netdev - Re: [PATCH bpf-next 2/4] libbpf: fix libbpf build on compilers missing __builtin_mul

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: <e145cd71-8432-59d0-81a5-b253935385e1@fb.com>
Date:   Thu, 20 Aug 2020 07:21:12 -0700
From:   Yonghong Song <yhs@...com>
To:     Andrii Nakryiko <andriin@...com>, <bpf@...r.kernel.org>,
        <netdev@...r.kernel.org>, <ast@...com>, <daniel@...earbox.net>
CC:     <andrii.nakryiko@...il.com>, <kernel-team@...com>
Subject: Re: [PATCH bpf-next 2/4] libbpf: fix libbpf build on compilers
 missing __builtin_mul_overflow



On 8/19/20 11:14 PM, Andrii Nakryiko wrote:
> GCC compilers older than version 5 don't support __builtin_mul_overflow yet.
> Given GCC 4.9 is the minimal supported compiler for building kernel and the
> fact that libbpf is a dependency of resolve_btfids, which is dependency of
> CONFIG_DEBUG_INFO_BTF=y, this needs to be handled. This patch fixes the issue
> by falling back to slower detection of integer overflow in such cases.
> 
> Fixes: 029258d7b228 ("libbpf: Remove any use of reallocarray() in libbpf")
> Signed-off-by: Andrii Nakryiko <andriin@...com>

Acked-by: Yonghong Song <yhs@...com>