Commit f835bb62 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

bpf: Add kernel/bpftool asm support for new instructions 



Add asm support for new instructions so kernel verifier and bpftool
xlated insn dumps can have proper asm syntax for new instructions.

Acked-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Acked-by: default avatarQuentin Monnet <quentin@isovalent.com>
Signed-off-by: default avatarYonghong Song <yonghong.song@linux.dev>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 4cd58e9a

kernel/bpf/disasm.c

+51 −6
Original line number Diff line number Diff line
@@ -87,6 +87,17 @@ const char *const bpf_alu_string[16] = { 
	[BPF_END >> 4]  = "endian",

};



const char *const bpf_alu_sign_string[16] = {

	[BPF_DIV >> 4]  = "s/=",

	[BPF_MOD >> 4]  = "s%=",

};



const char *const bpf_movsx_string[4] = {

	[0] = "(s8)",

	[1] = "(s16)",

	[3] = "(s32)",

};



static const char *const bpf_atomic_alu_string[16] = {

	[BPF_ADD >> 4]  = "add",

	[BPF_AND >> 4]  = "and",
@@ -101,6 +112,12 @@ static const char *const bpf_ldst_string[] = { 
	[BPF_DW >> 3] = "u64",

};



static const char *const bpf_ldsx_string[] = {

	[BPF_W >> 3]  = "s32",

	[BPF_H >> 3]  = "s16",

	[BPF_B >> 3]  = "s8",

};



static const char *const bpf_jmp_string[16] = {

	[BPF_JA >> 4]   = "jmp",

	[BPF_JEQ >> 4]  = "==",
@@ -128,6 +145,26 @@ static void print_bpf_end_insn(bpf_insn_print_t verbose, 
		insn->imm, insn->dst_reg);

}



static void print_bpf_bswap_insn(bpf_insn_print_t verbose,

			       void *private_data,

			       const struct bpf_insn *insn)

{

	verbose(private_data, "(%02x) r%d = bswap%d r%d\n",

		insn->code, insn->dst_reg,

		insn->imm, insn->dst_reg);

}



static bool is_sdiv_smod(const struct bpf_insn *insn)

{

	return (BPF_OP(insn->code)  == BPF_DIV || BPF_OP(insn->code) == BPF_MOD) &&

	       insn->off == 1;

}



static bool is_movsx(const struct bpf_insn *insn)

{

	return BPF_OP(insn->code) == BPF_MOV && insn->off != 0;

}



void print_bpf_insn(const struct bpf_insn_cbs *cbs,

		    const struct bpf_insn *insn,

		    bool allow_ptr_leaks)
@@ -138,7 +175,7 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, 
	if (class == BPF_ALU || class == BPF_ALU64) {

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

			if (class == BPF_ALU64)

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

				print_bpf_bswap_insn(verbose, cbs->private_data, insn);

			else

				print_bpf_end_insn(verbose, cbs->private_data, insn);

		} else if (BPF_OP(insn->code) == BPF_NEG) {
@@ -147,17 +184,20 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, 
				insn->dst_reg, class == BPF_ALU ? 'w' : 'r',

				insn->dst_reg);

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

			verbose(cbs->private_data, "(%02x) %c%d %s %c%d\n",

			verbose(cbs->private_data, "(%02x) %c%d %s %s%c%d\n",

				insn->code, class == BPF_ALU ? 'w' : 'r',

				insn->dst_reg,

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

				is_sdiv_smod(insn) ? bpf_alu_sign_string[BPF_OP(insn->code) >> 4]

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

				is_movsx(insn) ? bpf_movsx_string[(insn->off >> 3) - 1] : "",

				class == BPF_ALU ? 'w' : 'r',

				insn->src_reg);

		} else {

			verbose(cbs->private_data, "(%02x) %c%d %s %d\n",

				insn->code, class == BPF_ALU ? 'w' : 'r',

				insn->dst_reg,

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

				is_sdiv_smod(insn) ? bpf_alu_sign_string[BPF_OP(insn->code) >> 4]

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

				insn->imm);

		}

	} else if (class == BPF_STX) {
@@ -218,13 +258,15 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, 
			verbose(cbs->private_data, "BUG_st_%02x\n", insn->code);

		}

	} else if (class == BPF_LDX) {

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

		if (BPF_MODE(insn->code) != BPF_MEM && BPF_MODE(insn->code) != BPF_MEMSX) {

			verbose(cbs->private_data, "BUG_ldx_%02x\n", insn->code);

			return;

		}

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

			insn->code, insn->dst_reg,

			bpf_ldst_string[BPF_SIZE(insn->code) >> 3],

			BPF_MODE(insn->code) == BPF_MEM ?

				 bpf_ldst_string[BPF_SIZE(insn->code) >> 3] :

				 bpf_ldsx_string[BPF_SIZE(insn->code) >> 3],

			insn->src_reg, insn->off);

	} else if (class == BPF_LD) {

		if (BPF_MODE(insn->code) == BPF_ABS) {
@@ -279,6 +321,9 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, 
		} else if (insn->code == (BPF_JMP | BPF_JA)) {

			verbose(cbs->private_data, "(%02x) goto pc%+d\n",

				insn->code, insn->off);

		} else if (insn->code == (BPF_JMP32 | BPF_JA)) {

			verbose(cbs->private_data, "(%02x) gotol pc%+d\n",

				insn->code, insn->imm);

		} else if (insn->code == (BPF_JMP | BPF_EXIT)) {

			verbose(cbs->private_data, "(%02x) exit\n", insn->code);

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