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author | 2019-08-28 00:30:12 +0200 | |
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committer | 2019-08-28 00:30:12 +0200 | |
commit | 08eea4f312c09e1c203ad3e7840978fe3240888e (patch) | |
tree | c8c9b43deac7ef02e98c10b851c9f3d9bcf99bc3 | |
parent | tools: bpftool: add "bpftool map freeze" subcommand (diff) | |
parent | selftests/bpf: add precision tracking test (diff) | |
download | linux-08eea4f312c09e1c203ad3e7840978fe3240888e.tar.gz linux-08eea4f312c09e1c203ad3e7840978fe3240888e.tar.bz2 linux-08eea4f312c09e1c203ad3e7840978fe3240888e.zip |
Merge branch 'bpf-precision-tracking-tests'
Alexei Starovoitov says:
====================
Add few additional tests for precision tracking in the verifier.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
-rw-r--r-- | include/linux/bpf_verifier.h | 1 | ||||
-rw-r--r-- | include/uapi/linux/bpf.h | 3 | ||||
-rw-r--r-- | kernel/bpf/syscall.c | 1 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 5 | ||||
-rw-r--r-- | tools/include/uapi/linux/bpf.h | 3 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/test_verifier.c | 68 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/verifier/precise.c | 142 |
7 files changed, 211 insertions, 12 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 5fe99f322b1c..26a6d58ca78c 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -355,6 +355,7 @@ struct bpf_verifier_env { struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ int stack_size; /* number of states to be processed */ bool strict_alignment; /* perform strict pointer alignment checks */ + bool test_state_freq; /* test verifier with different pruning frequency */ struct bpf_verifier_state *cur_state; /* current verifier state */ struct bpf_verifier_state_list **explored_states; /* search pruning optimization */ struct bpf_verifier_state_list *free_list; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b5889257cc33..5d2fb183ee2d 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -285,6 +285,9 @@ enum bpf_attach_type { */ #define BPF_F_TEST_RND_HI32 (1U << 2) +/* The verifier internal test flag. Behavior is undefined */ +#define BPF_F_TEST_STATE_FREQ (1U << 3) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * two extensions: * diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index c0f62fd67c6b..ca60eafa6922 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1629,6 +1629,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | BPF_F_ANY_ALIGNMENT | + BPF_F_TEST_STATE_FREQ | BPF_F_TEST_RND_HI32)) return -EINVAL; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 10c0ff93f52b..f340cfe53c6e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7222,7 +7222,7 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) struct bpf_verifier_state_list *sl, **pprev; struct bpf_verifier_state *cur = env->cur_state, *new; int i, j, err, states_cnt = 0; - bool add_new_state = false; + bool add_new_state = env->test_state_freq ? true : false; cur->last_insn_idx = env->prev_insn_idx; if (!env->insn_aux_data[insn_idx].prune_point) @@ -9262,6 +9262,9 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, env->allow_ptr_leaks = is_priv; + if (is_priv) + env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ; + ret = replace_map_fd_with_map_ptr(env); if (ret < 0) goto skip_full_check; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index b5889257cc33..5d2fb183ee2d 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -285,6 +285,9 @@ enum bpf_attach_type { */ #define BPF_F_TEST_RND_HI32 (1U << 2) +/* The verifier internal test flag. Behavior is undefined */ +#define BPF_F_TEST_STATE_FREQ (1U << 3) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * two extensions: * diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 44e2d640b088..d27fd929abb9 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -61,6 +61,7 @@ #define UNPRIV_SYSCTL "kernel/unprivileged_bpf_disabled" static bool unpriv_disabled = false; static int skips; +static bool verbose = false; struct bpf_test { const char *descr; @@ -92,7 +93,8 @@ struct bpf_test { enum { UNDEF, ACCEPT, - REJECT + REJECT, + VERBOSE_ACCEPT, } result, result_unpriv; enum bpf_prog_type prog_type; uint8_t flags; @@ -859,6 +861,36 @@ static int do_prog_test_run(int fd_prog, bool unpriv, uint32_t expected_val, return 0; } +static bool cmp_str_seq(const char *log, const char *exp) +{ + char needle[80]; + const char *p, *q; + int len; + + do { + p = strchr(exp, '\t'); + if (!p) + p = exp + strlen(exp); + + len = p - exp; + if (len >= sizeof(needle) || !len) { + printf("FAIL\nTestcase bug\n"); + return false; + } + strncpy(needle, exp, len); + needle[len] = 0; + q = strstr(log, needle); + if (!q) { + printf("FAIL\nUnexpected verifier log in successful load!\n" + "EXP: %s\nRES:\n", needle); + return false; + } + log = q + len; + exp = p + 1; + } while (*p); + return true; +} + static void do_test_single(struct bpf_test *test, bool unpriv, int *passes, int *errors) { @@ -897,14 +929,20 @@ static void do_test_single(struct bpf_test *test, bool unpriv, pflags |= BPF_F_STRICT_ALIGNMENT; if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS) pflags |= BPF_F_ANY_ALIGNMENT; + if (test->flags & ~3) + pflags |= test->flags; + expected_ret = unpriv && test->result_unpriv != UNDEF ? + test->result_unpriv : test->result; + expected_err = unpriv && test->errstr_unpriv ? + test->errstr_unpriv : test->errstr; memset(&attr, 0, sizeof(attr)); attr.prog_type = prog_type; attr.expected_attach_type = test->expected_attach_type; attr.insns = prog; attr.insns_cnt = prog_len; attr.license = "GPL"; - attr.log_level = 4; + attr.log_level = verbose || expected_ret == VERBOSE_ACCEPT ? 