The sys_ni_posix_timers() definition causes a warning when the declaration
is missing, so this needs to be added along with the normal syscalls,
outside of the #ifdef.

kernel/time/posix-stubs.c:26:17: error: no previous prototype for 'sys_ni_posix_timers' [-Werror=missing-prototypes]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230607142925.3126422-1-arnd@kernel.org

The ratelimit logic in report_idle_softirq() is broken because the
exit condition is always true:

	static int ratelimit;

	if (ratelimit < 10)
		return false;  ---> always returns here

	ratelimit++;           ---> no chance to run

Make it check for >= 10 instead.

Fixes: 0345691b ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/tencent_5AAA3EEAB42095C9B7740BE62FBF9A67E007@qq.com

Pointers of type void * do not require a type cast when they are assigned
to a real pointer.
Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609182059.4509-1-zeming@nfschina.com

ret is assigned before checked, so it does not need to initialize the
variable
Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609182856.4660-1-zeming@nfschina.com

Commit c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
turns an ifdef CONFIG_HIGH_RES_TIMERS into an conditional on
"IS_ENABLED(CONFIG_HIGHRES_TIMERS)"; note that the new conditional refers
to "HIGHRES_TIMERS" not "HIGH_RES_TIMERS" as before.

Fix this typo introduced in that refactoring.

Fixes: c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609094643.26253-1-lukas.bulwahn@gmail.com

Make it consistent with the TIP tree documentation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.888493625@linutronix.de

Documenting the obvious is just consuming space for no value.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.832240451@linutronix.de

Make the issues vs. SIG_IGN understandable and remove the 15 years old
promise that a proper solution is already on the horizon.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/874jnrdmrq.ffs@tglx

Yet another incomprehensible piece of art.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.724863461@linutronix.de

Replace the word salad.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.672220780@linutronix.de

The comment about timer lifetime at the end of the function is misplaced
and uncomprehensible.

Make it understandable and put it at the right place. Add a new comment
about the visibility of the new timer ID to user space.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.619897296@linutronix.de

The descriptions for common_nsleep() is wrong and common_nsleep_timens()
lacks any form of comment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.567072835@linutronix.de

The documentation of sys_clock_settime() permissions is at a random place
and mostly word salad.

Remove it and add a concise comment into sys_clock_settime().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.514700292@linutronix.de

Document the syscall in detail and with coherent sentences.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.462051641@linutronix.de

Replace another confusing and inaccurate set of comments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.409169321@linutronix.de

The decades old comment about Posix clock resolution is confusing at best.

Remove it and add a proper explanation to sys_clock_getres().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.356427330@linutronix.de

release_posix_timers() is called for cleaning up both hashed and unhashed
timers. The cases are differentiated by an argument and the usage is
hideous.

Seperate the actual free path out and use it for unhashed timers. Provide a
function for hashed timers.

No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.301432503@linutronix.de

All usage of hash_lock is in thread context. No point in using
spin_lock_irqsave()/irqrestore() for a single usage site.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.249063953@linutronix.de

Technically it's not required to set k_itimer::it_signal to NULL on exit()
because there is no other thread anymore which could lookup the timer
concurrently.

Set it to NULL for consistency sake and add a comment to that effect.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.196462644@linutronix.de

k_itimer::it_signal is read lockless in the RCU protected hash lookup, but
it can be written concurrently in the timer_create() and timer_delete()
path. Annotate these places with READ_ONCE() and WRITE_ONCE()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.143596887@linutronix.de

Document how the timer ID validation in the hash table works.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.091081515@linutronix.de

Describe the hash table properly and remove the IDR leftover comments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.038444551@linutronix.de

Explain it better and add the CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y aspect
for completeness.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183312.985681995@linutronix.de

posix_timer_add() tries to allocate a posix timer ID by starting from the
cached ID which was stored by the last successful allocation.

This is done in a loop searching the ID space for a free slot one by
one. The loop has to terminate when the search wrapped around to the
starting point.

But that's racy vs. establishing the starting point. That is read out
lockless, which leads to the following problem:

CPU0	  	      	     	   CPU1
posix_timer_add()
  start = sig->posix_timer_id;
  lock(hash_lock);
  ...				   posix_timer_add()
  if (++sig->posix_timer_id < 0)
      			             start = sig->posix_timer_id;
     sig->posix_timer_id = 0;

So CPU1 can observe a negative start value, i.e. -1, and the loop break
never happens because the condition can never be true:

  if (sig->posix_timer_id == start)
     break;

While this is unlikely to ever turn into an endless loop as the ID space is
huge (INT_MAX), the racy read of the start value caught the attention of
KCSAN and Dmitry unearthed that incorrectness.

Rewrite it so that all id operations are under the hash lock.

