When CONFIG_BPF_LSM is not configured, running bpf selftesting will show
BPF_F_BPRM_SECUREEXEC undefined error for bprm_opts.c.

The problem is that bprm_opts.c includes vmliunx.h. The vmlinux.h is
generated by "bpftool btf dump file ./vmlinux format c". On the other
hand, BPF_F_BPRM_SECUREEXEC is defined in include/uapi/linux/bpf.h
and used only in bpf_lsm.c. When CONFIG_BPF_LSM is not set, bpf_lsm
will not be compiled, so vmlinux.h will not include definition of
BPF_F_BPRM_SECUREEXEC.

Ideally, we want to compile bpf selftest regardless of the configuration
setting, so change the include file from vmlinux.h to bpf.h.
Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20201224011242.585967-1-jiang.wang@bytedance.com

Daniel Borkmann says:

====================
pull-request: bpf 2020-12-28

The following pull-request contains BPF updates for your *net* tree.

There is a small merge conflict between bpf tree commit 69ca310f
("bpf: Save correct stopping point in file seq iteration") and net tree
commit 66ed5944 ("bpf/task_iter: In task_file_seq_get_next use
task_lookup_next_fd_rcu"). The get_files_struct() does not exist anymore
in net, so take the hunk in HEAD and add the `info->tid = curr_tid` to
the error path:

  [...]
                curr_task = task_seq_get_next(ns, &curr_tid, true);
                if (!curr_task) {
                        info->task = NULL;
                        info->tid = curr_tid;
                        return NULL;
                }

                /* set info->task and info->tid */
  [...]

We've added 10 non-merge commits during the last 9 day(s) which contain
a total of 11 files changed, 75 insertions(+), 20 deletions(-).

The main changes are:

1) Various AF_XDP fixes such as fill/completion ring leak on failed bind and
   fixing a race in skb mode's backpressure mechanism, from Magnus Karlsson.

2) Fix latency spikes on lockdep enabled kernels by adding a rescheduling
   point to BPF hashtab initialization, from Eric Dumazet.

3) Fix a splat in task iterator by saving the correct stopping point in the
   seq file iteration, from Jonathan Lemon.

4) Fix BPF maps selftest by adding retries in case hashtab returns EBUSY
   errors on update/deletes, from Andrii Nakryiko.

5) Fix BPF selftest error reporting to something more user friendly if the
   vmlinux BTF cannot be found, from Kamal Mostafa.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

ppp_cp_event is called directly or indirectly by ppp_rx with "ppp->lock"
held. It may call mod_timer to add a new timer. However, at the same time
ppp_timer may be already running and waiting for "ppp->lock". In this
case, there's no need for ppp_timer to continue running and it can just
exit.

If we let ppp_timer continue running, it may call add_timer. This causes
kernel panic because add_timer can't be called with a timer pending.
This patch fixes this problem.

Fixes: e022c2f0 ("WAN: new synchronous PPP implementation for generic HDLC.")
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This was tested on a RaptorCS Talos II with IBM POWER9 DD2.2 CPUs and an
ASUS XG-C100F PCI-e card without any issue. Speeds of ~8Gbps could be
attained with not-very-scientific (wget HTTP) both-ways measurements on
a local network. No warning or error reported in kernel logs. The
drivers seems to be portable enough for it not to be gated like such.
Signed-off-by: Léo Le Bouter <lle-bout@zaclys.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Both version 0 and version 1 use ETH_P_ERSPAN, but version 0 does not
have an erspan header. So the check in gre_parse_header() is wrong,
we have to distinguish version 1 from version 0.

We can just check the gre header length like is_erspan_type1().

Fixes: cb73ee40 ("net: ip_gre: use erspan key field for tunnel lookup")
Reported-by: syzbot+f583ce3d4ddf9836b27a@syzkaller.appspotmail.com
Cc: William Tu <u9012063@gmail.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function skb_copy() could return NULL, the return value
need to be checked.

