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| author | Eduard Zingerman <eddyz87@gmail.com> | 2022-12-09 15:57:33 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-12-10 13:36:22 -0800 |
| commit | efd6286ff74a2fa2b45ed070d344cc0822b8ea6e (patch) | |
| tree | de4c47b1ac47deceb055aef7fbab79f30dabebc0 /tools/testing/selftests | |
| parent | 2026f2062df860e5d282ffd4962ea5d5ed53dc51 (diff) | |
| download | linux-efd6286ff74a2fa2b45ed070d344cc0822b8ea6e.tar.bz2 | |
selftests/bpf: test case for relaxed prunning of active_lock.id
Check that verifier.c:states_equal() uses check_ids() to match
consistent active_lock/map_value configurations. This allows to prune
states with active spin locks even if numerical values of
active_lock ids do not match across compared states.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20221209135733.28851-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests')
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/spin_lock.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/spin_lock.c b/tools/testing/selftests/bpf/verifier/spin_lock.c index 0a8dcfc37fc6..eaf114f07e2e 100644 --- a/tools/testing/selftests/bpf/verifier/spin_lock.c +++ b/tools/testing/selftests/bpf/verifier/spin_lock.c @@ -370,3 +370,78 @@ .prog_type = BPF_PROG_TYPE_SCHED_CLS, .flags = BPF_F_TEST_STATE_FREQ, }, +/* Make sure that regsafe() compares ids for spin lock records using + * check_ids(): + * 1: r9 = map_lookup_elem(...) ; r9.id == 1 + * 2: r8 = map_lookup_elem(...) ; r8.id == 2 + * 3: r7 = ktime_get_ns() + * 4: r6 = ktime_get_ns() + * 5: if r6 > r7 goto <9> + * 6: spin_lock(r8) + * 7: r9 = r8 + * 8: goto <10> + * 9: spin_lock(r9) + * 10: spin_unlock(r9) ; r9.id == 1 || r9.id == 2 and lock is active, + * ; second visit to (10) should be considered safe + * ; if check_ids() is used. + * 11: exit(0) + */ +{ + "spin_lock: regsafe() check_ids() similar id mappings", + .insns = { + BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0), + /* r9 = map_lookup_elem(...) */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), + BPF_LD_MAP_FD(BPF_REG_1, + 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 24), + BPF_MOV64_REG(BPF_REG_9, BPF_REG_0), + /* r8 = map_lookup_elem(...) */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), + BPF_LD_MAP_FD(BPF_REG_1, + 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 18), + BPF_MOV64_REG(BPF_REG_8, BPF_REG_0), + /* r7 = ktime_get_ns() */ + BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns), + BPF_MOV64_REG(BPF_REG_7, BPF_REG_0), + /* r6 = ktime_get_ns() */ + BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + /* if r6 > r7 goto +5 ; no new information about the state is derived from + * ; this check, thus produced verifier states differ + * ; only in 'insn_idx' + * spin_lock(r8) + * r9 = r8 + * goto unlock + */ + BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 5), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4), + BPF_EMIT_CALL(BPF_FUNC_spin_lock), + BPF_MOV64_REG(BPF_REG_9, BPF_REG_8), + BPF_JMP_A(3), + /* spin_lock(r9) */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_9), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4), + BPF_EMIT_CALL(BPF_FUNC_spin_lock), + /* spin_unlock(r9) */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_9), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4), + BPF_EMIT_CALL(BPF_FUNC_spin_unlock), + /* exit(0) */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_spin_lock = { 3, 10 }, + .result = VERBOSE_ACCEPT, + .errstr = "28: safe", + .result_unpriv = REJECT, + .errstr_unpriv = "", + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + .flags = BPF_F_TEST_STATE_FREQ, +}, |