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Message-Id: <20210120133946.2107897-2-jackmanb@google.com>
Date: Wed, 20 Jan 2021 13:39:45 +0000
From: Brendan Jackman <jackmanb@...gle.com>
To: bpf@...r.kernel.org
Cc: Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Andrii Nakryiko <andrii.nakryiko@...il.com>,
KP Singh <kpsingh@...omium.org>,
Florent Revest <revest@...omium.org>,
Lukas Bulwahn <lukas.bulwahn@...il.com>,
linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
Jonathan Corbet <corbet@....net>,
Brendan Jackman <jackmanb@...gle.com>
Subject: [PATCH bpf-next v3 1/2] docs: bpf: Fixup atomics markup
This fixes up the markup to fix a warning, be more consistent with
use of monospace, and use the correct .rst syntax for <em> (* instead
of _).
Signed-off-by: Brendan Jackman <jackmanb@...gle.com>
Reviewed-by: Lukas Bulwahn <lukas.bulwahn@...il.com>
---
Documentation/networking/filter.rst | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/Documentation/networking/filter.rst b/Documentation/networking/filter.rst
index 45f6fde1776c..4c2bb4c6364d 100644
--- a/Documentation/networking/filter.rst
+++ b/Documentation/networking/filter.rst
@@ -1066,12 +1066,12 @@ memory location addresed by ``dst_reg + off`` is atomically modified, with
immediate, then these operations also overwrite ``src_reg`` with the
value that was in memory before it was modified.
-The more special operations are:
+The more special operations are::
BPF_XCHG
This atomically exchanges ``src_reg`` with the value addressed by ``dst_reg +
-off``.
+off``. ::
BPF_CMPXCHG
@@ -1081,18 +1081,19 @@ before is loaded back to ``R0``.
Note that 1 and 2 byte atomic operations are not supported.
-Except ``BPF_ADD`` _without_ ``BPF_FETCH`` (for legacy reasons), all 4 byte
+Except ``BPF_ADD`` *without* ``BPF_FETCH`` (for legacy reasons), all 4 byte
atomic operations require alu32 mode. Clang enables this mode by default in
architecture v3 (``-mcpu=v3``). For older versions it can be enabled with
``-Xclang -target-feature -Xclang +alu32``.
-You may encounter BPF_XADD - this is a legacy name for BPF_ATOMIC, referring to
-the exclusive-add operation encoded when the immediate field is zero.
+You may encounter ``BPF_XADD`` - this is a legacy name for ``BPF_ATOMIC``,
+referring to the exclusive-add operation encoded when the immediate field is
+zero.
-eBPF has one 16-byte instruction: BPF_LD | BPF_DW | BPF_IMM which consists
+eBPF has one 16-byte instruction: ``BPF_LD | BPF_DW | BPF_IMM`` which consists
of two consecutive ``struct bpf_insn`` 8-byte blocks and interpreted as single
instruction that loads 64-bit immediate value into a dst_reg.
-Classic BPF has similar instruction: BPF_LD | BPF_W | BPF_IMM which loads
+Classic BPF has similar instruction: ``BPF_LD | BPF_W | BPF_IMM`` which loads
32-bit immediate value into a register.
eBPF verifier
--
2.30.0.284.gd98b1dd5eaa7-goog
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