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From: Yonghong Song <yhs@fb.com>
To: Brendan Jackman <jackmanb@google.com>, <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	KP Singh <kpsingh@chromium.org>,
	Florent Revest <revest@chromium.org>,
	<linux-kernel@vger.kernel.org>, Jann Horn <jannh@google.com>
Subject: Re: [PATCH bpf-next v3 05/14] bpf: Rename BPF_XADD and prepare to encode other atomics in .imm
Date: Thu, 3 Dec 2020 20:49:49 -0800	[thread overview]
Message-ID: <33df38b3-60a6-9408-dfa7-f10b6273b226@fb.com> (raw)
In-Reply-To: <20201203160245.1014867-6-jackmanb@google.com>



On 12/3/20 8:02 AM, Brendan Jackman wrote:
> A subsequent patch will add additional atomic operations. These new
> operations will use the same opcode field as the existing XADD, with
> the immediate discriminating different operations.
> 
> In preparation, rename the instruction mode BPF_ATOMIC and start
> calling the zero immediate BPF_ADD.
> 
> This is possible (doesn't break existing valid BPF progs) because the
> immediate field is currently reserved MBZ and BPF_ADD is zero.
> 
> All uses are removed from the tree but the BPF_XADD definition is
> kept around to avoid breaking builds for people including kernel
> headers.
> 
> Signed-off-by: Brendan Jackman <jackmanb@google.com>

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

> Change-Id: Ib78f54acba37f7196cbf6c35ffa1c40805cb0d87

As pointed by Andrii earlier, this 'Change-Id' is weird. I didn't
see it in other submitted patches.

  reply	other threads:[~2020-12-04  4:51 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-03 16:02 [PATCH bpf-next v3 00/14] Atomics for eBPF Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 01/14] bpf: x86: Factor out emission of ModR/M for *(reg + off) Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 02/14] bpf: x86: Factor out emission of REX byte Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 03/14] bpf: x86: Factor out function to emit NEG Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 04/14] bpf: x86: Factor out a lookup table for some ALU opcodes Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 05/14] bpf: Rename BPF_XADD and prepare to encode other atomics in .imm Brendan Jackman
2020-12-04  4:49   ` Yonghong Song [this message]
2020-12-03 16:02 ` [PATCH bpf-next v3 06/14] bpf: Move BPF_STX reserved field check into BPF_STX verifier code Brendan Jackman
2020-12-04  4:51   ` Yonghong Song
2020-12-03 16:02 ` [PATCH bpf-next v3 07/14] bpf: Add BPF_FETCH field / create atomic_fetch_add instruction Brendan Jackman
2020-12-04  5:02   ` Yonghong Song
2020-12-04  5:27   ` Yonghong Song
2020-12-04  9:12     ` Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 08/14] bpf: Add instructions for atomic_[cmp]xchg Brendan Jackman
2020-12-04  5:34   ` Yonghong Song
2020-12-04  9:26     ` Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 09/14] bpf: Pull out a macro for interpreting atomic ALU operations Brendan Jackman
2020-12-04  6:30   ` Yonghong Song
2020-12-04  9:29     ` Brendan Jackman
2020-12-04 15:20       ` Yonghong Song
2020-12-03 16:02 ` [PATCH bpf-next v3 10/14] bpf: Add bitwise atomic instructions Brendan Jackman
2020-12-04  6:42   ` Yonghong Song
2020-12-04  9:36     ` Brendan Jackman
2020-12-04 15:21       ` Yonghong Song
2020-12-07 11:28         ` Brendan Jackman
2020-12-07 15:58           ` Yonghong Song
2020-12-07 16:14             ` Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 11/14] tools build: Implement feature check for BPF atomics in Clang Brendan Jackman
2020-12-03 21:02   ` Andrii Nakryiko
2020-12-03 16:02 ` [PATCH bpf-next v3 12/14] bpf: Pull tools/build/feature biz into selftests Makefile Brendan Jackman
2020-12-03 21:01   ` Andrii Nakryiko
2020-12-04  9:41     ` Brendan Jackman
2020-12-04 19:00       ` Andrii Nakryiko
2020-12-07 11:00         ` Brendan Jackman
2020-12-08  2:19           ` Andrii Nakryiko
2020-12-08 17:04             ` Brendan Jackman
2020-12-08 18:31               ` Andrii Nakryiko
2020-12-03 16:02 ` [PATCH bpf-next v3 13/14] bpf: Add tests for new BPF atomic operations Brendan Jackman
2020-12-04  7:06   ` Yonghong Song
2020-12-04  9:45     ` Brendan Jackman
2020-12-04 15:28       ` Yonghong Song
2020-12-04 19:49         ` Andrii Nakryiko
2020-12-07 15:48           ` Brendan Jackman
2020-12-03 16:02 ` [PATCH bpf-next v3 14/14] bpf: Document new atomic instructions Brendan Jackman
2020-12-03 16:10 ` [PATCH bpf-next v3 00/14] Atomics for eBPF Brendan Jackman
2020-12-04  4:46 ` Yonghong Song

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