Commit Graph
578 Commits
Author SHA1 Message Date
Kumar Kartikeya Dwivedi b198f8b67b bpf: Add file descriptor interface for program streams
The existing BPF_PROG_STREAM_READ_BY_FD command only supports polling a
program stream through repeated bpf() calls. It cannot block for new data
or integrate with poll-based event loops.

Add BPF_PROG_STREAM_OPEN to return a read-only, close-on-exec file
descriptor for a selected program stream. Reads block by default and
BPF_F_STREAM_NONBLOCK, the only accepted flag, provides non-blocking
behavior. poll reports readable data and reports hangup once the program
has been freed. Like pipes and sockets, the descriptor is not seekable and
lseek fails with ESPIPE.

A stream descriptor deliberately does not retain the program. Move each
stream into a separately refcounted allocation so program teardown can mark
it dead and wake descriptor users while outstanding descriptors drain
buffered data safely. Readers sample the dead flag before looking for data,
so EOF is reported only when the stream was already dead before it was
found empty; data published right before teardown is never skipped.

Only programs loaded through BPF_PROG_LOAD get streams. Classic BPF
filters, JIT subprograms and shim programs never write to one, and
kernel-side writers already resolve a subprogram to its main program, so
those programs no longer carry stream state.

Readiness needs its own counter. Stream capacity is charged before
allocation and before an element is published to the stream log, so using
that reservation as the read and poll condition can report readable data
while no element exists: a blocking reader retries instead of sleeping and
a lone non-blocking reader can see POLLIN followed by EAGAIN. Publish bytes
with release ordering after adding elements to the lockless log, use
acquire loads before consuming them or reporting readiness, limit each read
to its readable snapshot and subtract only bytes actually copied. This
keeps the aggregate count correct even when concurrent publishers update it
out of publication order. With several readers on one stream, readiness
remains advisory, as it is for pipes. The capacity counter is kept solely
for enforcing the stream size limit.

Wakeups are always deferred through irq_work. Stream writers run in
whatever context the program runs in: NMI context for perf_event programs,
sections with interrupts disabled inside bpf_spin_lock or rqspinlock
critical sections since bpf_stream_vprintk() is KF_SPINLOCK_SAFE, and
tracing programs attached anywhere in the kernel, including inside the wait
queue and epoll code itself. Waking waiters directly from there can
deadlock, and no cheap context check covers every case: on PREEMPT_RT,
spinlock_t sections do not disable interrupts, so in_nmi() or
irqs_disabled() cannot tell such a program apart from a benign one. Queue
an irq_work item instead, as bpf_ringbuf does.

Queue it only when a publication turns an empty stream readable. Readers
block and pollers wait only after finding the stream empty, and the
readable count never drops below zero because each read is bounded by its
snapshot, so the first publication after such an observation is the one
that makes the count positive, and it is the one that queues the wakeup.
Publications into a stream that already holds data raise no interrupt, so
a program that prints while nobody drains its stream pays for a single
irq_work until the stream is emptied again. This matches bpf_ringbuf, which
notifies only once the consumer has caught up. Blocking readers and
level-triggered pollers re-check the readable count before waiting, so they
cannot miss data, and edge-triggered epoll consumers drain until EAGAIN
before waiting again, as epoll(7) requires.

Synchronize pending work before releasing the final stream reference so
the callback cannot outlive the stream, but only when the work was ever
queued: irq_work_sync() waits for an RCU grace period on PREEMPT_RT and on
architectures without an irq_work interrupt.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260925045536.1480933-3-memxor@gmail.com
2026-10-02 05:41:50 -07:00
Alan Maguire d09ea52795 btf: Extend UAPI to support BTF location (inline site) info
Add BTF_KIND_LOC_PARAM, BTF_KIND_LOC_PROTO and BTF_KIND_LOCSEC
to help represent location information for functions.

BTF_KIND_LOC_PARAM is used to represent how we retrieve data at a
location; either via register(s), or register+offset, a dereference
of a register+offset or a constant value.

BTF_KIND_LOC_PROTO represents location information about a location
with multiple BTF_KIND_LOC_PARAMs.

And finally BTF_KIND_LOCSEC is a set of location sites, each
of which has

- a BTF_KIND_FUNC function associated with the inline site
- a location prototype specifying where to find the function
  parameters
- an address offset relative to the kernel base address

This can be used to support representing

- a fully-inlined function at potentially multiple inline sites
  with potentially different parameter availability
- a partially-inlined function where some _LOC_PROTOs represent
  inlined sites as above and others have normal _FUNC representations

Also BTF_KIND_LOCSEC struct btf_loc will have two type id
references; one for the associated func, the other for the loc_proto.
Accordingly increase the number of m_offs references in btf_field_desc
to 2.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260924111428.75957-2-alan.maguire@oracle.com
2026-10-02 05:41:50 -07:00
Puranjay Mohan 9b828bca53 bpf: Add bpf_call_rcu() kfunc
BPF programs that manage their own objects have no way to run their own
logic once an RCU grace period has elapsed.  bpf_obj_drop() defers a
free, but returning an index to an allocator or unpinning a resource
once readers are done has no equivalent.  sched_ext's BPF library works
around this today by pushing freed nodes onto a list and having a
userspace thread call membarrier(MEMBARRIER_CMD_GLOBAL) and then run a
BPF program to reclaim them.

Add:

	int bpf_call_rcu(struct bpf_rcu_head *rh, void *map,
			 int (*callback)(struct bpf_map *map, void *key,
					 void *value));

@rh is a struct bpf_rcu_head embedded in a value of @map, so the
callback runs as callback(map, key, value) for the element it lives in
and needs no cookie.  A head can only be armed once, which bounds
outstanding work by the number of elements.

struct bpf_rcu_head holds the callback state inline rather than a
pointer to it, as bpf_timer, bpf_wq and bpf_task_work do, because there
is nothing to cancel and so nothing that has to outlive the map value.
That avoids an allocation and a state machine on the arming path at the
cost of 48 bytes per element.

An RCU callback cannot be cancelled, so everything it touches has to
stay alive until it runs:

  - The callback is the program's text, so arming takes a program
    reference as bpf_timer, bpf_wq and bpf_task_work do, dropped once
    the callback returns.  bpf_prog_inc_not_zero() also fails the arm
    with -EBADF once the program is dying.

  - The map is held by that reference through used_maps.  An inner map
    is not, so bpf_rcu_head is rejected in one.

  - The field is only accepted in BPF_MAP_TYPE_ARRAY, whose elements
    are never freed individually.  A hash element can be deleted and
    recycled while a callback is queued on it.

  - The head is disarmed before the callback runs so it can be armed
    again from there, which takes a new program reference before the
    running callback drops its own.  Arming therefore fails with -EPERM
    once the map is held by neither a process nor bpffs.

bpf_iter hands a program a writable pointer to the live element, which
would let it overwrite a queued head, so bpf_iter_attach_map() rejects
maps carrying one.

The callback is verified non-sleepable even when the caller is
sleepable, and RCU invokes it with BH disabled.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260922200208.3203834-2-puranjay@kernel.org
2026-10-02 05:41:50 -07:00
Amery Hung bc48d4e164 bpf: tcp: Support parse/len/write header option hooks in bpf_tcp_ops
Add the TCP header option callbacks to the bpf_tcp_ops struct_ops type:

  parse_hdr     - parse the options of an incoming skb on an established
                  connection
  hdr_opt_len   - reserve space in the TCP header for bpf options
  write_hdr_opt - write the reserved bpf options

These mirror the BPF_SOCK_OPS_PARSE_HDR_OPT_CB, _HDR_OPT_LEN_CB and
_WRITE_HDR_OPT_CB legacy sockops callbacks, but are exposed as struct_ops
members so a program can implement them with normal function signatures
and per-member helper sets.

The reserved header window is shared between the legacy sockops and
bpf_tcp_ops paths. tcp_{syn,synack,established}_options() first run the
legacy BPF_SOCK_OPS_HDR_OPT_LEN_CB and then call hdr_opt_len, so both
sources accumulate into opts->bpf_opt_len; at write time the legacy
options are emitted first and bpf_tcp_ops writes after them.

API design

bpf_tcp_ops overloads the sock_ops header-option helpers rather than
introducing a new API: bpf_reserve_hdr_opt(), bpf_store_hdr_opt() and
bpf_load_hdr_opt() are exposed per-member (reserve for hdr_opt_len,
store/load for write_hdr_opt, load for parse_hdr) and share the existing
kernel option-walking core via _bpf_sock_ops{store,load}hdr_opt(), with
the bpf_tcp_ops wrappers synthesizing a temporary bpf_sock_ops_kern from
the program ctx. This keeps a port from the legacy
BPF_SOCK_OPS*_HDR_OPT_CB callbacks mechanical (same helper calls) and
adds no new UAPI helper/kfunc surface.

An alternative considered was to drop the option helpers entirely: have
hdr_opt_len reserve space purely through its return value, and introduce
a dedicated TCP-header-option dynptr used for both reading and writing.
That is a cleaner, more self-contained interface, but it is a larger
change and does not reuse the legacy helpers, making a port from sockops
less mechanical. It can be pursued as a follow-up; the helper-based
interface here keeps this series focused on moving the hooks to
struct_ops.

