[PATCH] dvb: frontend: add driver for LGDT3302

Add support for LGDT3302 (ATSC VSB/QAM) used in DViCO FusionHDTV3 Gold.

Signed-off-by: Mac Michaels <wmichaels1@earthlink.net>
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: fix timeout handling to be save with PREEMPT

Timeout handling fixed, especially for preemtible kernels and/or high system
load.

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: dont use HZ for timeouts

Don't use HZ for usb-transfer-timeouts.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: A800 rc and timeout fixes

o add some remote control codes
o not using HZ for control_msg-timeout

Signed-off-by: Andrew Hodgson <a.s.hodgson@gmail.com>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: IR input fixes

o fixed usage of the correct number of events in keymapping-array
o better place for return

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: vp7045 IR map fix

Correct two keys of the vp7045 remote control key mapping.

Signed-off-by: Michael Paxton <packo@tpg.com.au>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: fix WideView USB ids

o Steve Chang reported the real name behind 0x14aa: WideView,
  changed USB IDs accordingly.
o fixed an assignment

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: add vp7045 IR keymap

Add keymap for Twinhan vp7045 remote control.

Signed-off-by: Michael Paxton <packo@tpg.com.au>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb Kconfig help text update

o corrected some typos
o added the Wikilink pointing to the USB device list

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb doc update

o removed device listing (they are all in the linuxtv wiki now)
o misc updates

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: digitv memcpy fix

Fix memcpy copying into the wrong destination.  Thanks to Allan Third for
reporting.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: add VideoWalker DVB-T USB ids

Add another USB ID pair for the VideoWalker USB DVB-T.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: cxusb DVB-T fixes

cxusb DVB-T fixes.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: dvb_usb_properties init fix

There was no pid-filter-count set for some devices - led to an error.  Thanks
to Gerolf Wendland.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: digitv-usb fixes

Some more work on the digitv-usb driver:
o MT352 initialization and PLL-programming
o I2c-transfer fixed.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: add ALPS TDED4 PLL

Add dvb_pll_desc for ALPS TDED4 used in Nebula USB boxes.  Changed the
name-field of the FMD1216.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: add module parm to disable remote control polling

Add module parameter to deactive remote control polling.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: support Medion hybrid USB2.0 DVB-T/analogue box

Add preliminary support for the Medion Hybrid USB2.0 DVB-T/Analogue box.
Analogue part is not working yet (cx25842 --> ivtv?).

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: add FMD1216ME PLL

o change dvb-pll desc to take the frequency as parameter for setbw-callback
  into consideration
o added dvb-pll desc for Philips FMD1216ME (needed for cxusb)

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: add isochronous streaming method

Added isochronous-streaming method.  Changed memory (de)allocation behaviour
accordingly.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: usb: fix ADSTech Instant TV DVB-T USB2.0 support

Fixed support for the ADSTech Instant TV DVB-T USB (2.0 version).  Thanks to
Gerolf Wendland for his support.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: dvb-usb: support Artect T1 with broken USB ids

Add #define for device with broken USB ids.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: add support for Hauppauge/TT DVB-C budget

Add support for Hauppauge/TT DVB-C budget.

Signed-off-by: Gavin Hamill <gdh@acentral.co.uk>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: kj printk fix

printk() calls should include appropriate KERN_* constant.

Signed-off-by: Christophe Lucas <clucas@rotomalug.org>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: make av7110_fe_lock_fix() retryable

av7110_fe_lock_fix() modified in a way that it can be retried after
-ERESTARTSYS

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: cleanup indentation + whitespace

Fix indentation and add some whitepsace between operators.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: error handling fix

Change error handling in av7110_stop_feed() to stop as many filters as
possible in case of errors.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: more error handling for firmware communication

o propagate more errors back to caller or log them, mainly in
  av7110.c and av7110_av.c
o fix error message in StartHWFilter
o do not StopHWFilter for handle 0xffff

Signed-off-by: Wolfgang Rohdewald <wolfgang@rohdewald.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: budget-av / tu1216 fix for QAM128

Fix for QAM128 in VHF band suggested by Timo Helkiö.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: fix AUDUIO_CONTINUE ioctl

