Commit Graph

7796 Commits

Author SHA1 Message Date
Ido Schimmel
07e1a5809b psample: Add additional metadata attributes
Extend psample to report the following attributes when available:

* Output traffic class as a 16-bit value
* Output traffic class occupancy in bytes as a 64-bit value
* End-to-end latency of the packet in nanoseconds resolution
* Software timestamp in nanoseconds resolution (always available)
* Packet's protocol. Needed for packet dissection in user space (always
  available)

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-14 15:00:43 -07:00
Baowen Zheng
2ffe039528 net/sched: act_police: add support for packet-per-second policing
Allow a policer action to enforce a rate-limit based on packets-per-second,
configurable using a packet-per-second rate and burst parameters.

e.g.
tc filter add dev tap1 parent ffff: u32 match \
        u32 0 0 police pkts_rate 3000 pkts_burst 1000

Testing was unable to uncover a performance impact of this change on
existing features.

Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Louis Peens <louis.peens@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-13 14:18:09 -08:00
Ido Schimmel
710ec56223 nexthop: Add netlink defines and enumerators for resilient NH groups
- RTM_NEWNEXTHOP et.al. that handle resilient groups will have a new nested
  attribute, NHA_RES_GROUP, whose elements are attributes NHA_RES_GROUP_*.

- RTM_NEWNEXTHOPBUCKET et.al. is a suite of new messages that will
  currently serve only for dumping of individual buckets of resilient next
  hop groups. For nexthop group buckets, these messages will carry a nested
  attribute NHA_RES_BUCKET, whose elements are attributes NHA_RES_BUCKET_*.

  There are several reasons why a new suite of messages is created for
  nexthop buckets instead of overloading the information on the existing
  RTM_{NEW,DEL,GET}NEXTHOP messages.

  First, a nexthop group can contain a large number of nexthop buckets (4k
  is not unheard of). This imposes limits on the amount of information that
  can be encoded for each nexthop bucket given a netlink message is limited
  to 64k bytes.

  Second, while RTM_NEWNEXTHOPBUCKET is only used for notifications at
  this point, in the future it can be extended to provide user space with
  control over nexthop buckets configuration.

- The new group type is NEXTHOP_GRP_TYPE_RES. Note that nexthop code is
  adjusted to bounce groups with that type for now.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 16:12:59 -08:00
Maciej W. Rozycki
e56763ee50 FDDI: if_fddi.h: Update my e-mail address
Following the recent update to MAINTAINERS update my e-mail address.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-10 12:45:16 -08:00
David S. Miller
c1acda9807 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-03-09

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

We've added 90 non-merge commits during the last 17 day(s) which contain
a total of 114 files changed, 5158 insertions(+), 1288 deletions(-).

The main changes are:

1) Faster bpf_redirect_map(), from Björn.

2) skmsg cleanup, from Cong.

3) Support for floating point types in BTF, from Ilya.

4) Documentation for sys_bpf commands, from Joe.

5) Support for sk_lookup in bpf_prog_test_run, form Lorenz.

6) Enable task local storage for tracing programs, from Song.

7) bpf_for_each_map_elem() helper, from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-09 18:07:05 -08:00
Linus Torvalds
05a59d7979 Merge git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Fix transmissions in dynamic SMPS mode in ath9k, from Felix Fietkau.

 2) TX skb error handling fix in mt76 driver, also from Felix.

 3) Fix BPF_FETCH atomic in x86 JIT, from Brendan Jackman.

 4) Avoid double free of percpu pointers when freeing a cloned bpf prog.
    From Cong Wang.

 5) Use correct printf format for dma_addr_t in ath11k, from Geert
    Uytterhoeven.

 6) Fix resolve_btfids build with older toolchains, from Kun-Chuan
    Hsieh.

 7) Don't report truncated frames to mac80211 in mt76 driver, from
    Lorenzop Bianconi.

 8) Fix watcdog timeout on suspend/resume of stmmac, from Joakim Zhang.

 9) mscc ocelot needs NET_DEVLINK selct in Kconfig, from Arnd Bergmann.

10) Fix sign comparison bug in TCP_ZEROCOPY_RECEIVE getsockopt(), from
    Arjun Roy.

11) Ignore routes with deleted nexthop object in mlxsw, from Ido
    Schimmel.