Fixes: b5996f11 ("net: add Hisilicon Network Subsystem basic ethernet support")
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Check Scell_log shift size in red_check_params() and modify all callers
of red_check_params() to pass Scell_log.

This prevents a shift out-of-bounds as detected by UBSAN:
  UBSAN: shift-out-of-bounds in ./include/net/red.h:252:22
  shift exponent 72 is too large for 32-bit type 'int'

Fixes: 8afa10cb ("net_sched: red: Avoid illegal values")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: syzbot+97c5bd9cc81eca63d36e@syzkaller.appspotmail.com
Cc: Nogah Frankel <nogahf@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

pneigh_enqueue() tries to obtain a random delay by mod
NEIGH_VAR(p, PROXY_DELAY). However, NEIGH_VAR(p, PROXY_DELAY)
migth be zero at that point because someone could write zero
to /proc/sys/net/ipv4/neigh/[device]/proxy_delay after the
callers check it.

This patch uses prandom_u32_max() to get a random delay instead
which avoids potential division by zero.
Signed-off-by: weichenchen <weichen.chen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RT_TOS() only clears one of the ECN bits. Therefore, when
fib_compute_spec_dst() resorts to a fib lookup, it can return
different results depending on the value of the second ECN bit.

For example, ECT(0) and ECT(1) packets could be treated differently.

  $ ip netns add ns0
  $ ip netns add ns1
  $ ip link add name veth01 netns ns0 type veth peer name veth10 netns ns1
  $ ip -netns ns0 link set dev lo up
  $ ip -netns ns1 link set dev lo up
  $ ip -netns ns0 link set dev veth01 up
  $ ip -netns ns1 link set dev veth10 up

  $ ip -netns ns0 address add 192.0.2.10/24 dev veth01
  $ ip -netns ns1 address add 192.0.2.11/24 dev veth10

  $ ip -netns ns1 address add 192.0.2.21/32 dev lo
  $ ip -netns ns1 route add 192.0.2.10/32 tos 4 dev veth10 src 192.0.2.21
  $ ip netns exec ns1 sysctl -wq net.ipv4.icmp_echo_ignore_broadcasts=0

With TOS 4 and ECT(1), ns1 replies using source address 192.0.2.21
(ping uses -Q to set all TOS and ECN bits):

  $ ip netns exec ns0 ping -c 1 -b -Q 5 192.0.2.255
  [...]
  64 bytes from 192.0.2.21: icmp_seq=1 ttl=64 time=0.544 ms

But with TOS 4 and ECT(0), ns1 replies using source address 192.0.2.11
because the "tos 4" route isn't matched:

  $ ip netns exec ns0 ping -c 1 -b -Q 6 192.0.2.255
  [...]
  64 bytes from 192.0.2.11: icmp_seq=1 ttl=64 time=0.597 ms

After this patch the ECN bits don't affect the result anymore:

  $ ip netns exec ns0 ping -c 1 -b -Q 6 192.0.2.255
  [...]
  64 bytes from 192.0.2.21: icmp_seq=1 ttl=64 time=0.591 ms

Fixes: 35ebf65e ("ipv4: Create and use fib_compute_spec_dst() helper.")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The packet coalescing interrupt threshold has separated registers
for different aggregated/cpu (sw-thread). The required value should
be loaded for every thread but not only for 1 current cpu.

Fixes: 213f428f ("net: mvpp2: add support for TX interrupts and RX queue distribution modes")
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Link: https://lore.kernel.org/r/1608748521-11033-1-git-send-email-stefanc@marvell.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Alex Elder says:

====================
net: ipa: fix some new build warnings

I got a super friendly message from the Intel kernel test robot that
pointed out that two patches I posted last week caused new build
warnings.  I already had these problems fixed in my own tree but
the fix was not included in what I sent out last week.
====================

Link: https://lore.kernel.org/r/20201226213737.338928-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Callers of evt_ring_command() no longer care whether the command
times out, and don't use what evt_ring_command() returns.  Redefine
that function to have void return type.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 428b448e ("net: ipa: use state to determine event ring command success")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Callers of gsi_channel_command() no longer care whether the command
times out, and don't use what gsi_channel_command() returns.  Redefine
that function to have void return type.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 6ffddf3b ("net: ipa: use state to determine channel command success")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Michael Chan says:

====================
bnxt_en: Bug fixes.

