netdev - Re: [PATCH bpf] mips: bpf: fix encoding bug for mm_srlv32

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]

Message-ID: <20181203220423.ykfaagreljiejb5y@pburton-laptop>
Date:   Mon, 3 Dec 2018 22:04:24 +0000
From:   Paul Burton <paul.burton@...s.com>
To:     Jiong Wang <jiong.wang@...ronome.com>
CC:     "daniel@...earbox.net" <daniel@...earbox.net>,
        "ast@...nel.org" <ast@...nel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "oss-drivers@...ronome.com" <oss-drivers@...ronome.com>,
        Markos Chandras <markos.chandras@...tec.com>
Subject: Re: [PATCH bpf] mips: bpf: fix encoding bug for mm_srlv32_op

Hi Jiong,

On Sat, Dec 01, 2018 at 04:10:01AM -0500, Jiong Wang wrote:
> For micro-mips, srlv inside POOL32A encoding space should use 0x50
> sub-opcode, NOT 0x90.
> 
> Some early version ISA doc describes the encoding as 0x90 for both srlv and
> srav, this looks to me was a typo. I checked Binutils libopcode
> implementation which is using 0x50 for srlv and 0x90 for srav.

Are you aware of documentation that gets this right? Looking at the
latest microMIPS spec I have available (6.05) it looks like this is
still documented incorrectly. I'll pass this along to the architecture
team.

> Fixes: f31318fdf324 ("MIPS: uasm: Add srlv uasm instruction")
> CC: Markos Chandras <markos.chandras@...tec.com>
> CC: Paul Burton <paul.burton@...s.com>
> Acked-by: Jakub Kicinski <jakub.kicinski@...ronome.com>
> Signed-off-by: Jiong Wang <jiong.wang@...ronome.com>
> ---
>  arch/mips/include/uapi/asm/inst.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/mips/include/uapi/asm/inst.h b/arch/mips/include/uapi/asm/inst.h
> index c05dcf5..80f35e7 100644
> --- a/arch/mips/include/uapi/asm/inst.h
> +++ b/arch/mips/include/uapi/asm/inst.h
> @@ -370,7 +370,7 @@ enum mm_32a_minor_op {
>  	mm_pool32axf_op = 0x03c,
>  	mm_srl32_op = 0x040,
>  	mm_sra_op = 0x080,
> -	mm_srlv32_op = 0x090,
> +	mm_srlv32_op = 0x050,
>  	mm_rotr_op = 0x0c0,
>  	mm_lwxs_op = 0x118,
>  	mm_addu32_op = 0x150,

Could you also move it above mm_sra_op to keep them sorted by value?

When submitting v2 please also copy the linux-mips mailing list -
linux-mips@...r.kernel.org.

Thanks,
    Paul