linux-toradex.git/net/packet, branch v6.4-rc1 Linux kernel for Apalis and Colibri modules af_packet: Don't send zero-byte data in packet_sendmsg_spkt(). 2023-05-03T08:20:18+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2023-05-01T20:28:57+00:00 6a341729fb31b4c5df9f74f24b4b1c98410c9b87 syzkaller reported a warning below [0]. We can reproduce it by sending 0-byte data from the (AF_PACKET, SOCK_PACKET) socket via some devices whose dev->hard_header_len is 0. struct sockaddr_pkt addr = { .spkt_family = AF_PACKET, .spkt_device = "tun0", }; int fd; fd = socket(AF_PACKET, SOCK_PACKET, 0); sendto(fd, NULL, 0, 0, (struct sockaddr *)&addr, sizeof(addr)); We have a similar fix for the (AF_PACKET, SOCK_RAW) socket as commit dc633700f00f ("net/af_packet: check len when min_header_len equals to 0"). Let's add the same test for the SOCK_PACKET socket. [0]: skb_assert_len WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 skb_assert_len include/linux/skbuff.h:2552 [inline] WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 __dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159 Modules linked in: CPU: 1 PID: 19945 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:skb_assert_len include/linux/skbuff.h:2552 [inline] RIP: 0010:__dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159 Code: 89 de e8 1d a2 85 fd 84 db 75 21 e8 64 a9 85 fd 48 c7 c6 80 2a 1f 86 48 c7 c7 c0 06 1f 86 c6 05 23 cf 27 04 01 e8 fa ee 56 fd <0f> 0b e8 43 a9 85 fd 0f b6 1d 0f cf 27 04 31 ff 89 de e8 e3 a1 85 RSP: 0018:ffff8880217af6e0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90001133000 RDX: 0000000000040000 RSI: ffffffff81186922 RDI: 0000000000000001 RBP: ffff8880217af8b0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888030045640 R13: ffff8880300456b0 R14: ffff888030045650 R15: ffff888030045718 FS: 00007fc5864da640(0000) GS:ffff88806cd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020005740 CR3: 000000003f856003 CR4: 0000000000770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> dev_queue_xmit include/linux/netdevice.h:3085 [inline] packet_sendmsg_spkt+0xc4b/0x1230 net/packet/af_packet.c:2066 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0x1b4/0x200 net/socket.c:747 ____sys_sendmsg+0x331/0x970 net/socket.c:2503 ___sys_sendmsg+0x11d/0x1c0 net/socket.c:2557 __sys_sendmmsg+0x18c/0x430 net/socket.c:2643 __do_sys_sendmmsg net/socket.c:2672 [inline] __se_sys_sendmmsg net/socket.c:2669 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7fc58791de5d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48 RSP: 002b:00007fc5864d9cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007fc58791de5d RDX: 0000000000000001 RSI: 0000000020005740 RDI: 0000000000000004 RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc58797e530 R15: 0000000000000000 </TASK> ---[ end trace 0000000000000000 ]--- skb len=0 headroom=16 headlen=0 tailroom=304 mac=(16,0) net=(16,-1) trans=-1 shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0)) csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0) hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0 dev name=sit0 feat=0x00000006401d7869 sk family=17 type=10 proto=0 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
syzkaller reported a warning below [0].

We can reproduce it by sending 0-byte data from the (AF_PACKET,
SOCK_PACKET) socket via some devices whose dev->hard_header_len
is 0.

    struct sockaddr_pkt addr = {
        .spkt_family = AF_PACKET,
        .spkt_device = "tun0",
    };
    int fd;

    fd = socket(AF_PACKET, SOCK_PACKET, 0);
    sendto(fd, NULL, 0, 0, (struct sockaddr *)&addr, sizeof(addr));

We have a similar fix for the (AF_PACKET, SOCK_RAW) socket as
commit dc633700f00f ("net/af_packet: check len when min_header_len
equals to 0").

Let's add the same test for the SOCK_PACKET socket.

