Delay accounting can now calculate the average delay of processes, detect
the overall system load, and also record the 'delay max' to identify
potential abnormal delays. However, 'delay min' can help us identify
another useful delay peak. By comparing the difference between 'delay
max' and 'delay min', we can understand the optimization space for
latency, providing a reference for the optimization of latency
performance.
Use case
=========
bash-4.4# ./getdelays -d -t 242
print delayacct stats ON
TGID 242
CPU count real total virtual total delay total delay average delay max delay min
39 156000000 156576579 2111069 0.054ms 0.212296ms 0.031307ms
IO count delay total delay average delay max delay min
0 0 0.000ms 0.000000ms 0.000000ms
SWAP count delay total delay average delay max delay min
0 0 0.000ms 0.000000ms 0.000000ms
RECLAIM count delay total delay average delay max delay min
0 0 0.000ms 0.000000ms 0.000000ms
THRASHING count delay total delay average delay max delay min
0 0 0.000ms 0.000000ms 0.000000ms
COMPACT count delay total delay average delay max delay min
0 0 0.000ms 0.000000ms 0.000000ms
WPCOPY count delay total delay average delay max delay min
156 11215873 0.072ms 0.207403ms 0.033913ms
IRQ count delay total delay average delay max delay min
0 0 0.000ms 0.000000ms 0.000000ms
Link: https://lkml.kernel.org/r/20241220173105906EOdsPhzjMLYNJJBqgz1ga@zte.com.cn
Co-developed-by: Wang Yong <wang.yong12@zte.com.cn>
Signed-off-by: Wang Yong <wang.yong12@zte.com.cn>
Co-developed-by: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Wang Yaxin <wang.yaxin@zte.com.cn>
Co-developed-by: Kun Jiang <jiang.kun2@zte.com.cn>
Signed-off-by: Kun Jiang <jiang.kun2@zte.com.cn>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Fan Yu <fan.yu9@zte.com.cn>
Cc: Peilin He <he.peilin@zte.com.cn>
Cc: tuqiang <tu.qiang35@zte.com.cn>
Cc: ye xingchen <ye.xingchen@zte.com.cn>
Cc: Yunkai Zhang <zhang.yunkai@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce the use cases of delay max, which can help quickly detect
potential abnormal delays in the system and record the types and specific
details of delay spikes.
Problem
========
Delay accounting can track the average delay of processes to show
system workload. However, when a process experiences a significant
delay, maybe a delay spike, which adversely affects performance,
getdelays can only display the average system delay over a period
of time. Yet, average delay is unhelpful for diagnosing delay peak.
It is not even possible to determine which type of delay has spiked,
as this information might be masked by the average delay.
Solution
=========
the 'delay max' can display delay peak since the system's startup,
which can record potential abnormal delays over time, including
the type of delay and the maximum delay. This is helpful for
quickly identifying crash caused by delay.
Use case
=========
bash# ./getdelays -d -p 244
print delayacct stats ON
PID 244
CPU count real total virtual total delay total delay average delay max
68 192000000 213676651 705643 0.010ms 0.306381ms
IO count delay total delay average delay max
0 0 0.000ms 0.000000ms
SWAP count delay total delay average delay max
0 0 0.000ms 0.000000ms
RECLAIM count delay total delay average delay max
0 0 0.000ms 0.000000ms
THRASHING count delay total delay average delay max
0 0 0.000ms 0.000000ms
COMPACT count delay total delay average delay max
0 0 0.000ms 0.000000ms
WPCOPY count delay total delay average delay max
235 15648284 0.067ms 0.263842ms
IRQ count delay total delay average delay max
0 0 0.000ms 0.000000ms
[wang.yaxin@zte.com.cn: update docs and fix some spelling errors]
Link: https://lkml.kernel.org/r/20241213192700771XKZ8H30OtHSeziGqRVMs0@zte.com.cn
Link: https://lkml.kernel.org/r/20241203164848805CS62CQPQWG9GLdQj2_BxS@zte.com.cn
Co-developed-by: Wang Yong <wang.yong12@zte.com.cn>
Signed-off-by: Wang Yong <wang.yong12@zte.com.cn>
Co-developed-by: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Co-developed-by: Wang Yaxin <wang.yaxin@zte.com.cn>
Signed-off-by: Wang Yaxin <wang.yaxin@zte.com.cn>
Signed-off-by: Kun Jiang <jiang.kun2@zte.com.cn>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Fan Yu <fan.yu9@zte.com.cn>
Cc: Peilin He <he.peilin@zte.com.cn>
