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Commit f4ac7e0b authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

bpf: move instruction printing into a separate file 



Separate the instruction printing into a standalone source file.
This way sneaky code from tools/ can compile it in directly.

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarSimon Horman <simon.horman@netronome.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 61bd5218

kernel/bpf/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ obj-y := core.o 


obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o

obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o

obj-$(CONFIG_BPF_SYSCALL) += disasm.o

ifeq ($(CONFIG_NET),y)

obj-$(CONFIG_BPF_SYSCALL) += devmap.o

ifeq ($(CONFIG_STREAM_PARSER),y)

kernel/bpf/disasm.c

0 → 100644
+214 −0
Original line number Diff line number Diff line 
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com

 * Copyright (c) 2016 Facebook

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of version 2 of the GNU General Public

 * License as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 * General Public License for more details.

 */



#include <linux/bpf.h>



#include "disasm.h"



#define __BPF_FUNC_STR_FN(x) [BPF_FUNC_ ## x] = __stringify(bpf_ ## x)

static const char * const func_id_str[] = {

	__BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN)

};

#undef __BPF_FUNC_STR_FN



const char *func_id_name(int id)

{

	BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);



	if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id])

		return func_id_str[id];

	else

		return "unknown";

}



const char *const bpf_class_string[8] = {

	[BPF_LD]    = "ld",

	[BPF_LDX]   = "ldx",

	[BPF_ST]    = "st",

	[BPF_STX]   = "stx",

	[BPF_ALU]   = "alu",

	[BPF_JMP]   = "jmp",

	[BPF_RET]   = "BUG",

	[BPF_ALU64] = "alu64",

};



const char *const bpf_alu_string[16] = {

	[BPF_ADD >> 4]  = "+=",

	[BPF_SUB >> 4]  = "-=",

	[BPF_MUL >> 4]  = "*=",

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

	[BPF_OR  >> 4]  = "|=",

	[BPF_AND >> 4]  = "&=",

	[BPF_LSH >> 4]  = "<<=",

	[BPF_RSH >> 4]  = ">>=",

	[BPF_NEG >> 4]  = "neg",

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

	[BPF_XOR >> 4]  = "^=",

	[BPF_MOV >> 4]  = "=",

	[BPF_ARSH >> 4] = "s>>=",

	[BPF_END >> 4]  = "endian",

};



static const char *const bpf_ldst_string[] = {

	[BPF_W >> 3]  = "u32",

	[BPF_H >> 3]  = "u16",

	[BPF_B >> 3]  = "u8",

	[BPF_DW >> 3] = "u64",

};



static const char *const bpf_jmp_string[16] = {

	[BPF_JA >> 4]   = "jmp",

	[BPF_JEQ >> 4]  = "==",

	[BPF_JGT >> 4]  = ">",

	[BPF_JLT >> 4]  = "<",

	[BPF_JGE >> 4]  = ">=",

	[BPF_JLE >> 4]  = "<=",

	[BPF_JSET >> 4] = "&",

	[BPF_JNE >> 4]  = "!=",

	[BPF_JSGT >> 4] = "s>",

	[BPF_JSLT >> 4] = "s<",

	[BPF_JSGE >> 4] = "s>=",

	[BPF_JSLE >> 4] = "s<=",

	[BPF_CALL >> 4] = "call",

	[BPF_EXIT >> 4] = "exit",

};



static void print_bpf_end_insn(bpf_insn_print_cb verbose,

			       struct bpf_verifier_env *env,

			       const struct bpf_insn *insn)

{

	verbose(env, "(%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);

}



void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env,

		    const struct bpf_insn *insn, bool allow_ptr_leaks)

{

	u8 class = BPF_CLASS(insn->code);



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

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

			if (class == BPF_ALU64)

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

			else

				print_bpf_end_insn(verbose, env, insn);

		} else if (BPF_OP(insn->code) == BPF_NEG) {

			verbose(env, "(%02x) r%d = %s-r%d\n",

				insn->code, insn->dst_reg,

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

				insn->dst_reg);

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

			verbose(env, "(%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 {

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

				insn->code,

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

				insn->dst_reg,

				insn->off, insn->src_reg);

		else if (BPF_MODE(insn->code) == BPF_XADD)

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

				insn->code,

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

				insn->dst_reg, insn->off,

				insn->src_reg);

		else

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

	} else if (class == BPF_ST) {

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

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

			return;

		}

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

			insn->code,

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

			insn->dst_reg,

			insn->off, insn->imm);

	} else if (class == BPF_LDX) {

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

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

			return;

		}

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

			insn->code, insn->dst_reg,

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

			insn->src_reg, insn->off);

	} else if (class == BPF_LD) {

		if (BPF_MODE(insn->code) == BPF_ABS) {

			verbose(env, "(%02x) r0 = *(%s *)skb[%d]\n",

				insn->code,

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

				insn->imm);

		} else if (BPF_MODE(insn->code) == BPF_IND) {

			verbose(env, "(%02x) r0 = *(%s *)skb[r%d + %d]\n",

				insn->code,

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

				insn->src_reg, insn->imm);

		} else if (BPF_MODE(insn->code) == BPF_IMM &&

			   BPF_SIZE(insn->code) == BPF_DW) {

			/* At this point, we already made sure that the second

			 * part of the ldimm64 insn is accessible.