The first patch fixes recovery of fatal AER errors.  The second one
fixes a potential array out of bounds issue.
====================

Link: https://lore.kernel.org/r/1609096698-15009-1-git-send-email-michael.chan@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

TQM rings are hardware resources that require host context memory
managed by the driver.  The driver supports up to 9 TQM rings and
the number of rings to use is requested by firmware during run-time.
Cap this number to the maximum supported to prevent accessing beyond
the array.  Future firmware may request more than 9 TQM rings.  Define
macros to remove the magic number 9 from the C code.

Fixes: ac3158cb ("bnxt_en: Allocate TQM ring context memory according to fw specification.")
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

A recent change skips sending firmware messages to the firmware when
pci_channel_offline() is true during fatal AER error.  To make this
complete, we need to move the re-initialization sequence to
bnxt_io_resume(), otherwise the firmware messages to re-initialize
will all be skipped.  In any case, it is more correct to re-initialize
in bnxt_io_resume().

Also, fix the reverse x-mas tree format when defining variables
in bnxt_io_slot_reset().

Fixes: b340dc68 ("bnxt_en: Avoid sending firmware messages when AER error is detected.")
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Tony Nguyen says:

====================
Intel Wired LAN Driver Updates 2020-12-23

Commit e086ba2f ("e1000e: disable s0ix entry and exit flows for ME
systems") disabled S0ix flows for systems that have various incarnations of
the i219-LM ethernet controller.  This was done because of some regressions
caused by an earlier commit 632fbd5e ("e1000e: fix S0ix flows for
cable connected case") with i219-LM controller.

Per discussion with Intel architecture team this direction should be
changed and allow S0ix flows to be used by default.  This patch series
includes directional changes for their conclusions in
https://lkml.org/lkml/2020/12/13/15.

* '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue:
  e1000e: Export S0ix flags to ethtool
  Revert "e1000e: disable s0ix entry and exit flows for ME systems"
  e1000e: bump up timeout to wait when ME un-configures ULP mode
  e1000e: Only run S0ix flows if shutdown succeeded
====================

Link: https://lore.kernel.org/r/20201223233625.92519-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

the following syzkaller reproducer:

 r0 = socket$inet_mptcp(0x2, 0x1, 0x106)
 bind$inet(r0, &(0x7f0000000080)={0x2, 0x4e24, @multicast2}, 0x10)
 connect$inet(r0, &(0x7f0000000480)={0x2, 0x4e24, @local}, 0x10)
 sendto$inet(r0, &(0x7f0000000100)="f6", 0xffffffe7, 0xc000, 0x0, 0x0)

systematically triggers the following warning:

 WARNING: CPU: 2 PID: 8618 at net/core/stream.c:208 sk_stream_kill_queues+0x3fa/0x580
 Modules linked in:
 CPU: 2 PID: 8618 Comm: syz-executor Not tainted 5.10.0+ #334
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/04
 RIP: 0010:sk_stream_kill_queues+0x3fa/0x580
 Code: df 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 40 8b ab 20 02 00 00 e9 64 ff ff ff e8 df f0 81 2
 RSP: 0018:ffffc9000290fcb0 EFLAGS: 00010293
 RAX: ffff888011cb8000 RBX: 0000000000000000 RCX: ffffffff86eecf0e
 RDX: 0000000000000000 RSI: ffffffff86eecf6a RDI: 0000000000000005
 RBP: 0000000000000e28 R08: ffff888011cb8000 R09: fffffbfff1f48139
 R10: ffffffff8fa409c7 R11: fffffbfff1f48138 R12: ffff8880215e6220
 R13: ffffffff8fa409c0 R14: ffffc9000290fd30 R15: 1ffff92000521fa2
 FS:  00007f41c78f4800(0000) GS:ffff88802d000000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f95c803d088 CR3: 0000000025ed2000 CR4: 00000000000006f0
 Call Trace:
  __mptcp_destroy_sock+0x4f5/0x8e0
   mptcp_close+0x5e2/0x7f0
  inet_release+0x12b/0x270
  __sock_release+0xc8/0x270
  sock_close+0x18/0x20
  __fput+0x272/0x8e0
  task_work_run+0xe0/0x1a0
  exit_to_user_mode_prepare+0x1df/0x200
  syscall_exit_to_user_mode+0x19/0x50
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

