With the syscall common attrs support for link_create, add syscall common attrs support for xdp link_create in order to report the invalid target ifindex error and the underlying driver's error. Define a stub bpf_log() when CONFIG_BPF_SYSCALL is not set. Afterwards, bpf_log() can be called without CONFIG_BPF_SYSCALL guard in net/core/dev.c. Signed-off-by: Leon Hwang --- include/linux/bpf_verifier.h | 5 +++++ include/linux/netdevice.h | 3 ++- kernel/bpf/syscall.c | 2 +- net/core/dev.c | 7 ++++++- 4 files changed, 14 insertions(+), 3 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 54481da4ed2d..5270d3688c69 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -1266,8 +1266,13 @@ __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 3cff2174dc03..4548b0fd824d 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4417,7 +4417,8 @@ struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *d 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); +int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog, + struct bpf_verifier_log *log); 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 61d100e794b4..ebf5d7a6baa3 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -5938,7 +5938,7 @@ 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); + ret = bpf_xdp_link_attach(attr, prog, log); break; case BPF_PROG_TYPE_SCHED_CLS: if (attr->link_create.attach_type == BPF_TCX_INGRESS || diff --git a/net/core/dev.c b/net/core/dev.c index 18dc88990510..96be63b9331e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -97,6 +97,7 @@ #include #include #include +#include #include #include #include @@ -10771,7 +10772,8 @@ static const struct bpf_link_ops bpf_xdp_link_lops = { .update_prog = bpf_xdp_link_update, }; -int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog, + struct bpf_verifier_log *log) { struct net *net = current->nsproxy->net_ns; struct bpf_link_primer link_primer; @@ -10784,6 +10786,7 @@ 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"); return -EINVAL; } @@ -10812,6 +10815,8 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) if (err) { link->dev = NULL; bpf_link_cleanup(&link_primer); + if (extack._msg) + bpf_log(log, "%s\n", extack._msg); trace_bpf_xdp_link_attach_failed(extack._msg); goto out_put_dev; } -- 2.55.0