Now there are tracepoints, that cover all functionality of
tcp_hash_fail(), but also wire up missing places
They are also faster, can be disabled and provide filtering.
This potentially may create a regression if a userspace depends on dmesg
logs. Fingers crossed, let's see if anyone complains in reality.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Two reasons:
1. It's grown up enough
2. In order to not do header spaghetti by including
<trace/events/tcp.h>, which is necessary for TCP tracepoints.
While at it, unexport and make static tcp_inbound_ao_hash().
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's possible to clean-up some ifdefs by hiding that
tcp_{md5,ao}_needed static branch is defined and compiled only
under related configs, since commit 4c8530dc7d ("net/tcp: Only produce
AO/MD5 logs if there are any keys").
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kalle Valo says:
====================
wireless-next patches for v6.11
The first "new features" pull request for v6.11 with changes both in
stack and in drivers. Nothing out of ordinary, except that we have
two conflicts this time:
net/mac80211/cfg.c
https://lore.kernel.org/all/20240531124415.05b25e7a@canb.auug.org.au
drivers/net/wireless/microchip/wilc1000/netdev.c
https://lore.kernel.org/all/20240603110023.23572803@canb.auug.org.au
Major changes:
cfg80211/mac80211
* parse Transmit Power Envelope (TPE) data in mac80211 instead of in drivers
wilc1000
* read MAC address during probe to make it visible to user space
iwlwifi
* bump FW API to 91 for BZ/SC devices
* report 64-bit radiotap timestamp
* enable P2P low latency by default
* handle Transmit Power Envelope (TPE) advertised by AP
* start using guard()
rtlwifi
* RTL8192DU support
ath12k
* remove unsupported tx monitor handling
* channel 2 in 6 GHz band support
* Spatial Multiplexing Power Save (SMPS) in 6 GHz band support
* multiple BSSID (MBSSID) and Enhanced Multi-BSSID Advertisements (EMA)
support
* dynamic VLAN support
* add panic handler for resetting the firmware state
ath10k
* add qcom,no-msa-ready-indicator Device Tree property
* LED support for various chipsets
* tag 'wireless-next-2024-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next: (194 commits)
wifi: ath12k: add hw_link_id in ath12k_pdev
wifi: ath12k: add panic handler
wifi: rtw89: chan: Use swap() in rtw89_swap_sub_entity()
wifi: brcm80211: remove unused structs
wifi: brcm80211: use sizeof(*pointer) instead of sizeof(type)
wifi: ath12k: do not process consecutive RDDM event
dt-bindings: net: wireless: ath11k: Drop "qcom,ipq8074-wcss-pil" from example
wifi: ath12k: fix memory leak in ath12k_dp_rx_peer_frag_setup()
wifi: rtlwifi: handle return value of usb init TX/RX
wifi: rtlwifi: Enable the new rtl8192du driver
wifi: rtlwifi: Add rtl8192du/sw.c
wifi: rtlwifi: Constify rtl_hal_cfg.{ops,usb_interface_cfg} and rtl_priv.cfg
wifi: rtlwifi: Add rtl8192du/dm.{c,h}
wifi: rtlwifi: Add rtl8192du/fw.{c,h} and rtl8192du/led.{c,h}
wifi: rtlwifi: Add rtl8192du/rf.{c,h}
wifi: rtlwifi: Add rtl8192du/trx.{c,h}
wifi: rtlwifi: Add rtl8192du/phy.{c,h}
wifi: rtlwifi: Add rtl8192du/hw.{c,h}
wifi: rtlwifi: Add new members to struct rtl_priv for RTL8192DU
wifi: rtlwifi: Add rtl8192du/table.{c,h}
...
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================
Link: https://lore.kernel.org/r/20240607093517.41394C2BBFC@smtp.kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This removes the bogus check for max > hcon->le_conn_max_interval since
the later is just the initial maximum conn interval not the maximum the
stack could support which is really 3200=4000ms.
In order to pass GAP/CONN/CPUP/BV-05-C one shall probably enter values
of the following fields in IXIT that would cause hci_check_conn_params
to fail:
TSPX_conn_update_int_min
TSPX_conn_update_int_max
TSPX_conn_update_peripheral_latency
TSPX_conn_update_supervision_timeout
Link: https://github.com/bluez/bluez/issues/847
Fixes: e4b019515f ("Bluetooth: Enforce validation on max value of connection interval")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
When innerprotoinherit is set, the tunneled packets do not have an inner
Ethernet header.
Change 'maclen' to not always assume the header length is ETH_HLEN, as
there might not be a MAC header.
This resolves issues with drivers (e.g. mlx5, in
mlx5e_tx_tunnel_accel()) who rely on the skb inner network header offset
to be correct, and use it for TX offloads.
Fixes: d8a6213d70 ("geneve: fix header validation in geneve[6]_xmit_skb")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Its no longer used outside inet_timewait_sock.c, so move it there.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The TCP timewait timer is proving to be problematic for setups where
scheduler CPU isolation is achieved at runtime via cpusets (as opposed to
statically via isolcpus=domains).
