From 14507e35bd9dedcd14c24f9e5e0e0dd48e972e53 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 19 Dec 2018 22:13:05 -0800 Subject: [PATCH] selftests: bpf: verifier: add tests for JSET interpretation Validate that the verifier reasons correctly about the bounds and removes dead code based on results of JSET instruction. Signed-off-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_verifier.c | 96 +++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 580fc94..b246931 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -14265,6 +14265,102 @@ static struct bpf_test tests[] = { .retval = 2, .data = { 1, 0, 0, 0, 0, 0, 0, 1, }, }, + { + "jset: known const compare", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, + .retval_unpriv = 1, + .result_unpriv = ACCEPT, + .retval = 1, + .result = ACCEPT, + }, + { + "jset: known const compare bad", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, + .errstr_unpriv = "!read_ok", + .result_unpriv = REJECT, + .errstr = "!read_ok", + .result = REJECT, + }, + { + "jset: unknown const compare taken", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_prandom_u32), + BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 1), + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, + .errstr_unpriv = "!read_ok", + .result_unpriv = REJECT, + .errstr = "!read_ok", + .result = REJECT, + }, + { + "jset: unknown const compare not taken", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_prandom_u32), + BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, + .errstr_unpriv = "!read_ok", + .result_unpriv = REJECT, + .errstr = "!read_ok", + .result = REJECT, + }, + { + "jset: half-known const compare", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_prandom_u32), + BPF_ALU64_IMM(BPF_OR, BPF_REG_0, 2), + BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 3, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, + .result_unpriv = ACCEPT, + .result = ACCEPT, + }, + { + "jset: range", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_prandom_u32), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xff), + BPF_JMP_IMM(BPF_JSET, BPF_REG_1, 0xf0, 3), + BPF_JMP_IMM(BPF_JLT, BPF_REG_1, 0x10, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), + BPF_EXIT_INSN(), + BPF_JMP_IMM(BPF_JSET, BPF_REG_1, 0x10, 1), + BPF_EXIT_INSN(), + BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0x10, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, + .result_unpriv = ACCEPT, + .result = ACCEPT, + }, }; static int probe_filter_length(const struct bpf_insn *fp) -- 2.7.4