12) Need to undo tcp early demux lookup sometimes in nf_nat, from
    Florian Westphal.

13) Fix gro aggregation for udp encaps with zero csum, from Daniel
    Borkmann.

14) Make sure to always use imp*_ndo_send when necessaey, from Jason A.
    Donenfeld.

15) Fix TRSCER masks in sh_eth driver from Sergey Shtylyov.

16) prevent overly huge skb allocationsd in qrtr, from Pavel Skripkin.

17) Prevent rx ring copnsumer index loss of sync in enetc, from Vladimir
    Oltean.

18) Make sure textsearch copntrol block is large enough, from Wilem de
    Bruijn.

19) Revert MAC changes to r8152 leading to instability, from Hates Wang.

20) Advance iov in 9p even for empty reads, from Jissheng Zhang.

21) Double hook unregister in nftables, from PabloNeira Ayuso.

22) Fix memleak in ixgbe, fropm Dinghao Liu.

23) Avoid dups in pkt scheduler class dumps, from Maximilian Heyne.

24) Various mptcp fixes from Florian Westphal, Paolo Abeni, and Geliang
    Tang.

25) Fix DOI refcount bugs in cipso, from Paul Moore.

26) One too many irqsave in ibmvnic, from Junlin Yang.

27) Fix infinite loop with MPLS gso segmenting via virtio_net, from
    Balazs Nemeth.

* git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net: (164 commits)
  s390/qeth: fix notification for pending buffers during teardown
  s390/qeth: schedule TX NAPI on QAOB completion
  s390/qeth: improve completion of pending TX buffers
  s390/qeth: fix memory leak after failed TX Buffer allocation
  net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0
  net: check if protocol extracted by virtio_net_hdr_set_proto is correct
  net: dsa: xrs700x: check if partner is same as port in hsr join
  net: lapbether: Remove netif_start_queue / netif_stop_queue
  atm: idt77252: fix null-ptr-dereference
  atm: uPD98402: fix incorrect allocation
  atm: fix a typo in the struct description
  net: qrtr: fix error return code of qrtr_sendmsg()
  mptcp: fix length of ADD_ADDR with port sub-option
  net: bonding: fix error return code of bond_neigh_init()
  net: enetc: allow hardware timestamping on TX queues with tc-etf enabled
  net: enetc: set MAC RX FIFO to recommended value
  net: davicom: Use platform_get_irq_optional()
  net: davicom: Fix regulator not turned off on driver removal
  net: davicom: Fix regulator not turned off on failed probe
  net: dsa: fix switchdev objects on bridge master mistakenly being applied on ports
  ...
2021-03-09 17:15:56 -08:00
David S. Miller
9270bbe258 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Fix incorrect enum type definition in nfnetlink_cthelper UAPI,
   from Dmitry V. Levin.

2) Remove extra space in deprecated automatic helper assignment
   notice, from Klemen Košir.

3) Drop early socket demux socket after NAT mangling, from
   Florian Westphal. Add a test to exercise this bug.

4) Fix bogus invalid packet report in the conntrack TCP tracker,
   also from Florian.

5) Fix access to xt[NFPROTO_UNSPEC] list with no mutex
   in target/match_revfn(), from Vasily Averin.

6) Disallow updates on the table ownership flag.

7) Fix double hook unregistration of tables with owner.

8) Remove bogus check on the table owner in __nft_release_tables().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-06 17:02:40 -08:00
Xuesen Huang
d01b59c9ae bpf: Add bpf_skb_adjust_room flag BPF_F_ADJ_ROOM_ENCAP_L2_ETH
bpf_skb_adjust_room sets the inner_protocol as skb->protocol for packets
encapsulation. But that is not appropriate when pushing Ethernet header.

Add an option to further specify encap L2 type and set the inner_protocol
as ETH_P_TEB.

Suggested-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Xuesen Huang <huangxuesen@kuaishou.com>
Signed-off-by: Zhiyong Cheng <chengzhiyong@kuaishou.com>
Signed-off-by: Li Wang <wangli09@kuaishou.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/bpf/20210304064046.6232-1-hxseverything@gmail.com
2021-03-05 16:59:00 +01:00
Lorenz Bauer
7c32e8f8bc bpf: Add PROG_TEST_RUN support for sk_lookup programs
Allow to pass sk_lookup programs to PROG_TEST_RUN. User space
provides the full bpf_sk_lookup struct as context. Since the
context includes a socket pointer that can't be exposed
to user space we define that PROG_TEST_RUN returns the cookie
of the selected socket or zero in place of the socket pointer.