What happens there is a CPU goes through tcp_time_wait(), arming the
time_wait timer, then gets isolated. TCP_TIMEWAIT_LEN later, the timer
fires, causing interference for the now-isolated CPU. This is conceptually
similar to the issue described in commit e02b931248 ("workqueue: Unbind
kworkers before sending them to exit()")
Move inet_twsk_schedule() to within inet_twsk_hashdance(), with the ehash
lock held. Expand the lock's critical section from inet_twsk_kill() to
inet_twsk_deschedule_put(), serializing the scheduling vs descheduling of
the timer. IOW, this prevents the following race:
tcp_time_wait()
inet_twsk_hashdance()
inet_twsk_deschedule_put()
del_timer_sync()
inet_twsk_schedule()
Thanks to Paolo Abeni for suggesting to leverage the ehash lock.
This also restores a comment from commit ec94c2696f ("tcp/dccp: avoid
one atomic operation for timewait hashdance") as inet_twsk_hashdance() had
a "Step 1" and "Step 3" comment, but the "Step 2" had gone missing.
inet_twsk_deschedule_put() now acquires the ehash spinlock to synchronize
with inet_twsk_hashdance_schedule().
To ease possible regression search, actual un-pin is done in next patch.
Link: https://lore.kernel.org/all/ZPhpfMjSiHVjQkTk@localhost.localdomain/
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/pensando/ionic/ionic_txrx.c
d9c0420999 ("ionic: Mark error paths in the data path as unlikely")
491aee894a ("ionic: fix kernel panic in XDP_TX action")
net/ipv6/ip6_fib.c
b4cb4a1391 ("net: use unrcu_pointer() helper")
b01e1c0307 ("ipv6: fix possible race in __fib6_drop_pcpu_from()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
reqsk_alloc() has a single caller, no need to expose it
in include/net/request_sock.h.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In reqsk_free(), use DEBUG_NET_WARN_ON_ONCE()
instead of WARN_ON_ONCE() for a condition which never fired.
In reqsk_put() directly call __reqsk_free(), there is no
point checking rsk_refcnt again right after a transition to zero.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Adding a sysctl knob to allow user to specify a default
rto_min at socket init time, other than using the hard
coded 200ms default rto_min.
Note that the rto_min route option has the highest precedence
for configuring this setting, followed by the TCP_BPF_RTO_MIN
socket option, followed by the tcp_rto_min_us sysctl.
Signed-off-by: Kevin Yang <yyd@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jaroslav reports Dell's OMSA Systems Management Data Engine
expects NLM_DONE in a separate recvmsg(), both for rtnl_dump_ifinfo()
and inet_dump_ifaddr(). We already added a similar fix previously in
commit 460b0d33cf ("inet: bring NLM_DONE out to a separate recv() again")
Instead of modifying all the dump handlers, and making them look
different than modern for_each_netdev_dump()-based dump handlers -
put the workaround in rtnetlink code. This will also help us move
the custom rtnl-locking from af_netlink in the future (in net-next).
Note that this change is not touching rtnl_dump_all(). rtnl_dump_all()
is different kettle of fish and a potential problem. We now mix families
in a single recvmsg(), but NLM_DONE is not coalesced.
Tested:
./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_addr.yaml \
--dump getaddr --json '{"ifa-family": 2}'
./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
--dump getroute --json '{"rtm-family": 2}'
./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_link.yaml \
--dump getlink
Fixes: 3e41af9076 ("rtnetlink: use xarray iterator to implement rtnl_dump_ifinfo()")
Fixes: cdb2f80f1c ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Jaroslav Pulchart <jaroslav.pulchart@gooddata.com>
Link: https://lore.kernel.org/all/CAK8fFZ7MKoFSEzMBDAOjoUt+vTZRRQgLDNXEOfdCCXSoXXKE0g@mail.gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
"struct devlink_dpipe_table_ops" only contains some function pointers.
Update "struct devlink_dpipe_table" and the 'table_ops' parameter of
devl_dpipe_table_register() so that structures in drivers can be
constified.
Constifying these structures will move some data to a read-only section, so
increase overall security.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
'cfpktq' has been unused since
commit 73d6ac633c ("caif: code cleanup").
'caif_packet_funcs' is declared but never defined.
Remove both of them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When I was doing some experiments, I found that when using the first
parameter, namely, struct net, in ip_metrics_convert() always triggers NULL
pointer crash. Then I digged into this part, realizing that we can remove
this one due to its uselessness.
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
TLS (and hopefully soon PSP will) use EOR to prevent skbs
with different decrypted state from getting merged, without
adding new tests to the skb handling. In both cases once
the connection switches to an "encrypted" state, all subsequent
skbs will be encrypted, so a single "EOR fence" is sufficient
to prevent mixing.
Add a helper for setting the EOR bit, to make this arrangement
more explicit.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
tcp_skb_can_collapse() checks for conditions which don't make
sense on input. Because of this we ended up sprinkling a few
pairs of mptcp_skb_can_collapse() and skb_cmp_decrypted() calls
on the input path. Group them in a new helper. This should make
it less likely that someone will check mptcp and not decrypted
or vice versa when adding new code.
