From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Since commit 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF
programs in net_device"), the XDP program attachment info is now maintained
in the core code. This interacts badly with the xdp_attachment_flags_ok()
check that prevents unloading an XDP program with different load flags than
it was loaded with. In practice, two kinds of failures are seen:
- An XDP program loaded without specifying a mode (and which then ends up
in driver mode) cannot be unloaded if the program mode is specified on
unload.
- The dev_xdp_uninstall() hook always calls the driver callback with the
mode set to the type of the program but an empty flags argument, which
means the flags_ok() check prevents the program from being removed,
leading to bpf prog reference leaks.
Since we offloaded and non-offloaded programs can co-exist there doesn't
really seem to be any reason for the check anyway, and it's only used in
three drivers so let's just get rid of the callback entirely.
Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
---
.../net/ethernet/netronome/nfp/nfp_net_common.c | 6 ------
drivers/net/ethernet/ti/cpsw_priv.c | 3 ---
drivers/net/netdevsim/bpf.c | 3 ---
include/net/xdp.h | 2 --
net/core/xdp.c | 12 ------------
5 files changed, 26 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index b150da43adb2..437226866ce8 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -3562,9 +3562,6 @@ static int nfp_net_xdp_setup_drv(struct nfp_net *nn, struct netdev_bpf *bpf)
struct nfp_net_dp *dp;
int err;
- if (!xdp_attachment_flags_ok(&nn->xdp, bpf))
- return -EBUSY;
-
if (!prog == !nn->dp.xdp_prog) {
WRITE_ONCE(nn->dp.xdp_prog, prog);
xdp_attachment_setup(&nn->xdp, bpf);
@@ -3593,9 +3590,6 @@ static int nfp_net_xdp_setup_hw(struct nfp_net *nn, struct netdev_bpf *bpf)
{
int err;
- if (!xdp_attachment_flags_ok(&nn->xdp_hw, bpf))
- return -EBUSY;
-
err = nfp_app_xdp_offload(nn->app, nn, bpf->prog, bpf->extack);
if (err)
return err;
diff --git a/drivers/net/ethernet/ti/cpsw_priv.c b/drivers/net/ethernet/ti/cpsw_priv.c
index 31c5e36ff706..424e644724e4 100644
--- a/drivers/net/ethernet/ti/cpsw_priv.c
+++ b/drivers/net/ethernet/ti/cpsw_priv.c
@@ -1265,9 +1265,6 @@ static int cpsw_xdp_prog_setup(struct cpsw_priv *priv, struct netdev_bpf *bpf)
if (!priv->xdpi.prog && !prog)
return 0;
- if (!xdp_attachment_flags_ok(&priv->xdpi, bpf))
- return -EBUSY;
-
WRITE_ONCE(priv->xdp_prog, prog);
xdp_attachment_setup(&priv->xdpi, bpf);
diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c
index 2e90512f3bbe..85546664bdd5 100644
--- a/drivers/net/netdevsim/bpf.c
+++ b/drivers/net/netdevsim/bpf.c
@@ -190,9 +190,6 @@ nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf,
{
int err;
- if (!xdp_attachment_flags_ok(xdp, bpf))
- return -EBUSY;
-
if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) {
NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS");
return -EOPNOTSUPP;
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 3814fb631d52..9dab2bc6f187 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -240,8 +240,6 @@ struct xdp_attachment_info {
};
struct netdev_bpf;
-bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
- struct netdev_bpf *bpf);
void xdp_attachment_setup(struct xdp_attachment_info *info,
struct netdev_bpf *bpf);
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 491ad569a79c..d900cebc0acd 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -403,18 +403,6 @@ void __xdp_release_frame(void *data, struct xdp_mem_info *mem)
}
EXPORT_SYMBOL_GPL(__xdp_release_frame);
-bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
- struct netdev_bpf *bpf)
-{
- if (info->prog && (bpf->flags ^ info->flags) & XDP_FLAGS_MODES) {
- NL_SET_ERR_MSG(bpf->extack,
- "program loaded with different flags");
- return false;
- }
- return true;
-}
-EXPORT_SYMBOL_GPL(xdp_attachment_flags_ok);
-
void xdp_attachment_setup(struct xdp_attachment_info *info,
struct netdev_bpf *bpf)
{