[0]:
skb_assert_len
WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 skb_assert_len include/linux/skbuff.h:2552 [inline]
WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 __dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159
Modules linked in:
CPU: 1 PID: 19945 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:skb_assert_len include/linux/skbuff.h:2552 [inline]
RIP: 0010:__dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159
Code: 89 de e8 1d a2 85 fd 84 db 75 21 e8 64 a9 85 fd 48 c7 c6 80 2a 1f 86 48 c7 c7 c0 06 1f 86 c6 05 23 cf 27 04 01 e8 fa ee 56 fd <0f> 0b e8 43 a9 85 fd 0f b6 1d 0f cf 27 04 31 ff 89 de e8 e3 a1 85
RSP: 0018:ffff8880217af6e0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90001133000
RDX: 0000000000040000 RSI: ffffffff81186922 RDI: 0000000000000001
RBP: ffff8880217af8b0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888030045640
R13: ffff8880300456b0 R14: ffff888030045650 R15: ffff888030045718
FS:  00007fc5864da640(0000) GS:ffff88806cd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005740 CR3: 000000003f856003 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 dev_queue_xmit include/linux/netdevice.h:3085 [inline]
 packet_sendmsg_spkt+0xc4b/0x1230 net/packet/af_packet.c:2066
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0x1b4/0x200 net/socket.c:747
 ____sys_sendmsg+0x331/0x970 net/socket.c:2503
 ___sys_sendmsg+0x11d/0x1c0 net/socket.c:2557
 __sys_sendmmsg+0x18c/0x430 net/socket.c:2643
 __do_sys_sendmmsg net/socket.c:2672 [inline]
 __se_sys_sendmmsg net/socket.c:2669 [inline]
 __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2669
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fc58791de5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007fc5864d9cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007fc58791de5d
RDX: 0000000000000001 RSI: 0000000020005740 RDI: 0000000000000004
RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fc58797e530 R15: 0000000000000000
 </TASK>
---[ end trace 0000000000000000 ]---
skb len=0 headroom=16 headlen=0 tailroom=304
mac=(16,0) net=(16,-1) trans=-1
shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0)
hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0
dev name=sit0 feat=0x00000006401d7869
sk family=17 type=10 proto=0

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/packet: support mergeable feature of virtio 2023-04-21T11:01:58+00:00 Jianfeng Tan henry.tjf@antgroup.com 2023-04-19T07:24:16+00:00 dfc39d4026fb2432363c0f77543c4cf3adca4c7b Packet sockets, like tap, can be used as the backend for kernel vhost. In packet sockets, virtio net header size is currently hardcoded to be the size of struct virtio_net_hdr, which is 10 bytes; however, it is not always the case: some virtio features, such as mrg_rxbuf, need virtio net header to be 12-byte long. Mergeable buffers, as a virtio feature, is worthy of supporting: packets that are larger than one-mbuf size will be dropped in vhost worker's handle_rx if mrg_rxbuf feature is not used, but large packets cannot be avoided and increasing mbuf's size is not economical. With this virtio feature enabled by virtio-user, packet sockets with hardcoded 10-byte virtio net header will parse mac head incorrectly in packet_snd by taking the last two bytes of virtio net header as part of mac header. This incorrect mac header parsing will cause packet to be dropped due to invalid ether head checking in later under-layer device packet receiving. By adding extra field vnet_hdr_sz with utilizing holes in struct packet_sock to record currently used virtio net header size and supporting extra sockopt PACKET_VNET_HDR_SZ to set specified vnet_hdr_sz, packet sockets can know the exact length of virtio net header that virtio user gives. In packet_snd, tpacket_snd and packet_recvmsg, instead of using hardcoded virtio net header size, it can get the exact vnet_hdr_sz from corresponding packet_sock, and parse mac header correctly based on this information to avoid the packets being mistakenly dropped. Signed-off-by: Jianfeng Tan <henry.tjf@antgroup.com> Co-developed-by: Anqi Shen <amy.saq@antgroup.com> Signed-off-by: Anqi Shen <amy.saq@antgroup.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Packet sockets, like tap, can be used as the backend for kernel vhost.
In packet sockets, virtio net header size is currently hardcoded to be
the size of struct virtio_net_hdr, which is 10 bytes; however, it is not
always the case: some virtio features, such as mrg_rxbuf, need virtio
net header to be 12-byte long.