The hdr_opt_len fast path in tcp_established_options() is gated by
cgroup_bpf_enabled(CGROUP_TCP_SOCK_OPS). Note this is a global,
per-attach-type static branch: it is enabled whenever any bpf_tcp_ops is
attached, even one that does not implement hdr_opt_len or that is attached
to a different cgroup. In those cases the block still runs but
bpf_tcp_ops_hdr_opt_len() no-ops via the per-member check in the dispatch
macro. A per-member/per-cgroup gate could be added later if the extra
fast-path work proves measurable.

Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://patch.msgid.link/20260917200542.3689605-13-ameryhung@gmail.com
2026-10-02 05:41:50 -07:00
Martin KaFai Lau a7ee927845 bpf: Add infrastructure to support attaching struct_ops to cgroups
This patch adds necessary infrastructure to attach a struct_ops
map to a cgroup. The initial need was to support migrating
the legacy BPF_PROG_TYPE_SOCK_OPS to a struct_ops.
Recently, there are other struct_ops use cases that
need to attach struct_ops to a cgroup. For example,
the recent BPF OOM and memcg discussion in LSFMMBPF 2026.

The motivation is to create a consistent expectation
for attaching struct_ops to cgroup instead of each subsystem
creating its own infrastructure. This logic includes
hierarchy expectation, ordering expectation,
attachment API, and rcu gp.

There is already an existing implementation for attaching
multiple bpf progs to a cgroup. There are also tools
built around it for querying. Attaching a struct_ops map
(which is a group of bpf programs) could also adhere to
a similar API and potentially reuse most of the existing
implementation.

A couple of ideas have been tried. One of them
is to use mprog.c. In terms of the amount of changes,
I eventually came to the same conclusion as in
commit 120933984460 ("bpf: Implement mprog API on top of existing cgroup progs").
I then shifted the focus to reusing the current
{update,compute,activate,purge}_effective_progs() which has
the main logic that implements the mprog API.

Since then, I tried to add a 'struct cgroup *cgroup' member
to the existing 'struct bpf_struct_ops_link' and link_create
will create a 'struct bpf_struct_ops_link' object to be stored
in the pl->link. This turns out to have more changes on
both cgroup.c and bpf_struct_ops.c than I like.

This patch directly reuses the 'struct bpf_cgroup_link' which
cgroup.c already understands. Add 'struct bpf_map *map'
to 'struct bpf_cgroup_link'. In the future, as more subsystems
are extended by struct_ops, we may consider to make
'struct bpf_map *map' as a primary citizen of a link
like 'struct bpf_prog *prog' and directly add
'struct bpf_map *map' to the generic 'struct bpf_link'.

The pl->link could be the traditional 'prog' link or the
new 'map' link. The places that need to handle them differently
have already been refactored into the new prog_list_*() added in
the earlier patch. In those new prog_list_*(), this patch will
check "pl->link && pl->link->map", learn that it is a 'map' link
and handle it correctly.

The bpf_prog_array also needs to handle that its item can store
the traditional 'prog' or it can store a struct_ops map.
The places that need to handle them differently have also
been refactored into the new bpf_cgroup_array_*() added
in the earlier patch. The two differences are:
  - different sentinel (dummy_bpf_prog in prog vs cfi_stub in struct_ops)
  - the array for struct_ops may need to go through different
    rcu gp.
The bpf_cgroup_array_*() functions use the cgroup_bpf_attach_type (ie atype)
to distinguish the array is storing prog or storing struct_ops map.

This patch also implements a separate struct bpf_link_ops
"cgroup_struct_ops_link_ops" to have a separate link_ops implementation
that only handles the cgroup's struct_ops link.

Questions:
- Although this patch did not change it, it is not obvious to me how
  the replace_effective_progs() and purge_effective_progs() handle
  cases when there are existing BPF_F_PREORDER progs attached
  in the hlist.

Misc notes:
- CGROUP_TCP_SOCK_OPS is added to the 'enum cgroup_bpf_attach_type'.
  The actual implementation of the tcp_bpf_ops (a struct_ops)
  will be added in the next patch.

- free_after_mult_rcu_gp is added to 'struct bpf_struct_ops' such that
  the bpf_prog_array can have a mix of sleepable and
  non-sleepable prog in a struct_ops. This can tell
  how the bpf_prog_array should be freed.

- For a struct_ops that supports cgroup attachment, it does not need to
  implement its own reg/unreg function. reg/unreg to a cgroup is
  done by the common infrastructure added in this patch.

- The cgroup's struct_ops link only supports BPF_F_ALLOW_MULTI.
  This is enforced internally in cgroup_bpf_struct_ops_attach.
  This should be consistent with the current prog's link
  behavior in cgroup_bpf_link_attach.

  In the future, we may allow each subsystem to choose differently.

- A cgroup_atype member is added to 'struct bpf_struct_ops'.
  When a subsystem struct_ops needs to support cgroup attachment,
  it needs to add a value to 'enum cgroup_bpf_attach_type'
  and then assign it to the newly added cgroup_atype member
  in the bpf_struct_ops.

- During LINK_CREATE in syscall, the patch uses the same
  BPF_STRUCT_OPS (in attr->link_create.attach_type).
  The bpf_struct_ops_link_create learns the map and
  from the map it learns the st_ops. If the st_ops->cgroup_atype
  is not 0, it will create a cgroup's link.

- When a subsystem registers a struct_ops that supports cgroup
  attachment, the struct_ops infrastructure will also ask the
  cgroup infrastructure to remember a few things. This is done
  by calling cgroup_bpf_struct_ops_register().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260917200542.3689605-10-ameryhung@gmail.com
2026-10-02 05:41:50 -07:00
Stanislav Fomichev 6de1eac4cd xsk: align TX metadata layout across ABIs
Add explicit padding before launch_time so xsk_tx_metadata has the same
layout on 32-bit and 64-bit systems.

On several architectures (csky, i386, nios2, m65k, openrisc, sh), the old
native 32-bit layout put launch_time at offset 12 and had a natural size of
20 bytes. Using sizeof(struct xsk_tx_metadata) as tx_metadata_len was already
rejected because the length must be a multiple of eight, so the
straightforward use of the interface was broken on those ABIs. Userspace
could still register a padded length of 24 bytes, though; mixing the old and
new layouts then silently reads launch_time from the wrong offset and
misprograms packet launch times. This intentionally replaces that
incompatible layout because the affected architectures are unlikely to
have any notable users. (x86_64 and arm64 have the most users and are _not_
affected)

Fixes: ca4419f15abd ("xsk: Add launch time hardware offload support to XDP Tx metadata")
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260819160535.1472459-2-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-02 05:41:50 -07:00
Bobby Eshleman 7183e9519f net: devmem: allow rx-page-size > PAGE_SIZE per dmabuf binding
Every devmem dmabuf binding today hands the page_pool PAGE_SIZE niovs.
This caps a single RX descriptor at PAGE_SIZE, burning CPU on buffer
churn for large flows.

Add a bind-time netlink attribute, NETDEV_A_DMABUF_RX_PAGE_SIZE, that
lets userspace request a larger niov size. The value must be a power of
two >= PAGE_SIZE.

The TX path is changed to always pass PAGE_SIZE.

Measurements:
Setup: kperf in devmem RX/TX cuda mode, 4 flows, 64 MB messages, 60s,
dctcp, num-rx-queues=4, dmabuf-rx/tx-size-mb=2048, 10 runs per niov
size, mlx5.

CPU Util:

   niov        net sirq %        net idle %         app sys %        app idle %
  -----  ----------------  ----------------  ----------------  ----------------
     4K   62.38 +/-  8.27   33.40 +/-  7.51   54.15 +/- 10.23   43.67 +/- 10.53
    16K   58.91 +/-  5.35   35.23 +/-  5.88   41.05 +/-  8.87   56.42 +/-  9.24
    32K   64.12 +/-  0.68   31.09 +/-  1.48   44.54 +/-  3.51   52.63 +/-  3.65
    64K   54.69 +/-  5.54   39.67 +/-  5.81   35.47 +/-  3.11   61.97 +/-  3.27

RX app sys % drops ~19% from 4K to 64K.

Throughput:

   niov       RX dev Gbps   RX flow avg Gbps
  -----  ----------------  -----------------
     4K  300.63 +/- 53.21    75.16 +/- 13.30
    16K  321.35 +/- 28.20    80.34 +/-  7.05
    32K  347.63 +/-  2.20    86.91 +/-  0.55
    64K  332.11 +/- 14.26    83.03 +/-  3.56

Throughput seems to increase, but the stdev is pretty wide so could just
be noise.

kperf support (not yet merged):
https://github.com/facebookexperimental/kperf/commit/8837577f920876bce6986ec18869ac04439ebcd2

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260805-tcpdm-large-niovs-v8-1-3e0225e2808c@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-02 05:41:50 -07:00
Nick Hudson 19e98d95e9 bpf: Add BPF_F_ADJ_ROOM_DECAP_* flags for tunnel decapsulation
Add new bpf_skb_adjust_room() decapsulation flags:

- BPF_F_ADJ_ROOM_DECAP_L4_GRE
- BPF_F_ADJ_ROOM_DECAP_L4_UDP
- BPF_F_ADJ_ROOM_DECAP_IPXIP4
- BPF_F_ADJ_ROOM_DECAP_IPXIP6

These flags let BPF programs describe which tunnel layer is being
removed, so later changes can update tunnel-related GSO state
accordingly during decapsulation.

