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Commit Graph

109057 Commits

Author SHA1 Message Date
Tomas Winkler
8e7cdbb633 mac80211: filter probes in ieee80211_rx_mgmt_probe_resp
This patch moves filtering statement from ieee80211_rx_bss_info
which is called for both beacon and probe to ieee80211_rx_mgmt_probe_resp
and save few cycles in beacon parsing.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:58 -04:00
Jasper Bryant-Greene
f698d856f6 replace net_device arguments with ieee80211_{local,sub_if_data} as appropriate
This patch replaces net_device arguments to mac80211 internal functions
with ieee80211_{local,sub_if_data} as appropriate.

It also does the same for many 802.11s mesh functions, and changes the
mesh path table to be indexed on sub_if_data rather than net_device.

If the mesh part needs to be a separate patch let me know, but since
mesh uses a lot of mac80211 functions which were being converted anyway,
the changes go hand-in-hand somewhat.

This patch probably does not convert all the functions which could be
converted, but it is a large chunk and followup patches will be
provided.

Signed-off-by: Jasper Bryant-Greene <jasper@amiton.co.nz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:58 -04:00
Jasper Bryant-Greene
fef1643bf0 move ETH_P_PAE from ieee80211_i.h to if_ether.h
ETH_P_PAE belongs in if_ether.h with the other ETH_P_* definitions. This
patch moves it there.

Signed-off-by: Jasper Bryant-Greene <jasper@amiton.co.nz>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:57 -04:00
Henrique de Moraes Holschuh
96c87607ac rfkill: introduce RFKILL_STATE_MAX
While it is interesting to not add last-enum-markers because it allows gcc
to warn us of switch() statements missing a valid state, we really should
be handling memory corruption on a rfkill state with default clauses,
anyway.

So add RFKILL_STATE_MAX and use it where applicable.  It makes for safer
code in the long run.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:57 -04:00
Henrique de Moraes Holschuh
77fba13ccc rfkill: add __must_check annotations
rfkill is not a small, mere detail in wireless support.  Once it starts
supporting rfkill and users start counting on that support, a wireless
device is at risk of operating in dangerous conditions should rfkill
support fail to properly activate.

Therefore, add the required __must_check annotations on some key functions
of the rfkill API, for which the wireless drivers absolutely MUST handle
the failure mode safely in order to avoid a potentially dangerous situation
where the wireless transmitter is left enabled when the user don't want it
to.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:57 -04:00
Henrique de Moraes Holschuh
9961920199 rfkill: add default global states (v2)
Add a second set of global states, "rfkill_default_states", to track the
state that will be used when the first rfkill class of a given type is
registered, and also to save "undo" information when rfkill_epo is called.

Add a new exported function, rfkill_set_default(), which can be used by
platform drivers to restore radio state saved by the platform across
reboots or shutdown.

Also, fix rfkill_epo to properly update rfkill_states, but still preserve a
copy of the state so that we can undo the effect of rfkill_epo later if we
want to.  Add rfkill_restore_states() to restore rfkill_states from the
copy.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:56 -04:00
Henrique de Moraes Holschuh
02589f6051 rfkill: detect bogus double-registering (v2)
Detect and abort with -EEXIST if rfkill_register is called twice on the
same rfkill struct.  And WARN_ON(it) for good measure.

