diff options
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 231 |
1 files changed, 129 insertions, 102 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 6841e61a6bd0..6cbf77bc61fc 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -69,6 +69,7 @@ #include <net/dst.h> #include <net/sock.h> #include <net/checksum.h> +#include <net/gro.h> #include <net/gso.h> #include <net/hotdata.h> #include <net/ip6_checksum.h> @@ -95,7 +96,9 @@ static struct kmem_cache *skbuff_ext_cache __ro_after_init; #endif -#define SKB_SMALL_HEAD_SIZE SKB_HEAD_ALIGN(MAX_TCP_HEADER) +#define GRO_MAX_HEAD_PAD (GRO_MAX_HEAD + NET_SKB_PAD + NET_IP_ALIGN) +#define SKB_SMALL_HEAD_SIZE SKB_HEAD_ALIGN(max(MAX_TCP_HEADER, \ + GRO_MAX_HEAD_PAD)) /* We want SKB_SMALL_HEAD_CACHE_SIZE to not be a power of two. * This should ensure that SKB_SMALL_HEAD_HEADROOM is a unique @@ -220,67 +223,9 @@ static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr) #define NAPI_SKB_CACHE_BULK 16 #define NAPI_SKB_CACHE_HALF (NAPI_SKB_CACHE_SIZE / 2) -#if PAGE_SIZE == SZ_4K - -#define NAPI_HAS_SMALL_PAGE_FRAG 1 -#define NAPI_SMALL_PAGE_PFMEMALLOC(nc) ((nc).pfmemalloc) - -/* specialized page frag allocator using a single order 0 page - * and slicing it into 1K sized fragment. Constrained to systems - * with a very limited amount of 1K fragments fitting a single - * page - to avoid excessive truesize underestimation - */ - -struct page_frag_1k { - void *va; - u16 offset; - bool pfmemalloc; -}; - -static void *page_frag_alloc_1k(struct page_frag_1k *nc, gfp_t gfp) -{ - struct page *page; - int offset; - - offset = nc->offset - SZ_1K; - if (likely(offset >= 0)) - goto use_frag; - - page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); - if (!page) - return NULL; - - nc->va = page_address(page); - nc->pfmemalloc = page_is_pfmemalloc(page); - offset = PAGE_SIZE - SZ_1K; - page_ref_add(page, offset / SZ_1K); - -use_frag: - nc->offset = offset; - return nc->va + offset; -} -#else - -/* the small page is actually unused in this build; add dummy helpers - * to please the compiler and avoid later preprocessor's conditionals - */ -#define NAPI_HAS_SMALL_PAGE_FRAG 0 -#define NAPI_SMALL_PAGE_PFMEMALLOC(nc) false - -struct page_frag_1k { -}; - -static void *page_frag_alloc_1k(struct page_frag_1k *nc, gfp_t gfp_mask) -{ - return NULL; -} - -#endif - struct napi_alloc_cache { local_lock_t bh_lock; struct page_frag_cache page; - struct page_frag_1k page_small; unsigned int skb_count; void *skb_cache[NAPI_SKB_CACHE_SIZE]; }; @@ -290,23 +235,6 @@ static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache) = { .bh_lock = INIT_LOCAL_LOCK(bh_lock), }; -/* Double check that napi_get_frags() allocates skbs with - * skb->head being backed by slab, not a page fragment. - * This is to make sure bug fixed in 3226b158e67c - * ("net: avoid 32 x truesize under-estimation for tiny skbs") - * does not accidentally come back. - */ -void napi_get_frags_check(struct napi_struct *napi) -{ - struct sk_buff *skb; - - local_bh_disable(); - skb = napi_get_frags(napi); - WARN_ON_ONCE(!NAPI_HAS_SMALL_PAGE_FRAG && skb && skb->head_frag); - napi_free_frags(napi); - local_bh_enable(); -} - void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) { struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); @@ -367,6 +295,68 @@ static struct sk_buff *napi_skb_cache_get(void) return