This patch only introduces the UAPI flag definitions and helper
documentation.

Co-developed-by: Max Tottenham <mtottenh@akamai.com>
Co-developed-by: Anna Glasgall <aglasgal@akamai.com>
Signed-off-by: Max Tottenham <mtottenh@akamai.com>
Signed-off-by: Anna Glasgall <aglasgal@akamai.com>
Signed-off-by: Nick Hudson <nhudson@akamai.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/bpf/20260812083115.73100-4-nhudson@akamai.com
2026-10-02 05:41:50 -07:00
Nick Hudson aaafcbda3b bpf: Name the enum for BPF_FUNC_skb_adjust_room flags
The existing anonymous enum for BPF_FUNC_skb_adjust_room flags is
named to enum bpf_adj_room_flags to enable CO-RE (Compile Once -
Run Everywhere) lookups in BPF programs.

Co-developed-by: Max Tottenham <mtottenh@akamai.com>
Co-developed-by: Anna Glasgall <aglasgal@akamai.com>
Signed-off-by: Max Tottenham <mtottenh@akamai.com>
Signed-off-by: Anna Glasgall <aglasgal@akamai.com>
Signed-off-by: Nick Hudson <nhudson@akamai.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/bpf/20260812083115.73100-2-nhudson@akamai.com
2026-10-02 05:41:50 -07:00
Jianlin Shi cd08bc2420 docs: bpf: Document BPF_RB_OVERWRITE_POS in bpf_ringbuf_query
BPF_RB_OVERWRITE_POS is supported by bpf_ringbuf_query() but was missing
from the helper documentation. Add it to the flags list in both the
kernel UAPI header and its tools/ mirror.

Signed-off-by: Jianlin Shi <shijianlin11@foxmail.com>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/bpf/tencent_22134645443B75ED907D2A85A47AD554A709@qq.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-10-02 05:41:50 -07:00
Avinash Duduskar 1810ef6cdb bpf: Add BPF_FIB_LOOKUP_VLAN_INPUT flag to bpf_fib_lookup() helper
BPF_FIB_LOOKUP_VLAN resolves a VLAN egress. The reverse is also
useful: an XDP program receiving a VLAN-tagged frame on a physical
device wants the lookup to behave as if the packet had arrived on the
corresponding VLAN subinterface, so iif-based policy routing and VRF
table selection use the right ingress.

Add BPF_FIB_LOOKUP_VLAN_INPUT. When set, params->h_vlan_proto and
params->h_vlan_TCI are read as an input VLAN tag and the matching VLAN
device of params->ifindex is resolved with __vlan_find_dev_deep_rcu().
The device must be up and in the same network namespace as
params->ifindex (a VLAN device can be moved to another netns while
registered on its parent; receive would deliver into that other
namespace, which a lookup here cannot represent). If params->ifindex
is itself a VLAN device, its inner (QinQ) subinterface is matched.
For a bond or team, a tag on a port matches no device and returns
NOT_FWDED; pass the master's ifindex.
The lookup then runs with the resolved device as the ingress;
params->ifindex itself is not modified on the input side. When the
resolved device is enslaved to a VRF, both the full lookup (via the
l3mdev rule) and BPF_FIB_LOOKUP_DIRECT (via l3mdev_fib_table_rcu())
select the VRF's table from the resolved ingress. That follows from
feeding the resolved device to the flow as the ingress
(fl4.flowi4_iif = dev->ifindex), which is what makes l3mdev resolve
the VRF master from the subinterface rather than from
params->ifindex.

The two failure classes get different treatment on purpose. A
h_vlan_proto other than 802.1Q/802.1ad is API misuse and returns
-EINVAL, since it would otherwise reach the WARN in vlan_proto_idx()
with a program-controlled value. An unmatched VID, a device that is
down, or one in another namespace is a data outcome and returns
BPF_FIB_LKUP_RET_NOT_FWDED, matching the DIRECT path when
fib_get_table() finds no table and mirroring real ingress, where the
receive path drops such frames. A VID of 0 (a priority tag) is looked
up literally and normally fails the same way; receive instead
processes such frames untagged, so callers should not set the flag for
priority tags. Proceeding on the physical device for any of these
would be fail-open for the policy-routing cases above.

The h_vlan fields share a union with tbid, so the flag cannot be
combined with BPF_FIB_LOOKUP_TBID. It describes ingress, so it also
cannot be combined with BPF_FIB_LOOKUP_OUTPUT. Both combinations
return -EINVAL; restricting now keeps a later relaxation backward
compatible. Combining with BPF_FIB_LOOKUP_VLAN is allowed: the tag is
consumed on the ingress side and the egress tag is written on
success.

Under !CONFIG_VLAN_8021Q the __vlan_find_dev_deep_rcu() stub returns
NULL, so every lookup with a valid proto returns NOT_FWDED, which is
correct since no VLAN device can exist.

Suggested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Avinash Duduskar <avinash.duduskar@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/bpf/20260713162305.1237211-3-avinash.duduskar@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-10-02 05:41:50 -07:00
Avinash Duduskar a432251e60 bpf: Add BPF_FIB_LOOKUP_VLAN flag to bpf_fib_lookup() helper
bpf_fib_lookup() returns the FIB-resolved egress ifindex straight
from the fib result. When the egress is a VLAN device, the returned
ifindex is the VLAN netdev's, which has no XDP xmit handler; XDP
programs that want to forward the frame (e.g. xdp-forward) must
instead target the underlying physical device and push the VLAN tag
themselves. Today the program has no way to learn either the
underlying ifindex or the VLAN tag without maintaining its own
VLAN-to-ifindex map in userspace and refreshing it on netlink
events.

Add BPF_FIB_LOOKUP_VLAN. When the caller sets this flag and the fib
result is a VLAN device whose immediate parent is a real (non-VLAN)
device in the same network namespace, populate the existing output
fields params->h_vlan_proto and params->h_vlan_TCI from the VLAN
device and replace params->ifindex with the parent's ifindex.
params->h_vlan_TCI carries the VID only, with PCP and DEI bits zero; a
consumer wanting to set egress priority writes PCP itself.
params->smac is the VLAN device's own address, which can differ from
the parent's.

Only the immediate parent is resolved, via vlan_dev_priv(dev)->real_dev
and not vlan_dev_real_dev(), which walks to the bottom of a stack. When
the immediate parent is not a real device in the same namespace, the
lookup returns BPF_FIB_LKUP_RET_VLAN_FAILURE and leaves params->ifindex
at the input. This covers a stacked VLAN (QinQ), where the immediate
parent is itself a VLAN device and one h_vlan_proto/h_vlan_TCI pair
cannot describe two tags, and a parent in another network namespace (a
VLAN device can be moved while its parent stays), whose ifindex would
be meaningless in the caller's namespace. A program that wants the
VLAN device's own ifindex re-issues the lookup, with a re-initialized
params, without BPF_FIB_LOOKUP_VLAN, so the unreducible case stays
distinct from a physical egress. That distinction matters for XDP: a
program cannot xmit on a VLAN device, so a success carrying the VLAN
ifindex would make it redirect to a device with no ndo_xdp_xmit and
drop the frame at xdp_do_flush(). The swap and the vlan fields are
written only on the reduce path; other output fields keep their
existing behaviour, so a frag-needed result still reports the route
mtu in params->mtu_result.

BPF_FIB_LOOKUP_VLAN is only useful to XDP, which cannot redirect to a
VLAN device. A tc program can redirect to the VLAN device directly, so
bpf_skb_fib_lookup() rejects the flag with -EINVAL; bpf_xdp_fib_lookup()
accepts it. When the flag is not set, behaviour is unchanged:
h_vlan_proto and h_vlan_TCI are zeroed and ifindex is left at the FIB
result.

The new block is compiled only under CONFIG_VLAN_8021Q since
vlan_dev_priv() is not defined otherwise; without that config
is_vlan_dev() is constant false and the flag is accepted but never
acts. That is safe because no VLAN device can exist there, so every
egress is already physical.

This lets an XDP redirect target the physical device and learn the
tag to push in a single lookup, which xdp-forward's optional VLAN
mode (xdp-project/xdp-tools#504) wants from the kernel side.

The helper's input semantics are unchanged; the reverse direction
(supplying a tag as lookup input) is added in the following patch.

Suggested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Avinash Duduskar <avinash.duduskar@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/bpf/20260713162305.1237211-2-avinash.duduskar@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-10-02 05:41:50 -07:00
Christian Brauner d8b7bfc9f6 fs: support FD_FAILFS_ROOT in fchdir()
Add a new file descriptor sentinel FD_FAILFS_ROOT following
FD_PIDFS_ROOT and FD_NSFS_ROOT and teach fchdir() to accept it. A
process calling fchdir(FD_FAILFS_ROOT) moves its working directory
into failfs. Every AT_FDCWD-relative lookup afterwards fails with
EOPNOTSUPP including "." and ".." and getcwd() reports the working
directory as unreachable from the process root by returning a path
prefixed with "(unreachable)". Lookups relative to explicit directory
file descriptors are unaffected.