Cc: tuqiang <tu.qiang35@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: ye xingchen <ye.xingchen@zte.com.cn>
Cc: Yunkai Zhang <zhang.yunkai@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Updates for v6.14
MDSS:
- properly described UBWC registers
- added SM6150 (aka QCS615) support
MDP4:
- several small fixes
DPU:
- added SM6150 (aka QCS615) support
- enabled wide planes if virtual planes are enabled (by using two SSPPs for a single plane)
- fixed modes filtering for platforms w/o 3DMux
- fixed DSPP DSPP_2 / _3 links on several platforms
- corrected DSPP definitions on SDM670
- added CWB hardware blocks support
- added VBIF to DPU snapshots
- dropped struct dpu_rm_requirements
DP:
- reworked DP audio support
DSI:
- added SM6150 (aka QCS615) support
GPU:
- Print GMU core fw version
- GMU bandwidth voting for a740 and a750
- Expose uche trap base via uapi
- UAPI error reporting
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rob Clark <robdclark@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CAF6AEGsutUu4ff6OpXNXxqf1xaV0rV6oV23VXNRiF0_OEfe72Q@mail.gmail.com
So far we notify the sequencer client and port changes upon UMP FB
changes, but those aren't really corresponding to the UMP updates.
e.g. when a FB info gets updated, it's not notified but done only when
some of sequencer port attribute is changed. This is no ideal
behavior.
This patch adds the two new sequencer event types for notifying the
UMP EP and FB changes via the announce port. The new event takes
snd_seq_ev_ump_notify type data, which is compatible with
snd_seq_addr (where the port number is replaced with the block
number).
The events are sent when the EP and FB info gets updated explicitly
via ioctl, or the backend UMP receives the corresponding UMP
messages.
The sequencer protocol version is bumped to 1.0.5 along with it.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250110155943.31578-9-tiwai@suse.de
The UMP legacy rawmidi may turn on/off the substream dynamically
depending on the UMP Function Block information. So far, there was no
direct way to know whether the substream is disabled (inactive) or
not; at most one can take a look at the substream name string or try
to open and get -ENODEV.
This patch extends the rawmidi info ioctl to show the current inactive
state of the given substream. When the selected substream is
inactive, info flags field contains the new bit flag
SNDRV_RAWMIDI_INFO_STREAM_INACTIVE.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250110155943.31578-3-tiwai@suse.de
The UMP legacy rawmidi is derived from the UMP rawmidi, but currently
there is no way to know which device is involved in other side.
This patch extends the rawmidi info ioctl to show the tied device
number. As default it stores -1, indicating that no tied device.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250110155943.31578-2-tiwai@suse.de
Steffen Klassert says:
====================
ipsec-next-2025-01-09
1) Implement the AGGFRAG protocol and basic IP-TFS (RFC9347) functionality.
From Christian Hopps.
2) Support ESN context update to hardware for TX.
From Jianbo Liu.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a separate dio read align field, as many out of place write
file systems can easily do reads aligned to the device sector size,
but require bigger alignment for writes.
This is usually papered over by falling back to buffered I/O for smaller
writes and doing read-modify-write cycles, but performance for this
sucks, so applications benefit from knowing the actual write alignment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250109083109.1441561-3-hch@lst.de
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Nadia Pinaeva writes:
I am working on a tool that allows collecting network performance
metrics by using conntrack events.
Start time of a conntrack entry is used to evaluate seen_reply
latency, therefore the sooner it is timestamped, the better the
precision is.
In particular, when using this tool to compare the performance of the
same feature implemented using iptables/nftables/OVS it is crucial
to have the entry timestamped earlier to see any difference.
At this time, conntrack events can only get timestamped at recv time in
userspace, so there can be some delay between the event being generated
and the userspace process consuming the message.
