diff options
| author | Puranjay Mohan <puranjay@kernel.org> | 2026-02-03 08:51:01 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-02-03 10:34:33 -0800 |
| commit | f6ef5584ccb5683542abb38461970e969b580fba (patch) | |
| tree | 0f6f419a47f4b3b663cd18d3397ed6fcd3546f1c | |
| parent | b0388bafa4949bd30af7b3be5ee415f2a25ac014 (diff) | |
selftests/bpf: Add a test for ids=0 to verifier_scalar_ids test
Test that two registers with their id=0 (unlinked) in the cached state
can be mapped to a single id (linked) in the current state.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20260203165102.2302462-6-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_scalar_ids.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c b/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c index c8f8820336b7..3072fee9a448 100644 --- a/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c +++ b/tools/testing/selftests/bpf/progs/verifier_scalar_ids.c @@ -715,6 +715,51 @@ __naked void ignore_unique_scalar_ids_old(void) : __clobber_all); } +/* Check that two registers with 0 scalar IDs in a verified state can be mapped + * to the same scalar ID in current state. + */ +SEC("socket") +__success __log_level(2) +/* The states should be equivalent on reaching insn 12. + */ +__msg("12: safe") +__msg("processed 17 insns") +__flag(BPF_F_TEST_STATE_FREQ) +__naked void two_nil_old_ids_one_cur_id(void) +{ + asm volatile ( + /* Give unique scalar IDs to r{6,7} */ + "call %[bpf_ktime_get_ns];" + "r0 &= 0xff;" + "r6 = r0;" + "r6 *= 1;" + "call %[bpf_ktime_get_ns];" + "r0 &= 0xff;" + "r7 = r0;" + "r7 *= 1;" + "r0 = 0;" + /* Maybe make r{6,7} IDs identical */ + "if r6 > r7 goto l0_%=;" + "goto l1_%=;" +"l0_%=:" + "r6 = r7;" +"l1_%=:" + /* Mark r{6,7} precise. + * Get here in two states: + * - first: r6{.id=0}, r7{.id=0} (cached state) + * - second: r6{.id=A}, r7{.id=A} + * Verifier considers such states equivalent. + * Thus "exit;" would be verified only once. + */ + "r2 = r10;" + "r2 += r6;" + "r2 += r7;" + "exit;" + : + : __imm(bpf_ktime_get_ns) + : __clobber_all); +} + /* Check that two different scalar IDs in a verified state can't be * mapped to the same scalar ID in current state. */ |