Fixed typo in AUDUIO_CONTINUE ioctl:  AUDIO_CMD_MUTE -> AUDIO_CMD_UNMUTE

Signed-off-by: "Dr. Werner Fink" <werner@suse.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: fix bug in timeout handling

Fix bug in timeout handling.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: fix error handling for firmware communication

o make sure ERESTARTSYS will be propagated
o ReleaseBitmap: starting with Firmware 261e, also release when
  BMP_LOADING
o removes unused #define BMP_LOADINGS
o in many cases changed the return value from -1 to something more
  meaningful like ETIMEDOUT, EINVAL
o changed syslog message timeout waiting for COMMAND such that it
  indicates what command did not complete
o reduce # of arguments for LoadBitmap and BlitBitmap
o av7110_osd_cmd: remove the out: label

Signed-off-by: Wolfgang Rohdewald <wolfgang@rohdewald.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: support for new TT DVB-T-CI

Support for new TT DVB-T-CI, thanks to Andre Weidemann

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttpci: add support for Technotrend/Hauppauge DVB-S SE

Add support for s5h1420 frontend (new Technotrend/Hauppauge DVB-S SE).

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: ttusb-dec: kfree cleanup

The Coverity checker discovered that these two kfree's can never be executed.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: Twinhan DST: frontend polarization fix

Fix a bug that caused the polarization (V/H) to be interchanged.

Signed-off-by: Allan Stirling <Dibblahdvb0042@pendor.org>
Signed-off-by: Manu Abraham <manu@kromtek.com>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: Twinhan DST: frontend fixes

o Make the inversion setting specific, ie, only for the 200103A DVB-S
  This should not be flagged on other cards.
o Make the frequency setting card specific
o Make the bandwidth setting generic such that it supports more DVB-T cards
o Set QAM size for DVB-C cards that do not autodetect QAM size
o Fix a bug that caused the polarization not to be set.
  Set polarization for cards that do not autodetect polarization
o Fix a bogus frontend signal lock, that caused a tuning delay as well.
o Make the Symbolrate setting card specific

Signed-off-by: Manu Abraham <manu@kromtek.com>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: flexcop: woraround irq stop problem

The flexcop chip often stops generating interrupts after some hours of
operation.  Apparently this can be fixed by resetting register block 0x300 at
each channel change (this is not detailed in the flexcop data books).

This patch also restructures DMA handling and adds a bit of debug code for the
irq problem in case it still happens for someone.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: flexcop: add big endian register definitions

Add big-endian register definitions for running on a PowerPC.
(Thanks to Paavo Hartikainen for testing.)

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: saa7146: kj pci_module_init cleanup

http://kerneljanitors.org/TODO
- convert from pci_module_init to pci_register_driver

Signed-off-by: Christophe Lucas <c.lucas@ifrance.com>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: add Pluto2 driver

Add driver for the Satelco Easywatch Mobile DVB-T card (based on Pluto2 chip).

Signed-off-by: Andreas Oberritter <obi@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: DVB update

Increase some timeouts by a factor of 10 as suggested by Mikko Hamalainen and
Timo Ketolainen, to improve tuning for QAM128 / weak signal.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: l64781: improve tuning

Disable zig-zag and set min_delay_ms = 4000 as suggested by Allan Guild to
improve tuning with weak signal.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: cx22702: support for cxusb

Add .get_tune_settings callback (min_delay_ms = 1sec) and output_mode-field
(parallel/serial) to support cxusb; minor cleanups.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: tda1004x: support tda827x tuners

o added preliminary support for tda827x tuners
o set parameters for drift compensation to 0
  makes no sense for DVB-T but can prevent lock

Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t-online.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: add missing release_firmware() calls

Add missing release_firmware() calls to fix memory leaks.

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: bcm3510: fix firmware version check

Fix limit for firmware version check was too low for tda10045.

Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t-online.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: tda1004x update

o added config options for IF frequency and AGC
o support DSP boot from on board eeprom
o added pll sleep call

Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t-online.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: frontend: remove unused I2C ids

Remove I2C_DRIVERID_DVBFE_ cruft.