Reported-by: syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/87bkhzdn6g.ffs@tglx

itimer_delete() has a retry loop when the timer is concurrently expired. On
non-RT kernels this just spin-waits until the timer callback has completed,
except for posix CPU timers which have HAVE_POSIX_CPU_TIMERS_TASK_WORK
enabled.

In that case and on RT kernels the existing task could live lock when
preempting the task which does the timer delivery.

Replace spin_unlock() with an invocation of timer_wait_running() to handle
it the same way as the other retry loops in the posix timer code.

Fixes: ec8f954a ("posix-timers: Use a callback for cancel synchronization on PREEMPT_RT")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/87v8g7c50d.ffs@tglx

The arch_get_vdso_data() function is defined separately on each architecture,
but only called when CONFIG_TIME_NS is set. If the definition is a global
function, this causes a W=1 warning without TIME_NS:

arch/x86/entry/vdso/vma.c:35:19: error: no previous prototype for 'arch_get_vdso_data' [-Werror=missing-prototypes]

Move the prototype out of the #ifdef block to reliably turn off that
warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230517131102.934196-15-arnd@kernel.org

Pull x86 cpu fix from Thomas Gleixner:
 "A single fix for x86:

   - Prevent a bogus setting for the number of HT siblings, which is
     caused by the CPUID evaluation trainwreck of X86. That recomputes
     the value for each CPU, so the last CPU "wins". That can cause
     completely bogus sibling values"

* tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms

Pull perf fixes from Thomas Gleixner:
 "A small set of perf fixes:

   - Make the MSR-readout based CHA discovery work around broken
     discovery tables in some SPR firmwares.

   - Prevent saving PEBS configuration which has software bits set that
     cause a crash when restored into the relevant MSR"

* tag 'perf-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore: Correct the number of CHAs on SPR
  perf/x86/intel: Save/restore cpuc->active_pebs_data_cfg when using guest PEBS

Pull unwinder fixes from Thomas Gleixner:
 "A set of unwinder and tooling fixes:

   - Ensure that the stack pointer on x86 is aligned again so that the
     unwinder does not read past the end of the stack

   - Discard .note.gnu.property section which has a pointlessly
     different alignment than the other note sections. That confuses
     tooling of all sorts including readelf, libbpf and pahole"

* tag 'objtool-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/show_trace_log_lvl: Ensure stack pointer is aligned, again
  vmlinux.lds.h: Discard .note.gnu.property section

Pull debugobjects fixes from Thomas Gleixner:
 "Two fixes for debugobjects:

   - Prevent the allocation path from waking up kswapd.

     That's a long standing issue due to the GFP_ATOMIC allocation flag.
     As debug objects can be invoked from pretty much any context waking
     kswapd can end up in arbitrary lock chains versus the waitqueue
     lock

   - Correct the explicit lockdep wait-type violation in
     debug_object_fill_pool()"

* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  debugobjects: Don't wake up kswapd from fill_pool()
  debugobjects,locking: Annotate debug_object_fill_pool() wait type violation

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for interrupt chip drivers:

   - Prevent loss of state in the MIPS GIC interrupt controller

   - Disable pseudo NMIs on Mediatek based Chromebooks as they have
     firmware issues which cause instantenous chrashes and freezes wen
     pseudo NMIs are used

   - Fix the error handling path in the MBIGEN driver and a defined but
     not used warning in the meson-gpio interrupt chip driver"

* tag 'irq-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mbigen: Unify the error handling in mbigen_of_create_domain()
  irqchip/meson-gpio: Mark OF related data as maybe unused
  irqchip/mips-gic: Use raw spinlock for gic_lock
  irqchip/mips-gic: Don't touch vl_map if a local interrupt is not routable
  irqchip/gic-v3: Disable pseudo NMIs on Mediatek devices w/ firmware issues
  dt-bindings: interrupt-controller: arm,gic-v3: Add quirk for Mediatek SoCs w/ broken FW

Pull MIPS fixes from Thomas Bogendoerfer:

 - fixes to get alchemy platform back in shape

 - fix for initrd detection

* tag 'mips-fixes_6.4_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  mips: Move initrd_start check after initrd address sanitisation.
  MIPS: Alchemy: fix dbdma2
  MIPS: Restore Au1300 support
  MIPS: unhide PATA_PLATFORM

Pull powerpc fix from Michael Ellerman:

 - Reinstate ARCH_FORCE_MAX_ORDER ranges to fix various breakage

* tag 'powerpc-6.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Reinstate ARCH_FORCE_MAX_ORDER ranges

Pull xen fixes from Juergen Gross:

 - a double free fix in the Xen pvcalls backend driver

 - a fix for a regression causing the MSI related sysfs entries to not
   being created in Xen PV guests

 - a fix in the Xen blkfront driver for handling insane input data
   better

* tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/pci/xen: populate MSI sysfs entries
  xen/pvcalls-back: fix double frees with pvcalls_new_active_socket()
  xen/blkfront: Only check REQ_FUA for writes

Pull char/misc fixes from Greg KH:
 "Here are some small driver fixes for 6.4-rc4. They are just two
  different types:

   - binder fixes and reverts for reported problems and regressions in
     the binder "driver".