We don't support testing programs that select a reuseport socket,
since this would mean running another (unrelated) BPF program
from the sk_lookup test handler.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210303101816.36774-3-lmb@cloudflare.com
2021-03-04 19:11:29 -08:00
Joe Stringer
923a932c98 scripts/bpf: Abstract eBPF API target parameter
Abstract out the target parameter so that upcoming commits, more than
just the existing "helpers" target can be called to generate specific
portions of docs from the eBPF UAPI headers.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-10-joe@cilium.io
2021-03-04 18:39:45 -08:00
Joe Stringer
0cb8045479 bpf: Document BPF_MAP_*_BATCH syscall commands
Based roughly on the following commits:
* Commit cb4d03ab49 ("bpf: Add generic support for lookup batch op")
* Commit 057996380a ("bpf: Add batch ops to all htab bpf map")
* Commit aa2e93b8e5 ("bpf: Add generic support for update and delete
  batch ops")

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Brian Vazquez <brianvv@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-9-joe@cilium.io
2021-03-04 18:39:45 -08:00
Joe Stringer
5d999994e0 bpf: Document BPF_PROG_QUERY syscall command
Commit 468e2f64d2 ("bpf: introduce BPF_PROG_QUERY command") originally
introduced this, but there have been several additions since then.
Unlike BPF_PROG_ATTACH, it appears that the sockmap progs are not able
to be queried so far.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-8-joe@cilium.io
2021-03-04 18:39:45 -08:00
Joe Stringer
2a3fdca4e3 bpf: Document BPF_PROG_TEST_RUN syscall command
Based on a brief read of the corresponding source code.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-7-joe@cilium.io
2021-03-04 18:39:44 -08:00
Joe Stringer
32e76b187a bpf: Document BPF_PROG_ATTACH syscall command
Document the prog attach command in more detail, based on git commits:
* commit f432455148 ("bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH
  commands")
* commit 4f738adba3 ("bpf: create tcp_bpf_ulp allowing BPF to monitor
  socket TX/RX data")
* commit f4364dcfc8 ("media: rc: introduce BPF_PROG_LIRC_MODE2")
* commit d58e468b11 ("flow_dissector: implements flow dissector BPF
  hook")

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-6-joe@cilium.io
2021-03-04 18:39:44 -08:00
Joe Stringer
8aacb3c8d1 bpf: Document BPF_PROG_PIN syscall command
Commit b2197755b2 ("bpf: add support for persistent maps/progs")
contains the original implementation and git logs, used as reference for
this documentation.

Also pull in the filename restriction as documented in commit 6d8cb045cd
("bpf: comment why dots in filenames under BPF virtual FS are not allowed")

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-5-joe@cilium.io
2021-03-04 18:39:44 -08:00
Joe Stringer
6690523bcc bpf: Document BPF_F_LOCK in syscall commands
Document the meaning of the BPF_F_LOCK flag for the map lookup/update
descriptions. Based on commit 96049f3afd ("bpf: introduce BPF_F_LOCK
flag").

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-4-joe@cilium.io
2021-03-04 18:39:44 -08:00
Joe Stringer
f67c9cbf6c bpf: Add minimal bpf() command documentation
Introduce high-level descriptions of the intent and return codes of the
bpf() syscall commands. Subsequent patches may further flesh out the
content to provide a more useful programming reference.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-3-joe@cilium.io
2021-03-04 18:39:44 -08:00
Joe Stringer
7799e4d9d8 bpf: Import syscall arg documentation
These descriptions are present in the man-pages project from the
original submissions around 2015-2016. Import them so that they can be
kept up to date as developers extend the bpf syscall commands.

These descriptions follow the pattern used by scripts/bpf_helpers_doc.py
so that we can take advantage of the parser to generate more up-to-date
man page writing based upon these headers.

