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From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, 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>, John Fastabend <john.fastabend@gmail.com>, KP Singh <kpsingh@kernel.org>, Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>, "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>, Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com>, Christophe Leroy <christophe.leroy@csgroup.eu>, "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>, Hari Bathini <hbathini@linux.ibm.com>, bpf@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, paulmck@kernel.org, Puranjay Mohan <puranjay@kernel.org>
Cc: Puranjay Mohan <puranjay@kernel.org>
In-Reply-To: <20240513100248.110535-1-puranjay@kernel.org>
References: <20240513100248.110535-1-puranjay@kernel.org>
Subject: Re: [PATCH bpf v3] powerpc/bpf: enforce full ordering for ATOMIC operations with BPF_FETCH
Message-Id: <171738271132.1517513.12789013884540856700.b4-ty@ellerman.id.au>
Date: Mon, 03 Jun 2024 12:45:11 +1000
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On Mon, 13 May 2024 10:02:48 +0000, Puranjay Mohan wrote:
> The Linux Kernel Memory Model [1][2] requires RMW operations that have a
> return value to be fully ordered.
> 
> BPF atomic operations with BPF_FETCH (including BPF_XCHG and
> BPF_CMPXCHG) return a value back so they need to be JITed to fully
> ordered operations. POWERPC currently emits relaxed operations for
> these.
> 
> [...]

Applied to powerpc/fixes.

[1/1] powerpc/bpf: enforce full ordering for ATOMIC operations with BPF_FETCH
      https://git.kernel.org/powerpc/c/b1e7cee96127468c2483cf10c2899c9b5cf79bf8

cheers