There is sys/net/netfilter/nf_conntrack_timestamp, which adds a
64bit timestamp (ns resolution) that records start and stop times,
but its not suited for this either, start time is the 'hashtable insertion
time', not 'conntrack allocation time'.
There is concern that moving the start-time moment to conntrack
allocation will add overhead in case of flooding, where conntrack
entries are allocated and released right away without getting inserted
into the hashtable.
Also, even if this was changed it would not with events other than
new (start time) and destroy (stop time).
Pablo suggested to add new CTA_TIMESTAMP_EVENT, this adds this feature.
The timestamp is recorded in case both events are requested and the
sys/net/netfilter/nf_conntrack_timestamp toggle is enabled.
Reported-by: Nadia Pinaeva <n.m.pinaeva@gmail.com>
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This change introduces a mechanism for notifying userspace
applications about changes to IPv6 anycast addresses via netlink. It
includes:
* Addition and deletion of IPv6 anycast addresses are reported using
RTM_NEWANYCAST and RTM_DELANYCAST.
* A new netlink group (RTNLGRP_IPV6_ACADDR) for subscribing to these
notifications.
This enables user space applications(e.g. ip monitor) to efficiently
track anycast addresses through netlink messages, improving metrics
collection and system monitoring. It also unlocks the potential for
advanced anycast management in user space, such as hardware offload
control and fine grained network control.
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250107114355.1766086-1-yuyanghuang@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
NT waits can optionally be made "alertable". This is a special channel for
thread wakeup that is mildly similar to SIGIO. A thread has an internal single
bit of "alerted" state, and if a thread is alerted while an alertable wait, the
wait will return a special value, consume the "alerted" state, and will not
consume any of its objects.
Alerts are implemented using events; the user-space NT emulator is expected to
create an internal ntsync event for each thread and pass that event to wait
functions.
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20241213193511.457338-16-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This correspond to the NT syscall NtCreateEvent().
An NT event holds a single bit of state denoting whether it is signaled or
unsignaled.
There are two types of events: manual-reset and automatic-reset. When an
automatic-reset event is acquired via a wait function, its state is reset to
unsignaled. Manual-reset events are not affected by wait functions.
Whether the event is manual-reset, and its initial state, are specified at
creation time.
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-9-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This does not correspond to any NT syscall. Rather, when a thread dies, it
should be called by the NT emulator for each mutex, with the TID of the dying
thread.
NT mutexes are robust (in the pthread sense). When an NT thread dies, any
mutexes it owned are immediately released. Acquisition of those mutexes by other
threads will return a special value indicating that the mutex was abandoned,
like EOWNERDEAD returned from pthread_mutex_lock(), and EOWNERDEAD is indeed
used here for that purpose.
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-8-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This corresponds to the NT syscall NtCreateMutant().
An NT mutex is recursive, with a 32-bit recursion counter. When acquired via
NtWaitForMultipleObjects(), the recursion counter is incremented by one. The OS
records the thread which acquired it.
The OS records the thread which acquired it. However, in order to keep this
driver self-contained, the owning thread ID is managed by user-space, and passed
as a parameter to all relevant ioctls.
The initial owner and recursion count, if any, are specified when the mutex is
created.
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-6-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is similar to NTSYNC_IOC_WAIT_ANY, but waits until all of the objects are
simultaneously signaled, and then acquires all of them as a single atomic
operation.
Because acquisition of multiple objects is atomic, some complex locking is
required. We cannot simply spin-lock multiple objects simultaneously, as that
may disable preëmption for a problematically long time.
Instead, modifying any object which may be involved in a wait-all operation takes
a device-wide sleeping mutex, "wait_all_lock", instead of the normal object
spinlock.
Because wait-for-all is a rare operation, in order to optimize wait-for-any,
this lock is only taken when necessary. "all_hint" is used to mark objects which
are involved in a wait-for-all operation, and if an object is not, only its
spinlock is taken.
The locking scheme used here was written by Peter Zijlstra.
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-5-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This corresponds to part of the functionality of the NT syscall
NtWaitForMultipleObjects(). Specifically, it implements the behaviour where
the third argument (wait_any) is TRUE, and it does not handle alertable waits.
Those features have been split out into separate patches to ease review.
This patch therefore implements the wait/wake infrastructure which comprises the
core of ntsync's functionality.
