diff options
| author | Eduard Zingerman <eddyz87@gmail.com> | 2023-02-15 01:20:28 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-02-15 11:48:47 -0800 |
| commit | 1a24af65bb5fed673a9377e794ee3cf416fec64d (patch) | |
| tree | f35daec7c6f523270757f40f9b0a30cb85ba6130 | |
| parent | ecdf985d7615356b78241fdb159c091830ed0380 (diff) | |
selftests/bpf: check if verifier tracks constants spilled by BPF_ST_MEM
Check that verifier tracks the value of 'imm' spilled to stack by
BPF_ST_MEM instruction. Cover the following cases:
- write of non-zero constant to stack;
- write of a zero constant to stack.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230214232030.1502829-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/bpf_st_mem.c | 37 |
1 files changed, 37 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 new file mode 100644 index 000000000000..932903f9e585 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/bpf_st_mem.c @@ -0,0 +1,37 @@ +{ + "BPF_ST_MEM stack imm non-zero", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 42), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, -42), + /* if value is tracked correctly R0 is zero */ + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + /* Use prog type that requires return value in range [0, 1] */ + .prog_type = BPF_PROG_TYPE_SK_LOOKUP, + .expected_attach_type = BPF_SK_LOOKUP, + .runs = -1, +}, +{ + "BPF_ST_MEM stack imm zero", + .insns = { + /* mark stack 0000 0000 */ + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + /* read and sum a few bytes */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_10, -8), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_10, -4), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_10, -1), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + /* if value is tracked correctly R0 is zero */ + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + /* Use prog type that requires return value in range [0, 1] */ + .prog_type = BPF_PROG_TYPE_SK_LOOKUP, + .expected_attach_type = BPF_SK_LOOKUP, + .runs = -1, +}, |