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Message-ID: <20240510232128.1105145-10-almasrymina@google.com>
Date: Fri, 10 May 2024 16:21:20 -0700
From: Mina Almasry <almasrymina@...gle.com>
To: netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-doc@...r.kernel.org, linux-alpha@...r.kernel.org,
linux-mips@...r.kernel.org, linux-parisc@...r.kernel.org,
sparclinux@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
linux-arch@...r.kernel.org, bpf@...r.kernel.org,
linux-kselftest@...r.kernel.org, linux-media@...r.kernel.org,
dri-devel@...ts.freedesktop.org
Cc: Mina Almasry <almasrymina@...gle.com>, Donald Hunter <donald.hunter@...il.com>,
Jakub Kicinski <kuba@...nel.org>, "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>,
Jonathan Corbet <corbet@....net>, Richard Henderson <richard.henderson@...aro.org>,
Ivan Kokshaysky <ink@...assic.park.msu.ru>, Matt Turner <mattst88@...il.com>,
Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
"James E.J. Bottomley" <James.Bottomley@...senPartnership.com>, Helge Deller <deller@....de>,
Andreas Larsson <andreas@...sler.com>, Jesper Dangaard Brouer <hawk@...nel.org>,
Ilias Apalodimas <ilias.apalodimas@...aro.org>, Steven Rostedt <rostedt@...dmis.org>,
Masami Hiramatsu <mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Arnd Bergmann <arnd@...db.de>, Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>,
Andrii Nakryiko <andrii@...nel.org>, Martin KaFai Lau <martin.lau@...ux.dev>,
Eduard Zingerman <eddyz87@...il.com>, Song Liu <song@...nel.org>,
Yonghong Song <yonghong.song@...ux.dev>, John Fastabend <john.fastabend@...il.com>,
KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...gle.com>, Hao Luo <haoluo@...gle.com>,
Jiri Olsa <jolsa@...nel.org>, Steffen Klassert <steffen.klassert@...unet.com>,
Herbert Xu <herbert@...dor.apana.org.au>, David Ahern <dsahern@...nel.org>,
Willem de Bruijn <willemdebruijn.kernel@...il.com>, Shuah Khan <shuah@...nel.org>,
Sumit Semwal <sumit.semwal@...aro.org>,
"Christian König" <christian.koenig@....com>, Pavel Begunkov <asml.silence@...il.com>,
David Wei <dw@...idwei.uk>, Jason Gunthorpe <jgg@...pe.ca>, Yunsheng Lin <linyunsheng@...wei.com>,
Shailend Chand <shailend@...gle.com>, Harshitha Ramamurthy <hramamurthy@...gle.com>,
Shakeel Butt <shakeel.butt@...ux.dev>, Jeroen de Borst <jeroendb@...gle.com>,
Praveen Kaligineedi <pkaligineedi@...gle.com>
Subject: [PATCH net-next v9 09/14] net: support non paged skb frags
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.
Signed-off-by: Mina Almasry <almasrymina@...gle.com>
---
v6:
- Rebased on top of the merged netmem changes.
Changes in v1:
- Fix illegal_highdma() (Yunsheng).
- Rework napi_pp_put_page() slightly to reduce code churn (Willem).
---
include/linux/skbuff.h | 42 +++++++++++++++++++++++++++++++++++++-
include/linux/skbuff_ref.h | 9 ++++----
net/core/dev.c | 3 ++-
net/core/gro.c | 3 ++-
net/core/skbuff.c | 11 ++++++++++
net/ipv4/esp4.c | 3 ++-
net/ipv4/tcp.c | 3 +++
net/ipv6/esp6.c | 3 ++-
8 files changed, 67 insertions(+), 10 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c0b97c93a6de0..0dcf1c5824415 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3490,21 +3490,58 @@ static inline void skb_frag_off_copy(skb_frag_t *fragto,
fragto->offset = fragfrom->offset;
}
+/* Returns true if the skb_frag contains a net_iov. */
+static inline bool skb_frag_is_net_iov(const skb_frag_t *frag)
+{
+ return netmem_is_net_iov(frag->netmem);
+}
+
+/**
+ * skb_frag_net_iov - retrieve the net_iov referred to by fragment
+ * @frag: the fragment
+ *
+ * Returns the &struct net_iov associated with @frag. Returns NULL if this
+ * frag has no associated net_iov.