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: core: dmxdev cleanups

- remove void casts
- not necessary to set filter state twice to STATE_FREE during
  dvb_dmxdev_init()

Signed-off-by: Peter Beutner <p.beutner@gmx.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: core: demux error handling fix

In dvb_dmxdev_filter_start if we go out because of an error, release
previously allocated demux_feed.

Signed-off-by: Peter Beutner <p.beutner@gmx.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: core: add workaround for tuning problem

Add workaround for signal lock loss issue, where the frontend loses the signal
after some hours without any visible reason.

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: core: fix race condition in FE_READ_STATUS ioctl

Fix a race condition where an application which issued a FE_READ_STATUS ioctl
directly after FE_SET_FRONTEND would see an old status, i.e.  FE_READ_STATUS
would be executed before the frontend thread has even seen the tungin request
from FE_SET_FRONTEND.

Signed-off-by: Peter Beutner <p.beutner@gmx.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: remove obsolete skystar2 driver

Remove the skystar2 driver which has been obsoleted by the generalized
flexcop-pci driver.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dvb: cinergyT2: endianness fix for raw remote-control keys

Fixed litte/big-endian conversion for raw remote-control keys.

Signed-off-by: Martin Loschwitz <madkiss@madkiss.org>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace: rename _mntput to mntput_no_expire

This patch renames _mntput() to something a little more descriptive:
mntput_no_expire().

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace: rename mnt_fslink to mnt_expire

This patch renames vfsmount->mnt_fslink to something a little more
descriptive: vfsmount->mnt_expire.

Signed-off-by: Mike Waychison <michael.waychison@sun.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] dcookies.c: use proper refcounting functions

Dcookies shouldn't play with the internals of dentry and vfsmnt
refcounting.  It defeats grepping, and is prone to break if implementation
details change.

In addition the function doesn't even seem to be performance critical: it
calls kmem_cache_alloc().

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] set mnt_namespace in the correct place

This patch sets ->mnt_namespace where it's actually added to the
namespace.

Previously mnt_namespace was set in do_kern_mount() even if the filesystem
was never added to any process's namespace (most kernel-internal
filesystems).

This discrepancy doesn't actually cause any problems, but it's cleaner if
mnt_namespace is NULL for these non exported filesystems.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace.c: fix mnt_namespace zeroing for expired mounts

This patch clears mnt_namespace in an expired mount.

If mnt_namespace is not cleared, it's possible to attach a new mount to the
already detached mount, because check_mnt() can return true.

The effect is a resource leak, since the resulting tree will never be
freed.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace.c: fix expiring of detached mount

This patch fixes a bug noticed by Al Viro:

   However, we still have a problem here - just what would
   happen if vfsmount is detached while we were grabbing namespace
   semaphore?  Refcount alone is not useful here - we might be held by
   whoever had detached the vfsmount.  IOW, we should check that it's
   still attached (i.e. that mnt->mnt_parent != mnt).  If it's not -
   just leave it alone, do mntput() and let whoever holds it deal with
   the sucker.  No need to put it back on lists.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace.c: split mark_mounts_for_expiry()

This patch splits the mark_mounts_for_expiry() function.  It's too complex and
too deeply nested, even without the bugfix in the following patch.

Otherwise code is completely the same.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace.c: cleanup in mark_mounts_for_expiry()

This patch simplifies mark_mounts_for_expiry() by using detach_mnt() instead
of duplicating everything it does.

It should be an equivalent transformation except for righting the dput/mntput
order.

Al Viro said: "Looks sane".

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace.c: fix race in mark_mounts_for_expiry()

This patch fixes a race found by Ram in mark_mounts_for_expiry() in
fs/namespace.c.

The bug can only be triggered with simultaneous exiting of a process having
a private namespace, and expiry of a mount from within that namespace.
It's practically impossible to trigger, and I haven't even tried.  But
still, a bug is a bug.

The race happens when put_namespace() is called by another task, while
mark_mounts_for_expiry() is between atomic_read() and get_namespace().  In
that case get_namespace() will be called on an already dead namespace with
unforeseeable results.