This implicitly adds a decrypted check early in tcp_collapse().
AFAIU this will very slightly increase our ability to collapse
packets under memory pressure, not a real bug.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Dissect [no]csum, [no]dontfrag, [no]oam, [no]crit flags from skb metadata.
This is a prerequisite for matching these control flags using TC flower.
Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
TCP_CLOSE may or may not have current/rnext keys and should not be
considered "established". The fast-path for TCP_CLOSE is
SKB_DROP_REASON_TCP_CLOSE. This is what tcp_rcv_state_process() does
anyways. Add an early drop path to not spend any time verifying
segment signatures for sockets in TCP_CLOSE state.
Cc: stable@vger.kernel.org # v6.7
Fixes: 0a3a809089 ("net/tcp: Verify inbound TCP-AO signed segments")
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20240529-tcp_ao-sk_state-v1-1-d69b5d323c52@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.
RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).
Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.
Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.
Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.
Many thanks to Clement Lecigne for tracking this issue.
This old bug became visible after the blamed commit, using UDP sockets.
Fixes: a87cb3e48e ("net: Facility to report route quality of connected sockets")
Reported-by: Clement Lecigne <clecigne@google.com>
Diagnosed-by: Clement Lecigne <clecigne@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-05-28
We've added 23 non-merge commits during the last 11 day(s) which contain
a total of 45 files changed, 696 insertions(+), 277 deletions(-).
The main changes are:
1) Rename skb's mono_delivery_time to tstamp_type for extensibility
and add SKB_CLOCK_TAI type support to bpf_skb_set_tstamp(),
from Abhishek Chauhan.
2) Add netfilter CT zone ID and direction to bpf_ct_opts so that arbitrary
CT zones can be used from XDP/tc BPF netfilter CT helper functions,
from Brad Cowie.
3) Several tweaks to the instruction-set.rst IETF doc to address
the Last Call review comments, from Dave Thaler.
4) Small batch of riscv64 BPF JIT optimizations in order to emit more
compressed instructions to the JITed image for better icache efficiency,
from Xiao Wang.
5) Sort bpftool C dump output from BTF, aiming to simplify vmlinux.h
diffing and forcing more natural type definitions ordering,
from Mykyta Yatsenko.
6) Use DEV_STATS_INC() macro in BPF redirect helpers to silence
a syzbot/KCSAN race report for the tx_errors counter,
from Jiang Yunshui.
7) Un-constify bpf_func_info in bpftool to fix compilation with LLVM 17+
which started treating const structs as constants and thus breaking
full BTF program name resolution, from Ivan Babrou.
8) Fix up BPF program numbers in test_sockmap selftest in order to reduce
some of the test-internal array sizes, from Geliang Tang.
9) Small cleanup in Makefile.btf script to use test-ge check for v1.25-only
pahole, from Alan Maguire.
10) Fix bpftool's make dependencies for vmlinux.h in order to avoid needless
rebuilds in some corner cases, from Artem Savkov.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (23 commits)
bpf, net: Use DEV_STAT_INC()
bpf, docs: Fix instruction.rst indentation
bpf, docs: Clarify call local offset
bpf, docs: Add table captions
bpf, docs: clarify sign extension of 64-bit use of 32-bit imm
bpf, docs: Use RFC 2119 language for ISA requirements
bpf, docs: Move sentence about returning R0 to abi.rst
bpf: constify member bpf_sysctl_kern:: Table
riscv, bpf: Try RVC for reg move within BPF_CMPXCHG JIT
riscv, bpf: Use STACK_ALIGN macro for size rounding up
riscv, bpf: Optimize zextw insn with Zba extension
selftests/bpf: Handle forwarding of UDP CLOCK_TAI packets
net: Add additional bit to support clockid_t timestamp type
net: Rename mono_delivery_time to tstamp_type for scalabilty
selftests/bpf: Update tests for new ct zone opts for nf_conntrack kfuncs
net: netfilter: Make ct zone opts configurable for bpf ct helpers
selftests/bpf: Fix prog numbers in test_sockmap
bpf: Remove unused variable "prev_state"
bpftool: Un-const bpf_func_info to fix it for llvm 17 and newer
bpf: Fix order of args in call to bpf_map_kvcalloc
...
====================
Link: https://lore.kernel.org/r/20240528105924.30905-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After the tagged commit, @netdev got documented twice and the kdoc
script didn't notice that. Remove the second description added later
and move the initial one according to the field position.
After merging commit 5f8e4007c1 ("kernel-doc: fix
struct_group_tagged() parsing"), kdoc requires to describe struct
groups as well. &page_pool_params has 2 struct groups which
generated new warnings, describe them to resolve this.
Fixes: 403f11ac9a ("page_pool: don't use driver-set flags field directly")
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20240524112859.2757403-1-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jason commit made checks against ACK sequence less strict
and can be exploited by attackers to establish spoofed flows
with less probes.
Innocent users might use tcp_rmem[1] == 1,000,000,000,
or something more reasonable.
