Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 86 insertions, 0 deletions

diff --git a/drivers/net/arcnet/Kconfig b/drivers/net/arcnet/Kconfig
new file mode 100644
index 000000000..4611a3716
--- /dev/null
+++ b/drivers/net/arcnet/Kconfig
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Arcnet configuration
+#
+
+menuconfig ARCNET
+	depends on NETDEVICES && PCI && HAS_IOPORT
+	tristate "ARCnet support"
+	help
+	  If you have a network card of this type, say Y and check out the
+	  (arguably) beautiful poetry in
+	  <file:Documentation/networking/arcnet.rst>.
+
+	  You need both this driver, and the driver for the particular ARCnet
+	  chipset of your card.
+
+	  To compile this driver as a module, choose M here. The module will
+	  be called arcnet.
+
+if ARCNET
+
+config ARCNET_1201
+	tristate "Enable standard ARCNet packet format (RFC 1201)"
+	help
+	  This allows you to use RFC1201 with your ARCnet card via the virtual
+	  arc0 device.  You need to say Y here to communicate with
+	  industry-standard RFC1201 implementations, like the arcether.com
+	  packet driver or most DOS/Windows ODI drivers.  Please read the
+	  ARCnet documentation in <file:Documentation/networking/arcnet.rst>
+	  for more information about using arc0.
+
+config ARCNET_1051
+	tristate "Enable old ARCNet packet format (RFC 1051)"
+	help
+	  This allows you to use RFC1051 with your ARCnet card via the virtual
+	  arc0s device. You only need arc0s if you want to talk to ARCnet
+	  software complying with the "old" standard, specifically, the DOS
+	  arcnet.com packet driver, Amigas running AmiTCP, and some variants
+	  of NetBSD. You do not need to say Y here to communicate with
+	  industry-standard RFC1201 implementations, like the arcether.com
+	  packet driver or most DOS/Windows ODI drivers. RFC1201 is included
+	  automatically as the arc0 device. Please read the ARCnet
+	  documentation in <file:Documentation/networking/arcnet.rst> for more
+	  information about using arc0e and arc0s.
+
+config ARCNET_RAW
+	tristate "Enable raw mode packet interface"
+	help
+	  ARCnet "raw mode" packet encapsulation, no soft headers.  Unlikely
+	  to work unless talking to a copy of the same Linux arcnet driver,
+	  but perhaps marginally faster in that case.
+
+config ARCNET_CAP
+	tristate "Enable CAP mode packet interface"
+	help
+	  ARCnet "cap mode" packet encapsulation. Used to get the hardware
+	  acknowledge back to userspace. After the initial protocol byte every
+	  packet is stuffed with an extra 4 byte "cookie" which doesn't
+	  actually appear on the network. After transmit the driver will send
+	  back a packet with protocol byte 0 containing the status of the
+	  transmission:
+	     0=no hardware acknowledge
+	     1=excessive nak
+	     2=transmission accepted by the receiver hardware
+
+	  Received packets are also stuffed with the extra 4 bytes but it will
+	  be random data.
+
+	  Cap only listens to protocol 1-8.
+
+config ARCNET_COM20020
+	tristate "ARCnet COM20020 chipset driver"
+	depends on LEDS_CLASS
+	help
+	  This is the driver for the new COM20020 chipset. It supports such
+	  things as promiscuous mode, so packet sniffing is possible, and
+	  extra diagnostic information.
+
+	  To compile this driver as a module, choose M here. The module will
+	  be called com20020.
+
+config ARCNET_COM20020_PCI
+	tristate "Support for COM20020 on PCI"
+	depends on ARCNET_COM20020 && PCI
+
+endif # ARCNET