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authorJakub Kicinski <jakub.kicinski@netronome.com>2017-10-09 13:30:12 -0400
committerDavid S. Miller <davem@davemloft.net>2017-10-10 15:30:16 -0400
commitf4ac7e0b5cc8d16004ac57ff679266d573f30f77 (patch)
tree46db6c2ebd91e1fd4316b1775c6381aef1eb5ec5 /kernel/bpf/disasm.c
parent61bd5218eef349fcacc4976a251bc83a4748b4af (diff)
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: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/bpf/disasm.c')
-rw-r--r--kernel/bpf/disasm.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
new file mode 100644
index 000000000000..e682850c9715
--- /dev/null
+++ b/kernel/bpf/disasm.c
@@ -0,0 +1,214 @@
1/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
2 * Copyright (c) 2016 Facebook
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 */
13
14#include <linux/bpf.h>
15
16#include "disasm.h"
17
18#define __BPF_FUNC_STR_FN(x) [BPF_FUNC_ ## x] = __stringify(bpf_ ## x)
19static const char * const func_id_str[] = {
20 __BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN)
21};
22#undef __BPF_FUNC_STR_FN
23
24const char *func_id_name(int id)
25{
26 BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);
27
28 if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id])
29 return func_id_str[id];
30 else
31 return "unknown";
32}
33
34const char *const bpf_class_string[8] = {
35 [BPF_LD] = "ld",
36 [BPF_LDX] = "ldx",
37 [BPF_ST] = "st",
38 [BPF_STX] = "stx",
39 [BPF_ALU] = "alu",
40 [BPF_JMP] = "jmp",
41 [BPF_RET] = "BUG",
42 [BPF_ALU64] = "alu64",
43};
44
45const char *const bpf_alu_string[16] = {
46 [BPF_ADD >> 4] = "+=",
47 [BPF_SUB >> 4] = "-=",
48 [BPF_MUL >> 4] = "*=",
49 [BPF_DIV >> 4] = "/=",
50 [BPF_OR >> 4] = "|=",
51 [BPF_AND >> 4] = "&=",
52 [BPF_LSH >> 4] = "<<=",
53 [BPF_RSH >> 4] = ">>=",
54 [BPF_NEG >> 4] = "neg",
55 [BPF_MOD >> 4] = "%=",
56 [BPF_XOR >> 4] = "^=",
57 [BPF_MOV >> 4] = "=",
58 [BPF_ARSH >> 4] = "s>>=",
59 [BPF_END >> 4] = "endian",
60};
61
62static const char *const bpf_ldst_string[] = {
63 [BPF_W >> 3] = "u32",
64 [BPF_H >> 3] = "u16",
65 [BPF_B >> 3] = "u8",
66 [BPF_DW >> 3] = "u64",
67};
68
69static const char *const bpf_jmp_string[16] = {
70 [BPF_JA >> 4] = "jmp",
71 [BPF_JEQ >> 4] = "==",
72 [BPF_JGT >> 4] = ">",
73 [BPF_JLT >> 4] = "<",
74 [BPF_JGE >> 4] = ">=",
75 [BPF_JLE >> 4] = "<=",
76 [BPF_JSET >> 4] = "&",
77 [BPF_JNE >> 4] = "!=",
78 [BPF_JSGT >> 4] = "s>",
79 [BPF_JSLT >> 4] = "s<",
80 [BPF_JSGE >> 4] = "s>=",
81 [BPF_JSLE >> 4] = "s<=",
82 [BPF_CALL >> 4] = "call",
83 [BPF_EXIT >> 4] = "exit",
84};
85
86static void print_bpf_end_insn(bpf_insn_print_cb verbose,
87 struct bpf_verifier_env *env,
88 const struct bpf_insn *insn)
89{
90 verbose(env, "(%02x) r%d = %s%d r%d\n", insn->code, insn->dst_reg,
91 BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le",
92 insn->imm, insn->dst_reg);
93}
94
95void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env,
96 const struct bpf_insn *insn, bool allow_ptr_leaks)
97{
98 u8 class = BPF_CLASS(insn->code);
99
100 if (class == BPF_ALU || class == BPF_ALU64) {
101 if (BPF_OP(insn->code) == BPF_END) {
102 if (class == BPF_ALU64)
103 verbose(env, "BUG_alu64_%02x\n", insn->code);
104 else
105 print_bpf_end_insn(verbose, env, insn);
106 } else if (BPF_OP(insn->code) == BPF_NEG) {
107 verbose(env, "(%02x) r%d = %s-r%d\n",
108 insn->code, insn->dst_reg,
109 class == BPF_ALU ? "(u32) " : "",
110 insn->dst_reg);
111 } else if (BPF_SRC(insn->code) == BPF_X) {
112 verbose(env, "(%02x) %sr%d %s %sr%d\n",