An attacker can use a regular TCP connection to learn the server
initial tp->rcv_wnd, and use it to optimize the attack.
If we make sure that only the announced window (smaller than 65535)
is used for ACK validation, we force an attacker to use
65537 packets to complete the 3WHS (assuming server ISN is unknown)
Fixes: 378979e94e ("tcp: remove 64 KByte limit for initial tp->rcv_wnd value")
Link: https://datatracker.ietf.org/meeting/119/materials/slides-119-tcpm-ghost-acks-00
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20240523130528.60376-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mono_delivery_time was added to check if skb->tstamp has delivery
time in mono clock base (i.e. EDT) otherwise skb->tstamp has
timestamp in ingress and delivery_time at egress.
Renaming the bitfield from mono_delivery_time to tstamp_type is for
extensibilty for other timestamps such as userspace timestamp
(i.e. SO_TXTIME) set via sock opts.
As we are renaming the mono_delivery_time to tstamp_type, it makes
sense to start assigning tstamp_type based on enum defined
in this commit.
Earlier we used bool arg flag to check if the tstamp is mono in
function skb_set_delivery_time, Now the signature of the functions
accepts tstamp_type to distinguish between mono and real time.
Also skb_set_delivery_type_by_clockid is a new function which accepts
clockid to determine the tstamp_type.
In future tstamp_type:1 can be extended to support userspace timestamp
by increasing the bitfield.
Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Annotate 'sub_specs' of 'struct cfg80211_sar_specs', 'channels'
of 'struct cfg80211_sched_scan_request', 'channels' of 'struct
cfg80211_wowlan_nd_match', and 'matches' of 'struct
cfg80211_wowlan_nd_info' with '__counted_by' attribute. Briefly
tested with clang 18.1.1 and CONFIG_UBSAN_BOUNDS running iwlwifi.
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://msgid.link/20240517153332.18271-1-dmantipov@yandex.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Instead of passing the full TPE elements, in all their glory
and mixed up data formats for HE backward compatibility, parse
them fully into the right values, and pass that to the drivers.
Also introduce proper validation already in mac80211, so that
drivers don't need to do it, and parse the EHT portions.
The code now passes the values in the right order according to
the channel used by an interface, which could also be a subset
of the data advertised by the AP, if we couldn't connect with
the full bandwidth (for whatever reason.)
Also add kunit tests for the more complicated bits of it.
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Acked-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240506214536.2aa839969b60.I265b28209e0b29772b2f125f7f83de44a4da877b@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Pull more s390 updates from Alexander Gordeev:
- Switch read and write software bits for PUDs
- Add missing hardware bits for PUDs and PMDs
- Generate unwind information for C modules to fix GDB unwind error for
vDSO functions
- Create .build-id links for unstripped vDSO files to enable vDSO
debugging with symbols
- Use standard stack frame layout for vDSO generated stack frames to
manually walk stack frames without DWARF information
- Rework perf_callchain_user() and arch_stack_walk_user() functions to
reduce code duplication
- Skip first stack frame when walking user stack
- Add basic checks to identify invalid instruction pointers when
walking stack frames
- Introduce and use struct stack_frame_vdso_wrapper within vDSO user
wrapper code to automatically generate an asm-offset define. Also use
STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document
that the code works with user space stack
- Clear the backchain of the extra stack frame added by the vDSO user
wrapper code. This allows the user stack walker to detect and skip
the non-standard stack frame. Without this an incorrect instruction
pointer would be added to stack traces.
- Rewrite psw_idle() function in C to ease maintenance and further
enhancements
- Remove get_vtimer() function and use get_cpu_timer() instead
- Mark psw variable in __load_psw_mask() as __unitialized to avoid
superfluous clearing of PSW
- Remove obsolete and superfluous comment about removed TIF_FPU flag
- Replace memzero_explicit() and kfree() with kfree_sensitive() to fix
warnings reported by Coccinelle
- Wipe sensitive data and all copies of protected- or secure-keys from
stack when an IOCTL fails
- Both do_airq_interrupt() and do_io_interrupt() functions set
CIF_NOHZ_DELAY flag. Move it in do_io_irq() to simplify the code
- Provide iucv_alloc_device() and iucv_release_device() helpers, which
can be used to deduplicate more or less identical IUCV device
allocation and release code in four different drivers
- Make use of iucv_alloc_device() and iucv_release_device() helpers to
get rid of quite some code and also remove a cast to an incompatible
function (clang W=1)
- There is no user of iucv_root outside of the core IUCV code left.