userspace programs provide arbitrarily high values of 'len' in sendmsg():
this is causing integer overflow of 'amount'. Cap forward allocation to 1
megabyte: higher values are not really useful.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Fixes: e93da928 ("mptcp: implement wmem reservation")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/3334d00d8b2faecafdfab9aa593efcbf61442756.1608584474.git.dcaratti@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Currently the tun_napi_alloc_frags() function returns -ENOMEM when the
number of iovs exceeds MAX_SKB_FRAGS + 1. However this is inappropriate,
we should use -EMSGSIZE instead of -ENOMEM.

The following distinctions are matters:
1. the caller need to drop the bad packet when -EMSGSIZE is returned,
   which means meeting a persistent failure.
2. the caller can try again when -ENOMEM is returned, which means
   meeting a transient failure.

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/1608864736-24332-1-git-send-email-wangyunjian@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The CPTS driver registers PTP PHC clock when first netif is going up and
unregister it when all netif are down. Now ethtool will show:
 - PTP PHC clock index 0 after boot until first netif is up;
 - the last assigned PTP PHC clock index even if PTP PHC clock is not
registered any more after all netifs are down.

This patch ensures that -1 is returned by ethtool when PTP PHC clock is not
registered any more.

Fixes: 8a2c9a5a ("net: ethernet: ti: cpts: rework initialization/deinitialization")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20201224162405.28032-1-grygorii.strashko@ti.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Antoine Tenart says:

====================
net-sysfs: fix race conditions in the xps code

This series fixes race conditions in the xps code, where out of bound
accesses can occur when dev->num_tc is updated, triggering oops. The
root cause is linked to locking issues. An explanation is given in each
of the commit logs.

We had a discussion on the v1 of this series about using the xps_map
mutex instead of the rtnl lock. While that seemed a better compromise,
v2 showed the added complexity wasn't best for fixes. So we decided to
go back to v1 and use the rtnl lock.

Because of this, the only differences between v1 and v3 are improvements
in the commit messages.
====================

Link: https://lore.kernel.org/r/20201223212323.3603139-1-atenart@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Accesses to dev->xps_rxqs_map (when using dev->num_tc) should be
protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't
see an actual bug being triggered, but let's be safe here and take the
rtnl lock while accessing the map in sysfs.

Fixes: 8af2c06f ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Two race conditions can be triggered when storing xps rxqs, resulting in
various oops and invalid memory accesses:

1. Calling netdev_set_num_tc while netif_set_xps_queue:

   - netif_set_xps_queue uses dev->tc_num as one of the parameters to
     compute the size of new_dev_maps when allocating it. dev->tc_num is
     also used to access the map, and the compiler may generate code to
     retrieve this field multiple times in the function.

   - netdev_set_num_tc sets dev->tc_num.

   If new_dev_maps is allocated using dev->tc_num and then dev->tc_num
   is set to a higher value through netdev_set_num_tc, later accesses to
   new_dev_maps in netif_set_xps_queue could lead to accessing memory
   outside of new_dev_maps; triggering an oops.

