linux.git/arch/s390/kernel, branch master

Merge tag 'net-7.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-07-23T19:58:08+00:00

Pull networking fixes from Jakub Kicinski:
 "Lots of fixes, double the count even for the 'new normal'. Largely due
  to my time off followed by a networking conference which distracted
  most maintainers (less so the AI generators).

  Including fixes from Bluetooth and WiFi.

  Current release - regressions:

   - wifi: mt76: fix MAC address for non OF pcie cards

  Current release - new code bugs:

   - mptcp: fix BUILD_BUG_ON on legacy ARM config

   - wifi: cfg80211: guard optional PMSR nominal time

  Previous releases - regressions:

   - qrtr: ns: raise node count limit to 512, we arbitrarily picked
     256 as a limit, turns out it was too low for real world deployments

   - vhost-net: fix TX stall when vhost owns virtio-net header

   - eth: amd-xgbe: fix MAC_AUTO_SW handling in CL37 AN

   - wifi: ath12k: fix low MLO RX throughput on WCN7850

  Previous releases - always broken:

   - number of random AI fixes for SCTP, RDS and TIPC protocols

   - more AI-looking fixes for WiFi drivers

   - number of fixes for missing pointer reloading after skb pull

   - reject BPF redirect use from qdisc qevent block

   - tcp: initialize standalone TCP-AO response padding

   - vsock/virtio: collapse receive queue under memory pressure to avoid
     client OOMing the host with tiny messages

   - ipv4: icmp: fill flow parameters in icmp_route_lookup decoy lookup,
     make sure the ICMP response routing follows the routing policy

   - gro: fix double aggregation of flush-marked skbs

   - ovpn: fix various refcount bugs

   - tls: device: push pending open record on splice EOF

   - eth: mlx5:
      - use sender devcom for MPV master-up
      - fix MCIA register buffer overflow on 32 dword reads"

* tag 'net-7.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (234 commits)
  drop_monitor: perform u64_stats updates under IRQ-disabled section
  drop_monitor: fix size calculations for 64-bit attributes
  net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD
  mptcp: fix BUILD_BUG_ON on legacy ARM config
  selftests: mptcp: userspace_pm: fix undefined variable port
  mptcp: fix stale skb->sk reference on subflow close
  mptcp: pm: userspace: fix use-after-free in get_local_id
  mptcp: decrement subflows counter on failed passive join
  mac802154: hold an interface reference across the scan worker
  sctp: don't free the ASCONF's own transport in DEL-IP processing
  phonet: check register_netdevice_notifier() error in phonet_device_init()
  phonet: pep: fix use-after-free in pep_get_sb()
  bnge/bng_re: fix ring ID widths
  tipc: fix integer overflow in tipc_recvmsg() and tipc_recvstream()
  net: airoha: fix ETS channel derivation in airoha_tc_setup_qdisc_ets()
  mctp: check register_netdevice_notifier() error in mctp_device_init()
  ptp: netc: explicitly clear TMR_OFF during initialization
  rds: tcp: unregister sysctl before tearing down listen socket
  ipv6: Change allocation flags to match rcu_read_lock section requirements
  net: slip: serialize receive against buffer reallocation
  ...

s390/ptff: Export ptff_function_mask[]

2026-07-23T14:02:34+00:00

Export the ptff_function_mask to make ptff_query() usable in modules.

Signed-off-by: Sven Schnelle 
Acked-by: Heiko Carstens 
Link: https://patch.msgid.link/20260714130342.1971700-2-svens@linux.ibm.com
Signed-off-by: Jakub Kicinski

s390/perf_cpum_cf: Add missing array_index_nospec() to __hw_perf_event_init()

2026-07-15T15:35:42+00:00

ev variable is userspace controlled via event->attr.config and used
as an array index after bounds checking, but without speculation
barriers.

Add the missing array_index_nospec() call to prevent speculative
execution.

Cc: stable@vger.kernel.org
Fixes: 212188a596d1 ("[S390] perf: add support for s390x CPU counters")
Signed-off-by: Sumanth Korikkar 
Reviewed-by: Ilya Leoshkevich 
Acked-by: Thomas Richter 
Signed-off-by: Vasily Gorbik

s390: Add build salt to the vDSO

2026-07-08T15:02:48+00:00

The vDSO needs to have a unique build id in a similar manner
to the kernel and modules. Use the build salt macro.

Signed-off-by: Bastian Blank 
Reviewed-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev 
Signed-off-by: Vasily Gorbik

s390/diag: Add missing array_index_nospec() call to memtop_get_page_count()

2026-07-08T15:02:47+00:00

'level' is user space controlled and used to read from an array. Add the
missing array_index_nospec() call to prevent speculative execution.

Cc: stable@vger.kernel.org
Fixes: 0d30871739ab ("s390/diag: Add memory topology information via diag310")
Signed-off-by: Heiko Carstens 
Reviewed-by: Mete Durlu 
Signed-off-by: Vasily Gorbik

s390/idle: Add missing EXPORT_SYMBOL_GPL()

2026-06-18T12:44:44+00:00

Uwe Kleine-König reported this build breakage caused by a recent commit
which provides arch specific kcpustat_field_idle()/kcpustat_field_iowait()
functions:

ERROR: modpost: "arch_kcpustat_field_idle" [drivers/leds/trigger/ledtrig-activity.ko] undefined!
ERROR: modpost: "arch_kcpustat_field_iowait" [drivers/leds/trigger/ledtrig-activity.ko] undefined!

Fix this by adding the missing EXPORT_SYMBOL_GPL().