Therefore remove the EXPORT_SYMBOL
- __apply_alternatives() contains a runtime check which verifies that
the size of the to be patched code area is even. Convert this to a
compile time check
- Increase size of buffers for sending z/VM CP DIAGNOSE X'008' commands
from 128 to 240
- Do not accept z/VM CP DIAGNOSE X'008' commands longer than maximally
allowed
- Use correct defines IPL_BP_NVME_LEN and IPL_BP0_NVME_LEN instead of
IPL_BP_FCP_LEN and IPL_BP0_FCP_LEN ones to initialize NVMe reIPL
block on 'scp_data' sysfs attribute update
- Initialize the correct fields of the NVMe dump block, which were
confused with FCP fields
- Refactor macros for 'scp_data' (re-)IPL sysfs attribute to reduce
code duplication
- Introduce 'scp_data' sysfs attribute for dump IPL to allow tools such
as dumpconf passing additional kernel command line parameters to a
stand-alone dumper
- Rework the CPACF query functions to use the correct RRE or RRF
instruction formats and set instruction register fields correctly
- Instead of calling BUG() at runtime force a link error during compile
when a unsupported opcode is used with __cpacf_query() or
__cpacf_check_opcode() functions
- Fix a crash in ap_parse_bitmap_str() function on /sys/bus/ap/apmask
or /sys/bus/ap/aqmask sysfs file update with a relative mask value
- Fix "bindings complete" udev event which should be sent once all AP
devices have been bound to device drivers and again when unbind/bind
actions take place and all AP devices are bound again
- Facility list alt_stfle_fac_list is nowhere used in the decompressor,
therefore remove it there
- Remove custom kprobes insn slot allocator in favour of the standard
module_alloc() one, since kernel image and module areas are located
within 4GB
- Use kvcalloc() instead of kvmalloc_array() in zcrypt driver to avoid
calling memset() with a large byte count and get rid of the sparse
warning as result
* tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
s390/zcrypt: Use kvcalloc() instead of kvmalloc_array()
s390/kprobes: Remove custom insn slot allocator
s390/boot: Remove alt_stfle_fac_list from decompressor
s390/ap: Fix bind complete udev event sent after each AP bus scan
s390/ap: Fix crash in AP internal function modify_bitmap()
s390/cpacf: Make use of invalid opcode produce a link error
s390/cpacf: Split and rework cpacf query functions
s390/ipl: Introduce sysfs attribute 'scp_data' for dump ipl
s390/ipl: Introduce macros for (re)ipl sysfs attribute 'scp_data'
s390/ipl: Fix incorrect initialization of nvme dump block
s390/ipl: Fix incorrect initialization of len fields in nvme reipl block
s390/ipl: Do not accept z/VM CP diag X'008' cmds longer than max length
s390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds
s390/alternatives: Convert runtime sanity check into compile time check
s390/iucv: Unexport iucv_root
tty: hvc-iucv: Make use of iucv_alloc_device()
s390/smsgiucv_app: Make use of iucv_alloc_device()
s390/netiucv: Make use of iucv_alloc_device()
s390/vmlogrdr: Make use of iucv_alloc_device()
s390/iucv: Provide iucv_alloc_device() / iucv_release_device()
...
Pull dma-mapping updates from Christoph Hellwig:
- optimize DMA sync calls when they are no-ops (Alexander Lobakin)
- fix swiotlb padding for untrusted devices (Michael Kelley)
- add documentation for swiotb (Michael Kelley)
* tag 'dma-mapping-6.10-2024-05-20' of git://git.infradead.org/users/hch/dma-mapping:
dma: fix DMA sync for drivers not calling dma_set_mask*()
xsk: use generic DMA sync shortcut instead of a custom one
page_pool: check for DMA sync shortcut earlier
page_pool: don't use driver-set flags field directly
page_pool: make sure frag API fields don't span between cachelines
iommu/dma: avoid expensive indirect calls for sync operations
dma: avoid redundant calls for sync operations
dma: compile-out DMA sync op calls when not used
iommu/dma: fix zeroing of bounce buffer padding used by untrusted devices
swiotlb: remove alloc_size argument to swiotlb_tbl_map_single()
Documentation/core-api: add swiotlb documentation
Pull mm updates from Andrew Morton:
"The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.
Notable series include:
- Lucas Stach has provided some page-mapping cleanup/consolidation/
maintainability work in the series "mm/treewide: Remove pXd_huge()
API".
- In the series "Allow migrate on protnone reference with
MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
one test.
- In their series "Memory allocation profiling" Kent Overstreet and
Suren Baghdasaryan have contributed a means of determining (via
/proc/allocinfo) whereabouts in the kernel memory is being
allocated: number of calls and amount of memory.
- Matthew Wilcox has provided the series "Various significant MM
patches" which does a number of rather unrelated things, but in
largely similar code sites.
- In his series "mm: page_alloc: freelist migratetype hygiene"
Johannes Weiner has fixed the page allocator's handling of
migratetype requests, with resulting improvements in compaction
efficiency.
- In the series "make the hugetlb migration strategy consistent"
Baolin Wang has fixed a hugetlb migration issue, which should
improve hugetlb allocation reliability.
- Liu Shixin has hit an I/O meltdown caused by readahead in a
memory-tight memcg. Addressed in the series "Fix I/O high when
memory almost met memcg limit".
- In the series "mm/filemap: optimize folio adding and splitting"
Kairui Song has optimized pagecache insertion, yielding ~10%
performance improvement in one test.
- Baoquan He has cleaned up and consolidated the early zone
initialization code in the series "mm/mm_init.c: refactor
free_area_init_core()".