2. Calling netif_set_xps_queue while netdev_set_num_tc is running:

   2.1. netdev_set_num_tc starts by resetting the xps queues,
        dev->tc_num isn't updated yet.

   2.2. netif_set_xps_queue is called, setting up the map with the
        *old* dev->num_tc.

   2.3. netdev_set_num_tc updates dev->tc_num.

   2.4. Later accesses to the map lead to out of bound accesses and
        oops.

   A similar issue can be found with netdev_reset_tc.

One way of triggering this is to set an iface up (for which the driver
uses netdev_set_num_tc in the open path, such as bnx2x) and writing to
xps_rxqs in a concurrent thread. With the right timing an oops is
triggered.

Both issues have the same fix: netif_set_xps_queue, netdev_set_num_tc
and netdev_reset_tc should be mutually exclusive. We do that by taking
the rtnl lock in xps_rxqs_store.

Fixes: 8af2c06f ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Accesses to dev->xps_cpus_map (when using dev->num_tc) should be
protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't
see an actual bug being triggered, but let's be safe here and take the
rtnl lock while accessing the map in sysfs.

Fixes: 184c449f ("net: Add support for XPS with QoS via traffic classes")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Two race conditions can be triggered when storing xps cpus, resulting in
various oops and invalid memory accesses:

1. Calling netdev_set_num_tc while netif_set_xps_queue:

   - netif_set_xps_queue uses dev->tc_num as one of the parameters to
     compute the size of new_dev_maps when allocating it. dev->tc_num is
     also used to access the map, and the compiler may generate code to
     retrieve this field multiple times in the function.

   - netdev_set_num_tc sets dev->tc_num.

   If new_dev_maps is allocated using dev->tc_num and then dev->tc_num
   is set to a higher value through netdev_set_num_tc, later accesses to
   new_dev_maps in netif_set_xps_queue could lead to accessing memory
   outside of new_dev_maps; triggering an oops.

2. Calling netif_set_xps_queue while netdev_set_num_tc is running:

   2.1. netdev_set_num_tc starts by resetting the xps queues,
        dev->tc_num isn't updated yet.

   2.2. netif_set_xps_queue is called, setting up the map with the
        *old* dev->num_tc.

   2.3. netdev_set_num_tc updates dev->tc_num.

   2.4. Later accesses to the map lead to out of bound accesses and
        oops.

   A similar issue can be found with netdev_reset_tc.

One way of triggering this is to set an iface up (for which the driver
uses netdev_set_num_tc in the open path, such as bnx2x) and writing to
xps_cpus in a concurrent thread. With the right timing an oops is
triggered.

Both issues have the same fix: netif_set_xps_queue, netdev_set_num_tc
and netdev_reset_tc should be mutually exclusive. We do that by taking
the rtnl lock in xps_cpus_store.

Fixes: 184c449f ("net: Add support for XPS with QoS via traffic classes")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The cdc_ncm driver passes network connection notifications up to
usbnet_link_change(), which is the right place for any logging.
Remove the netdev_info() duplicating this from the driver itself.

This stops devices such as my "TRENDnet USB 10/100/1G/2.5G LAN"
(ID 20f4:e02b) adapter from spamming the kernel log with

    cdc_ncm 2-2:2.0 enp0s2u2c2: network connection: connected

messages every 60 msec or so.
Signed-off-by: Roland Dreier <roland@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20201224032116.2453938-1-roland@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Instead of directly comparing task->tgid and task->pid, use the
thread_group_leader() helper.  This helps with readability, and
there should be no functional change.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201218185032.2464558-3-jonathan.lemon@gmail.com

On some systems, some variant of the following splat is
repeatedly seen.  The common factor in all traces seems
to be the entry point to task_file_seq_next().  With the
patch, all warnings go away.

