forked from luck/tmp_suning_uos_patched
bpf: free up BPF_JMP | BPF_CALL | BPF_X opcode
free up BPF_JMP | BPF_CALL | BPF_X opcode to be used by actual indirect call by register and use kernel internal opcode to mark call instruction into bpf_tail_call() helper. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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@ -586,7 +586,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
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break;
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}
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/* tail call */
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case BPF_JMP | BPF_CALL | BPF_X:
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case BPF_JMP | BPF_TAIL_CALL:
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if (emit_bpf_tail_call(ctx))
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return -EFAULT;
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break;
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@ -938,7 +938,7 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
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/*
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* Tail call
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*/
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case BPF_JMP | BPF_CALL | BPF_X:
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case BPF_JMP | BPF_TAIL_CALL:
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ctx->seen |= SEEN_TAILCALL;
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bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
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break;
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@ -991,7 +991,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
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}
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break;
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}
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case BPF_JMP | BPF_CALL | BPF_X:
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case BPF_JMP | BPF_TAIL_CALL:
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/*
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* Implicit input:
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* B1: pointer to ctx
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@ -1217,7 +1217,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
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}
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/* tail call */
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case BPF_JMP | BPF_CALL |BPF_X:
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case BPF_JMP | BPF_TAIL_CALL:
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emit_tail_call(ctx);
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break;
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@ -877,7 +877,7 @@ xadd: if (is_imm8(insn->off))
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}
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break;
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case BPF_JMP | BPF_CALL | BPF_X:
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case BPF_JMP | BPF_TAIL_CALL:
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emit_bpf_tail_call(&prog);
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break;
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@ -57,6 +57,9 @@ struct bpf_prog_aux;
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#define BPF_REG_AX MAX_BPF_REG
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#define MAX_BPF_JIT_REG (MAX_BPF_REG + 1)
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/* unused opcode to mark special call to bpf_tail_call() helper */
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#define BPF_TAIL_CALL 0xf0
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/* As per nm, we expose JITed images as text (code) section for
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* kallsyms. That way, tools like perf can find it to match
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* addresses.
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@ -824,7 +824,7 @@ static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn)
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[BPF_ALU64 | BPF_NEG] = &&ALU64_NEG,
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/* Call instruction */
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[BPF_JMP | BPF_CALL] = &&JMP_CALL,
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[BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL,
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[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
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/* Jumps */
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[BPF_JMP | BPF_JA] = &&JMP_JA,
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[BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
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@ -3469,7 +3469,7 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
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* that doesn't support bpf_tail_call yet
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*/
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insn->imm = 0;
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insn->code |= BPF_X;
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insn->code = BPF_JMP | BPF_TAIL_CALL;
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continue;
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}
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