- Baoquan has also redone some MM initializatio code in the series
"mm/init: minor clean up and improvement".
- MM helper cleanups from Christoph Hellwig in his series "remove
follow_pfn".
- More cleanups from Matthew Wilcox in the series "Various
page->flags cleanups".
- Vlastimil Babka has contributed maintainability improvements in the
series "memcg_kmem hooks refactoring".
- More folio conversions and cleanups in Matthew Wilcox's series:
"Convert huge_zero_page to huge_zero_folio"
"khugepaged folio conversions"
"Remove page_idle and page_young wrappers"
"Use folio APIs in procfs"
"Clean up __folio_put()"
"Some cleanups for memory-failure"
"Remove page_mapping()"
"More folio compat code removal"
- David Hildenbrand chipped in with "fs/proc/task_mmu: convert
hugetlb functions to work on folis".
- Code consolidation and cleanup work related to GUP's handling of
hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
- Rick Edgecombe has developed some fixes to stack guard gaps in the
series "Cover a guard gap corner case".
- Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
series "mm/ksm: fix ksm exec support for prctl".
- Baolin Wang has implemented NUMA balancing for multi-size THPs.
This is a simple first-cut implementation for now. The series is
"support multi-size THP numa balancing".
- Cleanups to vma handling helper functions from Matthew Wilcox in
the series "Unify vma_address and vma_pgoff_address".
- Some selftests maintenance work from Dev Jain in the series
"selftests/mm: mremap_test: Optimizations and style fixes".
- Improvements to the swapping of multi-size THPs from Ryan Roberts
in the series "Swap-out mTHP without splitting".
- Kefeng Wang has significantly optimized the handling of arm64's
permission page faults in the series
"arch/mm/fault: accelerate pagefault when badaccess"
"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
- GUP cleanups from David Hildenbrand in "mm/gup: consistently call
it GUP-fast".
- hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
path to use struct vm_fault".
- selftests build fixes from John Hubbard in the series "Fix
selftests/mm build without requiring "make headers"".
- Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
series "Improved Memory Tier Creation for CPUless NUMA Nodes".
Fixes the initialization code so that migration between different
memory types works as intended.
- David Hildenbrand has improved follow_pte() and fixed an errant
driver in the series "mm: follow_pte() improvements and acrn
follow_pte() fixes".
- David also did some cleanup work on large folio mapcounts in his
series "mm: mapcount for large folios + page_mapcount() cleanups".
- Folio conversions in KSM in Alex Shi's series "transfer page to
folio in KSM".
- Barry Song has added some sysfs stats for monitoring multi-size
THP's in the series "mm: add per-order mTHP alloc and swpout
counters".
- Some zswap cleanups from Yosry Ahmed in the series "zswap
same-filled and limit checking cleanups".
- Matthew Wilcox has been looking at buffer_head code and found the
documentation to be lacking. The series is "Improve buffer head
documentation".
- Multi-size THPs get more work, this time from Lance Yang. His
series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
optimizes the freeing of these things.
- Kemeng Shi has added more userspace-visible writeback
instrumentation in the series "Improve visibility of writeback".
- Kemeng Shi then sent some maintenance work on top in the series
"Fix and cleanups to page-writeback".
- Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
the series "Improve anon_vma scalability for anon VMAs". Intel's
test bot reported an improbable 3x improvement in one test.
- SeongJae Park adds some DAMON feature work in the series
"mm/damon: add a DAMOS filter type for page granularity access recheck"
"selftests/damon: add DAMOS quota goal test"
- Also some maintenance work in the series
"mm/damon/paddr: simplify page level access re-check for pageout"
"mm/damon: misc fixes and improvements"
- David Hildenbrand has disabled some known-to-fail selftests ni the
series "selftests: mm: cow: flag vmsplice() hugetlb tests as
XFAIL".
- memcg metadata storage optimizations from Shakeel Butt in "memcg:
reduce memory consumption by memcg stats".
- DAX fixes and maintenance work from Vishal Verma in the series
"dax/bus.c: Fixups for dax-bus locking""
* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
selftests: cgroup: add tests to verify the zswap writeback path
mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
mm/damon/core: fix return value from damos_wmark_metric_value
mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
selftests: cgroup: remove redundant enabling of memory controller
Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
Docs/mm/damon/design: use a list for supported filters
Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
selftests/damon: classify tests for functionalities and regressions
selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
selftests/damon: add a test for DAMOS quota goal
...
Pull more io_uring updates from Jens Axboe:
"This adds support for IORING_CQE_F_SOCK_NONEMPTY for io_uring accept
requests.
This is very similar to previous work that enabled the same hint for
doing receives on sockets. By far the majority of the work here is
refactoring to enable the networking side to pass back whether or not
the socket had more pending requests after accepting the current one,
the last patch just wires it up for io_uring.
Not only does this enable applications to know whether there are more
connections to accept right now, it also enables smarter logic for
io_uring multishot accept on whether to retry immediately or wait for
a poll trigger"
* tag 'net-accept-more-20240515' of git://git.kernel.dk/linux:
io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for accept
net: pass back whether socket was empty post accept
net: have do_accept() take a struct proto_accept_arg argument
net: change proto and proto_ops accept type
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Complete rework of garbage collection of AF_UNIX sockets.
