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>

diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 897daa0..53fb09f 100644 (file)
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -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)

diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
new file mode 100644 (file)
index 0000000..e682850
--- /dev/null
+++ b/kernel/bpf/disasm.c
@@ -0,0 +1,214 @@
+/* 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]);
+       }
+}

diff --git a/kernel/bpf/disasm.h b/kernel/bpf/disasm.h
new file mode 100644 (file)
index 0000000..8de977e
--- /dev/null
+++ b/kernel/bpf/disasm.h
@@ -0,0 +1,32 @@
+/* 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

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a352f93..274c658 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -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);