The sentinel is the only way in. No privilege or gating is required.
Setting the working directory to a directory in which every operation
fails grants nothing and loses nothing that closing file descriptors
couldn't lose. An unlinked working directory behaves the same way today
modulo errno. The working directory also plays no role in confining ".."
resolution so no boundary is weakened.

Link: https://patch.msgid.link/20260724-work-failfs-v2-2-485dabbae185@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-10-02 05:41:50 -07:00
Jiri Olsa d36d49e72c bpf: Add tracing_multi link info support
Adding BPF_OBJ_GET_INFO_BY_FD support for tracing_multi links.

We expose following tracing_multi link data:
- attach_type of the program
- number of ids
- array of BTF ids
- array of its related kernel addresses
- array of cookies

The change follows the kprobe_multi and uprobe_multi link-info convention
of optional output arrays with an in/out count,

On top of standard tracing link data we also expose addresses, because they
are useful info for user (especially when the attachment was done via pattern).
This data is hidden when kallsyms does not allow exposing kernel pointer values.

Assisted-by: Codex:GPT-5

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Leon Hwang <leon.hwang@linux.dev>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260629212208.895962-2-jolsa@kernel.org
2026-06-29 23:22:06 +02:00
Jordan Rife 8dae7836fb bpf: Support BPF_F_EGRESS with bpf_redirect_peer
We have several use cases where a pod injects traffic into the datapath
of another so that the traffic appears to have originated from that
pod. One such use case is a synthetic flow generator which injects
synthetic traffic into a pod's datapath to enable dynamic probing and
debugging. Another is a transparent proxy where connections originating
from one pod are redirected towards another which proxies that
connection. The new connection is bound to the IP of the original pod
using IP_TRANSPARENT and its traffic is injected into that pod's
datapath and handled as if it had originated there. This can be used for
mTLS, etc.

We use bpf_redirect(BPF_F_INGRESS) to direct traffic leaving the proxy,
flow generator, etc. towards the target pod, ensuring that eBPF programs
that are meant to intercept traffic leaving that pod are executed.
However, this doesn't work with netkit.

With netkit, an ingress redirection from proxy to workload skips eBPF
programs that are meant to intercept traffic leaving the pod, since they
reside on the netkit peer device. One workaround is to attach the
same program to both the netkit peer device and the TCX ingress hook for
the netkit pair's primary interface, but

a) This seems hacky and we need to be careful not to run the same
   program twice for the same skb in cases where we want to pass that
   traffic to the host stack.
b) We're trying to keep the proxy redirection / traffic injection
   systems as modular and separated from Cilium as possible, the system
   that manages netkit setup and core eBPF programming.

It would be handy if instead we could redirect traffic directly from
one netkit peer device to another. This patch proposes an extension
to bpf_redirect_peer to allow us to do just that.

With this patch, the BPF_F_EGRESS flag tells bpf_redirect_peer to emit
the skb in the egress direction of the target interface's peer device
While the main use case is netkit, I suppose you could also use this
mode with veth as well if, e.g., there were some eBPF programs attached
to that side of the veth pair that needed to intercept traffic.

 +---------------------------------------------------------------------+
 | +-------------------------+         6. bpf_redirect_neigh(eth0)     |
 | | pod (10.244.0.10)       |           ------------------------      |
 | |                         |          |                        |     |
 | |              +--------+ |          |      +---------+       |     |
 | | 1. packet -->|        | |          |      |         |       |     |
 | |    leaves ^  | netkit |<===========|======| netkit  |       |     |
 | |           |  | peer   |=======(eBPF)=====>| primary |       |     |
 | |           |  |        | |          |      |         |       |     |
 | |           |  +--------+ |          |      +---------+       |     |
 | |           |             |          | 2. bpf_redirect        v     |
 | +-----------|-------------+          |___________________   +-------|
 |             |                                            |  | eth0  |
 |             | 5. bpf_redirect_peer(BPF_F_EGRESS)         |  +-------|
 |             |________________________                    |          |
 | +-------------------------+          |                   |          |
 | | proxy (10.244.0.11)     |          |                   |          |
 | | IP_TRANSPARENT          |          |                   |          |
 | |              +--------+ |          |      +---------+  |          |
 | | 3. packet <--|        | |          |      |         |<--          |
 | |    enters    | netkit |<===========|======| netkit  |             |
 | |    [proxy]   | peer   |=======(eBPF)=====>| primary |             |
 | | 4. packet -->|        | |                 |         |             |
 | |    leaves    +--------+ |                 +---------+             |
 | |    sip=10.244.0.10      |                                         |
 | +-------------------------+                                         |
 +---------------------------------------------------------------------+

Using the proxy use case as an example, in step 5 we would redirect
traffic leaving the proxy towards the pod's peer device using
bpf_redirect_peer(BPF_F_EGRESS).

As a bonus, since the skb doesn't have to go through the backlog queue
it can take full advantage of netkit's performance benefits. I set up a
test where outgoing iperf3 traffic is injected into the datapath of
another pod using either bpf_redirect_peer(BPF_F_EGRESS) or
bpf_redirect(BPF_F_INGRESS). I used Cilium's eBPF host routing mode
which skips the host stack and uses BPF redirect helpers to do all the
routing.

  (net.ipv4.tcp_congestion_control=cubic,mtu=1500,100GiB link,Cilium
   eBPF host routing mode)

BASELINE [bpf_redirect(BPF_F_INGRESS)]
  1. [iperf pod] ==bpf_redirect([pod b], BPF_F_INGRESS)==> [pod b]
  2. [pod b]     ==bpf_redirect_neigh([eth0])==>           eth0
  3. eth0        ==over network==>                         [host b]

  [ ID] Interval           Transfer     Bitrate         Retr
  [  5]   0.00-60.00  sec   231 GBytes  33.0 Gbits/sec  12060     sender
  [  5]   0.00-60.00  sec   230 GBytes  33.0 Gbits/sec            receiver

TEST [bpf_redirect_peer(BPF_F_EGRESS)]
  1. [iperf pod] ==bpf_redirect_peer([pod b], BPF_F_EGRESS)==> [pod b]
  2. [pod b]     ==bpf_redirect_neigh([eth0])==>               eth0
  3. eth0        ==over network==>                             [host b]

  [ ID] Interval           Transfer     Bitrate         Retr
  [  5]   0.00-60.00  sec   272 GBytes  38.9 Gbits/sec    0       sender
  [  5]   0.00-60.00  sec   272 GBytes  38.9 Gbits/sec            receiver

In this test, using bpf_redirect_peer(BPF_F_EGRESS) for the hop from
[iperf pod] to [pod b] led to ~18% more throughput compared to
bpf_redirect(BPF_F_INGRESS).

Signed-off-by: Jordan Rife <jordan@jrife.io>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paul Chaignon <paul.chaignon@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260618182035.43811-2-jordan@jrife.io
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Jiri Olsa 82d3303c39 bpf: Add support to specify uprobe_multi target via file descriptor
Allow uprobe_multi link to identify the target binary by an already
opened file descriptor.

Adding new BPF_F_UPROBE_MULTI_PATH_FD flag and the path_fd field for
the attr.link_create.uprobe_multi struct.

When the flag is set, we resolve the target from path_fd, without the
flag, we keep the existing string path behavior.

I don't see a use case for supporting O_PATH file descriptors, because
we need to read the binary first to get probes offsets, so I'm using
the CLASS(fd, f), which fails for O_PATH fds.

Assisted-by: Codex:GPT-5.4
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260611114230.950379-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Jiri Olsa ed2a823a50 bpf: Add support for tracing_multi link session
Adding support to use session attachment with tracing_multi link.

Adding new BPF_TRACE_FSESSION_MULTI program attach type, that follows
the BPF_TRACE_FSESSION behaviour but on the tracing_multi link.

Such program is called on entry and exit of the attached function
and allows to pass cookie value from entry to exit execution.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-16-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Jiri Olsa 1ba74665c7 bpf: Add support for tracing_multi link cookies
Add support to specify cookies for tracing_multi link.

Cookies are provided in array where each value is paired with provided
BTF ID value with the same array index.

Such cookie can be retrieved by bpf program with bpf_get_attach_cookie
helper call.

We need to sort cookies array together with ids array in check_dup_ids,
to keep the id->cookie relation.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-15-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Jiri Olsa 622bb934a9 bpf: Add support for tracing multi link
Adding new link to allow to attach program to multiple function
BTF IDs. The link is represented by struct bpf_tracing_multi_link.

To configure the link, new fields are added to bpf_attr::link_create
to pass array of BTF IDs;

  struct {
    __aligned_u64 ids;
    __u32         cnt;
  } tracing_multi;

Each BTF ID represents function (BTF_KIND_FUNC) that the link will
attach bpf program to.

We use previously added bpf_trampoline_multi_attach/detach functions
to attach/detach the link.

The linkinfo/fdinfo callbacks will be implemented in following changes.

Note this is supported only for archs (x86_64) with ftrace direct and
have single ops support.

  CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS &&
  CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS

Note using sort_r (instead of plain sort) in check_dup_ids, because we
will use the swap callback in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-14-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Jiri Olsa 4e48554f9f bpf: Add multi tracing attach types
Adding new program attach types multi tracing attachment:
  BPF_TRACE_FENTRY_MULTI
  BPF_TRACE_FEXIT_MULTI

and their base support in verifier code.

