> When debugging converted (and other) programs it is useful
> to see disassembled eBPF output.
>
> Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
> ---
> lib/bpf/bpf_convert.c | 7 ++-
> lib/bpf/bpf_dump.c | 118 ++++++++++++++++++++++++++++++++++++++++++
> lib/bpf/meson.build | 1 +
> lib/bpf/rte_bpf.h | 14 +++++
> lib/bpf/version.map | 1 +
> 5 files changed, 140 insertions(+), 1 deletion(-)
> create mode 100644 lib/bpf/bpf_dump.c
>
> diff --git a/lib/bpf/bpf_convert.c b/lib/bpf/bpf_convert.c
> index a46ffeb067dd..db84add7dcce 100644
> --- a/lib/bpf/bpf_convert.c
> +++ b/lib/bpf/bpf_convert.c
> @@ -331,7 +331,12 @@ static int bpf_convert_filter(const struct bpf_insn
> *prog, size_t len,
> case BPF_LD | BPF_IND | BPF_H:
> case BPF_LD | BPF_IND | BPF_B:
> /* All arithmetic insns map as-is. */
> - *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0,
> fp->k);
> + insn->code = fp->code;
> + insn->dst_reg = BPF_REG_A;
> + bpf_src = BPF_SRC(fp->code);
> + insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0;
> + insn->off = 0;
> + insn->imm = fp->k;
> break;
Should it be part of that patch?
Looks like belongs to previous one, no?
>
> /* Jump transformation cannot use BPF block macros
> diff --git a/lib/bpf/bpf_dump.c b/lib/bpf/bpf_dump.c
> new file mode 100644
> index 000000000000..a6a431e64903
> --- /dev/null
> +++ b/lib/bpf/bpf_dump.c
> @@ -0,0 +1,118 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright (c) 2021 Stephen Hemminger
> + * Based on filter2xdp
> + * Copyright (C) 2017 Tobias Klauser
> + */
> +
> +#include <stdio.h>
> +#include <stdint.h>
> +
> +#include "rte_bpf.h"
> +
> +#define BPF_OP_INDEX(x) (BPF_OP(x) >> 4)
> +#define BPF_SIZE_INDEX(x) (BPF_SIZE(x) >> 3)
> +
> +static const char *const class_tbl[] = {
> + [BPF_LD] = "ld", [BPF_LDX] = "ldx", [BPF_ST] = "st",
> + [BPF_STX] = "stx", [BPF_ALU] = "alu", [BPF_JMP] = "jmp",
> + [BPF_RET] = "ret", [BPF_MISC] = "alu64",
> +};
> +
> +static const char *const alu_op_tbl[16] = {
> + [BPF_ADD >> 4] = "add", [BPF_SUB >> 4] = "sub",
> + [BPF_MUL >> 4] = "mul", [BPF_DIV >> 4] = "div",
> + [BPF_OR >> 4] = "or", [BPF_AND >> 4] = "and",
> + [BPF_LSH >> 4] = "lsh", [BPF_RSH >> 4] = "rsh",
> + [BPF_NEG >> 4] = "neg", [BPF_MOD >> 4] = "mod",
> + [BPF_XOR >> 4] = "xor", [EBPF_MOV >> 4] = "mov",
> + [EBPF_ARSH >> 4] = "arsh", [EBPF_END >> 4] = "endian",
> +};
> +
> +static const char *const size_tbl[] = {
> + [BPF_W >> 3] = "w",
> + [BPF_H >> 3] = "h",
> + [BPF_B >> 3] = "b",
> + [EBPF_DW >> 3] = "dw",
> +};
> +
> +static const char *const jump_tbl[16] = {
> + [BPF_JA >> 4] = "ja", [BPF_JEQ >> 4] = "jeq",
> + [BPF_JGT >> 4] = "jgt", [BPF_JGE >> 4] = "jge",
> + [BPF_JSET >> 4] = "jset", [EBPF_JNE >> 4] = "jne",
> + [EBPF_JSGT >> 4] = "jsgt", [EBPF_JSGE >> 4] = "jsge",
> + [EBPF_CALL >> 4] = "call", [EBPF_EXIT >> 4] = "exit",
> +};
> +
> +static void ebpf_dump(FILE *f, const struct ebpf_insn insn, size_t n)
> +{
> + const char *op, *postfix = "";
> + uint8_t cls = BPF_CLASS(insn.code);
> +
> + fprintf(f, " L%zu:\t", n);
> +
> + switch (cls) {
> + default:
> + fprintf(f, "unimp 0x%x // class: %s\n", insn.code,
> + class_tbl[cls]);
> + break;
