Date: Thu, 14 Apr 2022 18:01:23 GMT From: "Bjoern A. Zeeb" <bz@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 48e84cceac14 - stable/13 - LinuxKPI: skbuff: handle dev_alloc_skb() correctly Message-ID: <202204141801.23EI1N1s015919@gitrepo.freebsd.org>
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The branch stable/13 has been updated by bz: URL: https://cgit.FreeBSD.org/src/commit/?id=48e84cceac14038ae1f9a51bc28f305a29f04af7 commit 48e84cceac14038ae1f9a51bc28f305a29f04af7 Author: Bjoern A. Zeeb <bz@FreeBSD.org> AuthorDate: 2022-04-07 18:06:55 +0000 Commit: Bjoern A. Zeeb <bz@FreeBSD.org> CommitDate: 2022-04-14 16:38:01 +0000 LinuxKPI: skbuff: handle dev_alloc_skb() correctly dev_alloc_skb() comapred to alloc_skb() reserves some headroom at the beginning of the skb which is used by drivers. Split the code for the two cases and reserve NET_SKB_PAD space, which should at least be 32 octets. Sponsored by: The FreeBSD Foundation (cherry picked from commit 9df5f29caf1a818999d0e908cab95c83bd1f4323) --- sys/compat/linuxkpi/common/include/linux/skbuff.h | 8 +++++--- sys/compat/linuxkpi/common/src/linux_skbuff.c | 21 +++++++++++++++++++-- 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/sys/compat/linuxkpi/common/include/linux/skbuff.h b/sys/compat/linuxkpi/common/include/linux/skbuff.h index 21ea7ee560e2..79d65c0169b3 100644 --- a/sys/compat/linuxkpi/common/include/linux/skbuff.h +++ b/sys/compat/linuxkpi/common/include/linux/skbuff.h @@ -38,6 +38,7 @@ #ifndef _LINUXKPI_LINUX_SKBUFF_H #define _LINUXKPI_LINUX_SKBUFF_H +#include <linux/kernel.h> #include <linux/page.h> #include <linux/dma-mapping.h> #include <linux/netdev_features.h> @@ -84,7 +85,7 @@ enum sk_buff_pkt_type { PACKET_OTHERHOST, }; -#define NET_SKB_PAD CACHE_LINE_SIZE /* ? */ +#define NET_SKB_PAD max(CACHE_LINE_SIZE, 32) struct sk_buff_head { /* XXX TODO */ @@ -168,6 +169,7 @@ struct sk_buff { /* -------------------------------------------------------------------------- */ struct sk_buff *linuxkpi_alloc_skb(size_t, gfp_t); +struct sk_buff *linuxkpi_dev_alloc_skb(size_t, gfp_t); void linuxkpi_kfree_skb(struct sk_buff *); /* -------------------------------------------------------------------------- */ @@ -187,7 +189,7 @@ __dev_alloc_skb(size_t len, gfp_t gfp) { struct sk_buff *skb; - skb = alloc_skb(len, gfp); + skb = linuxkpi_dev_alloc_skb(len, gfp); SKB_IMPROVE(); SKB_TRACE(skb); return (skb); @@ -198,7 +200,7 @@ dev_alloc_skb(size_t len) { struct sk_buff *skb; - skb = alloc_skb(len, GFP_NOWAIT); + skb = __dev_alloc_skb(len, GFP_NOWAIT); SKB_IMPROVE(); SKB_TRACE(skb); return (skb); diff --git a/sys/compat/linuxkpi/common/src/linux_skbuff.c b/sys/compat/linuxkpi/common/src/linux_skbuff.c index efb97fa2f126..dfa9dfb2ceb4 100644 --- a/sys/compat/linuxkpi/common/src/linux_skbuff.c +++ b/sys/compat/linuxkpi/common/src/linux_skbuff.c @@ -80,7 +80,7 @@ linuxkpi_alloc_skb(size_t size, gfp_t gfp) skb = malloc(len, M_LKPISKB, linux_check_m_flags(gfp) | M_ZERO); if (skb == NULL) return (skb); - skb->_alloc_len = size; + skb->_alloc_len = len; skb->truesize = size; skb->head = skb->data = skb->tail = (uint8_t *)(skb+1); @@ -90,7 +90,24 @@ linuxkpi_alloc_skb(size_t size, gfp_t gfp) skb->shinfo = (struct skb_shared_info *)(skb->end); - SKB_TRACE_FMT(skb, "data %p size %zu", skb->data, size); + SKB_TRACE_FMT(skb, "data %p size %zu", (skb) ? skb->data : NULL, size); + return (skb); +} + +struct sk_buff * +linuxkpi_dev_alloc_skb(size_t size, gfp_t gfp) +{ + struct sk_buff *skb; + size_t len; + + len = size + NET_SKB_PAD; + skb = linuxkpi_alloc_skb(len, gfp); + + if (skb != NULL) + skb_reserve(skb, NET_SKB_PAD); + + SKB_TRACE_FMT(skb, "data %p size %zu len %zu", + (skb) ? skb->data : NULL, size, len); return (skb); }
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