Programs with such attach type will use specific link attachment
interface coming in following changes.

This was suggested by Andrii some (long) time ago and turned out
to be easier than having special program flag for that.

Bpf programs with such types have 'bpf_multi_func' function set as
their attach_btf_id and keep module reference when it's specified
by attach_prog_fd.

They are also accepted as sleepable programs during verification,
and the real validation for specific BTF_IDs/functions will happen
during the multi link attachment in following changes.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Leon Hwang c25c836734 bpf: Check tail zero of bpf_prog_info
Since there're 4 bytes padding at the end of struct bpf_prog_info, they
won't be checked by bpf_check_uarg_tail_zero().

pahole -C bpf_prog_info ./vmlinux
struct bpf_prog_info {
	...
	__u32                      attach_btf_obj_id;    /*   220     4 */
	__u32                      attach_btf_id;        /*   224     4 */

	/* size: 232, cachelines: 4, members: 38 */
	/* sum members: 224 */
	/* sum bitfield members: 1 bits, bit holes: 1, sum bit holes: 31 bits */
	/* padding: 4 */
	/* forced alignments: 9 */
	/* last cacheline: 40 bytes */
} __attribute__((__aligned__(8)));

If a future kernel extension adds a new 4-byte field, older userspace
programs allocating this structure on the stack might inadvertently pass
uninitialized stack garbage into the new field, permanently breaking
backward compatibility. -- sashiko [1]

Fix it by changing sizeof(info) to
offsetofend(struct bpf_prog_info, attach_btf_id).

And, add "__u32 :32" to the tail of struct bpf_prog_info.

[1] https://lore.kernel.org/bpf/20260513224823.6494FC19425@smtp.kernel.org/

Fixes: aba64c7da983 ("bpf: Add verified_insns to bpf_prog_info and fdinfo")
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260605155249.20772-3-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Leon Hwang b8612dd587 bpf: Check tail zero of bpf_map_info
Since there're 4 bytes padding at the end of struct bpf_map_info, they
won't be checked by bpf_check_uarg_tail_zero().

pahole -C bpf_map_info ./vmlinux
struct bpf_map_info {
	...
	__u64                      hash __attribute__((__aligned__(8))); /*    88     8 */
	__u32                      hash_size;            /*    96     4 */

	/* size: 104, cachelines: 2, members: 18 */
	/* padding: 4 */
	/* forced alignments: 1 */
	/* last cacheline: 40 bytes */
} __attribute__((__aligned__(8)));

If a future kernel extension adds a new 4-byte field, older userspace
programs allocating this structure on the stack might inadvertently pass
uninitialized stack garbage into the new field, permanently breaking
backward compatibility. -- sashiko [1]

Fix it by changing sizeof(info) to
offsetofend(struct bpf_map_info, hash_size).

And, add "__u32 :32" to the tail of struct bpf_map_info.

[1] https://lore.kernel.org/bpf/20260513224823.6494FC19425@smtp.kernel.org/

Fixes: ea2e6467ac36 ("bpf: Return hashes of maps in BPF_OBJ_GET_INFO_BY_FD")
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260605155249.20772-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Mykyta Yatsenko 1369dc002d bpf: Implement resizable hashmap basic functions
Use rhashtable_lookup_likely() for lookups, rhashtable_remove_fast()
for deletes, and rhashtable_lookup_get_insert_fast() for inserts.

Updates modify values in place under RCU rather than allocating a
new element and swapping the pointer (as regular htab does). This
trades read consistency for performance: concurrent readers may
see partial updates. BPF_F_LOCK support and special-field
handling (timers, kptrs, etc.) follow in a later commit.

Initialize rhashtable with bpf_mem_alloc element cache. Require
BPF_F_NO_PREALLOC. Limit max_entries to 2^31. Free elements via
rhashtable_free_and_destroy().

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260605-rhash-v7-4-5b8e05f8630d@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-30 10:49:46 -07:00
Dragos Tatulea 04e0c4cdbf netdev: expose io_uring rx_page_order order via netlink
This adds observability for the io_uring zcrx rx-buf-len configuration.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Yael Chemla <ychemla@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Acked-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/20260612211709.1456966-3-dtatulea@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-30 10:49:46 -07:00
Louis Scalbert 1c1b4bdf74 bonding: 3ad: add lacp_strict configuration knob
When an 802.3ad (LACP) bonding interface has no slaves in the
collecting/distributing state, the bonding master still reports
carrier as up as long as at least 'min_links' slaves have carrier.

In this situation, only one slave is effectively used for TX/RX,
while traffic received on other slaves is dropped. Upper-layer
daemons therefore consider the interface operational, even though
traffic may be blackholed if the lack of LACP negotiation means
the partner is not ready to deal with traffic.

Introduce a configuration knob to control this behavior. It allows
the bonding master to assert carrier only when at least 'min_links'
slaves are in Collecting_Distributing state.

The default mode preserves the existing behavior. This patch only
introduces the knob; its behavior is implemented in the subsequent
commit.

Fixes: 655f8919d549 ("bonding: add min links parameter to 802.3ad")
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Acked-by: Jay Vosburgh <jv@jvosburgh.net>
Link: https://patch.msgid.link/20260603150331.1919611-4-louis.scalbert@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-30 10:49:46 -07:00
Kuniyuki Iwashima 494ba2a44d geneve: Introduce IFLA_GENEVE_LOCAL and IFLA_GENEVE_LOCAL6.
By default, a GENEVE device bind()s its underlying UDP socket(s) to
the IPv4 or IPv6 wildcard address because there is no way to specify
a specific local IP address to bind() to.

This prevents deploying multiple GENEVE devices on a multi-homed host
where each device should be isolated and bound to a different local IP
address on the same UDP port.

Let's introduce new options, IFLA_GENEVE_LOCAL and IFLA_GENEVE_LOCAL6,
to allow specifying a local IPv4/IPv6 address for the backend UDP
socket.

By default, when collect metadata mode (IFLA_GENEVE_COLLECT_METADATA)
is enabled, both IPv4 and IPv6 sockets are created.  However, if a
source address is specified via the new attributes, only a single
socket corresponding to that specific address family is created.

Accordingly, geneve_find_sock() and geneve_find_dev() are updated to
take the source address into account, ensuring that multiple devices
and sockets configured with different source addresses can coexist
without conflict.

In addition, the source address is validated in geneve_xmit_skb()
and geneve6_xmit_skb(), so the BPF prog must set it in bpf_tunnel_key.

With this change, multiple GENEVE devices can be successfully created
and bound to their respective local IP addresses:

  (*) "local" is the keyword for IFLA_GENEVE_LOCAL / IFLA_GENEVE_LOCAL6

  # for i in $(seq 1 2);
  do
          ip link add geneve4_${i} type geneve local 192.168.0.${i} external
          ip addr add 192.168.0.${i}/24 dev geneve4_${i}
          ip link set geneve4_${i} up

          ip link add geneve6_${i} type geneve local 2001:9292::${i} external
          ip addr add 2001:9292::${i}/64 dev geneve6_${i} nodad
          ip link set geneve6_${i} up
  done

  # ip -d l | grep geneve
  9: geneve4_1: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
      geneve external id 0 local 192.168.0.1 ...
  10: geneve6_1: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
      geneve external id 0 local 2001:9292::1 ...
  11: geneve4_2: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
      geneve external id 0 local 192.168.0.2 ...
  12: geneve6_2: <BROADCAST,MULTICAST,UP,LOWER_UP> ...
      geneve external id 0 local 2001:9292::2 ...

  # ss -ua | grep geneve
  UNCONN 0      0         192.168.0.2:geneve      0.0.0.0:*
  UNCONN 0      0         192.168.0.1:geneve      0.0.0.0:*
  UNCONN 0      0      [2001:9292::2]:geneve            *:*
  UNCONN 0      0      [2001:9292::1]:geneve            *:*

Note that even if the local address is explicitly configured with
the wildcard address, kernel does not dump it except for devices with
IFLA_GENEVE_COLLECT_METADATA.  This is consistent with the behaviour
of is_tnl_info_zero(), which treats the wildcard remote address as not
configured.

  ## ynl example.
  # ./tools/net/ynl/pyynl/cli.py \
    --spec ./Documentation/netlink/specs/rt-link.yaml \
    --do newlink --create \
    --json '{"ifname": "geneve0",
             "linkinfo": {"kind":"geneve",
	                  "data": {"local": "0.0.0.0",
			           "collect-metadata": true}}}'

  # ./tools/net/ynl/pyynl/cli.py \
    --spec ./Documentation/netlink/specs/rt-link.yaml \
    --do getlink \
    --json '{"ifname": "geneve0"}' --output-json | \
    jq .linkinfo.data.local
  "0.0.0.0"

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260602190436.139591-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-30 10:49:46 -07:00
Danielle Ratson cc1ee3742d bridge: uapi: Add neigh_forward_grat netlink attributes
Add netlink attributes for controlling gratuitous ARP and unsolicited NA
forwarding when neighbor suppression is enabled.

Add IFLA_BRPORT_NEIGH_FORWARD_GRAT for port-level control and
BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT for per-VLAN control.

The new attributes provide independent control of gratuitous ARP and
unsolicited NA packets. Operators can enable forwarding for those packets
for fast mobility across VTEPs while keeping general neighbor suppression
active.