The solution was suggested by Al Viro, with his own words:

      Instead of screwing with atomic_read() in there, why don't we
      simply do the following:
       a) atomic_dec_and_lock() in put_namespace()
       b) __put_namespace() called without dropping lock
       c) the first thing done by __put_namespace would be
      struct vfsmount *root = namespace->root;
      namespace->root = NULL;
      spin_unlock(...);
      ....
      umount_tree(root);
      ...
       d) check in mark_... would be simply namespace && namespace->root.

      And we are all set; no screwing around with atomic_read(), no magic
      at all.  Dying namespace gets NULL ->root.
      All changes of ->root happen under spinlock.
      If under a spinlock we see non-NULL ->mnt_namespace, it won't be
      freed until we drop the lock (we will set ->mnt_namespace to NULL
      under that lock before we get to freeing namespace).
      If under a spinlock we see non-NULL ->mnt_namespace and
      ->mnt_namespace->root, we can grab a reference to namespace and be
      sure that it won't go away.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] namespace.c: fix mnt_namespace clearing

This patch clears mnt_namespace on unmount.

Not clearing mnt_namespace has two effects:

   1) It is possible to attach a new mount to a detached mount,
      because check_mnt() returns true.

      This means, that when no other references to the detached mount
      remain, it still can't be freed.  This causes a resource leak,
      and possibly un-removable modules.

   2) If mnt_namespace is dereferenced (only in mark_mounts_for_expiry())
      after the namspace has been freed, it can cause an Oops, memory
      corruption, etc.

1) has been tested before and after the patch, 2) is only speculation.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add documentation file

Add documentation for InfiniBand userspace verbs.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca user QP support

Add support for userspace queue pairs (QPs) to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca user CQ support

Add support for userspace completion queues (CQs) to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca user MR support

Add support for userspace memory regions (MRs) to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca user PD support

Add support for userspace protection domains (PDs) to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca mmap support

Add support for mmap() method to mthca, so that userspace can get access to
doorbell registers.  This allows userspace to get direct access to the HCA for
data path operations.

Each userspace context gets its own copy of the doorbell registers and is only
allowed to use resources that the kernel has given it access to.  In other
words, this is safe.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca user context support

Add support for managing userspace contexts to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca user doorbell record support

Add support for userspace doorbell records to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add mthca ABI header

Add the mthca_user.h header file, which defines the device-specific ABI used
by the mthca low-level driver for kernel/user communication.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: hook up Kconfig/Makefile

Hook up InfiniBand userspace verbs to Kconfig and the make system.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: memory pinning implementation

Add support for pinning userspace memory regions and returning a list of pages
in the region.  This includes tracking pinned memory against vm_locked and
preventing unprivileged users from exceeding RLIMIT_MEMLOCK.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: core implementation

Add the core of the InfiniBand userspace verbs implementation, including
creating character device nodes, dispatching requests from userspace, and
passing event notifications back up to userspace.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: add user verbs ABI header

Add the ib_user_verbs.h header file, which defines the ABI used by InfiniBand
userspace verbs for kernel/user communication.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: update mthca for new API

Update mthca to compile against the updated API for low-level drivers.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: update kernel midlayer for new API

Update kernel InfiniBand midlayer to compile against the updated API for
low-level drivers.  This just amounts to passing NULL for all
userspace-related parameters, and setting userspace-related structure members
to NULL.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] IB uverbs: core API extensions

First of a series of patches which add support for direct userspace access to
InfiniBand hardware -- so-called "userspace verbs." I believe these patches
are ready to merge, but a final review would be useful.

These patches should incorporate all of the feedback from the discussion when
I posted an earlier version back in April (see
http://lkml.org/lkml/2005/4/4/267 for the start of the thread).  In
particular, memory pinned for use by userspace is accounted for in
current->mm->vm_locked and requests to pin memory are checked against
RLIMIT_MEMLOCK.

This patch:

Modify the ib_verbs.h header file with changes required for InfiniBand
userspace verbs support.  We add a few structures to keep track of userspace
context, and extend the driver API so that low-level drivers know when they're
creating resources that will be used from userspace.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] alpha(): pgprot_noncached

The infiniband code expects that the arch implements pgprot_noncached().

