Commit 2b7c6ba9 authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
Browse files

bpf/verifier: improve disassembly of BPF_END instructions 



print_bpf_insn() was treating all BPF_ALU[64] the same, but BPF_END has a
 different structure: it has a size in insn->imm (even if it's BPF_X) and
 uses the BPF_SRC (X or K) to indicate which endianness to use.  So it
 needs different code to print it.

Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4d8806fd

kernel/bpf/verifier.c

+16 −2
Original line number Diff line number Diff line
@@ -332,26 +332,40 @@ static const char *const bpf_jmp_string[16] = { 
	[BPF_EXIT >> 4] = "exit",

};



static void print_bpf_end_insn(const struct bpf_verifier_env *env,

			       const struct bpf_insn *insn)

{

	verbose("(%02x) r%d = %s%d r%d\n", insn->code, insn->dst_reg,

		BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le",

		insn->imm, insn->dst_reg);

}



static void print_bpf_insn(const struct bpf_verifier_env *env,

			   const struct bpf_insn *insn)

{

	u8 class = BPF_CLASS(insn->code);



	if (class == BPF_ALU || class == BPF_ALU64) {

		if (BPF_SRC(insn->code) == BPF_X)

		if (BPF_OP(insn->code) == BPF_END) {

			if (class == BPF_ALU64)

				verbose("BUG_alu64_%02x\n", insn->code);

			else

				print_bpf_end_insn(env, insn);

		} else if (BPF_SRC(insn->code) == BPF_X) {

			verbose("(%02x) %sr%d %s %sr%d\n",

				insn->code, class == BPF_ALU ? "(u32) " : "",

				insn->dst_reg,

				bpf_alu_string[BPF_OP(insn->code) >> 4],

				class == BPF_ALU ? "(u32) " : "",

				insn->src_reg);

		else

		} else {

			verbose("(%02x) %sr%d %s %s%d\n",

				insn->code, class == BPF_ALU ? "(u32) " : "",

				insn->dst_reg,

				bpf_alu_string[BPF_OP(insn->code) >> 4],

				class == BPF_ALU ? "(u32) " : "",

				insn->imm);

		}

	} else if (class == BPF_STX) {

		if (BPF_MODE(insn->code) == BPF_MEM)

			verbose("(%02x) *(%s *)(r%d %+d) = r%d\n",

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