+ */
+static inline struct net_iov *skb_frag_net_iov(const skb_frag_t *frag)
+{
+ if (!skb_frag_is_net_iov(frag))
+ return NULL;
+
+ return netmem_to_net_iov(frag->netmem);
+}
+
/**
* 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)
{
+ if (skb_frag_is_net_iov(frag))
+ return NULL;
+
return netmem_to_page(frag->netmem);
}
+/**
+ * skb_frag_netmem - retrieve the netmem referred to by a fragment
+ * @frag: the fragment
+ *
+ * Returns the &netmem_ref associated with @frag.
+ */
+static inline netmem_ref skb_frag_netmem(const skb_frag_t *frag)
+{
+ return frag->netmem;
+}
+
int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
unsigned int headroom);
int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
struct bpf_prog *prog);
+
/**
* skb_frag_address - gets the address of the data contained in a paged fragment
* @frag: the paged fragment buffer
@@ -3514,6 +3551,9 @@ int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
*/
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/include/linux/skbuff_ref.h b/include/linux/skbuff_ref.h
index 16c241a234728..0f3c58007488a 100644
--- a/include/linux/skbuff_ref.h
+++ b/include/linux/skbuff_ref.h
@@ -34,14 +34,13 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f)
bool napi_pp_put_page(netmem_ref netmem);
-static inline void
-skb_page_unref(struct page *page, bool recycle)
+static inline void skb_page_unref(netmem_ref netmem, bool recycle)
{
#ifdef CONFIG_PAGE_POOL
- if (recycle && napi_pp_put_page(page_to_netmem(page)))
+ if (recycle && napi_pp_put_page(netmem))
return;
#endif
- put_page(page);
+ put_page(netmem_to_page(netmem));
}
/**
@@ -54,7 +53,7 @@ skb_page_unref(struct page *page, bool recycle)
*/
static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
{
- skb_page_unref(skb_frag_page(frag), recycle);
+ skb_page_unref(skb_frag_netmem(frag), recycle);
}
/**
diff --git a/net/core/dev.c b/net/core/dev.c
index b879da266c1f3..704c434d8d60c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3433,8 +3433,9 @@ 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 e2f84947fb743..10fb2145bcb2b 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -410,7 +410,8 @@ static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
pinfo = skb_shinfo(skb);
frag0 = &pinfo->frags[0];
- if (pinfo->nr_frags && !PageHighMem(skb_frag_page(frag0)) &&
+ if (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);
NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 2e49a6ea21af3..99cf1ee73836d 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1352,6 +1352,14 @@ void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt)
struct page *p;
u8 *vaddr;
+ if (skb_frag_is_net_iov(frag)) {
+ printk("%sskb frag %d: not readable\n", level, i);
+ len -= skb_frag_size(frag);
+ if (!len)
+ break;
+ continue;
+ }
+
skb_frag_foreach_page(frag, skb_frag_off(frag),
skb_frag_size(frag), p, p_off, p_len,
copied) {
@@ -3142,6 +3150,9 @@ 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/esp4.c b/net/ipv4/esp4.c
index 3968d3f98e083..4ce0bc41e7806 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -115,7 +115,8 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb)
*/
if (req->src != req->dst)
for (sg = sg_next(req->src); sg; sg = sg_next(sg))
- skb_page_unref(sg_page(sg), skb->pp_recycle);
+ skb_page_unref(page_to_netmem(sg_page(sg)),
+ skb->pp_recycle);
}
#ifdef CONFIG_INET_ESPINTCP
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 06aab937d60a6..7e7f32f95c684 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2171,6 +2171,9 @@ 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;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 34a9a5b9ed00b..0318aea0d4ce6 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -132,7 +132,8 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb)
*/
if (req->src != req->dst)
for (sg = sg_next(req->src); sg; sg = sg_next(sg))
- skb_page_unref(sg_page(sg), skb->pp_recycle);
+ skb_page_unref(page_to_netmem(sg_page(sg)),
+ skb->pp_recycle);
}
#ifdef CONFIG_INET6_ESPINTCP
--
2.45.0.118.g7fe29c98d7-goog
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