    rcu: INFO: rcu_sched self-detected stall on CPU
    rcu: \x0926-....: (20992 ticks this GP) idle=d7e/1/0x4000000000000002 softirq=81556231/81556231 fqs=4876
    \x09(t=21033 jiffies g=159148529 q=223125)
    NMI backtrace for cpu 26
    CPU: 26 PID: 2015853 Comm: bpftool Kdump: loaded Not tainted 5.6.13-0_fbk4_3876_gd8d1f9bf80bb #1
    Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A12 10/08/2018
    Call Trace:
     <IRQ>
     dump_stack+0x50/0x70
     nmi_cpu_backtrace.cold.6+0x13/0x50
     ? lapic_can_unplug_cpu.cold.30+0x40/0x40
     nmi_trigger_cpumask_backtrace+0xba/0xca
     rcu_dump_cpu_stacks+0x99/0xc7
     rcu_sched_clock_irq.cold.90+0x1b4/0x3aa
     ? tick_sched_do_timer+0x60/0x60
     update_process_times+0x24/0x50
     tick_sched_timer+0x37/0x70
     __hrtimer_run_queues+0xfe/0x270
     hrtimer_interrupt+0xf4/0x210
     smp_apic_timer_interrupt+0x5e/0x120
     apic_timer_interrupt+0xf/0x20
     </IRQ>
    RIP: 0010:get_pid_task+0x38/0x80
    Code: 89 f6 48 8d 44 f7 08 48 8b 00 48 85 c0 74 2b 48 83 c6 55 48 c1 e6 04 48 29 f0 74 19 48 8d 78 20 ba 01 00 00 00 f0 0f c1 50 20 <85> d2 74 27 78 11 83 c2 01 78 0c 48 83 c4 08 c3 31 c0 48 83 c4 08
    RSP: 0018:ffffc9000d293dc8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
    RAX: ffff888637c05600 RBX: ffffc9000d293e0c RCX: 0000000000000000
    RDX: 0000000000000001 RSI: 0000000000000550 RDI: ffff888637c05620
    RBP: ffffffff8284eb80 R08: ffff88831341d300 R09: ffff88822ffd8248
    R10: ffff88822ffd82d0 R11: 00000000003a93c0 R12: 0000000000000001
    R13: 00000000ffffffff R14: ffff88831341d300 R15: 0000000000000000
     ? find_ge_pid+0x1b/0x20
     task_seq_get_next+0x52/0xc0
     task_file_seq_get_next+0x159/0x220
     task_file_seq_next+0x4f/0xa0
     bpf_seq_read+0x159/0x390
     vfs_read+0x8a/0x140
     ksys_read+0x59/0xd0
     do_syscall_64+0x42/0x110
     entry_SYSCALL_64_after_hwframe+0x44/0xa9
    RIP: 0033:0x7f95ae73e76e
    Code: Bad RIP value.
    RSP: 002b:00007ffc02c1dbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
    RAX: ffffffffffffffda RBX: 000000000170faa0 RCX: 00007f95ae73e76e
    RDX: 0000000000001000 RSI: 00007ffc02c1dc30 RDI: 0000000000000007
    RBP: 00007ffc02c1ec70 R08: 0000000000000005 R09: 0000000000000006
    R10: fffffffffffff20b R11: 0000000000000246 R12: 00000000019112a0
    R13: 0000000000000000 R14: 0000000000000007 R15: 00000000004283c0

If unable to obtain the file structure for the current task,
proceed to the next task number after the one returned from
task_seq_get_next(), instead of the next task number from the
original iterator.

Also, save the stopping task number from task_seq_get_next()
on failure in case of restarts.

Fixes: eaaacd23 ("bpf: Add task and task/file iterator targets")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201218185032.2464558-2-jonathan.lemon@gmail.com

20b6cc34 ("bpf: Avoid hashtab deadlock with map_locked") introduced
a possibility of getting EBUSY error on lock contention, which seems to happen
very deterministically in test_maps when running 1024 threads on low-CPU
machine. In libbpf CI case, it's a 2 CPU VM and it's hitting this 100% of the
time. Work around by retrying on EBUSY (and EAGAIN, while we are at it) after
a small sleep. sched_yield() is too agressive and fails even after 20 retries,
so I went with usleep(1) for backoff.

