Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted

Pull futex fix from Ingo Molnar:

 - Also allocate a default private futex hash on vfork() as well, to
   avoid races with (private) futex waiters (Peter Zijlstra)

* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Also allocate private hash on vfork()

1 files changed, 94 insertions, 0 deletions

diff --git a/Documentation/input/devices/appletouch.rst b/Documentation/input/devices/appletouch.rst
new file mode 100644
index 000000000..c94470e66
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+++ b/Documentation/input/devices/appletouch.rst
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+.. include:: <isonum.txt>
+
+----------------------------------
+Apple Touchpad Driver (appletouch)
+----------------------------------
+
+:Copyright: |copy| 2005 Stelian Pop <stelian@popies.net>
+
+appletouch is a Linux kernel driver for the USB touchpad found on post
+February 2005 and October 2005 Apple Aluminium Powerbooks.
+
+This driver is derived from Johannes Berg's appletrackpad driver [#f1]_,
+but it has been improved in some areas:
+
+	* appletouch is a full kernel driver, no userspace program is necessary
+	* appletouch can be interfaced with the synaptics X11 driver, in order
+	  to have touchpad acceleration, scrolling, etc.
+
+Credits go to Johannes Berg for reverse-engineering the touchpad protocol,
+Frank Arnold for further improvements, and Alex Harper for some additional
+information about the inner workings of the touchpad sensors. Michael
+Hanselmann added support for the October 2005 models.
+
+Usage
+-----
+
+In order to use the touchpad in the basic mode, compile the driver and load
+the module. A new input device will be detected and you will be able to read
+the mouse data from /dev/input/mice (using gpm, or X11).
+
+In X11, you can configure the touchpad to use the synaptics X11 driver, which
+will give additional functionalities, like acceleration, scrolling, 2 finger
+tap for middle button mouse emulation, 3 finger tap for right button mouse
+emulation, etc. In order to do this, make sure you're using a recent version of
+the synaptics driver (tested with 0.14.2, available from [#f2]_), and configure
+a new input device in your X11 configuration file (take a look below for an
+example). For additional configuration, see the synaptics driver documentation::
+
+	Section "InputDevice"
+		Identifier      "Synaptics Touchpad"
+		Driver          "synaptics"
+		Option          "SendCoreEvents"        "true"
+		Option          "Device"                "/dev/input/mice"
+		Option          "Protocol"              "auto-dev"
+		Option		"LeftEdge"		"0"
+		Option		"RightEdge"		"850"
+		Option		"TopEdge"		"0"
+		Option		"BottomEdge"		"645"
+		Option		"MinSpeed"		"0.4"
+		Option		"MaxSpeed"		"1"
+		Option		"AccelFactor"		"0.02"
+		Option		"FingerLow"		"0"
+		Option		"FingerHigh"		"30"
+		Option		"MaxTapMove"		"20"
+		Option		"MaxTapTime"		"100"
+		Option		"HorizScrollDelta"	"0"
+		Option		"VertScrollDelta"	"30"
+		Option		"SHMConfig"		"on"
+	EndSection
+
+	Section "ServerLayout"
+		...
+		InputDevice	"Mouse"
+		InputDevice	"Synaptics Touchpad"
+	...
+	EndSection
+
+Fuzz problems
+-------------
+
+The touchpad sensors are very sensitive to heat, and will generate a lot of
+noise when the temperature changes. This is especially true when you power-on
+the laptop for the first time.
+
+The appletouch driver tries to handle this noise and auto adapt itself, but it
+is not perfect. If finger movements are not recognized anymore, try reloading
+the driver.
+
+You can activate debugging using the 'debug' module parameter. A value of 0
+deactivates any debugging, 1 activates tracing of invalid samples, 2 activates
+full tracing (each sample is being traced)::
+
+	modprobe appletouch debug=1
+
+or::
+
+	echo "1" > /sys/module/appletouch/parameters/debug
+
+
+.. Links:
+
+.. [#f1] http://johannes.sipsolutions.net/PowerBook/touchpad/
+
+.. [#f2] `<http://web.archive.org/web/*/http://web.telia.com/~u89404340/touchpad/index.html>`_