selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 157 insertions, 0 deletions

diff --git a/drivers/s390/char/Kconfig b/drivers/s390/char/Kconfig
new file mode 100644
index 000000000..7416f941e
--- /dev/null
+++ b/drivers/s390/char/Kconfig
@@ -0,0 +1,157 @@
+# SPDX-License-Identifier: GPL-2.0
+comment "S/390 character device drivers"
+	depends on S390
+
+config TN3270
+	def_tristate y
+	prompt "Support for locally attached 3270 terminals"
+	depends on CCW && TTY
+	help
+	  Include support for IBM 3270 terminals.
+
+config TN3270_FS
+	def_tristate m
+	prompt "Support for fullscreen applications on 3270 terminals"
+	depends on TN3270
+	help
+	  Include support for fullscreen applications on an IBM 3270 terminal.
+
+config TN3270_CONSOLE
+	def_bool y
+	prompt "Support for console on 3270 terminal"
+	depends on TN3270=y
+	help
+	  Include support for using an IBM 3270 terminal as a Linux system
+	  console.  Available only if 3270 support is compiled in statically.
+
+config TN3215
+	def_bool y
+	prompt "Support for 3215 line mode terminal"
+	depends on CCW && TTY
+	help
+	  Include support for IBM 3215 line-mode terminals.
+
+config TN3215_CONSOLE
+	def_bool y
+	prompt "Support for console on 3215 line mode terminal"
+	depends on TN3215
+	help
+	  Include support for using an IBM 3215 line-mode terminal as a
+	  Linux system console.
+
+config CCW_CONSOLE
+	def_bool y if TN3215_CONSOLE || TN3270_CONSOLE
+
+config SCLP_TTY
+	def_bool y
+	prompt "Support for SCLP line mode terminal"
+	depends on S390 && TTY
+	help
+	  Include support for IBM SCLP line-mode terminals.
+
+config SCLP_CONSOLE
+	def_bool y
+	prompt "Support for console on SCLP line mode terminal"
+	depends on SCLP_TTY
+	help
+	  Include support for using an IBM HWC line-mode terminal as the Linux
+	  system console.
+
+config SCLP_VT220_TTY
+	def_bool y
+	prompt "Support for SCLP VT220-compatible terminal"
+	depends on S390 && TTY
+	help
+	  Include support for an IBM SCLP VT220-compatible terminal.
+
+config SCLP_VT220_CONSOLE
+	def_bool y
+	prompt "Support for console on SCLP VT220-compatible terminal"
+	depends on SCLP_VT220_TTY
+	help
+	  Include support for using an IBM SCLP VT220-compatible terminal as a
+	  Linux system console.
+
+config HMC_DRV
+	def_tristate m
+	prompt "Support for file transfers from HMC drive CD/DVD-ROM"
+	depends on S390
+	select CRC16
+	help
+	  This option enables support for file transfers from a Hardware
+	  Management Console (HMC) drive CD/DVD-ROM. It is available as a
+	  module, called 'hmcdrv', and also as kernel built-in. There is one
+	  optional parameter for this module: cachesize=N, which modifies the
+	  transfer cache size from its default value 0.5MB to N bytes. If N
+	  is zero, then no caching is performed.
+
+config S390_UV_UAPI
+	def_tristate m
+	prompt "Ultravisor userspace API"
+	depends on S390
+	help
+	  Selecting exposes parts of the UV interface to userspace
+	  by providing a misc character device at /dev/uv.
+	  Using IOCTLs one can interact with the UV.
+	  The device is only available if the Ultravisor
+	  Facility (158) is present.
+
+config S390_TAPE
+	def_tristate m
+	prompt "Support for 3490E tape on VTS"
+	depends on CCW
+	help
+	  Select this option if you want to access channel-attached IBM 3490E
+	  tape devices on VTS, such as IBM TS7700.
+	  This option is also available as a module.
+	  It is safe to say "Y" here.
+
+config VMLOGRDR
+	def_tristate m
+	prompt "Support for the z/VM recording system services (VM only)"
+	depends on IUCV
+	help
+	  Select this option if you want to be able to receive records collected
+	  by the z/VM recording system services, eg. from *LOGREC, *ACCOUNT or
+	  *SYMPTOM.
+	  This driver depends on the IUCV support driver.
+
+config VMCP
+	def_bool y
+	prompt "Support for the z/VM CP interface"
+	depends on S390
+	select CMA
+	help
+	  Select this option if you want to be able to interact with the control
+	  program on z/VM
+
+config VMCP_CMA_SIZE
+	int "Memory in MiB reserved for z/VM CP interface"
+	default "4"
+	depends on VMCP
+	help
+	  Specify the default amount of memory in MiB reserved for the z/VM CP
+	  interface. If needed this memory is used for large contiguous memory
+	  allocations. The default can be changed with the kernel command line
+	  parameter "vmcp_cma".
+
+config MONREADER
+	def_tristate m
+	prompt "API for reading z/VM monitor service records"
+	depends on IUCV
+	help
+	  Character device driver for reading z/VM monitor service records
+
+config MONWRITER
+	def_tristate m
+	prompt "API for writing z/VM monitor service records"
+	depends on S390
+	help
+	  Character device driver for writing z/VM monitor service records
+
+config S390_VMUR
+	def_tristate m
+	prompt "z/VM unit record device driver"
+	depends on S390
+	help
+	  Character device driver for z/VM reader, puncher and printer.