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Link: https://patch.msgid.link/20260511065936.4173106-2-danieller@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-30 10:49:46 -07:00
Stephen Hemminger 1729da885e net/sched: netem: add per-impairment extended statistics
Add 64-bit counters for each impairment netem applies (delay, loss,
ECN marking, corruption, duplication, reordering) and for skb
allocation failures during enqueue. Exposed through TCA_STATS_APP
as struct tc_netem_xstats.

Counters increment when an impairment is occurs, independent of later
events that may mask its on-wire effect. Added allocation_errors
(similar to sch_fq) to account for when impairment could not be
applied due to memory pressure, etc.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://patch.msgid.link/20260509171123.307549-6-stephen@networkplumber.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-30 10:49:46 -07:00
Dorjoy Chowdhury b03713be6f openat2: new OPENAT2_REGULAR flag support
This flag indicates the path should be opened if it's a regular file.
This is useful to write secure programs that want to avoid being
tricked into opening device nodes with special semantics while thinking
they operate on regular files. This is a requested feature from the
uapi-group[1].

The previously introduced EFTYPE error code is returned when the path
doesn't refer to a regular file. For example, if openat2 is called on
path /dev/null with OPENAT2_REGULAR in the flag param, it will return
-EFTYPE.

When used in combination with O_CREAT, either the regular file is
created, or if the path already exists, it is opened if it's a regular
file. Otherwise, -EFTYPE is returned.

When OPENAT2_REGULAR is combined with O_DIRECTORY, -EINVAL is returned
as it doesn't make sense to open a path that is both a directory and a
regular file.

The UAPI bit lives in the upper 32 bits of open_how::flags
(((__u64)1 << 32)) so that open(2) and openat(2) -- whose @flags
argument is a C int -- cannot physically express it. This is a
structural guarantee, not a runtime mask: the bit is unrepresentable in
32 bits.

Because the rest of the VFS open path narrows to 32 bits in several
places (op->open_flag, f->f_flags, the unsigned open_flag argument of
i_op->atomic_open()), build_open_flags() translates OPENAT2_REGULAR
into a kernel-internal lower-32-bit carrier __O_REGULAR (bit 4, unused
as an O_* on every architecture) before the assignment to op->open_flag.
__O_REGULAR then rides through the existing channels exactly like
__FMODE_EXEC. do_dentry_open() strips it so it cannot leak back to
userspace via fcntl(F_GETFL).

Four BUILD_BUG_ON_MSG() invariants in build_open_flags() prevent any
future bit collision or accidental low-32 redefinition:

  - VALID_OPEN_FLAGS fits in 32 bits.
  - OPENAT2_REGULAR lives in the upper 32 bits.
  - OPENAT2_REGULAR does not alias any open()/openat() flag.
  - __O_REGULAR does not alias any user-visible flag.

[1]: https://uapi-group.org/kernel-features/#ability-to-only-open-regular-files

Christian Brauner <brauner@kernel.org> says:

Move OPENAT2_REGULAR to the upper 32 bits of open_how::flags with a
kernel-internal __O_REGULAR carrier so that open(2)/openat(2) cannot
encode the flag; add BUILD_BUG_ON_MSG() invariants and register
__O_REGULAR in the fcntl_init() allocation-uniqueness BUILD_BUG_ON()
(bit count 21 -> 22).

Signed-off-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
Link: https://patch.msgid.link/20260328172314.45807-2-dorjoychy111@gmail.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Aleksa Sarai <aleksa@amutable.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-30 10:49:46 -07:00
Leon Hwang 978fc80ec7 bpf: Extend BPF syscall with common attributes support
Add generic BPF syscall support for passing common attributes.

The initial set of common attributes includes:

1. 'log_buf': User-provided buffer for storing logs.
2. 'log_size': Size of the log buffer.
3. 'log_level': Log verbosity level.
4. 'log_true_size': Actual log size reported by kernel.

The common-attribute pointer and its size are passed as the 4th and 5th
syscall arguments. A new command bit, 'BPF_COMMON_ATTRS' ('1 << 16'),
indicates that common attributes are supplied.

This commit adds syscall and uapi plumbing. Command-specific handling is
added in follow-up patches.

Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260512153157.28382-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-05-30 20:45:51 -07:00
Alan Maguire 9801e02973 bpf: Extend BTF UAPI vlen, kinds to use unused bits
BTF maximum vlen is encoded using 16 bits with a maximum vlen
of 65535.  This has sufficed for structs, function parameters
and enumerated type values.  However, with upcoming BTF location
information - in particular information about inline sites -
this limit is surpassed.  Use bits 16-23 - currently unused in
BTF info - to extend to 24 bits, giving a max vlen of (2^24 - 1),
or 16 million.

Also extend BTF kind encoding from 5 to 7 bits, giving a maximum
available number of kinds of 128.  Since with the BTF location work
we use another 3 kinds, we are fast approaching the current limit
of 32.

Convert BTF_MAX_* values to enums to allow them to be encoded in
kernel BTF; this will allow us to detect if the running kernel
supports a 24-bit vlen or not.  Add one for max _possible_
(not used) kind.

Fix up a few places in the kernel where a 16-bit vlen is assumed;
remove BTF_INFO_MASK as now all bits are used.

The vlen expansion was suggested by Andrii in [1]; the kind expansion
is tackled here too as it may be needed also to support new kinds
in BTF.

[1] https://lore.kernel.org/bpf/CAEf4BzZx=X6vGqcA8SPU6D+v6k+TR=ZewebXMuXtpmML058piw@mail.gmail.com/

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260417143023.1551481-2-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-05-30 20:45:51 -07:00
Andy Roulin 86525c190b net: bridge: add stp_mode attribute for STP mode selection
The bridge-stp usermode helper is currently restricted to the initial
network namespace, preventing userspace STP daemons (e.g. mstpd) from
operating on bridges in other network namespaces. Since commit
ff62198553e4 ("bridge: Only call /sbin/bridge-stp for the initial
network namespace"), bridges in non-init namespaces silently fall
back to kernel STP with no way to use userspace STP.

Add a new bridge attribute IFLA_BR_STP_MODE that allows explicit
per-bridge control over STP mode selection:

  BR_STP_MODE_AUTO (default) - Existing behavior: invoke the
    /sbin/bridge-stp helper in init_net only; fall back to kernel STP
    if it fails or in non-init namespaces.

  BR_STP_MODE_USER - Directly enable userspace STP (BR_USER_STP)
    without invoking the helper. Works in any network namespace.
    Userspace is responsible for ensuring an STP daemon manages the
    bridge.

  BR_STP_MODE_KERNEL - Directly enable kernel STP (BR_KERNEL_STP)
    without invoking the helper.

The mode can only be changed while STP is disabled, or set to the
same value (-EBUSY otherwise). IFLA_BR_STP_MODE is processed before
IFLA_BR_STP_STATE in br_changelink(), so both can be set atomically
in a single netlink message. The mode can also be changed in the
same message that disables STP.

The stp_mode struct field is u8 since all possible values fit, while
NLA_U32 is used for the netlink attribute since it occupies the same
space in the netlink message as NLA_U8.

A new stp_helper_active boolean tracks whether the /sbin/bridge-stp
helper was invoked during br_stp_start(), so that br_stp_stop() only
calls the helper for stop when it was called for start. This avoids
calling the helper asymmetrically when stp_mode changes between
start and stop.

Suggested-by: Ido Schimmel <idosch@nvidia.com>
Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Andy Roulin <aroulin@nvidia.com>
Link: https://patch.msgid.link/20260405205224.3163000-2-aroulin@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-30 20:45:51 -07:00
Daniel Borkmann 8159a62fa8 netkit: Add single device mode for netkit
Add a single device mode for netkit instead of netkit pairs. The primary
target for the paired devices is to connect network namespaces, of course,
and support has been implemented in projects like Cilium [0]. For the rxq
leasing the plan is to support two main scenarios related to single device
mode:

* For the use-case of io_uring zero-copy, the control plane can either
  set up a netkit pair where the peer device can perform rxq leasing which
  is then tied to the lifetime of the peer device, or the control plane
  can use a regular netkit pair to connect the hostns to a Pod/container
  and dynamically add/remove rxq leasing through a single device without
  having to interrupt the device pair. In the case of io_uring, the memory
  pool is used as skb non-linear pages, and thus the skb will go its way
  through the regular stack into netkit. Things like the netkit policy when
  no BPF is attached or skb scrubbing etc apply as-is in case the paired
  devices are used, or if the backend memory is tied to the single device
  and traffic goes through a paired device.

