From patchwork Fri Dec 8 00:52:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mina Almasry X-Patchwork-Id: 13484559 X-Patchwork-Delegate: kuba@kernel.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CARj6FzP" Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 673111988 for ; Thu, 7 Dec 2023 16:53:18 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5d988d69812so18524347b3.0 for ; Thu, 07 Dec 2023 16:53:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701996797; x=1702601597; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ffR5lRGBwRWz92voabMKfnUxOBX9ei9jc/R/TuPbdfY=; b=CARj6FzPCQ1sS6YCVmsJB2NuIjXU5lWVvtkUA/k/Ll427ms3YefKFgMH2SMQQf4uBm Y2ixiCLENlCGWmGmNRwE04NsaWWaoc4v0jHlbOrFkzgIyF6Pu+sLahVyJ5wZPPRlSi4L kLQRg9ZKrOYxNvgxMBRA/rmTJwWc4ML4fjSMjZRL50MXqbO50Ww/Kf4PZtBI4Q1sNKsS 7nI8xXGI/uXnpLQUYfGgpCCEL7LIrUJhauFjUzSAypMIPyixSiMFc2VlLXB8UKV9yYkX ZP3x0ifY9/bD9o8CH1cl3tnMc12Q65gmXLdDzgfdTONQe3SLK3C9tEsoS2nOSd2zRAxy g3Cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701996797; x=1702601597; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ffR5lRGBwRWz92voabMKfnUxOBX9ei9jc/R/TuPbdfY=; b=lvrcBH3tgPlCe58Lmds6CMElgfdrzGXBi9NvSw+UOKFSqgQcxPBy/TVltHLb+5oEYp 98evAi80K+CuEwKMTQdG7JSYIxrOoFH2mT1PmMQoGHGjj5rsKlRwgwuQ+qokzz6PCykg 3BSE64sX6ra01yEOKMLWe99NIVTpZ/OKchDKgzjWXKM7reIV1kgAGXQM3VfCghc5uPaI 23huseqxsPsRXP8WWpZv3Cb6e+zFWL4+HBMLLZU+JhDH/wU8/cEEB97pUonB8lYZXNjt Rk9KewLgefAU27pvGLcTO8TZ76Hfu86vej2WAwr3f8tRBf9D/vRPlP0FjVD+CU8BB6yo ndSg== X-Gm-Message-State: AOJu0Yx6HDc1T9aM2Pc6P59nGPrh532WPWw0ZltVz6411h0IO4IjlKw0 UXpYQWZ2kwAppklAGt4csbGwIIghvF75hQGqdg== X-Google-Smtp-Source: AGHT+IH8QZVgyP79RbEsqH0j0RL1Mpin9iL/UFr2+o7Otvdv7pJ6u3sBW0Y9+P6SJHsoq2x+yqVIWLpUXWuYkWSTkw== X-Received: from almasrymina.svl.corp.google.com ([2620:15c:2c4:200:f1cf:c733:235b:9fff]) (user=almasrymina job=sendgmr) by 2002:a25:ccd5:0:b0:daf:6333:17c3 with SMTP id l204-20020a25ccd5000000b00daf633317c3mr42079ybf.1.1701996797568; Thu, 07 Dec 2023 16:53:17 -0800 (PST) Date: Thu, 7 Dec 2023 16:52:42 -0800 In-Reply-To: <20231208005250.2910004-1-almasrymina@google.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231208005250.2910004-1-almasrymina@google.com> X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog Message-ID: <20231208005250.2910004-12-almasrymina@google.com> Subject: [net-next v1 11/16] net: support non paged skb frags From: Mina Almasry To: Shailend Chand , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: Mina Almasry , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jonathan Corbet , Jeroen de Borst , Praveen Kaligineedi , Jesper Dangaard Brouer , Ilias Apalodimas , Arnd Bergmann , David Ahern , Willem de Bruijn , Shuah Khan , Sumit Semwal , " =?utf-8?q?Christian_K=C3=B6nig?= " , Yunsheng Lin , Harshitha Ramamurthy , Shakeel Butt X-Patchwork-Delegate: kuba@kernel.org Make skb_frag_page() fail in the case where the frag is not backed by a page, and fix its relevant callers to handle this case. Correctly handle skb_frag refcounting in the page_pool_iovs case. Signed-off-by: Mina Almasry --- Changes in v1: - Fix illegal_highdma() (Yunsheng). - Rework napi_pp_put_page() slightly to reduce code churn (Willem). --- include/linux/skbuff.h | 42 +++++++++++++++++++++++++++++++++++------- net/core/dev.c | 3 ++- net/core/gro.c | 2 +- net/core/skbuff.c | 3 +++ net/ipv4/tcp.c | 3 +++ 5 files changed, 44 insertions(+), 9 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index b370eb8d70f7..851f448d2181 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -37,6 +37,8 @@ #endif #include #include +#include +#include /** * DOC: skb checksums @@ -3414,15 +3416,38 @@ static inline void skb_frag_off_copy(skb_frag_t *fragto, fragto->bv_offset = fragfrom->bv_offset; } +/* Returns true if the skb_frag contains a page_pool_iov. */ +static inline bool skb_frag_is_page_pool_iov(const skb_frag_t *frag) +{ + return page_is_page_pool_iov(frag->bv_page); +} + /** * skb_frag_page - retrieve the page referred to by a paged fragment * @frag: the paged fragment * - * Returns the &struct page associated with @frag. + * Returns the &struct page associated with @frag. Returns NULL if this frag + * has no associated page. */ static inline struct page *skb_frag_page(const skb_frag_t *frag) { - return frag->bv_page; + if (!page_is_page_pool_iov(frag->bv_page)) + return frag->bv_page; + + return NULL; +} + +/** + * skb_frag_page_pool_iov - retrieve the page_pool_iov referred to by fragment + * @frag: the fragment + * + * Returns the &struct page_pool_iov associated with @frag. Returns NULL if this + * frag has no associated page_pool_iov. + */ +static inline struct page_pool_iov * +skb_frag_page_pool_iov(const skb_frag_t *frag) +{ + return page_to_page_pool_iov(frag->bv_page); } /** @@ -3433,7 +3458,7 @@ static inline struct page *skb_frag_page(const skb_frag_t *frag) */ static inline void __skb_frag_ref(skb_frag_t *frag) { - get_page(skb_frag_page(frag)); + page_pool_page_get_many(frag->bv_page, 1); } /** @@ -3453,13 +3478,13 @@ bool napi_pp_put_page(struct page *page, bool napi_safe); static inline void napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe) { - struct page *page = skb_frag_page(frag); - #ifdef CONFIG_PAGE_POOL - if (recycle && napi_pp_put_page(page, napi_safe)) + if (recycle && napi_pp_put_page(frag->bv_page, napi_safe)) return; + page_pool_page_put_many(frag->bv_page, 1); +#else + put_page(skb_frag_page(frag)); #endif - put_page(page); } /** @@ -3499,6 +3524,9 @@ static inline void skb_frag_unref(struct sk_buff *skb, int f) */ static inline void *skb_frag_address(const skb_frag_t *frag) { + if (!skb_frag_page(frag)) + return NULL; + return page_address(skb_frag_page(frag)) + skb_frag_off(frag); } diff --git a/net/core/dev.c b/net/core/dev.c index 30667e4c3b95..1ae9257df441 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3709,8 +3709,9 @@ static int illegal_highdma(struct net_device *dev, struct sk_buff *skb) if (!(dev->features & NETIF_F_HIGHDMA)) { for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + struct page *page = skb_frag_page(frag); - if (PageHighMem(skb_frag_page(frag))) + if (page && PageHighMem(page)) return 1; } } diff --git a/net/core/gro.c b/net/core/gro.c index 0759277dc14e..42d7f6755f32 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -376,7 +376,7 @@ static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff) NAPI_GRO_CB(skb)->frag0 = NULL; NAPI_GRO_CB(skb)->frag0_len = 0; - if (!skb_headlen(skb) && pinfo->nr_frags && + if (!skb_headlen(skb) && pinfo->nr_frags && skb_frag_page(frag0) && !PageHighMem(skb_frag_page(frag0)) && (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) { NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 07f802f1adf1..2ce64f57a0f6 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2999,6 +2999,9 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; + if (WARN_ON_ONCE(!skb_frag_page(f))) + return false; + if (__splice_segment(skb_frag_page(f), skb_frag_off(f), skb_frag_size(f), offset, len, spd, false, sk, pipe)) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 70a1bafbefba..e22681c4bfac 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2157,6 +2157,9 @@ static int tcp_zerocopy_receive(struct sock *sk, break; } page = skb_frag_page(frags); + if (WARN_ON_ONCE(!page)) + break; + prefetchw(page); pages[pages_to_map++] = page; length += PAGE_SIZE;