Commit 98ddcf38 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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bpf: honor env->test_state_freq flag in is_state_visited() 



env->test_state_freq flag can be set by user by passing
BPF_F_TEST_STATE_FREQ program flag. This is used in a bunch of selftests
to have predictable state checkpoints at every jump and so on.

Currently, bounded loop handling heuristic ignores this flag if number
of processed jumps and/or number of processed instructions is below some
thresholds, which throws off that reliable state checkpointing.

Honor this flag in all circumstances by disabling heuristic if
env->test_state_freq is set.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-5-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 6f876e75

kernel/bpf/verifier.c

+2 −1
Original line number Diff line number Diff line
@@ -14651,7 +14651,8 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) 
			 * This threshold shouldn't be too high either, since states

			 * at the end of the loop are likely to be useful in pruning.

			 */

			if (env->jmps_processed - env->prev_jmps_processed < 20 &&

			if (!env->test_state_freq &&

			    env->jmps_processed - env->prev_jmps_processed < 20 &&

			    env->insn_processed - env->prev_insn_processed < 100)

				add_new_state = false;

			goto miss;