diff options
| author | Hao Sun <sunhao.th@gmail.com> | 2023-11-01 13:33:52 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-11-01 22:30:27 -0700 |
| commit | 85eb035e6cfd615071256592e1dbe72c1d99c24b (patch) | |
| tree | fb460b6b1633d37877ab1ffe856a8d9ca5b30d21 /tools | |
| parent | 811c363645b33e6e22658634329e95f383dfc705 (diff) | |
selftests/bpf: Add test for immediate spilled to stack
Add a test to check if the verifier correctly reason about the sign
of an immediate spilled to stack by BPF_ST instruction.
Signed-off-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/r/20231101-fix-check-stack-write-v3-2-f05c2b1473d5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/bpf_st_mem.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/bpf_st_mem.c b/tools/testing/selftests/bpf/verifier/bpf_st_mem.c index 3af2501082b2..b616575c3b00 100644 --- a/tools/testing/selftests/bpf/verifier/bpf_st_mem.c +++ b/tools/testing/selftests/bpf/verifier/bpf_st_mem.c @@ -65,3 +65,35 @@ .expected_attach_type = BPF_SK_LOOKUP, .runs = -1, }, +{ + "BPF_ST_MEM stack imm sign", + /* Check if verifier correctly reasons about sign of an + * immediate spilled to stack by BPF_ST instruction. + * + * fp[-8] = -44; + * r0 = fp[-8]; + * if r0 s< 0 goto ret0; + * r0 = -1; + * exit; + * ret0: + * r0 = 0; + * exit; + */ + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, -44), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8), + BPF_JMP_IMM(BPF_JSLT, BPF_REG_0, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, -1), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + /* Use prog type that requires return value in range [0, 1] */ + .prog_type = BPF_PROG_TYPE_SK_LOOKUP, + .expected_attach_type = BPF_SK_LOOKUP, + .result = VERBOSE_ACCEPT, + .runs = -1, + .errstr = "0: (7a) *(u64 *)(r10 -8) = -44 ; R10=fp0 fp-8_w=-44\ + 2: (c5) if r0 s< 0x0 goto pc+2\ + R0_w=-44", +}, |