			 */

			u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;

			bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD;



			if (map_ptr && !allow_ptr_leaks)

				imm = 0;



			verbose(env, "(%02x) r%d = 0x%llx\n", insn->code,

				insn->dst_reg, (unsigned long long)imm);

		} else {

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

			return;

		}

	} else if (class == BPF_JMP) {

		u8 opcode = BPF_OP(insn->code);



		if (opcode == BPF_CALL) {

			verbose(env, "(%02x) call %s#%d\n", insn->code,

				func_id_name(insn->imm), insn->imm);

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

			verbose(env, "(%02x) goto pc%+d\n",

				insn->code, insn->off);

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

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

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

			verbose(env, "(%02x) if r%d %s r%d goto pc%+d\n",

				insn->code, insn->dst_reg,

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

				insn->src_reg, insn->off);

		} else {

			verbose(env, "(%02x) if r%d %s 0x%x goto pc%+d\n",

				insn->code, insn->dst_reg,

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

				insn->imm, insn->off);

		}

	} else {

		verbose(env, "(%02x) %s\n",

			insn->code, bpf_class_string[class]);

	}

}

kernel/bpf/disasm.h

0 → 100644
+32 −0
Original line number Diff line number Diff line 
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com

 * Copyright (c) 2016 Facebook

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of version 2 of the GNU General Public

 * License as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 * General Public License for more details.

 */



#ifndef __BPF_DISASM_H__

#define __BPF_DISASM_H__



#include <linux/bpf.h>

#include <linux/kernel.h>

#include <linux/stringify.h>



extern const char *const bpf_alu_string[16];

extern const char *const bpf_class_string[8];



const char *func_id_name(int id);



struct bpf_verifier_env;

typedef void (*bpf_insn_print_cb)(struct bpf_verifier_env *env,

				  const char *, ...);

void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env,

		    const struct bpf_insn *insn, bool allow_ptr_leaks);



#endif

kernel/bpf/verifier.c

+4 −198
Original line number Diff line number Diff line
@@ -21,6 +21,8 @@ 
#include <linux/vmalloc.h>

#include <linux/stringify.h>



#include "disasm.h"



/* bpf_check() is a static code analyzer that walks eBPF program

 * instruction by instruction and updates register/stack state.

 * All paths of conditional branches are analyzed until 'bpf_exit' insn.
@@ -194,22 +196,6 @@ static const char * const reg_type_str[] = { 
	[PTR_TO_PACKET_END]	= "pkt_end",

};



#define __BPF_FUNC_STR_FN(x) [BPF_FUNC_ ## x] = __stringify(bpf_ ## x)

static const char * const func_id_str[] = {

	__BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN)

};

#undef __BPF_FUNC_STR_FN



static const char *func_id_name(int id)

{

	BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);



	if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id])

		return func_id_str[id];

	else

		return "unknown";

}



static void print_verifier_state(struct bpf_verifier_env *env,

				 struct bpf_verifier_state *state)

{
@@ -278,187 +264,6 @@ static void print_verifier_state(struct bpf_verifier_env *env, 
	verbose(env, "\n");

}



static const char *const bpf_class_string[] = {

	[BPF_LD]    = "ld",

	[BPF_LDX]   = "ldx",

	[BPF_ST]    = "st",

	[BPF_STX]   = "stx",

	[BPF_ALU]   = "alu",

	[BPF_JMP]   = "jmp",

	[BPF_RET]   = "BUG",

	[BPF_ALU64] = "alu64",

};



static const char *const bpf_alu_string[16] = {

	[BPF_ADD >> 4]  = "+=",

	[BPF_SUB >> 4]  = "-=",

	[BPF_MUL >> 4]  = "*=",

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

	[BPF_OR  >> 4]  = "|=",

	[BPF_AND >> 4]  = "&=",

	[BPF_LSH >> 4]  = "<<=",

	[BPF_RSH >> 4]  = ">>=",

	[BPF_NEG >> 4]  = "neg",

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

	[BPF_XOR >> 4]  = "^=",

	[BPF_MOV >> 4]  = "=",

	[BPF_ARSH >> 4] = "s>>=",

	[BPF_END >> 4]  = "endian",

};



