From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Fri, 1 Dec 2017 15:08:57 -0800
Subject: net: xdp: make the stack take care of the tear down
Patch-mainline: v4.16-rc1
Git-commit: bd0b2e7fe611953470ec7c533b455fb2abd382cd
References: bsc#1109837
Since day one of XDP drivers had to remember to free the program
on the remove path. This leads to code duplication and is error
prone. Make the stack query the installed programs on unregister
and if something is installed, remove the program. Freeing of
program attached to XDP generic is moved from free_netdev() as well.
Because the remove will now be called before notifiers are
invoked, BPF offload state of the program will not get destroyed
before uninstall.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 2 -
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 3 -
drivers/net/ethernet/netronome/nfp/bpf/main.c | 32 --------------------
drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 3 -
drivers/net/ethernet/qlogic/qede/qede_main.c | 4 --
drivers/net/tun.c | 4 --
net/core/dev.c | 29 +++++++++++++-----
7 files changed, 23 insertions(+), 54 deletions(-)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -7800,8 +7800,6 @@ static void bnxt_remove_one(struct pci_d
bnxt_dcb_free(bp);
kfree(bp->edev);
bp->edev = NULL;
- if (bp->xdp_prog)
- bpf_prog_put(bp->xdp_prog);
bnxt_cleanup_pci(bp);
free_netdev(dev);
}
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -4278,9 +4278,6 @@ static void mlx5e_nic_cleanup(struct mlx
{
mlx5e_ipsec_cleanup(priv);
mlx5e_vxlan_cleanup(priv);
-
- if (priv->channels.params.xdp_prog)
- bpf_prog_put(priv->channels.params.xdp_prog);
}
static int mlx5e_init_nic_rx(struct mlx5e_priv *priv)
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.c
@@ -82,35 +82,6 @@ static const char *nfp_bpf_extra_cap(str
return nfp_net_ebpf_capable(nn) ? "BPF" : "";
}
-static int
-nfp_bpf_vnic_alloc(struct nfp_app *app, struct nfp_net *nn, unsigned int id)
-{
- int err;
-
- nn->app_priv = kzalloc(sizeof(struct nfp_bpf_vnic), GFP_KERNEL);
- if (!nn->app_priv)
- return -ENOMEM;
-
- err = nfp_app_nic_vnic_alloc(app, nn, id);
- if (err)
- goto err_free_priv;
-
- return 0;
-err_free_priv:
- kfree(nn->app_priv);
- return err;
-}
-
-static void nfp_bpf_vnic_free(struct nfp_app *app, struct nfp_net *nn)
-{
- struct nfp_bpf_vnic *bv = nn->app_priv;
-
- if (nn->dp.bpf_offload_xdp)
- nfp_bpf_xdp_offload(app, nn, NULL);
- WARN_ON(bv->tc_prog);
- kfree(bv);
-}
-
static int nfp_bpf_setup_tc_block_cb(enum tc_setup_type type,
void *type_data, void *cb_priv)
{
@@ -200,8 +171,7 @@ const struct nfp_app_type app_bpf = {
.extra_cap = nfp_bpf_extra_cap,
- .vnic_alloc = nfp_bpf_vnic_alloc,
- .vnic_free = nfp_bpf_vnic_free,
+ .vnic_alloc = nfp_app_nic_vnic_alloc,
.setup_tc = nfp_bpf_setup_tc,
.tc_busy = nfp_bpf_tc_busy,
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -3565,9 +3565,6 @@ struct nfp_net *nfp_net_alloc(struct pci
*/
void nfp_net_free(struct nfp_net *nn)
{
- if (nn->xdp_prog)
- bpf_prog_put(nn->xdp_prog);
-
if (nn->dp.netdev)
free_netdev(nn->dp.netdev);
else
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -1068,10 +1068,6 @@ static void __qede_remove(struct pci_dev
pci_set_drvdata(pdev, NULL);
- /* Release edev's reference to XDP's bpf if such exist */
- if (edev->xdp_prog)
- bpf_prog_put(edev->xdp_prog);
-
/* Use global ops since we've freed edev */
qed_ops->common->slowpath_stop(cdev);
if (system_state == SYSTEM_POWER_OFF)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -680,7 +680,6 @@ static void tun_detach(struct tun_file *
static void tun_detach_all(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
- struct bpf_prog *xdp_prog = rtnl_dereference(tun->xdp_prog);
struct tun_file *tfile, *tmp;
int i, n = tun->numqueues;
@@ -717,9 +716,6 @@ static void tun_detach_all(struct net_de
}
BUG_ON(tun->numdisabled != 0);
- if (xdp_prog)
- bpf_prog_put(xdp_prog);
-
if (tun->flags & IFF_PERSIST)
module_put(THIS_MODULE);
}
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7111,6 +7111,27 @@ static int dev_xdp_install(struct net_de
return bpf_op(dev, &xdp);
}
+static void dev_xdp_uninstall(struct net_device *dev)
+{
+ struct netdev_bpf xdp;
+ bpf_op_t ndo_bpf;
+
+ /* Remove generic XDP */
+ WARN_ON(dev_xdp_install(dev, generic_xdp_install, NULL, 0, NULL));
+
+ /* Remove from the driver */
+ ndo_bpf = dev->netdev_ops->ndo_bpf;
+ if (!ndo_bpf)
+ return;
+
+ __dev_xdp_query(dev, ndo_bpf, &xdp);
+ if (xdp.prog_attached == XDP_ATTACHED_NONE)
+ return;
+
+ /* Program removal should always succeed */
+ WARN_ON(dev_xdp_install(dev, ndo_bpf, NULL, xdp.prog_flags, NULL));
+}
+
/**
* dev_change_xdp_fd - set or clear a bpf program for a device rx path
* @dev: device
@@ -7241,6 +7262,7 @@ static void rollback_registered_many(str
/* Shutdown queueing discipline. */
dev_shutdown(dev);
+ dev_xdp_uninstall(dev);
/* Notify protocols, that we are about to destroy
* this device. They should clean all the things.
@@ -8200,7 +8222,6 @@ EXPORT_SYMBOL(alloc_netdev_mqs);
void free_netdev(struct net_device *dev)
{
struct napi_struct *p, *n;
- struct bpf_prog *prog;
might_sleep();
netif_free_tx_queues(dev);
@@ -8219,12 +8240,6 @@ void free_netdev(struct net_device *dev)
free_percpu(dev->pcpu_refcnt);
dev->pcpu_refcnt = NULL;
- prog = rcu_dereference_protected(dev->xdp_prog, 1);
- if (prog) {
- bpf_prog_put(prog);
- static_key_slow_dec(&generic_xdp_needed);
- }
-
/* Compatibility with error handling in drivers */
if (dev->reg_state == NETREG_UNINITIALIZED) {
netdev_freemem(dev);