verifier testsuite from user space. Tests valid and invalid programs and expects predefined error log messages from kernel. 42 tests so far. $ sudo ./test_verifier #0 add+sub+mul OK #1 dropmon OK #2 dropmon with non-looping jump back OK #3 unreachable OK ... #40 access memory with incorrect alignment OK #41 sometimes access memory with incorrect alignment OK Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxxxx> --- samples/bpf/Makefile | 3 +- samples/bpf/test_verifier.c | 599 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 601 insertions(+), 1 deletion(-) create mode 100644 samples/bpf/test_verifier.c diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 8dfbacaef9ba..7264ba51d496 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -2,9 +2,10 @@ obj- := dummy.o # List of programs to build -hostprogs-y := dropmon +hostprogs-y := dropmon test_verifier dropmon-objs := dropmon.o libbpf.o +test_verifier-objs := test_verifier.o libbpf.o # Tell kbuild to always build the programs always := $(hostprogs-y) diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c new file mode 100644 index 000000000000..aa70aa33d84c --- /dev/null +++ b/samples/bpf/test_verifier.c @@ -0,0 +1,599 @@ +/* + * Testsuite for eBPF verifier + * + * Copyright (c) 2014 PLUMgrid, http://plumgrid.com + * + * 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. + */ +#include <stdio.h> +#include <unistd.h> +#include <linux/bpf.h> +#include <errno.h> +#include <linux/unistd.h> +#include <string.h> +#include <linux/filter.h> +#include "libbpf.h" + +#define MAX_INSNS 512 +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) + +struct bpf_test { + const char *descr; + struct bpf_insn insns[MAX_INSNS]; + int fixup[32]; + const char *errstr; + enum { + ACCEPT, + REJECT + } result; +}; + +static struct bpf_test tests[] = { + { + "add+sub+mul", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 2), + BPF_MOV64_IMM(BPF_REG_2, 3), + BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -1), + BPF_ALU64_IMM(BPF_MUL, BPF_REG_1, 3), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "dropmon", + .insns = { + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1, 8), /* r2 = *(u64 *)(r1 + 8) */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -8), /* *(u64 *)(fp - 8) = r2 */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), /* r2 = fp - 8 */ + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */ + BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */ + BPF_EXIT_INSN(), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 1), /* *(u64 *)(fp - 16) = 1 */ + BPF_MOV64_REG(BPF_REG_3, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -16), /* r3 = fp - 16 */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), /* r2 = fp - 8 */ + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_update_elem), + BPF_EXIT_INSN(), + }, + .fixup = {4, 16}, + .result = ACCEPT, + }, + { + "dropmon with non-looping jump back", + .insns = { + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1, 8), /* r2 = *(u64 *)(r1 + 8) */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -8), /* *(u64 *)(fp - 8) = r2 */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), /* r2 = fp - 8 */ + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */ + BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */ + BPF_EXIT_INSN(), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 1), /* *(u64 *)(fp - 16) = 1 */ + BPF_MOV64_REG(BPF_REG_3, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -16), /* r3 = fp - 16 */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), /* r2 = fp - 8 */ + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_update_elem), + BPF_JMP_IMM(BPF_JA, 0, 0, -10), + }, + .fixup = {4, 16}, + .result = ACCEPT, + }, + { + "unreachable", + .insns = { + BPF_EXIT_INSN(), + BPF_EXIT_INSN(), + }, + .errstr = "unreachable", + .result = REJECT, + }, + { + "unreachable2", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_JMP_IMM(BPF_JA, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "unreachable", + .result = REJECT, + }, + { + "out of range jump", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_EXIT_INSN(), + }, + .errstr = "jump out of range", + .result = REJECT, + }, + { + "out of range jump2", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, -2), + BPF_EXIT_INSN(), + }, + .errstr = "jump out of range", + .result = REJECT, + }, + { + "test1 ld_imm64", + .insns = { + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_LD_IMM insn", + .result = REJECT, + }, + { + "test2 ld_imm64", + .insns = { + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_LD_IMM insn", + .result = REJECT, + }, + { + "test3 ld_imm64", + .insns = { + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_LD_IMM64(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_ld_imm64 insn", + .result = REJECT, + }, + { + "test4 ld_imm64", + .insns = { + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid bpf_ld_imm64 insn", + .result = REJECT, + }, + { + "test5 ld_imm64", + .insns = { + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0), + }, + .errstr = "invalid bpf_ld_imm64 insn", + .result = REJECT, + }, + { + "no bpf_exit", + .insns = { + BPF_ALU64_REG(BPF_MOV, BPF_REG_0, BPF_REG_2), + }, + .errstr = "jump out of range", + .result = REJECT, + }, + { + "loop (back-edge)", + .insns = { + BPF_JMP_IMM(BPF_JA, 0, 0, -1), + BPF_EXIT_INSN(), + }, + .errstr = "back-edge", + .result = REJECT, + }, + { + "loop2 (back-edge)", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_3, BPF_REG_0), + BPF_JMP_IMM(BPF_JA, 0, 0, -4), + BPF_EXIT_INSN(), + }, + .errstr = "back-edge", + .result = REJECT, + }, + { + "conditional loop", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_3, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, -3), + BPF_EXIT_INSN(), + }, + .errstr = "back-edge", + .result = REJECT, + }, + { + "read uninitialized register", + .insns = { + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_EXIT_INSN(), + }, + .errstr = "R2 !read_ok", + .result = REJECT, + }, + { + "read invalid register", + .insns = { + BPF_MOV64_REG(BPF_REG_0, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R15 is invalid", + .result = REJECT, + }, + { + "program doesn't init R0 before exit", + .insns = { + BPF_ALU64_REG(BPF_MOV, BPF_REG_2, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .errstr = "R0 !read_ok", + .result = REJECT, + }, + { + "stack out of bounds", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, 8, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid stack", + .result = REJECT, + }, + { + "invalid call insn1", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL | BPF_X, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_CALL uses reserved", + .result = REJECT, + }, + { + "invalid call insn2", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 1, 0), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_CALL uses reserved", + .result = REJECT, + }, + { + "invalid function call", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, 1234567), + BPF_EXIT_INSN(), + }, + .errstr = "invalid func 1234567", + .result = REJECT, + }, + { + "uninitialized stack1", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_EXIT_INSN(), + }, + .fixup = {2}, + .errstr = "invalid indirect read from stack", + .result = REJECT, + }, + { + "uninitialized stack2", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -8), + BPF_EXIT_INSN(), + }, + .errstr = "invalid read from stack", + .result = REJECT, + }, + { + "check valid spill/fill", + .insns = { + /* spill R1(ctx) into stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + + /* fill it back into R2 */ + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8), + + /* should be able to access R0 = *(R2 + 8) */ + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "check corrupted spill/fill", + .insns = { + /* spill R1(ctx) into stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + + /* mess up with R1 pointer on stack */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -7, 0x23), + + /* fill back into R0 should fail */ + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8), + + BPF_EXIT_INSN(), + }, + .errstr = "corrupted spill", + .result = REJECT, + }, + { + "invalid src register in STX", + .insns = { + BPF_STX_MEM(BPF_B, BPF_REG_10, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R15 is invalid", + .result = REJECT, + }, + { + "invalid dst register in STX", + .insns = { + BPF_STX_MEM(BPF_B, 14, BPF_REG_10, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R14 is invalid", + .result = REJECT, + }, + { + "invalid dst register in ST", + .insns = { + BPF_ST_MEM(BPF_B, 14, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "R14 is invalid", + .result = REJECT, + }, + { + "invalid src register in LDX", + .insns = { + BPF_LDX_MEM(BPF_B, BPF_REG_0, 12, 0), + BPF_EXIT_INSN(), + }, + .errstr = "R12 is invalid", + .result = REJECT, + }, + { + "invalid dst register in LDX", + .insns = { + BPF_LDX_MEM(BPF_B, 11, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .errstr = "R11 is invalid", + .result = REJECT, + }, + { + "junk insn", + .insns = { + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_LD_IMM", + .result = REJECT, + }, + { + "junk insn2", + .insns = { + BPF_RAW_INSN(1, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_LDX uses reserved fields", + .result = REJECT, + }, + { + "junk insn3", + .insns = { + BPF_RAW_INSN(-1, 0, 0, 0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_ALU opcode f0", + .result = REJECT, + }, + { + "junk insn4", + .insns = { + BPF_RAW_INSN(-1, -1, -1, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "invalid BPF_ALU opcode f0", + .result = REJECT, + }, + { + "junk insn5", + .insns = { + BPF_RAW_INSN(0x7f, -1, -1, -1, -1), + BPF_EXIT_INSN(), + }, + .errstr = "BPF_ALU uses reserved fields", + .result = REJECT, + }, + { + "misaligned read from stack", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -4), + BPF_EXIT_INSN(), + }, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "invalid map_fd for function call", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_ALU64_REG(BPF_MOV, BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_EXIT_INSN(), + }, + .errstr = "fd 0 is not pointing to valid bpf_map", + .result = REJECT, + }, + { + "don't check return value before access", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0), + BPF_EXIT_INSN(), + }, + .fixup = {3}, + .errstr = "R0 invalid mem access 'map_value_or_null'", + .result = REJECT, + }, + { + "access memory with incorrect alignment", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0), + BPF_EXIT_INSN(), + }, + .fixup = {3}, + .errstr = "misaligned access", + .result = REJECT, + }, + { + "sometimes access memory with incorrect alignment", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0), + BPF_EXIT_INSN(), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + }, + .fixup = {3}, + .errstr = "R0 invalid mem access", + .result = REJECT, + }, +}; + +static int probe_filter_length(struct bpf_insn *fp) +{ + int len = 0; + + for (len = MAX_INSNS - 1; len > 0; --len) + if (fp[len].code != 0 || fp[len].imm != 0) + break; + + return len + 1; +} + +static int create_map(void) +{ + long long key, value = 0; + int map_fd; + + map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value), 1024); + if (map_fd < 0) { + printf("failed to create map '%s'\n", strerror(errno)); + } + + return map_fd; +} + +static int test(void) +{ + int prog_fd, i; + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + struct bpf_insn *prog = tests[i].insns; + int prog_len = probe_filter_length(prog); + int *fixup = tests[i].fixup; + int map_fd = -1; + + if (*fixup) { + + map_fd = create_map(); + + do { + prog[*fixup].imm = map_fd; + fixup++; + } while (*fixup); + } + printf("#%d %s ", i, tests[i].descr); + + prog_fd = bpf_prog_load(BPF_PROG_TYPE_TRACING_FILTER, prog, + prog_len * sizeof(struct bpf_insn), + "GPL"); + + if (tests[i].result == ACCEPT) { + if (prog_fd < 0) { + printf("FAIL\nfailed to load prog '%s'\n", + strerror(errno)); + printf("%s", bpf_log_buf); + goto fail; + } + } else { + if (prog_fd >= 0) { + printf("FAIL\nunexpected success to load\n"); + printf("%s", bpf_log_buf); + goto fail; + } + if (strstr(bpf_log_buf, tests[i].errstr) == 0) { + printf("FAIL\nunexpected error message: %s", + bpf_log_buf); + goto fail; + } + } + + printf("OK\n"); +fail: + if (map_fd >= 0) + close(map_fd); + close(prog_fd); + + } + + return 0; +} + +int main(void) +{ + return test(); +} -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to 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