow@...il.com, tglx@...utronix.de, tony@...mide.com,
        will@...nel.org, yhs@...com
Subject: Re: [PATCH V2 14/15] ARM: bpf: cleanup cppcheck shifting error

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@...il.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
> 
> 

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up