lwn.git/tools/testing/selftests/bpf/progs/verifier_live_stack.c, branch masterLinux kernel documentation tree maintained by Jonathan Corbethttp://mirrors.hust.edu.cn/git/lwn.git/atom?h=master2026-04-15T15:40:48+00:00selftests/bpf: arg tracking for imprecise/multi-offset BPF_ST/STX2026-04-15T15:40:48+00:00Eduard Zingermaneddyz87@gmail.com2026-04-13T23:30:53+00:00urn:sha1:d97cc8fc997c77234580c77b21466164ff71307a
Add test cases for clear_stack_for_all_offs and dst_is_local_fp
handling of multi-offset and ARG_IMPRECISE stack pointers:
- st_imm_join_with_multi_off: BPF_ST through multi-offset dst should
join at_stack with none instead of overwriting both candidate slots.
- st_imm_join_with_imprecise_off: BPF_ST through offset-imprecise dst
should join at_stack with none instead of clearing all slots.
- st_imm_join_with_single_off: a canary checking that BPF_ST with a
known offset overwrites slot instead of joining.
- imprecise_dst_spill_join: BPF_STX through ARG_IMPRECISE dst should
be recognized as a local spill and join at_stack with the written
value.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260413-stacklive-fixes-v2-2-398e126e5cf3@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: add new tests for static stack liveness analysis2026-04-10T22:13:38+00:00Alexei Starovoitovast@kernel.org2026-04-10T20:56:04+00:00urn:sha1:27417e5eb9cd4151320866e0b2cca0c612f1cdf7
Add a bunch of new tests to verify the static stack
liveness analysis.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260410-patch-set-v4-13-5d4eecb343db@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: update existing tests due to liveness changes2026-04-10T22:13:37+00:00Alexei Starovoitovast@kernel.org2026-04-10T20:56:02+00:00urn:sha1:b42eb55f6ca29d9cc9d2239f8665cca5f16efecb
The verifier cleans all dead registers and stack slots in the current
state. Adjust expected output in tests or insert dummy stack/register
reads. Also update verifier_live_stack tests to adhere to new logging
scheme.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260410-patch-set-v4-11-5d4eecb343db@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: test the correct stack liveness of tail calls2025-11-22T01:45:30+00:00Eduard Zingermaneddyz87@gmail.com2025-11-19T16:03:55+00:00urn:sha1:8f7cf305a15eec663d5084e417f4773f1ef24e23
A new test is added: caller_stack_write_tail_call tests that the live
stack is correctly tracked for a tail call.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu>
Link: https://lore.kernel.org/r/20251119160355.1160932-5-martin.teichmann@xfel.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: test cases for callchain sensitive live stack tracking2025-09-19T16:27:24+00:00Eduard Zingermaneddyz87@gmail.com2025-09-19T02:18:45+00:00urn:sha1:fdcecdff905cf712279d3ba72ec8ac7bc02be7ff
- simple propagation of read/write marks;
- joining read/write marks from conditional branches;
- avoid must_write marks in when same instruction accesses different
stack offsets on different execution paths;
- avoid must_write marks in case same instruction accesses stack
and non-stack pointers on different execution paths;
- read/write marks propagation to outer stack frame;
- independent read marks for different callchains ending with the same
function;
- bpf_calls_callback() dependent logic in
liveness.c:bpf_stack_slot_alive().
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-12-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>