Fixes: 670e057744e0 ("s390/idle: Provide arch specific kcpustat_field_idle()/kcpustat_field_iowait()")
Reported-by: Uwe Kleine-König 
Closes: https://lore.kernel.org/r/ajKsG0JP6qTssQBX@monoceros
Acked-by: Alexander Gordeev 
Tested-by: Uwe Kleine-König 
Signed-off-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev

Merge branch 'idle-time-acc' into features

2026-06-16T14:21:46+00:00

Heiko Carstens says:

===================
This is supposed to improve s390 idle time accounting, and brings it
back to the state it was before arch_cpu_idle_time() was removed from
s390 [3].

In result all cpu time accounting is done by the s390 architecture backend
again, instead of having a mix of architecure specific and common code
accounting (common code: idle, s390 architecture: everything else).
===================

Signed-off-by: Alexander Gordeev

Merge tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux

2026-06-15T23:38:13+00:00

Pull s390 updates from Alexander Gordeev:

 - Use CIO device online variable instead of the internal FSM state to
   determine device availability during purge operations

 - Remove extra check of task_stack_page() because try_get_task_stack()
   already takes care of that when reading /proc//wchan

 - Allow user-space to use the new SCLP action qualifier 4 for to
   provide NVMe SMART log data to the platform.

 - Send AP CHANGE uevents on successful bind and successful association
   to notify user-space about SE operations on AP queue devices

 - Add an s390dbf kernel parameter to configure debug log levels and
   area sizes during early boot

 - On arm64 the empty zero page is going to be mapped read-only. Do the
   same for s390 with an explicit set_memory_ro() call

 - Improve s390-specific bcr_serialize() and cpu_relax() implementations

 - Remove all unused variables to avoid allmodconfig W=1 build fails
   with latest clang-23

 - Cleanup default Kconfig values for s390 selftests

 - Add a s390-tod trace clock to allow comparing trace timestamps
   between different systems or virtual machines on s390

 - Remove the s390 implementation of strlcat() in favor of the generic
   variant

 - Make consistent the calling order between
   page_table_check_pte_clear() and secure page conversion across all
   code paths

 - Rearrange some fields within AP and zcrypt structs to reduce memory
   consumption and unused holes

 - Shorten GR_NUM and VX_NUM macros and move them to a separate header

 - Replace __get_free_page() with kmalloc() in few sources

 - Introduce an infrastructure for more efficient this_cpu operations.
   Eliminate conditional branches when PREEMPT_NONE is removed

 - Enable Rust support

 - Use z10 as minimum architecture level, similar to the boot code, to
   enforce a defined architecture level set

 - Improve and convert various mem*() helper functions to C. For that
   add .noinstr.text section to avoid orphaned warnings from the linker

 - Fix the function pointer type in __ret_from_fork() to correct the
   indirect call to match kernel thread return type of int

 - Revert support for DCACHE_WORD_ACCESS to avoid an endless exception
   loop on read from donated Ultravisor pages at unaligned addresses

* tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits)
  s390: Revert support for DCACHE_WORD_ACCESS
  s390/process: Fix kernel thread function pointer type
  s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C
  s390/memmove: Optimize backward copy case
  s390/string: Convert memset(16|32|64)() to C
  s390/string: Convert memcpy() to C
  s390/string: Convert memset() to C
  s390/string: Convert memmove() to C
  s390/string: Add -ffreestanding compile option to string.o
  s390: Add .noinstr.text to boot and purgatory linker scripts
  s390/purgatory: Enforce z10 minimum architecture level
  s390: Enable Rust support
  s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers
  rust: helpers: Add memchr wrapper for string operations
  rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts
  s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros
  s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
  s390/ap: Fix locking issue in SE bind and associate sysfs functions
  s390/percpu: Provide arch_this_cpu_write() implementation
  s390/percpu: Provide arch_this_cpu_read() implementation
  ...

s390/idle: Remove idle time and count sysfs files

2026-06-15T14:33:40+00:00

Remove the s390 specific idle_time_us and idle_count per cpu sysfs
files. They do not provide any additional value. The risk that there
are existing applications which rely on these architecture specific
files should be very low.

However if it turns out such applications exist, this can be easily
reverted.

Signed-off-by: Heiko Carstens 
Acked-by: Frederic Weisbecker 
Signed-off-by: Alexander Gordeev

s390/idle: Provide arch specific kcpustat_field_idle()/kcpustat_field_iowait()

2026-06-15T14:33:40+00:00

The former s390 specific arch_cpu_idle_time() implementation was
removed, since its implementation was racy and reported idle time
could go backwards [1].

However this removal was not necessary, since independently of the s390
architecture specific races there exists the iowait counter update race,
which can also lead to reported idle time going backwards [2].

With Frederic Weisbecker's recent cpu idle time accounting refactoring
kernel_cpustat got a sequence counter. Use this to implement s390 specific
variants of kcpustat_field_idle() and kcpustat_field_iowait(). This is
logically a revert of [1] and moves cpu idle time accounting back into s390
architecture code, which is also more precise than the dyntick idle time
accounting by nohz/scheduler.

For comparing cross cpu time stamps it is necessary to use the stcke
instead of the stckf instruction in irq entry path. Furthermore this
open-codes a sequence lock in assembler and C code, which is required to
update the irq entry time stamp to the per cpu idle_data structure in a
race free manner.

[1] commit be76ea614460 ("s390/idle: remove arch_cpu_idle_time() and corresponding code")
[2] commit ead70b752373 ("timers/nohz: Add a comment about broken iowait counter update race")

Signed-off-by: Heiko Carstens 
Acked-by: Frederic Weisbecker 
Signed-off-by: Alexander Gordeev