The register track provides what registers already contain prefetched
expressions.
The expr->ops->reduce() operation already cancels register tracking in
case an expression updates overwrites existing prefetched expression.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d0c80e11557e..23540b1d6e8d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9150,7 +9150,16 @@ static int nft_prefetch_build(struct nft_regs_track *track,
static bool nft_expr_reduce(struct nft_regs_track *track,
const struct nft_expr *expr)
{
- return false;
+ if (!expr->ops->reduce) {
+ pr_warn_once("missing reduce for expression %s ",
+ expr->ops->type->name);
+ return false;
+ }
+
+ if (nft_reduce_is_readonly(expr))
+ return false;
+
+ return expr->ops->reduce(track, expr);
}
static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *chain)
--
2.30.2