1 : 4; attr.prog_flags = pflags; fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog)); @@ -914,14 +952,9 @@ static void do_test_single(struct bpf_test *test, bool unpriv, goto close_fds; } - expected_ret = unpriv && test->result_unpriv != UNDEF ? - test->result_unpriv : test->result; - expected_err = unpriv && test->errstr_unpriv ? - test->errstr_unpriv : test->errstr; - alignment_prevented_execution = 0; - if (expected_ret == ACCEPT) { + if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) { if (fd_prog < 0) { printf("FAIL\nFailed to load prog '%s'!\n", strerror(errno)); @@ -932,6 +965,9 @@ static void do_test_single(struct bpf_test *test, bool unpriv, (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS)) alignment_prevented_execution = 1; #endif + if (expected_ret == VERBOSE_ACCEPT && !cmp_str_seq(bpf_vlog, expected_err)) { + goto fail_log; + } } else { if (fd_prog >= 0) { printf("FAIL\nUnexpected success to load!\n"); @@ -957,6 +993,9 @@ static void do_test_single(struct bpf_test *test, bool unpriv, } } + if (verbose) + printf(", verifier log:\n%s", bpf_vlog); + run_errs = 0; run_successes = 0; if (!alignment_prevented_execution && fd_prog >= 0) { @@ -1097,17 +1136,24 @@ int main(int argc, char **argv) { unsigned int from = 0, to = ARRAY_SIZE(tests); bool unpriv = !is_admin(); + int arg = 1; + + if (argc > 1 && strcmp(argv[1], "-v") == 0) { + arg++; + verbose = true; + argc--; + } if (argc == 3) { - unsigned int l = atoi(argv[argc - 2]); - unsigned int u = atoi(argv[argc - 1]); + unsigned int l = atoi(argv[arg]); + unsigned int u = atoi(argv[arg + 1]); if (l < to && u < to) { from = l; to = u + 1; } } else if (argc == 2) { - unsigned int t = atoi(argv[argc - 1]); + unsigned int t = atoi(argv[arg]); if (t < to) { from = t; diff --git a/tools/testing/selftests/bpf/verifier/precise.c b/tools/testing/selftests/bpf/verifier/precise.c new file mode 100644 index 000000000000..a455a4a71f11 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/precise.c @@ -0,0 +1,142 @@ +{ + "precise: test 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_LD_MAP_FD(BPF_REG_6, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_FP, -8, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + + BPF_MOV64_REG(BPF_REG_9, BPF_REG_0), + + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + + BPF_MOV64_REG(BPF_REG_8, BPF_REG_0), + + BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_8), /* map_value_ptr -= map_value_ptr */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_9), + BPF_JMP_IMM(BPF_JLT, BPF_REG_2, 8, 1), + BPF_EXIT_INSN(), + + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, 1), /* R2=inv(umin=1, umax=8) */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_EMIT_CALL(BPF_FUNC_probe_read), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .fixup_map_array_48b = { 1 }, + .result = VERBOSE_ACCEPT, + .errstr = + "26: (85) call bpf_probe_read#4\ + last_idx 26 first_idx 20\ + regs=4 stack=0 before 25\ + regs=4 stack=0 before 24\ + regs=4 stack=0 before 23\ + regs=4 stack=0 before 22\ + regs=4 stack=0 before 20\ + parent didn't have regs=4 stack=0 marks\ + last_idx 19 first_idx 10\ + regs=4 stack=0 before 19\ + regs=200 stack=0 before 18\ + regs=300 stack=0 before 17\ + regs=201 stack=0 before 15\ + regs=201 stack=0 before 14\ + regs=200 stack=0 before 13\ + regs=200 stack=0 before 12\ + regs=200 stack=0 before 11\ + regs=200 stack=0 before 10\ + parent already had regs=0 stack=0 marks", +}, +{ + "precise: test 2", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_LD_MAP_FD(BPF_REG_6, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_FP, -8, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + + BPF_MOV64_REG(BPF_REG_9, BPF_REG_0), + + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + + BPF_MOV64_REG(BPF_REG_8, BPF_REG_0), + + BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_8), /* map_value_ptr -= map_value_ptr */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_9), + BPF_JMP_IMM(BPF_JLT, BPF_REG_2, 8, 1), + BPF_EXIT_INSN(), + + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, 1), /* R2=inv(umin=1, umax=8) */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_FP), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_EMIT_CALL(BPF_FUNC_probe_read), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .fixup_map_array_48b = { 1 }, + .result = VERBOSE_ACCEPT, + .flags = BPF_F_TEST_STATE_FREQ, + .errstr = + "26: (85) call bpf_probe_read#4\ + last_idx 26 first_idx 22\ + regs=4 stack=0 before 25\ + regs=4 stack=0 before 24\ + regs=4 stack=0 before 23\ + regs=4 stack=0 before 22\ + parent didn't have regs=4 stack=0 marks\ + last_idx 20 first_idx 20\ + regs=4 stack=0 before 20\ + parent didn't have regs=4 stack=0 marks\ + last_idx 19 first_idx 17\ + regs=4 stack=0 before 19\ + regs=200 stack=0 before 18\ + regs=300 stack=0 before 17\ + parent already had regs=0 stack=0 marks", +}, +{ + "precise: cross frame pruning", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32), + BPF_MOV64_IMM(BPF_REG_8, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_MOV64_IMM(BPF_REG_8, 1), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32), + BPF_MOV64_IMM(BPF_REG_9, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_MOV64_IMM(BPF_REG_9, 1), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 4), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_8, 1, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .flags = BPF_F_TEST_STATE_FREQ, + .errstr = "!read_ok", + .result = REJECT, +}, |