Commit 01793ed8 authored Jun 10, 2024 by Leon Hwang Committed by Alexei Starovoitov Jun 20, 2024

bpf, verifier: Correct tail_call_reachable for bpf prog

It's confusing to inspect 'prog->aux->tail_call_reachable' with drgn[0],
when bpf prog has tail call but 'tail_call_reachable' is false.

This patch corrects 'tail_call_reachable' when bpf prog has tail call.

Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20240610124224.34673-2-hffilwlqm@gmail.com

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

parent f6afdaf7

kernel/bpf/verifier.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -2982,8 +2982,10 @@ static int check_subprogs(struct bpf_verifier_env *env)

		if (code == (BPF_JMP \| BPF_CALL) &&
		insn[i].src_reg == 0 &&
		insn[i].imm == BPF_FUNC_tail_call)
		insn[i].imm == BPF_FUNC_tail_call) {
		subprog[cur_subprog].has_tail_call = true;
		subprog[cur_subprog].tail_call_reachable = true;
		}
		if (BPF_CLASS(code) == BPF_LD &&
		(BPF_MODE(code) == BPF_ABS \|\| BPF_MODE(code) == BPF_IND))
		subprog[cur_subprog].has_ld_abs = true;