netdev - Re: [PATCH v2 bpf] libbpf: fix global variable relocation

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CAADnVQ+A-Phuzir80BskhVug6YOuuT0qNiA0Vpn_pbbeT5BM3g@mail.gmail.com>
Date:   Wed, 27 Nov 2019 16:40:55 -0800
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Andrii Nakryiko <andriin@...com>
Cc:     bpf <bpf@...r.kernel.org>,
        Network Development <netdev@...r.kernel.org>,
        Alexei Starovoitov <ast@...com>,
        Daniel Borkmann <daniel@...earbox.net>,
        Yonghong Song <yhs@...com>,
        Andrii Nakryiko <andrii.nakryiko@...il.com>,
        Kernel Team <kernel-team@...com>
Subject: Re: [PATCH v2 bpf] libbpf: fix global variable relocation

On Wed, Nov 27, 2019 at 12:07 PM Andrii Nakryiko <andriin@...com> wrote:
>
> Similarly to a0d7da26ce86 ("libbpf: Fix call relocation offset calculation
> bug"), relocations against global variables need to take into account
> referenced symbol's st_value, which holds offset into a corresponding data
> section (and, subsequently, offset into internal backing map). For static
> variables this offset is always zero and data offset is completely described
> by respective instruction's imm field.
>
> Convert a bunch of selftests to global variables. Previously they were relying
> on `static volatile` trick to ensure Clang doesn't inline static variables,
> which with global variables is not necessary anymore.
>
> Fixes: 393cdfbee809 ("libbpf: Support initialized global variables")
> Acked-by: Yonghong Song <yhs@...com>
> Signed-off-by: Andrii Nakryiko <andriin@...com>

Applied. Thanks