* For the use-case of AF_XDP, the control plane needs to use netkit in the
  single device mode. The single device mode currently enforces only a
  pass policy when no BPF is attached, and does not yet support BPF link
  attachments for AF_XDP. skbs sent to that device get dropped at the
  moment. Given AF_XDP operates at a lower layer of the stack tying this
  to the netkit pair did not make sense. In future, the plan is to allow
  BPF at the XDP layer which can: i) process traffic coming from the AF_XDP
  application (e.g. QEMU with AF_XDP backend) to filter egress traffic or
  to push selected egress traffic up to the single netkit device to the
  local stack (e.g. DHCP requests), and ii) vice-versa skbs sent to the
  single netkit into the AF_XDP application (e.g. DHCP replies). Also,
  the control-plane can dynamically manage rxq leasing for the single
  netkit device without having to interrupt (e.g. down/up cycle) the main
  netkit pair for the Pod which has traffic going in and out.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Jordan Rife <jordan@jrife.io>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://docs.cilium.io/en/stable/operations/performance/tuning/#netkit-device-mode [0]
Link: https://patch.msgid.link/20260402231031.447597-11-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-30 20:45:51 -07:00
Daniel Borkmann c361e88771 net: Add queue-create operation
Add a ynl netdev family operation called queue-create that creates a
new queue on a netdevice:

      name: queue-create
      attribute-set: queue
      flags: [admin-perm]
      do:
        request:
          attributes:
            - ifindex
            - type
            - lease
        reply: &queue-create-op
          attributes:
            - id

This is a generic operation such that it can be extended for various
use cases in future. Right now it is mandatory to specify ifindex,
the queue type which is enforced to rx and a lease. The newly created
queue id is returned to the caller.

A queue from a virtual device can have a lease which refers to another
queue from a physical device. This is useful for memory providers
and AF_XDP operations which take an ifindex and queue id to allow
applications to bind against virtual devices in containers. The lease
couples both queues together and allows to proxy the operations from
a virtual device in a container to the physical device.

In future, the nested lease attribute can be lifted and made optional
for other use-cases such as dynamic queue creation for physical
netdevs. The lack of lease and the specification of the physical
device as an ifindex will imply that we need a real queue to be
allocated. Similarly, the queue type enforcement to rx can then be
lifted as well to support tx.

An early implementation had only driver-specific integration [0], but
in order for other virtual devices to reuse, it makes sense to have
this as a generic API in core net.

For leasing queues, the virtual netdev must have real_num_rx_queues
less than num_rx_queues at the time of calling queue-create. The
queue-type must be rx as only rx queues are supported for leasing
for now. We also enforce that the queue-create ifindex must point
to a virtual device, and that the nested lease attribute's ifindex
must point to a physical device. The nested lease attribute set
contains a netns-id attribute which is optional and can specify a
netns-id relative to the caller's netns. It requires cap_net_admin
and if the netns-id attribute is not specified, the lease ifindex
will be retrieved from the current netns. Also, it is modeled as
an s32 type similarly as done elsewhere in the stack.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://bpfconf.ebpf.io/bpfconf2025/bpfconf2025_material/lsfmmbpf_2025_netkit_borkmann.pdf [0]
Link: https://patch.msgid.link/20260402231031.447597-2-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-30 20:45:51 -07:00
Hangbin Liu b6f2d5c84d bonding: print churn state via netlink
Currently, the churn state is printed only in sysfs. Add netlink support
so users could get the state via netlink.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://patch.msgid.link/20260224020215.6012-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-30 20:45:51 -07:00
Eyal Birger c2838bdfe5 bpf: Clarify BPF_RB_NO_WAKEUP behavior for bpf_ringbuf_discard()
Clarify bpf_ringbuf_discard() documentation for BPF_RB_NO_WAKEUP.

Discarded ring buffer records are still left in the ring buffer and are
only skipped when user space consumes them. This can matter when
BPF_RB_NO_WAKEUP is used: a later submit relying on adaptive wakeup
might not wake the consumer, because the discarded record still needs to
be consumed first.

Scenario:

epoll_wait(rb_fd);                     // blocks

rec = bpf_ringbuf_reserve(&rb, ...);
bpf_ringbuf_discard(rec, BPF_RB_NO_WAKEUP);

rec = bpf_ringbuf_reserve(&rb, ...);
bpf_ringbuf_submit(rec, 0);           // valid record, but no wakeup

Document this in bpf_ringbuf_discard() to make the interaction between
discarded records, user-space consumption, and adaptive wakeups explicit.

Reported-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260331130612.3762433-1-eyal.birger@gmail.com

----

v2: adapt wording per feedback from Andrii.
2026-04-09 15:12:21 -07:00
Alan Maguire 462733ecb8 btf: Add BTF kind layout encoding to UAPI
BTF kind layouts provide information to parse BTF kinds. By separating
parsing BTF from using all the information it provides, we allow BTF
to encode new features even if they cannot be used by readers. This
will be helpful in particular for cases where older tools are used
to parse newer BTF with kinds the older tools do not recognize;
the BTF can still be parsed in such cases using kind layout.

The intent is to support encoding of kind layouts optionally so that
tools like pahole can add this information. For each kind, we record

- length of singular element following struct btf_type
- length of each of the btf_vlen() elements following
- a (currently unused) flags field

The ideas here were discussed at [1], [2]; hence

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260326145444.2076244-2-alan.maguire@oracle.com

[1] https://lore.kernel.org/bpf/CAEf4BzYjWHRdNNw4B=eOXOs_ONrDwrgX4bn=Nuc1g8JPFC34MA@mail.gmail.com/
[2] https://lore.kernel.org/bpf/20230531201936.1992188-1-alan.maguire@oracle.com/
2026-04-09 15:12:21 -07:00
Paolo Abeni a61d018702 geneve: add netlink support for GRO hint
Allow configuring and dumping the new device option, and cache its value
into the geneve socket itself.
The new option is not tie to it any code yet.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/2295d4e4d1e919a3189425141bbc71c7850a2de0.1769011015.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-17 20:15:42 -08:00
Jakub Kicinski 13ae2d1841 Revert "Merge branch 'netkit-support-for-io_uring-zero-copy-and-af_xdp'"
This reverts commit 77b9c4a438fc66e2ab004c411056b3fb71a54f2c, reversing
changes made to 4515ec4ad58a37e70a9e1256c0b993958c9b7497:

 931420a2fc36 ("selftests/net: Add netkit container tests")
 ab771c938d9a ("selftests/net: Make NetDrvContEnv support queue leasing")
 6be87fbb2776 ("selftests/net: Add env for container based tests")
 61d99ce3dfc2 ("selftests/net: Add bpf skb forwarding program")
 920da3634194 ("netkit: Add xsk support for af_xdp applications")
 eef51113f8af ("netkit: Add netkit notifier to check for unregistering devices")
 b5ef109d22d4 ("netkit: Implement rtnl_link_ops->alloc and ndo_queue_create")
 b5c3fa4a0b16 ("netkit: Add single device mode for netkit")
 0073d2fd679d ("xsk: Proxy pool management for leased queues")
 1ecea95dd3b5 ("xsk: Extend xsk_rcv_check validation")
 804bf334d08a ("net: Proxy netdev_queue_get_dma_dev for leased queues")
 0caa9a8ddec3 ("net: Proxy net_mp_{open,close}_rxq for leased queues")
 ff8889ff9107 ("net, ethtool: Disallow leased real rxqs to be resized")
 9e2103f36110 ("net: Add lease info to queue-get response")
 31127deddef4 ("net: Implement netdev_nl_queue_create_doit")
 a5546e18f77c ("net: Add queue-create operation")

The series will conflict with io_uring work, and the code needs more
polish.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-17 20:15:42 -08:00
Daniel Borkmann 05121e3fd9 netkit: Add single device mode for netkit
Add a single device mode for netkit instead of netkit pairs. The primary
target for the paired devices is to connect network namespaces, of course,
and support has been implemented in projects like Cilium [0]. For the rxq
leasing the plan is to support two main scenarios related to single device
mode:

* For the use-case of io_uring zero-copy, the control plane can either
  set up a netkit pair where the peer device can perform rxq leasing which
  is then tied to the lifetime of the peer device, or the control plane
  can use a regular netkit pair to connect the hostns to a Pod/container
  and dynamically add/remove rxq leasing through a single device without
  having to interrupt the device pair. In the case of io_uring, the memory
  pool is used as skb non-linear pages, and thus the skb will go its way
  through the regular stack into netkit. Things like the netkit policy when
  no BPF is attached or skb scrubbing etc apply as-is in case the paired
  devices are used, or if the backend memory is tied to the single device
  and traffic goes through a paired device.

* For the use-case of AF_XDP, the control plane needs to use netkit in the
  single device mode. The single device mode currently enforces only a
  pass policy when no BPF is attached, and does not yet support BPF link
  attachments for AF_XDP. skbs sent to that device get dropped at the
  moment. Given AF_XDP operates at a lower layer of the stack tying this
  to the netkit pair did not make sense. In future, the plan is to allow
  BPF at the XDP layer which can: i) process traffic coming from the AF_XDP
  application (e.g. QEMU with AF_XDP backend) to filter egress traffic or
  to push selected egress traffic up to the single netkit device to the
  local stack (e.g. DHCP requests), and ii) vice-versa skbs sent to the
  single netkit into the AF_XDP application (e.g. DHCP replies). Also,
  the control-plane can dynamically manage rxq leasing for the single
  netkit device without having to interrupt (e.g. down/up cycle) the main
  netkit pair for the Pod which has traffic going in and out.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Jordan Rife <jordan@jrife.io>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://docs.cilium.io/en/stable/operations/performance/tuning/#netkit-device-mode [0]
Link: https://patch.msgid.link/20260115082603.219152-10-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-17 20:15:42 -08:00
Daniel Borkmann a623828cdc net: Add queue-create operation
Add a ynl netdev family operation called queue-create that creates a
new queue on a netdevice:

      name: queue-create
      attribute-set: queue
      flags: [admin-perm]
      do:
        request:
          attributes:
            - ifindex
            - type
            - lease
        reply: &queue-create-op
          attributes:
            - id

This is a generic operation such that it can be extended for various
use cases in future. Right now it is mandatory to specify ifindex,
the queue type which is enforced to rx and a lease. The newly created
queue id is returned to the caller.

