[PATCH RFC bpf-next 07/52] net, xdp: remove redundant arguments from dev_xdp_{at,de}tach_link()

Alexander Lobakin
2022-06-28T19:51:26Z

dev_xdp_attach_link(): the sole caller always passes %NULL as
@extack and @link->dev as @dev, so they both can be omitted.
The very same story with dev_xdp_detach_link(): remove both
@dev and @extack as they both can be obtained inside the
function itself.
This decreases stack usage with no functional changes.

Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
net/bpf/dev.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/net/bpf/dev.c b/net/bpf/dev.c
index 68a7b2c49392..0010b20719e8 100644
--- a/net/bpf/dev.c
+++ b/net/bpf/dev.c
@@ -534,17 +534,14 @@ static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack
return 0;
}

-static int dev_xdp_attach_link(struct net_device *dev,
- struct netlink_ext_ack *extack,
- struct bpf_xdp_link *link)
+static int dev_xdp_attach_link(struct bpf_xdp_link *link)
{
- return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
+ return dev_xdp_attach(link->dev, NULL, link, NULL, NULL, link->flags);
}

-static int dev_xdp_detach_link(struct net_device *dev,
- struct netlink_ext_ack *extack,
- struct bpf_xdp_link *link)
+static int dev_xdp_detach_link(struct bpf_xdp_link *link)
{
+ struct net_device *dev = link->dev;
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;

@@ -570,7 +567,7 @@ static void bpf_xdp_link_release(struct bpf_link *link)
* already NULL, in which case link was already auto-detached
*/
if (xdp_link->dev) {
- WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
+ WARN_ON(dev_xdp_detach_link(xdp_link));
xdp_link->dev = NULL;
}

@@ -709,7 +706,7 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
goto unlock;
}

- err = dev_xdp_attach_link(dev, NULL, link);
+ err = dev_xdp_attach_link(link);
rtnl_unlock();

if (err) {
--
2.36.1