Mergeable buffers, as a virtio feature, is worthy of supporting: packets
that are larger than one-mbuf size will be dropped in vhost worker's
handle_rx if mrg_rxbuf feature is not used, but large packets
cannot be avoided and increasing mbuf's size is not economical.

With this virtio feature enabled by virtio-user, packet sockets with
hardcoded 10-byte virtio net header will parse mac head incorrectly in
packet_snd by taking the last two bytes of virtio net header as part of
mac header.
This incorrect mac header parsing will cause packet to be dropped due to
invalid ether head checking in later under-layer device packet receiving.

By adding extra field vnet_hdr_sz with utilizing holes in struct
packet_sock to record currently used virtio net header size and supporting
extra sockopt PACKET_VNET_HDR_SZ to set specified vnet_hdr_sz, packet
sockets can know the exact length of virtio net header that virtio user
gives.
In packet_snd, tpacket_snd and packet_recvmsg, instead of using
hardcoded virtio net header size, it can get the exact vnet_hdr_sz from
corresponding packet_sock, and parse mac header correctly based on this
information to avoid the packets being mistakenly dropped.

Signed-off-by: Jianfeng Tan <henry.tjf@antgroup.com>
Co-developed-by: Anqi Shen <amy.saq@antgroup.com>
Signed-off-by: Anqi Shen <amy.saq@antgroup.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: introduce a config option to tweak MAX_SKB_FRAGS 2023-03-28T02:29:22+00:00 Eric Dumazet edumazet@google.com 2023-03-23T16:28:42+00:00 3948b05950fdd64002a5f182c65ba5cf2d53cf71 Currently, MAX_SKB_FRAGS value is 17. For standard tcp sendmsg() traffic, no big deal because tcp_sendmsg() attempts order-3 allocations, stuffing 32768 bytes per frag. But with zero copy, we use order-0 pages. For BIG TCP to show its full potential, we add a config option to be able to fit up to 45 segments per skb. This is also needed for BIG TCP rx zerocopy, as zerocopy currently does not support skbs with frag list. We have used MAX_SKB_FRAGS=45 value for years at Google before we deployed 4K MTU, with no adverse effect, other than a recent issue in mlx4, fixed in commit 26782aad00cc ("net/mlx4: MLX4_TX_BOUNCE_BUFFER_SIZE depends on MAX_SKB_FRAGS") Back then, goal was to be able to receive full size (64KB) GRO packets without the frag_list overhead. Note that /proc/sys/net/core/max_skb_frags can also be used to limit the number of fragments TCP can use in tx packets. By default we keep the old/legacy value of 17 until we get more coverage for the updated values. Sizes of struct skb_shared_info on 64bit arches MAX_SKB_FRAGS | sizeof(struct skb_shared_info): ============================================== 17 320 21 320+64 = 384 25 320+128 = 448 29 320+192 = 512 33 320+256 = 576 37 320+320 = 640 41 320+384 = 704 45 320+448 = 768 This inflation might cause problems for drivers assuming they could pack both the incoming packet (for MTU=1500) and skb_shared_info in half a page, using build_skb(). v3: fix build error when CONFIG_NET=n v2: fix two build errors assuming MAX_SKB_FRAGS was "unsigned long" Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://lore.kernel.org/r/20230323162842.1935061-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Currently, MAX_SKB_FRAGS value is 17.

For standard tcp sendmsg() traffic, no big deal because tcp_sendmsg()
attempts order-3 allocations, stuffing 32768 bytes per frag.

But with zero copy, we use order-0 pages.

For BIG TCP to show its full potential, we add a config option
to be able to fit up to 45 segments per skb.

This is also needed for BIG TCP rx zerocopy, as zerocopy currently
does not support skbs with frag list.

We have used MAX_SKB_FRAGS=45 value for years at Google before
we deployed 4K MTU, with no adverse effect, other than
a recent issue in mlx4, fixed in commit 26782aad00cc
("net/mlx4: MLX4_TX_BOUNCE_BUFFER_SIZE depends on MAX_SKB_FRAGS")

Back then, goal was to be able to receive full size (64KB) GRO
packets without the frag_list overhead.