A queue from a virtual device can have a lease which refers to another
queue from a physical device. This is useful for memory providers
and AF_XDP operations which take an ifindex and queue id to allow
applications to bind against virtual devices in containers. The lease
couples both queues together and allows to proxy the operations from
a virtual device in a container to the physical device.

In future, the nested lease attribute can be lifted and made optional
for other use-cases such as dynamic queue creation for physical
netdevs. The lack of lease and the specification of the physical
device as an ifindex will imply that we need a real queue to be
allocated. Similarly, the queue type enforcement to rx can then be
lifted as well to support tx.

An early implementation had only driver-specific integration [0], but
in order for other virtual devices to reuse, it makes sense to have
this as a generic API in core net.

For leasing queues, the virtual netdev must have real_num_rx_queue
less than num_rx_queues at the time of calling queue-create. The
queue-type must be rx as only rx queues are supported for leasing
for now. We also enforce that the queue-create ifindex must point
to a virtual device, and that the nested lease attribute's ifindex
must point to a physical device. The nested lease attribute set
contains a netns-id attribute which is currently only intended for
dumping as part of the queue-get operation. Also, it is modeled as
an s32 type similarly as done elsewhere in the stack.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Link: https://bpfconf.ebpf.io/bpfconf2025/bpfconf2025_material/lsfmmbpf_2025_netkit_borkmann.pdf [0]
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260115082603.219152-2-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-17 20:15:42 -08:00
Jonas Köppeler 4f8bdd9ce3 net/sched: sch_cake: share shaper state across sub-instances of cake_mq
This commit adds shared shaper state across the cake instances beneath a
cake_mq qdisc. It works by periodically tracking the number of active
instances, and scaling the configured rate by the number of active
queues.

The scan is lockless and simply reads the qlen and the last_active state
variable of each of the instances configured beneath the parent cake_mq
instance. Locking is not required since the values are only updated by
the owning instance, and eventual consistency is sufficient for the
purpose of estimating the number of active queues.

The interval for scanning the number of active queues is set to 200 us.
We found this to be a good tradeoff between overhead and response time.
For a detailed analysis of this aspect see the Netdevconf talk:

https://netdevconf.info/0x19/docs/netdev-0x19-paper16-talk-paper.pdf

Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jonas Köppeler <j.koeppeler@tu-berlin.de>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20260109-mq-cake-sub-qdisc-v8-5-8d613fece5d8@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-17 20:15:42 -08:00
Dapeng Mi ad0d0e5112 perf/x86/intel: Add support for PEBS memory auxiliary info field in DMR
With the introduction of the OMR feature, the PEBS memory auxiliary info
field for load and store latency events has been restructured for DMR.

The memory auxiliary info field's bit[8] indicates whether a L2 cache
miss occurred for a memory load or store instruction. If bit[8] is 0,
it signifies no L2 cache miss, and bits[7:0] specify the exact cache data
source (up to the L2 cache level). If bit[8] is 1, bits[7:0] represent
the OMR encoding, indicating the specific L3 cache or memory region
involved in the memory access. A significant enhancement is OMR encoding
provides up to 8 fine-grained memory regions besides the cache region.

A significant enhancement for OMR encoding is the ability to provide
up to 8 fine-grained memory regions in addition to the cache region,
offering more detailed insights into memory access regions.

For detailed information on the memory auxiliary info encoding, please
refer to section 16.2 "PEBS LOAD LATENCY AND STORE LATENCY FACILITY" in
the ISE documentation.

This patch ensures that the PEBS memory auxiliary info field is correctly
interpreted and utilized in DMR.

Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260114011750.350569-3-dapeng1.mi@linux.intel.com
2026-02-11 12:04:56 -08:00
Bill Wendling 1317132162 compiler_types.h: Attributes: Add __counted_by_ptr macro
Introduce __counted_by_ptr(), which works like __counted_by(), but for
pointer struct members.

struct foo {
	int a, b, c;
	char *buffer __counted_by_ptr(bytes);
	short nr_bars;
	struct bar *bars __counted_by_ptr(nr_bars);
	size_t bytes;
};

Because "counted_by" can only be applied to pointer members in very
recent compiler versions, its application ends up needing to be distinct
from flexibe array "counted_by" annotations, hence a separate macro.

This is a reworking of Kees' previous patch [1].

Link: https://lore.kernel.org/all/20251020220118.1226740-1-kees@kernel.org/ [1]
Co-developed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Bill Wendling <morbo@google.com>
Link: https://patch.msgid.link/20260116005838.2419118-1-morbo@google.com
Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-11 12:04:56 -08:00
Matt Bobrowski ed6bb65cf1 bpf: add new BPF_CGROUP_ITER_CHILDREN control option
Currently, the BPF cgroup iterator supports walking descendants in
either pre-order (BPF_CGROUP_ITER_DESCENDANTS_PRE) or post-order
(BPF_CGROUP_ITER_DESCENDANTS_POST). These modes perform an exhaustive
depth-first search (DFS) of the hierarchy. In scenarios where a BPF
program may need to inspect only the direct children of a given parent
cgroup, a full DFS is unnecessarily expensive.

This patch introduces a new BPF cgroup iterator control option,
BPF_CGROUP_ITER_CHILDREN. This control option restricts the traversal
to the immediate children of a specified parent cgroup, allowing for
more targeted and efficient iteration, particularly when exhaustive
depth-first search (DFS) traversal is not required.

Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Link: https://lore.kernel.org/r/20260127085112.3608687-1-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-01-29 14:10:19 -08:00
Menglong Dong adde4f55b7 bpf: add fsession support
The fsession is something that similar to kprobe session. It allow to
attach a single BPF program to both the entry and the exit of the target
functions.

Introduce the struct bpf_fsession_link, which allows to add the link to
both the fentry and fexit progs_hlist of the trampoline.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Co-developed-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260124062008.8657-2-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-01-29 14:10:19 -08:00
Thomas Gleixner 5d02120e10 treewide: Update email address
In a vain attempt to consolidate the email zoo switch everything to the
kernel.org account.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-01-29 14:10:19 -08:00
Leon Hwang a6d7ceaaeb bpf: Introduce BPF_F_CPU and BPF_F_ALL_CPUS flags
Introduce BPF_F_CPU and BPF_F_ALL_CPUS flags and check them for
following APIs:

* 'map_lookup_elem()'
* 'map_update_elem()'
* 'generic_map_lookup_batch()'
* 'generic_map_update_batch()'

And, get the correct value size for these APIs.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260107022022.12843-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-01-29 14:10:19 -08:00
Thomas Weißschuh e64e125ef6 vfs: use UAPI types for new struct delegation definition
Using libc types and headers from the UAPI headers is problematic as it
introduces a dependency on a full C toolchain.

Use the fixed-width integer types provided by the UAPI headers instead.

Fixes: 1602bad16d7d ("vfs: expose delegation support to userland")
Fixes: 4be9e04ebf75 ("vfs: add needed headers for new struct delegation definition")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20251203-uapi-fcntl-v1-1-490c67bf3425@linutronix.de
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-29 14:10:19 -08:00
Amery Hung 1a41b12b4f bpf: Support associating BPF program with struct_ops
Add a new BPF command BPF_PROG_ASSOC_STRUCT_OPS to allow associating
a BPF program with a struct_ops map. This command takes a file
descriptor of a struct_ops map and a BPF program and set
prog->aux->st_ops_assoc to the kdata of the struct_ops map.

The command does not accept a struct_ops program nor a non-struct_ops
map. Programs of a struct_ops map is automatically associated with the
map during map update. If a program is shared between two struct_ops
maps, prog->aux->st_ops_assoc will be poisoned to indicate that the
associated struct_ops is ambiguous. The pointer, once poisoned, cannot
be reset since we have lost track of associated struct_ops. For other
program types, the associated struct_ops map, once set, cannot be
changed later. This restriction may be lifted in the future if there is
a use case.

A kernel helper bpf_prog_get_assoc_struct_ops() can be used to retrieve
the associated struct_ops pointer. The returned pointer, if not NULL, is
guaranteed to be valid and point to a fully updated struct_ops struct.
For struct_ops program reused in multiple struct_ops map, the return
will be NULL.

prog->aux->st_ops_assoc is protected by bumping the refcount for
non-struct_ops programs and RCU for struct_ops programs. Since it would
be inefficient to track programs associated with a struct_ops map, every
non-struct_ops program will bump the refcount of the map to make sure
st_ops_assoc stays valid. For a struct_ops program, it is protected by
RCU as map_free will wait for an RCU grace period before disassociating
the program with the map. The helper must be called in BPF program
context or RCU read-side critical section.

struct_ops implementers should note that the struct_ops returned may not
be initialized nor attached yet. The struct_ops implementer will be
responsible for tracking and checking the state of the associated
struct_ops map if the use case expects an initialized or attached
struct_ops.

Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20251203233748.668365-3-ameryhung@gmail.com
2025-12-16 09:52:07 -08:00