From: Björn Töpel <bjorn.topel@xxxxxxxxx>
Similar to query a driver for a loaded XDP program, each driver need
to check the attachment flags when a program is loaded.
E.g., if an XDP program was loaded without explicit flags (fallback
mode), it must be reloaded/removed without explicit flags.
This commit moves that check to generic code as well.
Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
---
net/core/dev.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index 8e9f5693a7da..bb5fbb395596 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8075,8 +8075,8 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
const struct net_device_ops *ops = dev->netdev_ops;
xdp_query_prog_t query, check;
struct bpf_prog *prog = NULL;
+ bool offload, expl;
bpf_op_t bpf_op;
- bool offload;
int err;
ASSERT_RTNL();
@@ -8124,6 +8124,14 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
}
}
+ expl = dev->xdp.explicit_mode;
+ if (!offload && query(dev) && !!expl ^ !!(flags & XDP_FLAGS_MODES)) {
+ NL_SET_ERR_MSG(extack, "program loaded with different flags");
+ if (prog)
+ bpf_prog_put(prog);
+ return -EBUSY;
+ }
+
err = dev_xdp_install(dev, bpf_op, extack, flags, prog);
if (err < 0 && prog)
bpf_prog_put(prog);
--
2.20.1