AF_UNIX is prone to forming reference count cycles due to fd
passing functionality. New method based on Tarjan's Strongly
Connected Components algorithm should be both faster and remove a
lot of workarounds we accumulated over the years.
- Add TCP fraglist GRO support, allowing chaining multiple TCP
packets and forwarding them together. Useful for small switches /
routers which lack basic checksum offload in some scenarios (e.g.
PPPoE).
- Support using SMP threads for handling packet backlog i.e. packet
processing from software interfaces and old drivers which don't use
NAPI. This helps move the processing out of the softirq jumble.
- Continue work of converting from rtnl lock to RCU protection.
Don't require rtnl lock when reading: IPv6 routing FIB, IPv6
address labels, netdev threaded NAPI sysfs files, bonding driver's
sysfs files, MPLS devconf, IPv4 FIB rules, netns IDs, tcp metrics,
TC Qdiscs, neighbor entries, ARP entries via ioctl(SIOCGARP), a lot
of the link information available via rtnetlink.
- Small optimizations from Eric to UDP wake up handling, memory
accounting, RPS/RFS implementation, TCP packet sizing etc.
- Allow direct page recycling in the bulk API used by XDP, for +2%
PPS.
- Support peek with an offset on TCP sockets.
- Add MPTCP APIs for querying last time packets were received/sent/acked
and whether MPTCP "upgrade" succeeded on a TCP socket.
- Add intra-node communication shortcut to improve SMC performance.
- Add IPv6 (and IPv{4,6}-over-IPv{4,6}) support to the GTP protocol
driver.
- Add HSR-SAN (RedBOX) mode of operation to the HSR protocol driver.
- Add reset reasons for tracing what caused a TCP reset to be sent.
- Introduce direction attribute for xfrm (IPSec) states. State can be
used either for input or output packet processing.
Things we sprinkled into general kernel code:
- Add bitmap_{read,write}(), bitmap_size(), expose BYTES_TO_BITS().
This required touch-ups and renaming of a few existing users.
- Add Endian-dependent __counted_by_{le,be} annotations.
- Make building selftests "quieter" by printing summaries like
"CC object.o" rather than full commands with all the arguments.
Netfilter:
- Use GFP_KERNEL to clone elements, to deal better with OOM
situations and avoid failures in the .commit step.
BPF:
- Add eBPF JIT for ARCv2 CPUs.
- Support attaching kprobe BPF programs through kprobe_multi link in
a session mode, meaning, a BPF program is attached to both function
entry and return, the entry program can decide if the return
program gets executed and the entry program can share u64 cookie
value with return program. "Session mode" is a common use-case for
tetragon and bpftrace.
- Add the ability to specify and retrieve BPF cookie for raw
tracepoint programs in order to ease migration from classic to raw
tracepoints.
- Add an internal-only BPF per-CPU instruction for resolving per-CPU
memory addresses and implement support in x86, ARM64 and RISC-V
JITs. This allows inlining functions which need to access per-CPU
state.
- Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
atomics in bpf_arena which can be JITed as a single x86
instruction. Support BPF arena on ARM64.
- Add a new bpf_wq API for deferring events and refactor
process-context bpf_timer code to keep common code where possible.
- Harden the BPF verifier's and/or/xor value tracking.
- Introduce crypto kfuncs to let BPF programs call kernel crypto
APIs.
- Support bpf_tail_call_static() helper for BPF programs with GCC 13.
- Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
program to have code sections where preemption is disabled.
Driver API:
- Skip software TC processing completely if all installed rules are
marked as HW-only, instead of checking the HW-only flag rule by
rule.
- Add support for configuring PoE (Power over Ethernet), similar to
the already existing support for PoDL (Power over Data Line)
config.
- Initial bits of a queue control API, for now allowing a single
queue to be reset without disturbing packet flow to other queues.
- Common (ethtool) statistics for hardware timestamping.
Tests and tooling:
- Remove the need to create a config file to run the net forwarding
tests so that a naive "make run_tests" can exercise them.
- Define a method of writing tests which require an external endpoint
to communicate with (to send/receive data towards the test
machine). Add a few such tests.
- Create a shared code library for writing Python tests. Expose the
YAML Netlink library from tools/ to the tests for easy Netlink
access.
- Move netfilter tests under net/, extend them, separate performance
tests from correctness tests, and iron out issues found by running
them "on every commit".
- Refactor BPF selftests to use common network helpers.
- Further work filling in YAML definitions of Netlink messages for:
nftables, team driver, bonding interfaces, vlan interfaces, VF
info, TC u32 mark, TC police action.
- Teach Python YAML Netlink to decode attribute policies.
- Extend the definition of the "indexed array" construct in the specs
to cover arrays of scalars rather than just nests.
- Add hyperlinks between definitions in generated Netlink docs.