Note that /proc/sys/net/core/max_skb_frags can also be used to limit
the number of fragments TCP can use in tx packets.

By default we keep the old/legacy value of 17 until we get
more coverage for the updated values.

Sizes of struct skb_shared_info on 64bit arches

MAX_SKB_FRAGS | sizeof(struct skb_shared_info):
==============================================
         17     320
         21     320+64  = 384
         25     320+128 = 448
         29     320+192 = 512
         33     320+256 = 576
         37     320+320 = 640
         41     320+384 = 704
         45     320+448 = 768

This inflation might cause problems for drivers assuming they could pack
both the incoming packet (for MTU=1500) and skb_shared_info in half a page,
using build_skb().

v3: fix build error when CONFIG_NET=n
v2: fix two build errors assuming MAX_SKB_FRAGS was "unsigned long"

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20230323162842.1935061-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/packet: remove po->xmit 2023-03-19T10:57:54+00:00 Eric Dumazet edumazet@google.com 2023-03-17T16:20:02+00:00 105a201ebf3312990b96c4fbaade22e31402f8cc Use PACKET_SOCK_QDISC_BYPASS atomic bit instead of a pointer. This removes one indirect call in fast path, and READ_ONCE()/WRITE_ONCE() annotations as well. Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Willem de Bruijn <willemb@google.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Use PACKET_SOCK_QDISC_BYPASS atomic bit instead of a pointer.

This removes one indirect call in fast path,
and READ_ONCE()/WRITE_ONCE() annotations as well.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Willem de Bruijn <willemb@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
af_packet: preserve const qualifier in pkt_sk() 2023-03-18T12:23:33+00:00 Eric Dumazet edumazet@google.com 2023-03-17T15:55:31+00:00 68ac9a8b6e65c7cbbe96541353dab1b3f8de2043 We can change pkt_sk() to propagate const qualifier of its argument, thanks to container_of_const() This should avoid some potential errors caused by accidental (const -> not_const) promotion. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
We can change pkt_sk() to propagate const qualifier of its argument,
thanks to container_of_const()

This should avoid some potential errors caused by accidental
(const -> not_const) promotion.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/packet: convert po->pressure to an atomic flag 2023-03-17T08:52:06+00:00 Eric Dumazet edumazet@google.com 2023-03-16T01:10:14+00:00 791a3e9f1a86fe8eb09173c9788493b8b5c957f4 Not only this removes some READ_ONCE()/WRITE_ONCE(), this also removes one integer. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Not only this removes some READ_ONCE()/WRITE_ONCE(),
this also removes one integer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/packet: convert po->running to an atomic flag 2023-03-17T08:52:06+00:00 Eric Dumazet edumazet@google.com 2023-03-16T01:10:13+00:00 61edf479818e63978cabd243b82ca80f8948a313 Instead of consuming 32 bits for po->running, use one available bit in po->flags. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Instead of consuming 32 bits for po->running, use
one available bit in po->flags.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/packet: convert po->has_vnet_hdr to an atomic flag 2023-03-17T08:52:05+00:00 Eric Dumazet edumazet@google.com 2023-03-16T01:10:12+00:00 50d935eafee292fc432d5ac8c8715a6492961abc po->has_vnet_hdr can be read locklessly. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
po->has_vnet_hdr can be read locklessly.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/packet: convert po->tp_loss to an atomic flag 2023-03-17T08:52:05+00:00 Eric Dumazet edumazet@google.com 2023-03-16T01:10:11+00:00 164bddace2e03f6005e650cb88f101a66ebdc05a tp_loss can be read locklessly. Convert it to an atomic flag to avoid races. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
tp_loss can be read locklessly.

Convert it to an atomic flag to avoid races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/packet: convert po->tp_tx_has_off to an atomic flag 2023-03-17T08:52:05+00:00 Eric Dumazet edumazet@google.com 2023-03-16T01:10:10+00:00 7438344660fa55b33b8234c1797c886eb73667a7 This is to use existing space in po->flags, and reclaim the storage used by the non atomic bit fields. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This is to use existing space in po->flags, and reclaim
the storage used by the non atomic bit fields.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>