We're mapping PCI areas anyway, so this probabyl wasn't needed and we should
make infiniband stop doing that..

Cc: Roland Dreier <rolandd@cisco.com>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] coverity: sunrpc/xprt task null check

In __xprt_lock_write() we check to see if `task' is NULL, but in other places
we just go and dereference it.

`task' shouldn't be NULL anyway, so remove this test.

This defect was found automatically by Coverity Prevent, a static analysis
tool.

Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] coverity: fs/locks.c flp null check

We're dereferencing `flp' and then we're testing it for NULLness.

Either the compiler accidentally saved us or the existing null-pointer checdk
is redundant.

This defect was found automatically by Coverity Prevent, a static analysis tool.

Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] coverity: fix fbsysfs null pointer check

Correctly test for a null pointer before going and dereferencing it.

This defect was found automatically by Coverity Prevent, a static analysis
tool.

Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Cc: <linux-fbdev-devel@lists.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] cond_resched(): fix bogus might_sleep() warning

The BKS might be reacquired before we have dropped PREEMPT_ACTIVE, which
could trigger a second could trigger a second cond_resched() call.  Bug
found by Hirofumi Ogawa.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] Keys: Base keyring size on key pointer not key struct

The attached patch makes the keyring functions calculate the new size of a
keyring's payload based on the size of pointer to the key struct, not the size
of the key struct itself.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] autofs4: mistake in debug print

Fix debugging printk.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] put_compat_shminfo() warning fix

GCC 4 complains because the function put_compat_shminfo() can't get to its
return statement if there is no error...  If the function does not return
-EFAULT, it doesn't return anything at all.  Looks like a typo.

Signed-off-by: Jesse Millan <jessem@cs.pdx.edu>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] ext3 xattr: Don't write to the in-inode xattr space of reserved inodes

We are not using the in-inode space for xattrs in reserved inodes because
mkfs.ext3 doesn't initialize it properly.  For those inodes, we set
i_extra_isize to 0.  Make sure that we also don't overwrite the
i_extra_isize field when writing out the inode in that case.  This is for
cleanliness only, and doesn't fix an actual bug.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] mostly_read data section

Add a new section called ".data.read_mostly" for data items that are read
frequently and rarely written to like cpumaps etc.

If these maps are placed in the .data section then these frequenly read
items may end up in cachelines with data is is frequently updated.  In that
case all processors in an SMP system must needlessly reload the cachelines
again and again containing elements of those frequently used variables.

The ability to share these cachelines will allow each cpu in an SMP system
to keep local copies of those shared cachelines thereby optimizing
performance.

Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com>
Signed-off-by: Christoph Lameter <christoph@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] propagate __nocast annotations

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] acl kconfig cleanup

Original patch from Matt Mackall <mpm@selenic.com>

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] page_uptodate locking scalability

Use a bit spin lock in the first buffer of the page to synchronise asynch
IO buffer completions, instead of the global page_uptodate_lock, which is
showing some scalabilty problems.

Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] tty output lossage fix

The patch fixes a few corner cases around tty line editing with
very long input lines:

- n_tty_receive_char(): don't simply drop eol characters,
  otherwise canon_data isn't increased and the reader isn't woken
  up.

- n_tty_receive_room(): If there is no newline pending and the
  edit buffer is full, allow only a single character to be written
  (until eol is found and the line is flushed), so characters from
  the next line aren't dropped.

- write_chan(): if an incomplete line was written, continue
  writing until write() returns 0, otherwise it might not write
  the eol character to flush the line and the writer goes to sleep
  without ever being woken up.

BTW the core problem is that part of this should be handled in the
receive_buf path, but for this it has to return the number of
written characters, as the amount of written characters may not be
the same as the amount of characters going into the write buffer,
so the receive_room() usage in pty_write() is not really reliable.

Alan said:

The problem looks valid. The behaviour of 'traditional unix' appears to
be the following

If you exceed the line limit then beep and drop the character
Always allow EOL to complete a canonical line input
Always do signal/control processing if enabled

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] xtensa: remove old syscalls

xtensa is now in -rc1, with the obsolete syscalls still in there, so I
guess this about the last chance to correct the ABI.  Applying the patch
obviously breaks all sorts of user space binaries and probably also
requires the appropriate changes to be made to libc.