NTSYNC_IOC_WAIT_ANY is a vectored wait function similar to poll(). Unlike
poll(), it "consumes" objects when they are signaled. For semaphores, this means
decreasing one from the internal counter. At most one object can be consumed by
this function.
This wait/wake model is fundamentally different from that used anywhere else in
the kernel, and for that reason ntsync does not use any existing infrastructure,
such as futexes, kernel mutexes or semaphores, or wait_event().
Up to 64 objects can be waited on at once. As soon as one is signaled, the
object with the lowest index is consumed, and that index is returned via the
"index" field.
A timeout is supported. The timeout is passed as a u64 nanosecond value, which
represents absolute time measured against either the MONOTONIC or REALTIME clock
(controlled by the flags argument). If U64_MAX is passed, the ioctl waits
indefinitely.
This ioctl validates that all objects belong to the relevant device. This is not
necessary for any technical reason related to NTSYNC_IOC_WAIT_ANY, but will be
necessary for NTSYNC_IOC_WAIT_ALL introduced in the following patch.
Some padding fields are added for alignment and for fields which will be added
in future patches (split out to ease review).
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-4-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sometimes one needs to be able not only to catch PPS signals but to
produce them also. For example, running a distributed simulation,
which requires computers' clock to be synchronized very tightly.
This patch adds PPS generators class in order to have a well-defined
interface for these devices.
Signed-off-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/20241108073115.759039-2-giometti@enneenne.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2025-01-07
We've added 7 non-merge commits during the last 32 day(s) which contain
a total of 11 files changed, 190 insertions(+), 103 deletions(-).
The main changes are:
1) Migrate the test_xdp_meta.sh BPF selftest into test_progs
framework, from Bastien Curutchet.
2) Add ability to configure head/tailroom for netkit devices,
from Daniel Borkmann.
3) Fixes and improvements to the xdp_hw_metadata selftest,
from Song Yoong Siang.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
selftests/bpf: Extend netkit tests to validate set {head,tail}room
netkit: Add add netkit {head,tail}room to rt_link.yaml
netkit: Allow for configuring needed_{head,tail}room
selftests/bpf: Migrate test_xdp_meta.sh into xdp_context_test_run.c
selftests/bpf: test_xdp_meta: Rename BPF sections
selftests/bpf: Enable Tx hwtstamp in xdp_hw_metadata
selftests/bpf: Actuate tx_metadata_len in xdp_hw_metadata
====================
Link: https://patch.msgid.link/20250107130908.143644-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Allow the user to configure needed_{head,tail}room for both netkit
devices. The idea is similar to 163e529200 ("veth: implement
ndo_set_rx_headroom") with the difference that the two parameters
can be specified upon device creation. By default the current behavior
stays as is which is needed_{head,tail}room is 0.
In case of Cilium, for example, the netkit devices are not enslaved
into a bridge or openvswitch device (rather, BPF-based redirection
is used out of tcx), and as such these parameters are not propagated
into the Pod's netns via peer device.
Given Cilium can run in vxlan/geneve tunneling mode (needed_headroom)
and/or be used in combination with WireGuard (needed_{head,tail}room),
allow the Cilium CNI plugin to specify these two upon netkit device
creation.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/bpf/20241220234658.490686-1-daniel@iogearbox.net
Pull networking fixes from Jakub Kicinski:
"Including fixes from wireles and netfilter.
Nothing major here. Over the last two weeks we gathered only around
two-thirds of our normal weekly fix count, but delaying sending these
until -rc7 seemed like a really bad idea.
AFAIK we have no bugs under investigation. One or two reverts for
stuff for which we haven't gotten a proper fix will likely come in the
next PR.
Current release - fix to a fix:
- netfilter: nft_set_hash: unaligned atomic read on struct
nft_set_ext
- eth: gve: trigger RX NAPI instead of TX NAPI in gve_xsk_wakeup
Previous releases - regressions:
- net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets
- mptcp:
- fix sleeping rcvmsg sleeping forever after bad recvbuffer adjust
- fix TCP options overflow
- prevent excessive coalescing on receive, fix throughput
- net: fix memory leak in tcp_conn_request() if map insertion fails
- wifi: cw1200: fix potential NULL dereference after conversion to
GPIO descriptors
- phy: micrel: dynamically control external clock of KSZ PHY, fix
suspend behavior
Previous releases - always broken:
- af_packet: fix VLAN handling with MSG_PEEK
- net: restrict SO_REUSEPORT to inet sockets
- netdev-genl: avoid empty messages in NAPI get
- dsa: microchip: fix set_ageing_time function on KSZ9477 and LAN937X
- eth:
- gve: XDP fixes around transmit, queue wakeup etc.
