BACKPORT: bpf: Inherit expanded/patched seen count from old aux data

[ Upstream commit d203b0fd863a2261e5d00b97f3d060c4c2a6db71 ]

Instead of relying on current env->pass_cnt, use the seen count from the
old aux data in adjust_insn_aux_data(), and expand it to the new range of
patched instructions. This change is valid given we always expand 1:n
with n>=1, so what applies to the old/original instruction needs to apply
for the replacement as well.

Not relying on env->pass_cnt is a prerequisite for a later change where we
want to avoid marking an instruction seen when verified under speculative
execution path.

Change-Id: Iac36d44ca455d2445ee94d481cb6b99fdefa33dd
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: John Fastabend <[email protected]>
Reviewed-by: Benedict Schlueter <[email protected]>
Reviewed-by: Piotr Krysiuk <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

kernel/bpf/verifier.c

@@ -10754,7 +10754,7 @@ static void adjust_insn_aux_data(struct bpf_verifier_env *env,
 {
 	struct bpf_insn_aux_data *old_data = env->insn_aux_data;
 	struct bpf_insn *insn = new_prog->insnsi;
-	bool old_seen = old_data[off].seen;
+	u32 old_seen = old_data[off].seen;
 	u32 prog_len;
 	int i;