static const char *const bpf_ldst_string[] = {

	[BPF_W >> 3]  = "u32",

	[BPF_H >> 3]  = "u16",

	[BPF_B >> 3]  = "u8",

	[BPF_DW >> 3] = "u64",

};



static const char *const bpf_jmp_string[16] = {

	[BPF_JA >> 4]   = "jmp",

	[BPF_JEQ >> 4]  = "==",

	[BPF_JGT >> 4]  = ">",

	[BPF_JLT >> 4]  = "<",

	[BPF_JGE >> 4]  = ">=",

	[BPF_JLE >> 4]  = "<=",

	[BPF_JSET >> 4] = "&",

	[BPF_JNE >> 4]  = "!=",

	[BPF_JSGT >> 4] = "s>",

	[BPF_JSLT >> 4] = "s<",

	[BPF_JSGE >> 4] = "s>=",

	[BPF_JSLE >> 4] = "s<=",

	[BPF_CALL >> 4] = "call",

	[BPF_EXIT >> 4] = "exit",

};



static void print_bpf_end_insn(struct bpf_verifier_env *env,

			       const struct bpf_insn *insn)

{

	verbose(env, "(%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(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_OP(insn->code) == BPF_END) {

			if (class == BPF_ALU64)

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

			else

				print_bpf_end_insn(env, insn);

		} else if (BPF_OP(insn->code) == BPF_NEG) {

			verbose(env, "(%02x) r%d = %s-r%d\n",

				insn->code, insn->dst_reg,

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

				insn->dst_reg);

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

			verbose(env, "(%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 {

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

				insn->code,

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

				insn->dst_reg,

				insn->off, insn->src_reg);

		else if (BPF_MODE(insn->code) == BPF_XADD)

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

				insn->code,

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

				insn->dst_reg, insn->off,

				insn->src_reg);

		else

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

	} else if (class == BPF_ST) {

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

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

			return;

		}

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

			insn->code,

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

			insn->dst_reg,

			insn->off, insn->imm);

	} else if (class == BPF_LDX) {

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

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

			return;

		}

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

			insn->code, insn->dst_reg,

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

			insn->src_reg, insn->off);

	} else if (class == BPF_LD) {

		if (BPF_MODE(insn->code) == BPF_ABS) {

			verbose(env, "(%02x) r0 = *(%s *)skb[%d]\n",

				insn->code,

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

				insn->imm);

		} else if (BPF_MODE(insn->code) == BPF_IND) {

			verbose(env, "(%02x) r0 = *(%s *)skb[r%d + %d]\n",

				insn->code,

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

				insn->src_reg, insn->imm);

		} else if (BPF_MODE(insn->code) == BPF_IMM &&

			   BPF_SIZE(insn->code) == BPF_DW) {

			/* At this point, we already made sure that the second

			 * part of the ldimm64 insn is accessible.

			 */

			u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;

			bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD;



			if (map_ptr && !env->allow_ptr_leaks)

				imm = 0;



			verbose(env, "(%02x) r%d = 0x%llx\n", insn->code,

				insn->dst_reg, (unsigned long long)imm);

		} else {

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

			return;

		}

	} else if (class == BPF_JMP) {

		u8 opcode = BPF_OP(insn->code);



		if (opcode == BPF_CALL) {

			verbose(env, "(%02x) call %s#%d\n", insn->code,

				func_id_name(insn->imm), insn->imm);

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

			verbose(env, "(%02x) goto pc%+d\n",

				insn->code, insn->off);

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

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

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

			verbose(env, "(%02x) if r%d %s r%d goto pc%+d\n",

				insn->code, insn->dst_reg,

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

				insn->src_reg, insn->off);

		} else {

			verbose(env, "(%02x) if r%d %s 0x%x goto pc%+d\n",

				insn->code, insn->dst_reg,

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

				insn->imm, insn->off);

		}

	} else {

		verbose(env, "(%02x) %s\n",

			insn->code, bpf_class_string[class]);

	}

}



static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx)

{

	struct bpf_verifier_stack_elem *elem;
@@ -3767,7 +3572,8 @@ static int do_check(struct bpf_verifier_env *env) 


		if (env->log.level) {

			verbose(env, "%d: ", insn_idx);

			print_bpf_insn(env, insn);

			print_bpf_insn(verbose, env, insn,

				       env->allow_ptr_leaks);

		}



		err = ext_analyzer_insn_hook(env, insn_idx, prev_insn_idx);