Also log actual error returned to make it easier to see what's going on.

Fixes: 20b6cc34 ("bpf: Avoid hashtab deadlock with map_locked")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201223200652.3417075-1-andrii@kernel.org

This flag can be used by an end user to disable S0ix flows on a
buggy system or by an OEM for development purposes.

If you need this flag to be persisted across reboots, it's suggested
to use a udev rule to call adjust it until the kernel could have your
configuration in a disallow list.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Yijun Shen <Yijun.shen@dell.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

commit e086ba2f ("e1000e: disable s0ix entry and exit flows for ME
systems") disabled s0ix flows for systems that have various incarnations of
the i219-LM ethernet controller.  This changed caused power consumption
regressions on the following shipping Dell Comet Lake based laptops:
* Latitude 5310
* Latitude 5410
* Latitude 5410
* Latitude 5510
* Precision 3550
* Latitude 5411
* Latitude 5511
* Precision 3551
* Precision 7550
* Precision 7750

This commit was introduced because of some regressions on certain Thinkpad
laptops.  This comment was potentially caused by an earlier
commit 632fbd5e ("e1000e: fix S0ix flows for cable connected case").
or it was possibly caused by a system not meeting platform architectural
requirements for low power consumption.  Other changes made in the driver
with extended timeouts are expected to make the driver more impervious to
platform firmware behavior.

Fixes: e086ba2f ("e1000e: disable s0ix entry and exit flows for ME systems")
Reviewed-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Yijun Shen <Yijun.shen@dell.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Per guidance from Intel ethernet architecture team, it may take
up to 1 second for unconfiguring ULP mode.

However in practice this seems to be taking up to 2 seconds on
some Lenovo machines.  Detect scenarios that take more than 1 second
but less than 2.5 seconds and emit a warning on resume for those
scenarios.
Suggested-by: Aaron Ma <aaron.ma@canonical.com>
Suggested-by: Sasha Netfin <sasha.neftin@intel.com>
Suggested-by: Hans de Goede <hdegoede@redhat.com>
CC: Mark Pearson <markpearson@lenovo.com>
Fixes: f15bb6dd ("e1000e: Add support for S0ix")
BugLink: https://bugs.launchpad.net/bugs/1865570
Link: https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20200323191639.48826-1-aaron.ma@canonical.com/
Link: https://lkml.org/lkml/2020/12/13/15
Link: https://lkml.org/lkml/2020/12/14/708Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Yijun Shen <Yijun.shen@dell.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

If the shutdown failed, the part will be thawed and running
S0ix flows will put it into an undefined state.
Reported-by: Alexander Duyck <alexander.duyck@gmail.com>
Reviewed-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Tested-by: Yijun Shen <Yijun.shen@dell.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Commit f9c6cea0 ("ibmvnic: Skip fatal error reset after passive init")
says "If the passive
CRQ initialization occurs before the FATAL reset task is processed,
the FATAL error reset task would try to access a CRQ message queue
that was freed, causing an oops. The problem may be most likely to
occur during DLPAR add vNIC with a non-default MTU, because the DLPAR
process will automatically issue a change MTU request.
Fix this by not processing fatal error reset if CRQ is passively
initialized after client-driven CRQ initialization fails."

The original commit skips a specific reset condition, but that does
not fix the problem it claims to fix, and misses a reset condition.
The effective fix is commit 0e435bef ("ibmvnic: fix NULL pointer
dereference in ibmvic_reset_crq") and commit a0faaa27 ("ibmvnic:
fix NULL pointer dereference in reset_sub_crq_queues"). With above
two fixes, there are no more crashes seen as described even without
the original commit, so I would like to revert the original commit.

