From: Leon Hwang <leon.hwang@linux.dev>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Jiri Olsa <jolsa@kernel.org>,
Emil Tsalapatis <emil@etsalapatis.com>,
Ihor Solodrai <ihor.solodrai@linux.dev>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@kernel.org>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>,
Jesper Dangaard Brouer <hawk@kernel.org>,
Stanislav Fomichev <sdf@fomichev.me>,
Kuniyuki Iwashima <kuniyu@google.com>,
Hangbin Liu <liuhangbin@gmail.com>,
Martin Karsten <mkarsten@uwaterloo.ca>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
Leon Hwang <leon.hwang@linux.dev>
Subject: [PATCH bpf-next] bpf: Pass extack to bpf_xdp_link_attach
Date: Wed, 21 Oct 2026 23:24:55 +0800 [thread overview]
Message-ID: <20261021152455.71524-1-leon.hwang@linux.dev> (raw)
In order to drop the dependency of bpf_verifier.h in net/core/dev.c, pass
extack to bpf_xdp_link_attach() in link_create(). Afterwards, transfer
the error message from extack to log buffer in link_create().
Drop the stub bpf_log(), because it is not used in net/core/dev.c
anymore when CONFIG_BPF_SYSCALL is not set.
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
---
Address Jakub's review in the series
"bpf: Add syscall common attrs support for xdp link_create" [1].
Links:
[1] https://lore.kernel.org/bpf/20261020152804.39863-1-leon.hwang@linux.dev/
---
include/linux/bpf_verifier.h | 5 -----
include/linux/netdevice.h | 2 +-
kernel/bpf/syscall.c | 8 +++++++-
net/core/dev.c | 10 +++-------
4 files changed, 11 insertions(+), 14 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 1d34ece19bcc..5926f13ff43c 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -1269,13 +1269,8 @@ __printf(2, 0) void bpf_verifier_vlog(struct bpf_verifier_log *log,
const char *fmt, va_list args);
__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
const char *fmt, ...);
-#ifdef CONFIG_BPF_SYSCALL
__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
const char *fmt, ...);
-#else
-__printf(2, 3) static inline void bpf_log(struct bpf_verifier_log *log,
- const char *fmt, ...) {}
-#endif
int bpf_vlog_init(struct bpf_verifier_log *log, u32 log_level,
char __user *log_buf, u32 log_size);
void bpf_vlog_reset(struct bpf_verifier_log *log, u64 new_pos);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4548b0fd824d..f5d6438c4b8f 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4418,7 +4418,7 @@ struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
struct netdev_queue *txq, int *ret);
int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog,
- struct bpf_verifier_log *log);
+ struct netlink_ext_ack *extack);
u8 dev_xdp_prog_count(struct net_device *dev);
int netif_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf);
int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 87cd122d1024..26917a1ecbb2 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -5944,8 +5944,14 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_a
break;
#ifdef CONFIG_NET
case BPF_PROG_TYPE_XDP:
- ret = bpf_xdp_link_attach(attr, prog, log);
+{
+ struct netlink_ext_ack extack = {};
+
+ ret = bpf_xdp_link_attach(attr, prog, &extack);
+ if (extack._msg)
+ bpf_log(log, "%s\n", extack._msg);
break;
+}
case BPF_PROG_TYPE_SCHED_CLS:
if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
attr->link_create.attach_type == BPF_TCX_EGRESS)
diff --git a/net/core/dev.c b/net/core/dev.c
index a142613536b0..d79a589206e1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -97,7 +97,6 @@
#include <linux/kthread.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
-#include <linux/bpf_verifier.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/busy_poll.h>
@@ -10773,11 +10772,10 @@ static const struct bpf_link_ops bpf_xdp_link_lops = {
};
int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog,
- struct bpf_verifier_log *log)
+ struct netlink_ext_ack *extack)
{
struct net *net = current->nsproxy->net_ns;
struct bpf_link_primer link_primer;
- struct netlink_ext_ack extack = {};
struct bpf_xdp_link *link;
struct net_device *dev;
int err, fd;
@@ -10786,7 +10784,7 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog,
dev = dev_get_by_index(net, attr->link_create.target_ifindex);
if (!dev) {
rtnl_unlock();
- bpf_log(log, "Invalid target_ifindex.\n");
+ NL_SET_ERR_MSG(extack, "Invalid target_ifindex.");
return -EINVAL;
}
@@ -10808,15 +10806,13 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog,
}
netdev_lock_ops(dev);
- err = dev_xdp_attach_link(dev, &extack, link);
+ err = dev_xdp_attach_link(dev, extack, link);
netdev_unlock_ops(dev);
rtnl_unlock();
if (err) {
link->dev = NULL;
bpf_link_cleanup(&link_primer);
- if (extack._msg)
- bpf_log(log, "%s\n", extack._msg);
goto out_put_dev;
}
--
2.55.0
reply other threads:[~2026-10-21 15:25 UTC|newest]
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