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authorYonghong Song <yonghong.song@linux.dev>2023-07-29 17:42:51 -0700
committerAlexei Starovoitov <ast@kernel.org>2023-07-29 18:57:51 -0700
commitfb213ecbb8ac56b2d5569737f59126e91f87829a (patch)
tree09609f28446d50fc0dc84dd4b99ad599a8d06ad4 /Documentation/bpf
parenteb03993a60780589e06e04a4dc23fda62b905ca6 (diff)
docs/bpf: Fix malformed documentation
Two issues are fixed: 1. Malformed table due to newly-introduced BPF_MOVSX 2. Missing reference link for ``Sign-extension load operations`` Fixes: 245d4c40c09b ("docs/bpf: Add documentation for new instructions") Cc: bpf@ietf.org Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202307291840.Cqhj7uox-lkp@intel.com/ Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230730004251.381307-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'Documentation/bpf')
-rw-r--r--Documentation/bpf/standardization/instruction-set.rst45
1 files changed, 24 insertions, 21 deletions
diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst
index fb8154cedd84..655494ac7af6 100644
--- a/Documentation/bpf/standardization/instruction-set.rst
+++ b/Documentation/bpf/standardization/instruction-set.rst
@@ -154,27 +154,27 @@ otherwise identical operations.
The 'code' field encodes the operation as below, where 'src' and 'dst' refer
to the values of the source and destination registers, respectively.
-======== ===== ======= ==========================================================
-code value offset description
-======== ===== ======= ==========================================================
-BPF_ADD 0x00 0 dst += src
-BPF_SUB 0x10 0 dst -= src
-BPF_MUL 0x20 0 dst \*= src
-BPF_DIV 0x30 0 dst = (src != 0) ? (dst / src) : 0
-BPF_SDIV 0x30 1 dst = (src != 0) ? (dst s/ src) : 0
-BPF_OR 0x40 0 dst \|= src
-BPF_AND 0x50 0 dst &= src
-BPF_LSH 0x60 0 dst <<= (src & mask)
-BPF_RSH 0x70 0 dst >>= (src & mask)
-BPF_NEG 0x80 0 dst = -dst
-BPF_MOD 0x90 0 dst = (src != 0) ? (dst % src) : dst
-BPF_SMOD 0x90 1 dst = (src != 0) ? (dst s% src) : dst
-BPF_XOR 0xa0 0 dst ^= src
-BPF_MOV 0xb0 0 dst = src
-BPF_MOVSX 0xb0 8/16/32 dst = (s8,s16,s32)src
-BPF_ARSH 0xc0 0 sign extending dst >>= (src & mask)
-BPF_END 0xd0 0 byte swap operations (see `Byte swap instructions`_ below)
-======== ===== ======= ==========================================================
+========= ===== ======= ==========================================================
+code value offset description
+========= ===== ======= ==========================================================
+BPF_ADD 0x00 0 dst += src
+BPF_SUB 0x10 0 dst -= src
+BPF_MUL 0x20 0 dst \*= src
+BPF_DIV 0x30 0 dst = (src != 0) ? (dst / src) : 0
+BPF_SDIV 0x30 1 dst = (src != 0) ? (dst s/ src) : 0
+BPF_OR 0x40 0 dst \|= src
+BPF_AND 0x50 0 dst &= src
+BPF_LSH 0x60 0 dst <<= (src & mask)
+BPF_RSH 0x70 0 dst >>= (src & mask)
+BPF_NEG 0x80 0 dst = -dst
+BPF_MOD 0x90 0 dst = (src != 0) ? (dst % src) : dst
+BPF_SMOD 0x90 1 dst = (src != 0) ? (dst s% src) : dst
+BPF_XOR 0xa0 0 dst ^= src
+BPF_MOV 0xb0 0 dst = src
+BPF_MOVSX 0xb0 8/16/32 dst = (s8,s16,s32)src
+BPF_ARSH 0xc0 0 sign extending dst >>= (src & mask)
+BPF_END 0xd0 0 byte swap operations (see `Byte swap instructions`_ below)
+========= ===== ======= ==========================================================
Underflow and overflow are allowed during arithmetic operations, meaning
the 64-bit or 32-bit value will wrap. If eBPF program execution would
@@ -397,6 +397,9 @@ instructions that transfer data between a register and memory.
Where size is one of: ``BPF_B``, ``BPF_H``, ``BPF_W``, or ``BPF_DW`` and
'unsigned size' is one of u8, u16, u32 or u64.
+Sign-extension load operations
+------------------------------
+
The ``BPF_MEMSX`` mode modifier is used to encode sign-extension load
instructions that transfer data between a register and memory.