Fixes: f9c6cea0 ("ibmvnic: Skip fatal error reset after passive init")
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/20201223204904.12677-1-ljp@linux.ibm.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

When mdiobus_register() fails, priv->mdio allocated
by mdiobus_alloc() has not been freed, which leads
to memleak.

Fixes: e7f4dc35 ("mdio: Move allocation of interrupts into core")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201223110615.31389-1-dinghao.liu@zju.edu.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

When aggregating ncsi interfaces and dedicated interfaces to bond
interfaces, the ncsi response handler will use the wrong net device to
find ncsi_dev, so that the ncsi interface will not work properly.
Here, we use the original net device to fix it.

Fixes: 138635cc ("net/ncsi: NCSI response packet handler")
Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>
Link: https://lore.kernel.org/r/20201223055523.2069-1-wangzhiqiang.bj@bytedance.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

DCB uses the same handler function for both RTM_GETDCB and RTM_SETDCB
messages. dcb_doit() bounces RTM_SETDCB mesasges if the user does not have
the CAP_NET_ADMIN capability.

However, the operation to be performed is not decided from the DCB message
type, but from the DCB command. Thus DCB_CMD_*_GET commands are used for
reading DCB objects, the corresponding SET and DEL commands are used for
manipulation.

The assumption is that set-like commands will be sent via an RTM_SETDCB
message, and get-like ones via RTM_GETDCB. However, this assumption is not
enforced.

It is therefore possible to manipulate DCB objects without CAP_NET_ADMIN
capability by sending the corresponding command in an RTM_GETDCB message.
That is a bug. Fix it by validating the type of the request message against
the type used for the response.

Fixes: 2f90b865 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver")
Signed-off-by: Petr Machata <me@pmachata.org>
Link: https://lore.kernel.org/r/a2a9b88418f3a58ef211b718f2970128ef9e3793.1608673640.git.me@pmachata.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Alex Elder says:

====================
net: ipa: GSI interrupt handling fixes

This series implements fixes for some issues related to handling
interrupts when GSI channel and event ring commands complete.

The first issue is that the completion condition for an event ring
or channel command could occur while the associated interrupt is
disabled.  This would cause the interrupt to fire when it is
subsequently enabled, even if the condition it signals had already
been handled.  The fix is to clear any pending interrupt conditions
before re-enabling the interrupt.

The second and third patches change how the success of an event ring
or channel command is determined.  These commands change the state
of an event ring or channel.  Previously the receipt of a completion
interrupt was required to consider a command successful.  Instead, a
command is successful if it changes the state of the target event
ring or channel in the way expected.  This way the command can
succeed even if the completion interrupt did not arrive while it was
enabled.
====================

Link: https://lore.kernel.org/r/20201222180012.22489-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This patch implements the same basic fix for event rings as the
previous one does for channels.

The result of issuing an event ring control command should be that
the event ring changes state.  If enabled, a completion interrupt
signals that the event ring state has changed.  This interrupt is
enabled by gsi_evt_ring_command() and disabled again after the
command has completed (or we time out).

There is a window of time during which the command could complete
successfully without interrupting.  This would cause the event ring
to transition to the desired new state.

So whether a event ring command ends via completion interrupt or
timeout, we can consider the command successful if the event ring
has entered the desired state (and a failure if it has not,
regardless of the cause).

Fixes: b4175f87 ("net: ipa: only enable GSI event control IRQs when needed")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The result of issuing a channel control command should be that the
channel changes state.  If enabled, a completion interrupt signals
that the channel state has changed.  This interrupt is enabled by
gsi_channel_command() and disabled again after the command has
completed (or we time out).

There is a window of time--after the completion interrupt is disabled
but before the channel state is read--during which the command could
complete successfully without interrupting.  This would cause the
channel to transition to the desired new state.

So whether a channel command ends via completion interrupt or
timeout, we can consider the command successful if the channel
has entered the desired state (and a failure if it has not,
regardless of the cause).

Fixes: d6c9e3f5 ("net: ipa: only enable generic command completion IRQ when needed");
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>