On the other hand, if a decision is made to keep the broken interface, it
should at least be a conscious one instead of an oversight.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] uml: remove winch sem

Replace a semaphore (winch_handler_sem) used in atomic code with a
spinlock, and reduces as needed the amount of protected code to the bare
minimum (for instance no kmalloc calls are needed).

This fixes the last problems with spinlocking (in UP mode with DEBUG
options); the semaphore, taken inside spinlocks, caused a "spin_lock was
already locked" warning, without this patch.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] uml: restore hppfs support

Some time ago a trivial patch broke HPPFS (one var became a pointer, not
all uses were updated).  It wasn't fixed at that time because not very
used, now it's been requested so I've fixed this, and it has been tested
positively (at least partially).

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] uml: Proper clone support for skas0

This patch implements the clone-stub mechanism, which allows skas0 to run
with proc_mm==0, even if the clib in UML uses modify_ldt.

Note: There is a bug in skas3.v7 host patch, that avoids UML-skas from
running properly on a SMP-box.  In full skas3, I never really saw problems,
but in skas0 they showed up.

More commentary by jdike - What this patch does is makes sure that the host
parent of each new host process matches the UML parent of the corresponding
UML process.  This ensures that any changed LDTs are inherited.  This is
done by having clone actually called by the UML process from its stub,
rather than by the kernel.  We have special syscall stubs that are loaded
onto the stub code page because that code must be completely
self-contained.  These stubs are given C interfaces, and used like normal C
functions, but there are subtleties.  Principally, we have to be careful
about stack variables in stub_clone_handler after the clone.  The code is
written so that there aren't any - everything boils down to a fixed
address.  If there were any locals, references to them after the clone
would be wrong because the stack just changed.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] uml: skas0 - separate kernel address space on stock hosts

UML has had two modes of operation - an insecure, slow mode (tt mode) in
which the kernel is mapped into every process address space which requires
no host kernel modifications, and a secure, faster mode (skas mode) in
which the UML kernel is in a separate host address space, which requires a
patch to the host kernel.

This patch implements something very close to skas mode for hosts which
don't support skas - I'm calling this skas0.  It provides the security of
the skas host patch, and some of the performance gains.

The two main things that are provided by the skas patch, /proc/mm and
PTRACE_FAULTINFO, are implemented in a way that require no host patch.

For the remote address space changing stuff (mmap, munmap, and mprotect),
we set aside two pages in the process above its stack, one of which
contains a little bit of code which can call mmap et al.

To update the address space, the system call information (system call
number and arguments) are written to the stub page above the code.  The
%esp is set to the beginning of the data, the %eip is set the the start of
the stub, and it repeatedly pops the information into its registers and
makes the system call until it sees a system call number of zero.  This is
to amortize the cost of the context switch across multiple address space
updates.

When the updates are done, it SIGSTOPs itself, and the kernel process
continues what it was doing.

For a PTRACE_FAULTINFO replacement, we set up a SIGSEGV handler in the
child, and let it handle segfaults rather than nullifying them.  The
handler is in the same page as the mmap stub.  The second page is used as
the stack.  The handler reads cr2 and err from the sigcontext, sticks them
at the base of the stack in a faultinfo struct, and SIGSTOPs itself.  The
kernel then reads the faultinfo and handles the fault.

A complication on x86_64 is that this involves resetting the registers to
the segfault values when the process is inside the kill system call.  This
breaks on x86_64 because %rcx will contain %rip because you tell SYSRET
where to return to by putting the value in %rcx.  So, this corrupts $rcx on
return from the segfault.  To work around this, I added an
arch_finish_segv, which on x86 does nothing, but which on x86_64 ptraces
the child back through the sigreturn.  This causes %rcx to be restored by
sigreturn and avoids the corruption.  Ultimately, I think I will replace
this with the trick of having it send itself a blocked signal which will be
unblocked by the sigreturn.  This will allow it to be stopped just after
the sigreturn, and PTRACE_SYSCALLed without all the back-and-forth of
PTRACE_SYSCALLing it through sigreturn.