   - coresight driver fixes for reported problems.

  All of these have been in linux-next for over a week with no reported
  problems"

* tag 'char-misc-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  binder: fix UAF of alloc->vma in race with munmap()
  binder: add lockless binder_alloc_(set|get)_vma()
  Revert "android: binder: stop saving a pointer to the VMA"
  Revert "binder_alloc: add missing mmap_lock calls when using the VMA"
  binder: fix UAF caused by faulty buffer cleanup
  coresight: perf: Release Coresight path when alloc trace id failed
  coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet()

Pull compute express link fixes from Dan Williams:
 "The 'media ready' series prevents the driver from acting on bad
  capacity information, and it moves some checks earlier in the init
  sequence which impacts topics in the queue for 6.5.

  Additional hotplug testing uncovered a missing enable for memory
  decode. A debug crash fix is also included.

  Summary:

   - Stop trusting capacity data before the "media ready" indication

   - Add missing HDM decoder capability enable for the cold-plug case

   - Fix a debug message induced crash"

* tag 'cxl-fixes-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl: Explicitly initialize resources when media is not ready
  cxl/port: Fix NULL pointer access in devm_cxl_add_port()
  cxl: Move cxl_await_media_ready() to before capacity info retrieval
  cxl: Wait Memory_Info_Valid before access memory related info
  cxl/port: Enable the HDM decoder capability for switch ports

Pull ARM SoC fixes from Arnd Bergmann:
 "There have not been a lot of fixes for for the soc tree in 6.4, but
  these have been sitting here for too long.

  For the devicetree side, there is one minor warning fix for vexpress,
  the rest all all for the the NXP i.MX platforms: SoC specific bugfixes
  for the iMX8 clocks and its USB-3.0 gadget device, as well as board
  specific fixes for regulators and the phy on some of the i.MX boards.

  The microchip risc-v and arm32 maintainers now also add a shared
  maintainer file entry for the arm64 parts.

  The remaining fixes are all for firmware drivers, addressing mistakes
  in the optee, scmi and ff-a firmware driver implementation, mostly in
  the error handling code, incorrect use of the alloc_workqueue()
  interface in SCMI, and compatibility with corner cases of the firmware
  implementation"

* tag 'arm-fixes-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  MAINTAINERS: update arm64 Microchip entries
  arm64: dts: imx8: fix USB 3.0 Gadget Failure in QM & QXPB0 at super speed
  dt-binding: cdns,usb3: Fix cdns,on-chip-buff-size type
  arm64: dts: colibri-imx8x: delete adc1 and dsp
  arm64: dts: colibri-imx8x: fix iris pinctrl configuration
  arm64: dts: colibri-imx8x: move pinctrl property from SoM to eval board
  arm64: dts: colibri-imx8x: fix eval board pin configuration
  arm64: dts: imx8mp: Fix video clock parents
  ARM: dts: imx6qdl-mba6: Add missing pvcie-supply regulator
  ARM: dts: imx6ull-dhcor: Set and limit the mode for PMIC buck 1, 2 and 3
  arm64: dts: imx8mn-var-som: fix PHY detection bug by adding deassert delay
  arm64: dts: imx8mn: Fix video clock parents
  firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors
  firmware: arm_ffa: Fix FFA device names for logical partitions
  firmware: arm_ffa: Fix usage of partition info get count flag
  firmware: arm_ffa: Check if ffa_driver remove is present before executing
  arm64: dts: arm: add missing cache properties
  ARM: dts: vexpress: add missing cache properties
  firmware: arm_scmi: Fix incorrect alloc_workqueue() invocation
  optee: fix uninited async notif value

Pull PCI fix from Bjorn Helgaas:

 - Quirk Ice Lake Root Ports to work around DPC log size issue (Mika
   Westerberg)

* tag 'pci-v6.4-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI/DPC: Quirk PIO log size for Intel Ice Lake Root Ports

Pull VFIO fix from Alex Williamson:

 - Test for and return error for invalid pfns through the pin pages
   interface (Yan Zhao)

* tag 'vfio-v6.4-rc4' of https://github.com/awilliam/linux-vfio:
  vfio/type1: check pfn valid before converting to struct page