- ti: icssg-prueth: fix firmware load sequence to prevent time
jump which breaks timesync related operations
Misc:
- netlink: specs: mptcp: add missing attr and improve documentation"
* tag 'net-6.13-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (50 commits)
net: ti: icssg-prueth: Fix clearing of IEP_CMP_CFG registers during iep_init
net: ti: icssg-prueth: Fix firmware load sequence.
mptcp: prevent excessive coalescing on receive
mptcp: don't always assume copied data in mptcp_cleanup_rbuf()
mptcp: fix recvbuffer adjust on sleeping rcvmsg
ila: serialize calls to nf_register_net_hooks()
af_packet: fix vlan_get_protocol_dgram() vs MSG_PEEK
af_packet: fix vlan_get_tci() vs MSG_PEEK
net: wwan: iosm: Properly check for valid exec stage in ipc_mmio_init()
net: restrict SO_REUSEPORT to inet sockets
net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets
net: sfc: Correct key_len for efx_tc_ct_zone_ht_params
net: wwan: t7xx: Fix FSM command timeout issue
sky2: Add device ID 11ab:4373 for Marvell 88E8075
mptcp: fix TCP options overflow.
net: mv643xx_eth: fix an OF node reference leak
gve: trigger RX NAPI instead of TX NAPI in gve_xsk_wakeup
eth: bcmsysport: fix call balance of priv->clk handling routines
net: llc: reset skb->transport_header
netlink: specs: mptcp: fix missing doc
...
Pull hardening fix from Kees Cook:
- stddef: make __struct_group() UAPI C++-friendly (Alexander Lobakin)
* tag 'hardening-v6.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
stddef: make __struct_group() UAPI C++-friendly
Add the ability to pass additional attributes along with read/write.
Application can prepare attibute specific information and pass its
address using the SQE field:
__u64 attr_ptr;
Along with setting a mask indicating attributes being passed:
__u64 attr_type_mask;
Overall 64 attributes are allowed and currently one attribute
'IORING_RW_ATTR_FLAG_PI' is supported.
With PI attribute, userspace can pass following information:
- flags: integrity check flags IO_INTEGRITY_CHK_{GUARD/APPTAG/REFTAG}
- len: length of PI/metadata buffer
- addr: address of metadata buffer
- seed: seed value for reftag remapping
- app_tag: application defined 16b value
Process this information to prepare uio_meta_descriptor and pass it down
using kiocb->private.
PI attribute is supported only for direct IO.
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20241128112240.8867-7-anuj20.g@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For the most part of the C++ history, it couldn't have type
declarations inside anonymous unions for different reasons. At the
same time, __struct_group() relies on the latters, so when the @TAG
argument is not empty, C++ code doesn't want to build (even under
`extern "C"`):
../linux/include/uapi/linux/pkt_cls.h:25:24: error:
'struct tc_u32_sel::<unnamed union>::tc_u32_sel_hdr,' invalid;
an anonymous union may only have public non-static data members
[-fpermissive]
The safest way to fix this without trying to switch standards (which
is impossible in UAPI anyway) etc., is to disable tag declaration
for that language. This won't break anything since for now it's not
buildable at all.
Use a separate definition for __struct_group() when __cplusplus is
defined to mitigate the error, including the version from tools/.
Fixes: 50d7bd38c3 ("stddef: Introduce struct_group() helper macro")
Reported-by: Christopher Ferris <cferris@google.com>
Closes: https://lore.kernel.org/linux-hardening/Z1HZpe3WE5As8UAz@google.com
Suggested-by: Kees Cook <kees@kernel.org> # __struct_group_tag()
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20241219135734.2130002-1-aleksander.lobakin@intel.com
Signed-off-by: Kees Cook <kees@kernel.org>
