* "BPF ADD" should be "BPF_ADD". * "src" should be "src_reg" in several places. The latter is the field name in the instruction. The former refers to the value of the register, or the immediate. * Add '' around field names in one sentence, for consistency with the rest of the document. Signed-off-by: Dave Thaler <dthaler1968@xxxxxxxxx> --- .../bpf/standardization/instruction-set.rst | 72 +++++++++---------- 1 file changed, 36 insertions(+), 36 deletions(-) diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst index 868d9f617..56b5e7dad 100644 --- a/Documentation/bpf/standardization/instruction-set.rst +++ b/Documentation/bpf/standardization/instruction-set.rst @@ -178,7 +178,7 @@ Unused fields shall be cleared to zero. As discussed below in `64-bit immediate instructions`_, a 64-bit immediate instruction uses two 32-bit immediate values that are constructed as follows. The 64 bits following the basic instruction contain a pseudo instruction -using the same format but with opcode, dst_reg, src_reg, and offset all set to zero, +using the same format but with 'opcode', 'dst_reg', 'src_reg', and 'offset' all set to zero, and imm containing the high 32 bits of the immediate value. This is depicted in the following figure:: @@ -392,27 +392,27 @@ otherwise identical operations, and indicates the base64 conformance group unless otherwise specified. The 'code' field encodes the operation as below: -======== ===== === =============================== ============================================= -code value src description notes -======== ===== === =============================== ============================================= -BPF_JA 0x0 0x0 PC += offset BPF_JMP | BPF_K only -BPF_JA 0x0 0x0 PC += imm BPF_JMP32 | BPF_K only -BPF_JEQ 0x1 any PC += offset if dst == src -BPF_JGT 0x2 any PC += offset if dst > src unsigned -BPF_JGE 0x3 any PC += offset if dst >= src unsigned -BPF_JSET 0x4 any PC += offset if dst & src -BPF_JNE 0x5 any PC += offset if dst != src -BPF_JSGT 0x6 any PC += offset if dst > src signed -BPF_JSGE 0x7 any PC += offset if dst >= src signed -BPF_CALL 0x8 0x0 call helper function by address BPF_JMP | BPF_K only, see `Helper functions`_ -BPF_CALL 0x8 0x1 call PC += imm BPF_JMP | BPF_K only, see `Program-local functions`_ -BPF_CALL 0x8 0x2 call helper function by BTF ID BPF_JMP | BPF_K only, see `Helper functions`_ -BPF_EXIT 0x9 0x0 return BPF_JMP | BPF_K only -BPF_JLT 0xa any PC += offset if dst < src unsigned -BPF_JLE 0xb any PC += offset if dst <= src unsigned -BPF_JSLT 0xc any PC += offset if dst < src signed -BPF_JSLE 0xd any PC += offset if dst <= src signed -======== ===== === =============================== ============================================= +======== ===== ======= =============================== ============================================= +code value src_reg description notes +======== ===== ======= =============================== ============================================= +BPF_JA 0x0 0x0 PC += offset BPF_JMP | BPF_K only +BPF_JA 0x0 0x0 PC += imm BPF_JMP32 | BPF_K only +BPF_JEQ 0x1 any PC += offset if dst == src +BPF_JGT 0x2 any PC += offset if dst > src unsigned +BPF_JGE 0x3 any PC += offset if dst >= src unsigned +BPF_JSET 0x4 any PC += offset if dst & src +BPF_JNE 0x5 any PC += offset if dst != src +BPF_JSGT 0x6 any PC += offset if dst > src signed +BPF_JSGE 0x7 any PC += offset if dst >= src signed +BPF_CALL 0x8 0x0 call helper function by address BPF_JMP | BPF_K only, see `Helper functions`_ +BPF_CALL 0x8 0x1 call PC += imm BPF_JMP | BPF_K only, see `Program-local functions`_ +BPF_CALL 0x8 0x2 call helper function by BTF ID BPF_JMP | BPF_K only, see `Helper functions`_ +BPF_EXIT 0x9 0x0 return BPF_JMP | BPF_K only +BPF_JLT 0xa any PC += offset if dst < src unsigned +BPF_JLE 0xb any PC += offset if dst <= src unsigned +BPF_JSLT 0xc any PC += offset if dst < src signed +BPF_JSLE 0xd any PC += offset if dst <= src signed +======== ===== ======= =============================== ============================================= The BPF program needs to store the return value into register R0 before doing a ``BPF_EXIT``. @@ -568,7 +568,7 @@ BPF_XOR 0xa0 atomic xor *(u32 *)(dst + offset) += src -``BPF_ATOMIC | BPF_DW | BPF_STX`` with 'imm' = BPF ADD means:: +``BPF_ATOMIC | BPF_DW | BPF_STX`` with 'imm' = BPF_ADD means:: *(u64 *)(dst + offset) += src @@ -601,24 +601,24 @@ and loaded back to ``R0``. ----------------------------- Instructions with the ``BPF_IMM`` 'mode' modifier use the wide instruction -encoding defined in `Instruction encoding`_, and use the 'src' field of the +encoding defined in `Instruction encoding`_, and use the 'src_reg' field of the basic instruction to hold an opcode subtype. The following table defines a set of ``BPF_IMM | BPF_DW | BPF_LD`` instructions -with opcode subtypes in the 'src' field, using new terms such as "map" +with opcode subtypes in the 'src_reg' field, using new terms such as "map" defined further below: -========================= ====== === ========================================= =========== ============== -opcode construction opcode src pseudocode imm type dst type -========================= ====== === ========================================= =========== ============== -BPF_IMM | BPF_DW | BPF_LD 0x18 0x0 dst = (next_imm << 32) | imm integer integer -BPF_IMM | BPF_DW | BPF_LD 0x18 0x1 dst = map_by_fd(imm) map fd map -BPF_IMM | BPF_DW | BPF_LD 0x18 0x2 dst = map_val(map_by_fd(imm)) + next_imm map fd data pointer -BPF_IMM | BPF_DW | BPF_LD 0x18 0x3 dst = var_addr(imm) variable id data pointer -BPF_IMM | BPF_DW | BPF_LD 0x18 0x4 dst = code_addr(imm) integer code pointer -BPF_IMM | BPF_DW | BPF_LD 0x18 0x5 dst = map_by_idx(imm) map index map -BPF_IMM | BPF_DW | BPF_LD 0x18 0x6 dst = map_val(map_by_idx(imm)) + next_imm map index data pointer -========================= ====== === ========================================= =========== ============== +========================= ====== ======= ========================================= =========== ============== +opcode construction opcode src_reg pseudocode imm type dst type +========================= ====== ======= ========================================= =========== ============== +BPF_IMM | BPF_DW | BPF_LD 0x18 0x0 dst = (next_imm << 32) | imm integer integer +BPF_IMM | BPF_DW | BPF_LD 0x18 0x1 dst = map_by_fd(imm) map fd map +BPF_IMM | BPF_DW | BPF_LD 0x18 0x2 dst = map_val(map_by_fd(imm)) + next_imm map fd data pointer +BPF_IMM | BPF_DW | BPF_LD 0x18 0x3 dst = var_addr(imm) variable id data pointer +BPF_IMM | BPF_DW | BPF_LD 0x18 0x4 dst = code_addr(imm) integer code pointer +BPF_IMM | BPF_DW | BPF_LD 0x18 0x5 dst = map_by_idx(imm) map index map +BPF_IMM | BPF_DW | BPF_LD 0x18 0x6 dst = map_val(map_by_idx(imm)) + next_imm map index data pointer +========================= ====== ======= ========================================= =========== ============== where -- 2.40.1