Drivers:
- Make sure unsupported flower control flags are rejected by drivers,
and make more drivers report errors directly to the application
rather than dmesg (large number of driver changes from Asbjørn
Sloth Tønnesen).
- Ethernet high-speed NICs:
- Broadcom (bnxt):
- support multiple RSS contexts and steering traffic to them
- support XDP metadata
- make page pool allocations more NUMA aware
- Intel (100G, ice, idpf):
- extract datapath code common among Intel drivers into a library
- use fewer resources in switchdev by sharing queues with the PF
- add PFCP filter support
- add Ethernet filter support
- use a spinlock instead of HW lock in PTP clock ops
- support 5 layer Tx scheduler topology
- nVidia/Mellanox:
- 800G link modes and 100G SerDes speeds
- per-queue IRQ coalescing configuration
- Marvell Octeon:
- support offloading TC packet mark action
- Ethernet NICs consumer, embedded and virtual:
- stop lying about skb->truesize in USB Ethernet drivers, it
messes up TCP memory calculations
- Google cloud vNIC:
- support changing ring size via ethtool
- support ring reset using the queue control API
- VirtIO net:
- expose flow hash from RSS to XDP
- per-queue statistics
- add selftests
- Synopsys (stmmac):
- support controllers which require an RX clock signal from the
MII bus to perform their hardware initialization
- TI:
- icssg_prueth: support ICSSG-based Ethernet on AM65x SR1.0 devices
- icssg_prueth: add SW TX / RX Coalescing based on hrtimers
- cpsw: minimal XDP support
- Renesas (ravb):
- support describing the MDIO bus
- Realtek (r8169):
- add support for RTL8168M
- Microchip Sparx5:
- matchall and flower actions mirred and redirect
- Ethernet switches:
- nVidia/Mellanox:
- improve events processing performance
- Marvell:
- add support for MV88E6250 family internal PHYs
- Microchip:
- add DCB and DSCP mapping support for KSZ switches
- vsc73xx: convert to PHYLINK
- Realtek:
- rtl8226b/rtl8221b: add C45 instances and SerDes switching
- Many driver changes related to PHYLIB and PHYLINK deprecated API
cleanup
- Ethernet PHYs:
- Add a new driver for Airoha EN8811H 2.5 Gigabit PHY.
- micrel: lan8814: add support for PPS out and external timestamp trigger
- WiFi:
- Disable Wireless Extensions (WEXT) in all Wi-Fi 7 devices
drivers. Modern devices can only be configured using nl80211.
- mac80211/cfg80211
- handle color change per link for WiFi 7 Multi-Link Operation
- Intel (iwlwifi):
- don't support puncturing in 5 GHz
- support monitor mode on passive channels
- BZ-W device support
- P2P with HE/EHT support
- re-add support for firmware API 90
- provide channel survey information for Automatic Channel Selection
- MediaTek (mt76):
- mt7921 LED control
- mt7925 EHT radiotap support
- mt7920e PCI support
- Qualcomm (ath11k):
- P2P support for QCA6390, WCN6855 and QCA2066
- support hibernation
- ieee80211-freq-limit Device Tree property support
- Qualcomm (ath12k):
- refactoring in preparation of multi-link support
- suspend and hibernation support
- ACPI support
- debugfs support, including dfs_simulate_radar support
- RealTek:
- rtw88: RTL8723CS SDIO device support
- rtw89: RTL8922AE Wi-Fi 7 PCI device support
- rtw89: complete features of new WiFi 7 chip 8922AE including
BT-coexistence and Wake-on-WLAN
- rtw89: use BIOS ACPI settings to set TX power and channels
- rtl8xxxu: enable Management Frame Protection (MFP) support
- Bluetooth:
- support for Intel BlazarI and Filmore Peak2 (BE201)
- support for MediaTek MT7921S SDIO
- initial support for Intel PCIe BT driver
- remove HCI_AMP support"
* tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1827 commits)
selftests: netfilter: fix packetdrill conntrack testcase
net: gro: fix napi_gro_cb zeroed alignment
Bluetooth: btintel_pcie: Refactor and code cleanup
Bluetooth: btintel_pcie: Fix warning reported by sparse
Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1
Bluetooth: btintel: Fix compiler warning for multi_v7_defconfig config
Bluetooth: btintel_pcie: Fix compiler warnings
Bluetooth: btintel_pcie: Add *setup* function to download firmware
Bluetooth: btintel_pcie: Add support for PCIe transport
Bluetooth: btintel: Export few static functions
Bluetooth: HCI: Remove HCI_AMP support
Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()
Bluetooth: qca: Fix error code in qca_read_fw_build_info()
Bluetooth: hci_conn: Use __counted_by() and avoid -Wfamnae warning
Bluetooth: btintel: Add support for Filmore Peak2 (BE201)
Bluetooth: btintel: Add support for BlazarI
LE Create Connection command timeout increased to 20 secs
dt-bindings: net: bluetooth: Add MediaTek MT7921S SDIO Bluetooth
Bluetooth: compute LE flow credits based on recvbuf space
Bluetooth: hci_sync: Use cmd->num_cis instead of magic number
...
