linux-kernel - Re: [PATCH bpf v2 1/1] bpf: btf: Fix bitfield extraction for big endian

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Date:   Thu, 12 Jul 2018 00:12:39 +0200
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Martin KaFai Lau <kafai@...com>, Okash Khawaja <osk@...com>
Cc:     Alexei Starovoitov <ast@...nel.org>, Yonghong Song <yhs@...com>,
        Jakub Kicinski <jakub.kicinski@...ronome.com>,
        "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        kernel-team@...com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH bpf v2 1/1] bpf: btf: Fix bitfield extraction for big
 endian

On 07/11/2018 01:46 AM, Martin KaFai Lau wrote:
> On Tue, Jul 10, 2018 at 02:33:07PM -0700, Okash Khawaja wrote:
>> When extracting bitfield from a number, btf_int_bits_seq_show() builds
>> a mask and accesses least significant byte of the number in a way
>> specific to little-endian. This patch fixes that by checking endianness
>> of the machine and then shifting left and right the unneeded bits.
>>
>> Thanks to Martin Lau for the help in navigating potential pitfalls when
>> dealing with endianess and for the final solution.
>>
>> Fixes: b00b8daec828 ("bpf: btf: Add pretty print capability for data with BTF type info")
>> Signed-off-by: Okash Khawaja <osk@...com>
> Acked-by: Martin KaFai Lau <kafai@...com>

Applied to bpf, thanks Okash!