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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2023-10-16 14:57:38 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-10-17 15:02:03 +0200 |
| commit | 9a675ba55a96a45a9fb69e6a5c43f80c6682e541 (patch) | |
| tree | c7d9260fe55b9ee3be40aae411dcba0a91556e1f /net/core | |
| parent | libbpf: Don't assume SHT_GNU_verdef presence for SHT_GNU_versym section (diff) | |
| download | linux-9a675ba55a96a45a9fb69e6a5c43f80c6682e541.tar.xz linux-9a675ba55a96a45a9fb69e6a5c43f80c6682e541.zip | |
net, bpf: Add a warning if NAPI cb missed xdp_do_flush().
A few drivers were missing a xdp_do_flush() invocation after
XDP_REDIRECT.
Add three helper functions each for one of the per-CPU lists. Return
true if the per-CPU list is non-empty and flush the list.
Add xdp_do_check_flushed() which invokes each helper functions and
creates a warning if one of the functions had a non-empty list.
Hide everything behind CONFIG_DEBUG_NET.
Suggested-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20231016125738.Yt79p1uF@linutronix.de
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 2 | ||||
| -rw-r--r-- | net/core/dev.h | 6 | ||||
| -rw-r--r-- | net/core/filter.c | 16 |
3 files changed, 24 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 97e7b9833db9..4420831180c6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6535,6 +6535,8 @@ static int __napi_poll(struct napi_struct *n, bool *repoll) if (test_bit(NAPI_STATE_SCHED, &n->state)) { work = n->poll(n, weight); trace_napi_poll(n, work, weight); + + xdp_do_check_flushed(n); } if (unlikely(work > weight)) diff --git a/net/core/dev.h b/net/core/dev.h index e075e198092c..f66125857af7 100644 --- a/net/core/dev.h +++ b/net/core/dev.h @@ -136,4 +136,10 @@ static inline void netif_set_gro_ipv4_max_size(struct net_device *dev, } int rps_cpumask_housekeeping(struct cpumask *mask); + +#if defined(CONFIG_DEBUG_NET) && defined(CONFIG_BPF_SYSCALL) +void xdp_do_check_flushed(struct napi_struct *napi); +#else +static inline void xdp_do_check_flushed(struct napi_struct *napi) { } +#endif #endif diff --git a/net/core/filter.c b/net/core/filter.c index cc2e4babc85f..21d75108c2e9 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -83,6 +83,8 @@ #include <net/netfilter/nf_conntrack_bpf.h> #include <linux/un.h> +#include "dev.h" + static const struct bpf_func_proto * bpf_sk_base_func_proto(enum bpf_func_id func_id); @@ -4208,6 +4210,20 @@ void xdp_do_flush(void) } EXPORT_SYMBOL_GPL(xdp_do_flush); +#if defined(CONFIG_DEBUG_NET) && defined(CONFIG_BPF_SYSCALL) +void xdp_do_check_flushed(struct napi_struct *napi) +{ + bool ret; + + ret = dev_check_flush(); + ret |= cpu_map_check_flush(); + ret |= xsk_map_check_flush(); + + WARN_ONCE(ret, "Missing xdp_do_flush() invocation after NAPI by %ps\n", + napi->poll); +} +#endif + void bpf_clear_redirect_map(struct bpf_map *map) { struct bpf_redirect_info *ri; |