113 insn->code, class == BPF_ALU ? "(u32) " : "",
114 insn->dst_reg,
115 bpf_alu_string[BPF_OP(insn->code) >> 4],
116 class == BPF_ALU ? "(u32) " : "",
117 insn->src_reg);
118 } else {
119 verbose(env, "(%02x) %sr%d %s %s%d\n",
120 insn->code, class == BPF_ALU ? "(u32) " : "",
121 insn->dst_reg,
122 bpf_alu_string[BPF_OP(insn->code) >> 4],
123 class == BPF_ALU ? "(u32) " : "",
124 insn->imm);
125 }
126 } else if (class == BPF_STX) {
127 if (BPF_MODE(insn->code) == BPF_MEM)
128 verbose(env, "(%02x) *(%s *)(r%d %+d) = r%d\n",
129 insn->code,
130 bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
131 insn->dst_reg,
132 insn->off, insn->src_reg);
133 else if (BPF_MODE(insn->code) == BPF_XADD)
134 verbose(env, "(%02x) lock *(%s *)(r%d %+d) += r%d\n",
135 insn->code,
136 bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
137 insn->dst_reg, insn->off,
138 insn->src_reg);
139 else
140 verbose(env, "BUG_%02x\n", insn->code);
141 } else if (class == BPF_ST) {
142 if (BPF_MODE(insn->code) != BPF_MEM) {
143 verbose(env, "BUG_st_%02x\n", insn->code);
144 return;
145 }
146 verbose(env, "(%02x) *(%s *)(r%d %+d) = %d\n",
147 insn->code,
148 bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
149 insn->dst_reg,
150 insn->off, insn->imm);
151 } else if (class == BPF_LDX) {
152 if (BPF_MODE(insn->code) != BPF_MEM) {
153 verbose(env, "BUG_ldx_%02x\n", insn->code);
154 return;
155 }
156 verbose(env, "(%02x) r%d = *(%s *)(r%d %+d)\n",
157 insn->code, insn->dst_reg,
158 bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
159 insn->src_reg, insn->off);
160 } else if (class == BPF_LD) {
161 if (BPF_MODE(insn->code) == BPF_ABS) {
162 verbose(env, "(%02x) r0 = *(%s *)skb[%d]\n",
163 insn->code,
164 bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
165 insn->imm);
166 } else if (BPF_MODE(insn->code) == BPF_IND) {
167 verbose(env, "(%02x) r0 = *(%s *)skb[r%d + %d]\n",
168 insn->code,
169 bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
170 insn->src_reg, insn->imm);
171 } else if (BPF_MODE(insn->code) == BPF_IMM &&
172 BPF_SIZE(insn->code) == BPF_DW) {
173 /* At this point, we already made sure that the second
174 * part of the ldimm64 insn is accessible.
175 */
176 u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
177 bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD;
178
179 if (map_ptr && !allow_ptr_leaks)
180 imm = 0;
181
182 verbose(env, "(%02x) r%d = 0x%llx\n", insn->code,
183 insn->dst_reg, (unsigned long long)imm);
184 } else {
185 verbose(env, "BUG_ld_%02x\n", insn->code);
186 return;
187 }
188 } else if (class == BPF_JMP) {
189 u8 opcode = BPF_OP(insn->code);
190
191 if (opcode == BPF_CALL) {
192 verbose(env, "(%02x) call %s#%d\n", insn->code,
193 func_id_name(insn->imm), insn->imm);
194 } else if (insn->code == (BPF_JMP | BPF_JA)) {
195 verbose(env, "(%02x) goto pc%+d\n",
196 insn->code, insn->off);
197 } else if (insn->code == (BPF_JMP | BPF_EXIT)) {
198 verbose(env, "(%02x) exit\n", insn->code);
199 } else if (BPF_SRC(insn->code) == BPF_X) {
200 verbose(env, "(%02x) if r%d %s r%d goto pc%+d\n",
201 insn->code, insn->dst_reg,
202 bpf_jmp_string[BPF_OP(insn->code) >> 4],
203 insn->src_reg, insn->off);
204 } else {
205 verbose(env, "(%02x) if r%d %s 0x%x goto pc%+d\n",
206 insn->code, insn->dst_reg,
207 bpf_jmp_string[BPF_OP(insn->code) >> 4],
208 insn->imm, insn->off);
209 }
210 } else {
211 verbose(env, "(%02x) %s\n",
212 insn->code, bpf_class_string[class]);
213 }
214}
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-05 17:13:02 -0400