From: Daniel Borkmann <daniel@iogearbox.net>
To: Andrea Righi <arighi@nvidia.com>, Alexei Starovoitov <ast@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@fomichev.me>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>,
bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
Andrii Nakryiko <andrii.nakryiko@gmail.com>
Subject: Re: [PATCH v2] bpf: Fix bpf_get_smp_processor_id() on !CONFIG_SMP
Date: Wed, 18 Dec 2024 13:22:37 +0100 [thread overview]
Message-ID: <3ec9783f-0331-41bb-9f02-6d35cb25e197@iogearbox.net> (raw)
In-Reply-To: <20241217195813.622568-1-arighi@nvidia.com>
On 12/17/24 8:58 PM, Andrea Righi wrote:
> On x86-64 calling bpf_get_smp_processor_id() in a kernel with CONFIG_SMP
> disabled can trigger the following bug, as pcpu_hot is unavailable:
>
> [ 8.471774] BUG: unable to handle page fault for address: 00000000936a290c
> [ 8.471849] #PF: supervisor read access in kernel mode
> [ 8.471881] #PF: error_code(0x0000) - not-present page
>
> Fix by inlining a return 0 in the !CONFIG_SMP case.
>
> Fixes: 1ae6921009e5 ("bpf: inline bpf_get_smp_processor_id() helper")
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
> Signed-off-by: Andrea Righi <arighi@nvidia.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
next prev parent reply other threads:[~2024-12-18 12:22 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-17 19:58 [PATCH v2] bpf: Fix bpf_get_smp_processor_id() on !CONFIG_SMP Andrea Righi
2024-12-18 0:20 ` patchwork-bot+netdevbpf
2024-12-18 12:22 ` Daniel Borkmann [this message]
-- strict thread matches above, loose matches on Subject: below --
2024-12-16 21:00 Andrea Righi
2024-12-17 18:38 ` Andrii Nakryiko
2024-12-17 19:53 ` Andrea Righi
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