Some minor wording adjustments were made to make the descriptions
more consistent for the description / return format.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-2-joe@cilium.io

Co-authored-by: Alexei Starovoitov <ast@kernel.org>
Co-authored-by: Michael Kerrisk <mtk.manpages@gmail.com>
2021-03-04 18:39:44 -08:00
Ilya Leoshkevich
8fd886911a bpf: Add BTF_KIND_FLOAT to uapi
Add a new kind value and expand the kind bitfield.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210226202256.116518-2-iii@linux.ibm.com
2021-03-04 17:58:15 -08:00
Linus Torvalds
cee407c5cc Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:

 - Doc fixes

 - selftests fixes

 - Add runstate information to the new Xen support

 - Allow compiling out the Xen interface

 - 32-bit PAE without EPT bugfix

 - NULL pointer dereference bugfix

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: SVM: Clear the CR4 register on reset
  KVM: x86/xen: Add support for vCPU runstate information
  KVM: x86/xen: Fix return code when clearing vcpu_info and vcpu_time_info
  selftests: kvm: Mmap the entire vcpu mmap area
  KVM: Documentation: Fix index for KVM_CAP_PPC_DAWR1
  KVM: x86: allow compiling out the Xen hypercall interface
  KVM: xen: flush deferred static key before checking it
  KVM: x86/mmu: Set SPTE_AD_WRPROT_ONLY_MASK if and only if PML is enabled
  KVM: x86: hyper-v: Fix Hyper-V context null-ptr-deref
  KVM: x86: remove misplaced comment on active_mmu_pages
  KVM: Documentation: rectify rst markup in kvm_run->flags
  Documentation: kvm: fix messy conversion from .txt to .rst
2021-03-04 11:26:17 -08:00
Matthias Schiffer
3e59e88567 net: l2tp: reduce log level of messages in receive path, add counter instead
Commit 5ee759cda5 ("l2tp: use standard API for warning log messages")
changed a number of warnings about invalid packets in the receive path
so that they are always shown, instead of only when a special L2TP debug
flag is set. Even with rate limiting these warnings can easily cause
significant log spam - potentially triggered by a malicious party
sending invalid packets on purpose.

In addition these warnings were noticed by projects like Tunneldigger [1],
which uses L2TP for its data path, but implements its own control
protocol (which is sufficiently different from L2TP data packets that it
would always be passed up to userspace even with future extensions of
L2TP).

Some of the warnings were already redundant, as l2tp_stats has a counter
for these packets. This commit adds one additional counter for invalid
packets that are passed up to userspace. Packets with unknown session are
not counted as invalid, as there is nothing wrong with the format of
these packets.

With the additional counter, all of these messages are either redundant
or benign, so we reduce them to pr_debug_ratelimited().

[1] https://github.com/wlanslovenija/tunneldigger/issues/160

Fixes: 5ee759cda5 ("l2tp: use standard API for warning log messages")
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-03 16:55:02 -08:00
David Woodhouse
30b5c851af KVM: x86/xen: Add support for vCPU runstate information
This is how Xen guests do steal time accounting. The hypervisor records
the amount of time spent in each of running/runnable/blocked/offline
states.

In the Xen accounting, a vCPU is still in state RUNSTATE_running while
in Xen for a hypercall or I/O trap, etc. Only if Xen explicitly schedules
does the state become RUNSTATE_blocked. In KVM this means that even when
the vCPU exits the kvm_run loop, the state remains RUNSTATE_running.

The VMM can explicitly set the vCPU to RUNSTATE_blocked by using the
KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT attribute, and can also use
KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST to retrospectively add a given
amount of time to the blocked state and subtract it from the running
state.

The state_entry_time corresponds to get_kvmclock_ns() at the time the
vCPU entered the current state, and the total times of all four states
should always add up to state_entry_time.

Co-developed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20210301125309.874953-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-02 14:30:54 -05:00
Dmitry V. Levin
c33cb0020e uapi: nfnetlink_cthelper.h: fix userspace compilation error
Apparently, <linux/netfilter/nfnetlink_cthelper.h> and
<linux/netfilter/nfnetlink_acct.h> could not be included into the same
compilation unit because of a cut-and-paste typo in the former header.

Fixes: 12f7a50533 ("netfilter: add user-space connection tracking helper infrastructure")
Cc: <stable@vger.kernel.org> # v3.6
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-02-28 00:24:41 +01:00
Linus Torvalds
5695e51619 Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block
Pull io_uring thread rewrite from Jens Axboe:
 "This converts the io-wq workers to be forked off the tasks in question
  instead of being kernel threads that assume various bits of the
  original task identity.