skb; } +/** + * napi_skb_cache_get_bulk - obtain a number of zeroed skb heads from the cache + * @skbs: pointer to an at least @n-sized array to fill with skb pointers + * @n: number of entries to provide + * + * Tries to obtain @n &sk_buff entries from the NAPI percpu cache and writes + * the pointers into the provided array @skbs. If there are less entries + * available, tries to replenish the cache and bulk-allocates the diff from + * the MM layer if needed. + * The heads are being zeroed with either memset() or %__GFP_ZERO, so they are + * ready for {,__}build_skb_around() and don't have any data buffers attached. + * Must be called *only* from the BH context. + * + * Return: number of successfully allocated skbs (@n if no actual allocation + * needed or kmem_cache_alloc_bulk() didn't fail). + */ +u32 napi_skb_cache_get_bulk(void **skbs, u32 n) +{ + struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + u32 bulk, total = n; + + local_lock_nested_bh(&napi_alloc_cache.bh_lock); + + if (nc->skb_count >= n) + goto get; + + /* No enough cached skbs. Try refilling the cache first */ + bulk = min(NAPI_SKB_CACHE_SIZE - nc->skb_count, NAPI_SKB_CACHE_BULK); + nc->skb_count += kmem_cache_alloc_bulk(net_hotdata.skbuff_cache, + GFP_ATOMIC | __GFP_NOWARN, bulk, + &nc->skb_cache[nc->skb_count]); + if (likely(nc->skb_count >= n)) + goto get; + + /* Still not enough. Bulk-allocate the missing part directly, zeroed */ + n -= kmem_cache_alloc_bulk(net_hotdata.skbuff_cache, + GFP_ATOMIC | __GFP_ZERO | __GFP_NOWARN, + n - nc->skb_count, &skbs[nc->skb_count]); + if (likely(nc->skb_count >= n)) + goto get; + + /* kmem_cache didn't allocate the number we need, limit the output */ + total -= n - nc->skb_count; + n = nc->skb_count; + +get: + for (u32 base = nc->skb_count - n, i = 0; i < n; i++) { + u32 cache_size = kmem_cache_size(net_hotdata.skbuff_cache); + + skbs[i] = nc->skb_cache[base + i]; + + kasan_mempool_unpoison_object(skbs[i], cache_size); + memset(skbs[i], 0, offsetof(struct sk_buff, tail)); + } + + nc->skb_count -= n; + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); + + return total; +} +EXPORT_SYMBOL_GPL(napi_skb_cache_get_bulk); + static inline void __finalize_skb_around(struct sk_buff *skb, void *data, unsigned int size) { @@ -736,7 +726,7 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, /* If requested length is either too small or too big, * we use kmalloc() for skb->head allocation. */ - if (len <= SKB_WITH_OVERHEAD(1024) || + if (len <= SKB_WITH_OVERHEAD(SKB_SMALL_HEAD_CACHE_SIZE) || len > SKB_WITH_OVERHEAD(PAGE_SIZE) || (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE); @@ -813,10 +803,8 @@ struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int len) /* If requested length is either too small or too big, * we use kmalloc() for skb->head allocation. - * When the small frag allocator is available, prefer it over kmalloc - * for small fragments */ - if ((!NAPI_HAS_SMALL_PAGE_FRAG && len <= SKB_WITH_OVERHEAD(1024)) || + if (len <= SKB_WITH_OVERHEAD(SKB_SMALL_HEAD_CACHE_SIZE) || len > SKB_WITH_OVERHEAD(PAGE_SIZE) || (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX | SKB_ALLOC_NAPI, @@ -826,32 +814,16 @@ struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int len) goto skb_success; } + len = SKB_HEAD_ALIGN(len); + if (sk_memalloc_socks()) gfp_mask |= __GFP_MEMALLOC; local_lock_nested_bh(&napi_alloc_cache.bh_lock); nc = this_cpu_ptr(&napi_alloc_cache); - if (NAPI_HAS_SMALL_PAGE_FRAG && len <= SKB_WITH_OVERHEAD(1024)) { - /* we are artificially inflating the allocation size, but - * that is not as bad as it may look like, as: - * - 'len' less than GRO_MAX_HEAD makes little sense - * - On most systems, larger 'len' values lead to fragment - * size above 512 bytes - * - kmalloc would use the kmalloc-1k slab for such values - * - Builds with smaller GRO_MAX_HEAD will very likely do - * little networking, as that implies no WiFi and no - * tunnels support, and 32 bits arches. - */ - len = SZ_1K; - - data = page_frag_alloc_1k(&nc->page_small, gfp_mask); - pfmemalloc = NAPI_SMALL_PAGE_PFMEMALLOC(nc->page_small); - } else { - len = SKB_HEAD_ALIGN(len); - data = page_frag_alloc(&nc->page, len, gfp_mask); - pfmemalloc = page_frag_cache_is_pfmemalloc(&nc->page); - } + data = page_frag_alloc(&nc->page, len, gfp_mask); + pfmemalloc = page_frag_cache_is_pfmemalloc(&nc->page); local_unlock_nested_bh(&napi_alloc_cache.bh_lock); if (unlikely(!data)) @@ -1009,7 +981,7 @@ int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, EXPORT_SYMBOL(skb_pp_cow_data); int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, - struct bpf_prog *prog) + const struct bpf_prog *prog) { if (!prog->aux->xdp_has_frags) return -EINVAL; @@ -5539,6 +5511,54 @@ err: } EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp); +static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb, + struct skb_shared_hwtstamps *hwtstamps, + int tstype) +{ + switch (tstype) { + case SCM_TSTAMP_SCHED: + return skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP; + case SCM_TSTAMP_SND: + return skb_shinfo(skb)->tx_flags & (hwtstamps ? SKBTX_HW_TSTAMP_NOBPF : + SKBTX_SW_TSTAMP); + case SCM_TSTAMP_ACK: + return TCP_SKB_CB(skb)->txstamp_ack & TSTAMP_ACK_SK; + case SCM_TSTAMP_COMPLETION: + return skb_shinfo(skb)->tx_flags & SKBTX_COMPLETION_TSTAMP; + } + + return false; +} + +static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb, + struct skb_shared_hwtstamps *hwtstamps, + struct sock *sk, + int tstype) +{ + int op; + + switch (tstype) { + case SCM_TSTAMP_SCHED: + op = BPF_SOCK_OPS_TSTAMP_SCHED_CB; + break; + case SCM_TSTAMP_SND: + if (hwtstamps) { + op = BPF_SOCK_OPS_TSTAMP_SND_HW_CB; + *skb_hwtstamps(skb) = *hwtstamps; + } else { + op = BPF_SOCK_OPS_TSTAMP_SND_SW_CB; + } + break; + case SCM_TSTAMP_ACK: + op = BPF_SOCK_OPS_TSTAMP_ACK_CB; + break; + default: + return; + } + + bpf_skops_tx_timestamping(sk, skb, op); +} + void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb, struct skb_shared_hwtstamps *hwtstamps, @@ -5551,6 +5571,13 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, if (!sk) return; + if (skb_shinfo(orig_skb)->tx_flags & SKBTX_BPF) + skb_tstamp_tx_report_bpf_timestamping(orig_skb, hwtstamps, + sk, tstype); + + if (!skb_tstamp_tx_report_so_timestamping(orig_skb, hwtstamps, tstype)) + return; + tsflags = READ_ONCE(sk->sk_tsflags); if (!hwtstamps && !(tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) && skb_shinfo(orig_skb)->tx_flags & SKBTX_IN_PROGRESS) @@ -6123,11 +6150,11 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet) skb->offload_fwd_mark = 0; skb->offload_l3_fwd_mark = 0; #endif + ipvs_reset(skb); if (!xnet) return; - ipvs_reset(skb); skb->mark = 0; skb_clear_tstamp(skb); } |