This runs on a stock host, so theoretically (and hopefully), tt mode isn't
needed any more.  We need to make sure that this is better in every way
than tt mode, though.  I'm concerned about the speed of address space
updates and page fault handling, since they involve extra round-trips to
the child.  We can amortize the round-trip cost for large address space
updates by writing all of the operations to the data page and having the
child execute them all at the same time.  This will help fork and exec, but
not page faults, since they involve only one page.

I can't think of any way to help page faults, except to add something like
PTRACE_FAULTINFO to the host.  There is PTRACE_SIGINFO, but UML doesn't use
siginfo for SIGSEGV (or anything else) because there isn't enough
information in the siginfo struct to handle page faults (the faulting
operation type is missing).  Adding that would make PTRACE_SIGINFO a usable
equivalent to PTRACE_FAULTINFO.

As for the code itself:

- The system call stub is in arch/um/kernel/sys-$(SUBARCH)/stub.S.  It is
  put in its own section of the binary along with stub_segv_handler in
  arch/um/kernel/skas/process.c.  This is manipulated with run_syscall_stub
  in arch/um/kernel/skas/mem_user.c.  syscall_stub will execute any system
  call at all, but it's only used for mmap, munmap, and mprotect.

- The x86_64 stub calls sigreturn by hand rather than allowing the normal
  sigreturn to happen, because the normal sigreturn is a SA_RESTORER in
  UML's address space provided by libc.  Needless to say, this is not
  available in the child's address space.  Also, it does a couple of odd
  pops before that which restore the stack to the state it was in at the
  time the signal handler was called.

- There is a new field in the arch mmu_context, which is now a union.
  This is the pid to be manipulated rather than the /proc/mm file
  descriptor.  Code which deals with this now checks proc_mm to see whether
  it should use the usual skas code or the new code.

- userspace_tramp is now used to create a new host process for every UML
  process, rather than one per UML processor.  It checks proc_mm and
  ptrace_faultinfo to decide whether to map in the pages above its stack.

- start_userspace now makes CLONE_VM conditional on proc_mm since we need
  separate address spaces now.

- switch_mm_skas now just sets userspace_pid[0] to the new pid rather
  than PTRACE_SWITCH_MM.  There is an addition to userspace which updates
  its idea of the pid being manipulated each time around the loop.  This is
  important on exec, when the pid will change underneath userspace().

- The stub page has a pte, but it can't be mapped in using tlb_flush
  because it is part of tlb_flush.  This is why it's required for it to be
  mapped in by userspace_tramp.

Other random things:

- The stub section in uml.lds.S is page aligned.  This page is written
  out to the backing vm file in setup_physmem because it is mapped from
  there into user processes.

- There's some confusion with TASK_SIZE now that there are a couple of
  extra pages that the process can't use.  TASK_SIZE is considered by the
  elf code to be the usable process memory, which is reasonable, so it is
  decreased by two pages.  This confuses the definition of
  USER_PGDS_IN_LAST_PML4, making it too small because of the rounding down
  of the uneven division.  So we round it to the nearest PGDIR_SIZE rather
  than the lower one.

- I added a missing PT_SYSCALL_ARG6_OFFSET macro.

- um_mmu.h was made into a userspace-usable file.

- proc_mm and ptrace_faultinfo are globals which say whether the host
  supports these features.

- There is a bad interaction between the mm.nr_ptes check at the end of
  exit_mmap, stack randomization, and skas0.  exit_mmap will stop freeing
  pages at the PGDIR_SIZE boundary after the last vma.  If the stack isn't
  on the last page table page, the last pte page won't be freed, as it
  should be since the stub ptes are there, and exit_mmap will BUG because
  there is an unfreed page.  To get around this, TASK_SIZE is set to the
  next lowest PGDIR_SIZE boundary and mm->nr_ptes is decremented after the
  calls to init_stub_pte.  This ensures that we know the process stack (and
  all other process mappings) will be below the top page table page, and
  thus we know that mm->nr_ptes will be one too many, and can be
  decremented.

Things that need fixing:

- We may need better assurrences that the stub code is PIC.

- The stub pte is set up in init_new_context_skas.

- alloc_pgdir is probably the right place.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>