From: Johan Almbladh <johan.almbladh@xxxxxxxxxxxxxxxxx> [ Upstream commit b61a28cf11d61f512172e673b8f8c4a6c789b425 ] Before, the interpreter allowed up to MAX_TAIL_CALL_CNT + 1 tail calls. Now precisely MAX_TAIL_CALL_CNT is allowed, which is in line with the behavior of the x86 JITs. Signed-off-by: Johan Almbladh <johan.almbladh@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Acked-by: Yonghong Song <yhs@xxxxxx> Link: https://lore.kernel.org/bpf/20210728164741.350370-1-johan.almbladh@xxxxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/bpf/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index b1a5fc04492b..fe807b203a6f 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1562,7 +1562,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) if (unlikely(index >= array->map.max_entries)) goto out; - if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) + if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT)) goto out; tail_call_cnt++; -- 2.30.2