  This kills > 400 lines of code from io_uring/io-wq, and it's the worst
  part of the code. We've had several bugs in this area, and the worry
  is always that we could be missing some pieces for file types doing
  unusual things (recent /dev/tty example comes to mind, userfaultfd
  reads installing file descriptors is another fun one... - both of
  which need special handling, and I bet it's not the last weird oddity
  we'll find).

  With these identical workers, we can have full confidence that we're
  never missing anything. That, in itself, is a huge win. Outside of
  that, it's also more efficient since we're not wasting space and code
  on tracking state, or switching between different states.

  I'm sure we're going to find little things to patch up after this
  series, but testing has been pretty thorough, from the usual
  regression suite to production. Any issue that may crop up should be
  manageable.

  There's also a nice series of further reductions we can do on top of
  this, but I wanted to get the meat of it out sooner rather than later.
  The general worry here isn't that it's fundamentally broken. Most of
  the little issues we've found over the last week have been related to
  just changes in how thread startup/exit is done, since that's the main
  difference between using kthreads and these kinds of threads. In fact,
  if all goes according to plan, I want to get this into the 5.10 and
  5.11 stable branches as well.

  That said, the changes outside of io_uring/io-wq are:

   - arch setup, simple one-liner to each arch copy_thread()
     implementation.

   - Removal of net and proc restrictions for io_uring, they are no
     longer needed or useful"

* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
  io-wq: remove now unused IO_WQ_BIT_ERROR
  io_uring: fix SQPOLL thread handling over exec
  io-wq: improve manager/worker handling over exec
  io_uring: ensure SQPOLL startup is triggered before error shutdown
  io-wq: make buffered file write hashed work map per-ctx
  io-wq: fix race around io_worker grabbing
  io-wq: fix races around manager/worker creation and task exit
  io_uring: ensure io-wq context is always destroyed for tasks
  arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
  io_uring: cleanup ->user usage
  io-wq: remove nr_process accounting
  io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
  net: remove cmsg restriction from io_uring based send/recvmsg calls
  Revert "proc: don't allow async path resolution of /proc/self components"
  Revert "proc: don't allow async path resolution of /proc/thread-self components"
  io_uring: move SQPOLL thread io-wq forked worker
  io-wq: make io_wq_fork_thread() available to other users
  io-wq: only remove worker from free_list, if it was there
  io_uring: remove io_identity
  io_uring: remove any grabbing of context
  ...
2021-02-27 08:29:02 -08:00
Yonghong Song
69c087ba62 bpf: Add bpf_for_each_map_elem() helper
The bpf_for_each_map_elem() helper is introduced which
iterates all map elements with a callback function. The
helper signature looks like
  long bpf_for_each_map_elem(map, callback_fn, callback_ctx, flags)
and for each map element, the callback_fn will be called. For example,
like hashmap, the callback signature may look like
  long callback_fn(map, key, val, callback_ctx)

There are two known use cases for this. One is from upstream ([1]) where
a for_each_map_elem helper may help implement a timeout mechanism
in a more generic way. Another is from our internal discussion
for a firewall use case where a map contains all the rules. The packet
data can be compared to all these rules to decide allow or deny
the packet.

For array maps, users can already use a bounded loop to traverse
elements. Using this helper can avoid using bounded loop. For other
type of maps (e.g., hash maps) where bounded loop is hard or
impossible to use, this helper provides a convenient way to
operate on all elements.

For callback_fn, besides map and map element, a callback_ctx,
allocated on caller stack, is also passed to the callback
function. This callback_ctx argument can provide additional
input and allow to write to caller stack for output.

If the callback_fn returns 0, the helper will iterate through next
element if available. If the callback_fn returns 1, the helper
will stop iterating and returns to the bpf program. Other return
values are not used for now.

Currently, this helper is only available with jit. It is possible
to make it work with interpreter with so effort but I leave it
as the future work.

[1]: https://lore.kernel.org/bpf/20210122205415.113822-1-xiyou.wangcong@gmail.com/

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204925.3884923-1-yhs@fb.com
2021-02-26 13:23:52 -08:00