> + case BPF_ALU:
> + postfix = "32";
> + /* fall through */
> + case EBPF_ALU64:
> + op = alu_op_tbl[BPF_OP_INDEX(insn.code)];
> + if (BPF_SRC(insn.code) == BPF_X)
> + fprintf(f, "%s%s r%u, r%u\n", op, postfix, insn.dst_reg,
> + insn.src_reg);
> + else
> + fprintf(f, "%s%s r%u, #0x%x\n", op, postfix,
> + insn.dst_reg, insn.imm);
> + break;
> + case BPF_LD:
> + op = "ld";
> + postfix = size_tbl[BPF_SIZE_INDEX(insn.code)];
> + if (BPF_MODE(insn.code) == BPF_IMM)
> + fprintf(f, "%s%s r%d, #0x%x\n", op, postfix,
> + insn.dst_reg, insn.imm);
> + else if (BPF_MODE(insn.code) == BPF_ABS)
> + fprintf(f, "%s%s r%d, [%d]\n", op, postfix,
> + insn.dst_reg, insn.imm);
> + else if (BPF_MODE(insn.code) == BPF_IND)
> + fprintf(f, "%s%s r%d, [r%u + %d]\n", op, postfix,
> + insn.dst_reg, insn.src_reg, insn.imm);
> + else
> + fprintf(f, "// BUG: LD opcode 0x%02x in eBPF insns\n",
> + insn.code);
> + break;
> + case BPF_LDX:
> + op = "ldx";
> + postfix = size_tbl[BPF_SIZE_INDEX(insn.code)];
> + fprintf(f, "%s%s r%d, [r%u + %d]\n", op, postfix, insn.dst_reg,
> + insn.src_reg, insn.off);
> + break;
> +#define L(pc, off) ((int)(pc) + 1 + (off))
> + case BPF_JMP:
> + op = jump_tbl[BPF_OP_INDEX(insn.code)];
> + if (op == NULL)
> + fprintf(f, "invalid jump opcode: %#x\n", insn.code);
> + else if (BPF_OP(insn.code) == BPF_JA)
> + fprintf(f, "%s L%d\n", op, L(n, insn.off));
> + else if (BPF_OP(insn.code) == EBPF_EXIT)
> + fprintf(f, "%s\n", op);
> + else
> + fprintf(f, "%s r%u, #0x%x, L%d\n", op, insn.dst_reg,
> + insn.imm, L(n, insn.off));
> + break;
> + case BPF_RET:
> + fprintf(f, "// BUG: RET opcode 0x%02x in eBPF insns\n",
> + insn.code);
> + break;
> + }
> +}
> +
> +void rte_bpf_dump(FILE *f, const struct ebpf_insn *buf, uint32_t len)
> +{
> + uint32_t i;
> +
> + for (i = 0; i < len; ++i)
> + ebpf_dump(f, buf[i], i);
> +}
> diff --git a/lib/bpf/meson.build b/lib/bpf/meson.build
> index 54f7610ae990..5b5585173aeb 100644
> --- a/lib/bpf/meson.build
> +++ b/lib/bpf/meson.build
> @@ -2,6 +2,7 @@
> # Copyright(c) 2018 Intel Corporation
>
> sources = files('bpf.c',
> + 'bpf_dump.c',
> 'bpf_exec.c',
> 'bpf_load.c',
> 'bpf_pkt.c',
> diff --git a/lib/bpf/rte_bpf.h b/lib/bpf/rte_bpf.h
> index 2f23e272a376..0d0a84b130a0 100644
> --- a/lib/bpf/rte_bpf.h
> +++ b/lib/bpf/rte_bpf.h
> @@ -198,6 +198,20 @@ rte_bpf_exec_burst(const struct rte_bpf *bpf, void
> *ctx[], uint64_t rc[],
> int
> rte_bpf_get_jit(const struct rte_bpf *bpf, struct rte_bpf_jit *jit);
>
> +/**
> + * Dump epf instructions to a file.
> + *
> + * @param f
> + * A pointer to a file for output
> + * @param buf
> + * A pointer to BPF instructions
> + * @param len
> + * Number of BPF instructions to dump.
> + */
> +__rte_experimental
> +void
> +rte_bpf_dump(FILE *f, const struct ebpf_insn *buf, uint32_t len);
> +
> #ifdef RTE_PORT_PCAP
>
> struct bpf_program;
> diff --git a/lib/bpf/version.map b/lib/bpf/version.map
> index 47082d5003ef..3b953f2f4592 100644
> --- a/lib/bpf/version.map
> +++ b/lib/bpf/version.map
> @@ -19,4 +19,5 @@ EXPERIMENTAL {
> global:
>
> rte_bpf_convert;
> + rte_bpf_dump;
> };
> --
Acked-by: Konstantin Ananyev <konstantin.anan...@intel.com>
> 2.30.2