While at it, flag when we are adding the first switch of a type, we will
need that information later.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:56 -04:00
Harvey Harrison
c94c93da90 wireless: replace __FUNCTION__ with __func__
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:56 -04:00
Luis Carlos Cobo
d9c6350431 libertas_tf: config and makefile
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:56 -04:00
Luis Carlos Cobo
c305a19a0d libertas_tf: usb specific functions
The libertas thin firmware only supports usb devices, but the usb functions have
been kept separate to ease future support for other devices.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:56 -04:00
Luis Carlos Cobo
691cdb4938 libertas_tf: command helper functions for libertas_tf
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:55 -04:00
Luis Carlos Cobo
06b16ae531 libertas_tf: main.c, data paths and mac80211 handlers
This patch contains most of the libertastf driver, just lacking command helper
functions and usb specific functions. Currently, monitor, managed, ap and mesh
interfaces are supported. Even though this driver supports the same hardware as
the "libertas" driver, it uses a different (thin) firmware, that makes it
suitable for a mac80211 driver.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:55 -04:00
Luis Carlos Cobo
7670e62c7e libertas_tf: header file
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:55 -04:00
Luis Carlos Cobo
bdbe819540 mac80211: allow no mac address until firmware load
Originally by Johannes Berg. This patch adds support for devices that do not
report their MAC address until the firmware is loaded. While the address is not
known, a multicast on is used.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:55 -04:00
Harvey Harrison
4eb2ae9a42 mac80211: remove WLAN_FC_DATA_PRESENT
All users are gone now.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:55 -04:00
Harvey Harrison
a4b7d7bda5 mac80211: remove rx/tx_data->fc member
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:54 -04:00
Harvey Harrison
358c8d9d33 mac80211: use ieee80211 frame control directly
Remove the last users of the rx/tx_data->fc data members and use the
le16 frame_control from the header directly.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:54 -04:00
Harvey Harrison
e7827a7031 mac80211: remove IEEE80211_FC helper
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:54 -04:00
Harvey Harrison
6b644e524b mac80211: remove ieee80211_get_hdrlen
All users have been moved over to the version taking a le16 frame control
rather than a cpu-endian value.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:54 -04:00
Harvey Harrison
b73d70ad86 mac80211: rx.c/tx.c remove more users of tx/rx_data->fc
Those functions that still use ieee80211_get_hdrlen are moved over
to use the little endian frame control.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:53 -04:00
Harvey Harrison
d298487260 mac80211: wep.c replace magic numbers in IV/ICV removal
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:53 -04:00
Harvey Harrison
c44d040e18 mac80211: wme.h remove unused QOS_CONTROL_LEN
linux/ieee80211.h now has IEEE80211_QOS_CTL_LEN for this purpose.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:53 -04:00
Harvey Harrison
62bf1d762e mac80211: explicitly check skb->len
ieee80211_get_hdrlen_from_skb internally checks the skb is long enough to
hold the full ieee80211_hdr, else it returns zero.  Use ieee80211_hdrlen
which always returns the hdrlen and check the remaining room in the
skb explicitly when removing encryption headers or the qos control field.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:53 -04:00
Harvey Harrison
798ee9850e ath5k: explicitly check skb->len
ieee80211_get_hdrlen_from_skb internally checks that the skb is long
enough to hold the full header, or it returns 0 if not.  The check in
ath5k does not check this case and assumes it always got the actual
header length which it then checks against the skb->len plus some headroom.

Change to ieee80211_hdrlen which always returns the hdrlen and keep the
existing headroom check.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:53 -04:00
Harvey Harrison
7294ec955c iwlwifi: use le16 frame control directly, use QOS symbolic constant mask
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:51 -04:00
Harvey Harrison
ba5b6efe5d b43legacy: use le16 frame control directly, avoid byteswapping
Acked-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:51 -04:00
Esti Kummer
ded2ae7c1f iwlwifi: add level for debugging host command
This patch adds another level for debugging host command. This adds an
option to suppress the debug prints for sensitivity and link quality
commands.

Signed-off-by: Esti Kummer <ester.kummer@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:51 -04:00
Tomas Winkler
39351fa343 iwlwifi: kill struct iwl4965_lq_mngr
This patch removes struct iwl4965_lq_mngr it is not used.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:51 -04:00
roel kluin
73ae98a133 iwl-4965: test below 0 on unsigned num_tbs
num_tbs is unsigned so the test doesn't work.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:51 -04:00
Bruno Randolf
6f0a2c4dfc iwlwifi: use generic mac80211 radiotap headers
remove drivers own implementation of radiotap in favor of the generic one
provided by mac80211.

also remove priv->add_radiotap because it is not used any more.

Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:50 -04:00
Bruno Randolf
9deb1ae572 mac80211: radiotap: assume modulation from rates
use the rates ERP flag to derive CCK or OFDM modulation for the radiotap
header.

(it might be more correct to get this information from the hardware itself, but it
seems safe to assume this in most practical cases.)

Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:50 -04:00
Bruno Randolf
b4f28bbb9b mac80211: add rx status flag for short preamble
and use it for the radiotap header

Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:50 -04:00
Bruno Randolf
63266a6535 ath5k: rates cleanup
cleanup the rates structures used by ath5k. instead of separate driver and
mac80211 rate structures we now setup a static ieee80211_rate array and use it
directly. no conversion between two different rate structures has to be done
any more. a lot of unused and confusing junk was deleted.

renamed ath5k_getchannels into ath5k_setup_bands because this is what it does.
rewrote it to copy the bitrates correctly for each band. this is necessary for
running different hardware with the same driver (e.g. 5211 and 5212 based
cards).

add special handling of rates for AR5211 chipsets: it uses different rate codes
for CCK rates (which are actually like the other chips but with a 0xF mask).

setup a hardware code to rate index reverse mapping table for getting the rate
index of received frames.

the rates for control frames which have to be set in
ath5k_hw_write_rate_duration are now in one single array.

drivers/net/wireless/ath5k/ath5k.h:     Changes-licensed-under: ISC
drivers/net/wireless/ath5k/base.c:      Changes-licensed-under: 3-Clause-BSD
drivers/net/wireless/ath5k/base.h:      Changes-licensed-under: 3-Clause-BSD
drivers/net/wireless/ath5k/hw.c:        Changes-licensed-under: ISC

Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:50 -04:00
Tomas Winkler
92ab853549 mac80211: add ieee80211_queue_stopped)
This patch adds ieee80211_queue_stopped that let drivers to query
queue status

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:50 -04:00
Robert P. J. Day
5442060c08 WIRELESS: Make wireless one-click selectable.
Use "menuconfig" to make wireless support one-click selectable.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:50 -04:00
Jiri Slaby
d7dc100374 Ath5k: unify resets
There were 3 code copy and pastes of reset. Unify the resets and place
in separate function.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Nick Kossifidis <mickflemm@gmail.com>
Cc: Luis R. Rodriguez <mcgrof@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:49 -04:00
Daniel Wagner
b9740c2396 rt2x00mac: In error case stop netdev queue, free skb and return NETDEV_TX_OK
It is not allowed to use NETDEV_TX_BUSY in tx path anymore.

Signed-off-by: Daniel Wagner <wagi@monom.org>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:49 -04:00
Andrey Yurovsky
8e5f3d0aaa ath5k: add Mesh Point support
This enables draft-802.11s Mesh Point operation.  For that we need mesh
beaconing.  Tested with AR5212/AR5213 PCI card against Zydas and b43 mesh
nodes.

Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:49 -04:00
Julia Lawall
d92a8e81e0 net/ieee80211: adjust error handling
Converts a test in error handling code to a sequence of labels.

The semantic match that found the problem is:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E,E1,E2;
@@

E = alloc_etherdev(...)
... when != E = E1
if (...) { ... free_netdev(E); ... return ...; }
... when != E = E2
(
  if (...)
   {
   ... when != free_netdev(E);
   return dev; }
|
* if (...)
   {
   ... when != free_netdev(E);
   return ...; }
|
register_netdev(E)
)

// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:49 -04:00
Brian Cavagnolo
1ff41eb0d9 libertas: add sysfs hooks to update boot2 and persistent firmware
To use these features, copy the boot2 and firmware images to /lib/firmware and:

echo <boot2_image_name> > /sys/class/net/ethX/lbs_flash_boot2
echo <firmware_image_name> > /sys/class/net/ethX/lbs_flash_fw

Signed-off-by: Brian Cavagnolo <brian@cozybit.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:49 -04:00
Brian Cavagnolo
1556c0f22d libertas: support boot commands to write persistent firmware and bootloader
Add locking and non-locking versions of if_usb_prog_firmware to support
programming firmware after and before driver bring-up respectively.  Add more
suitable error codes for firmware programming process.  Add capability checks
for persistent features before attempting to use them.

Based on patches from Brajesh Dave and Priyank Singh.

Signed-off-by: Brian Cavagnolo <brian@cozybit.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:49 -04:00
Herton Ronaldo Krzesinski
38e3b0d86e rtl818x: merge tx/rx descriptor flags
Tx/Rx descriptor flags are common between rtl818x devices, only with
additions for newer chips, thus use same flags in the code.

Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-22 16:29:48 -04:00
Jarek Poplawski
2540e0511e pkt_sched: Fix qdisc_watchdog() vs. dev_deactivate() race
dev_deactivate() can skip rescheduling of a qdisc by qdisc_watchdog()
or other timer calling netif_schedule() after dev_queue_deactivate().
We prevent this checking aliveness before scheduling the timer. Since
during deactivation the root qdisc is available only as qdisc_sleeping
additional accessor qdisc_root_sleeping() is created.

With feedback from Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-21 05:11:14 -07:00
Vlad Yasevich
5e739d1752 sctp: fix potential panics in the SCTP-AUTH API.
All of the SCTP-AUTH socket options could cause a panic
if the extension is disabled and the API is envoked.

Additionally, there were some additional assumptions that
certain pointers would always be valid which may not
always be the case.

This patch hardens the API and address all of the crash
scenarios.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-21 03:34:25 -07:00
Linus Torvalds
6a55617ed5 Linux v2.6.27-rc4 2008-08-20 19:35:56 -07:00
Al Viro
82d63fc9e3 cramfs: fix named-pipe handling
After commit a97c9bf33f (fix cramfs
making duplicate entries in inode cache) in kernel 2.6.14, named-pipe
on cramfs does not work properly.

It seems the commit make all named-pipe on cramfs share their inode
(and named-pipe buffer).

Make ..._test() refuse to merge inodes with ->i_ino == 1, take inode setup
back to get_cramfs_inode() and make ->drop_inode() evict ones with ->i_ino
== 1 immediately.

Reported-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>		[2.6.14 and later]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 15:40:32 -07:00
Ian Campbell
d847471d06 fbdefio: add set_page_dirty handler to deferred IO FB
Fixes kernel BUG at lib/radix-tree.c:473.

Previously the handler was incidentally provided by tmpfs but this was
removed with:

  commit 14fcc23fdc
  Author: Hugh Dickins <hugh@veritas.com>
  Date:   Mon Jul 28 15:46:19 2008 -0700

    tmpfs: fix kernel BUG in shmem_delete_inode

relying on this behaviour was incorrect in any case and the BUG also
appeared when the device node was on an ext3 filesystem.

v2: override a_ops at open() time rather than mmap() time to minimise
races per AKPM's concerns.

Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Kel Modderman <kel@otaku42.de>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: <stable@kernel.org> [14fcc23fd is in 2.6.25.14 and 2.6.26.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 15:40:32 -07:00
Anton Vorontsov
b42f931737 rtc: rtc-ds1374: fix 'no irq' case handling
On a PowerPC board with ds1374 RTC I'm getting this error while RTC tries
to probe:

rtc-ds1374 0-0068: unable to request IRQ

This happens because I2C probing code (drivers/of/of_i2c.c) is specifying
IRQ0 for 'no irq' case, which is correct.

The driver handles this incorrectly, though. This patch fixes it.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 15:40:32 -07:00
Nick Piggin
14bac5acfd mm: xip/ext2 fix block allocation race
XIP can call into get_xip_mem concurrently with the same file,offset with
create=1.  This usually maps down to get_block, which expects the page
lock to prevent such a situation.  This causes ext2 to explode for one
reason or another.

Serialise those calls for the moment.  For common usages today, I suspect
get_xip_mem rarely is called to create new blocks.  In future as XIP
technologies evolve we might need to look at which operations require
scalability, and rework the locking to suit.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jared Hulbert <jaredeh@gmail.com>
Acked-by: Carsten Otte <cotte@freenet.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 15:40:32 -07:00
Nick Piggin
538f8ea6c8 mm: xip fix fault vs sparse page invalidate race
XIP has a race between sparse pages being inserted into page tables, and
sparse pages being zapped when its time to put a non-sparse page in.

What can happen is that a process can be left with a dangling sparse page
in a MAP_SHARED mapping, while the rest of the world sees the non-sparse
version.  Ie.  data corruption.

Guard these operations with a seqlock, making fault-in-sparse-pages the
slowpath, and try-to-unmap-sparse-pages the fastpath.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jared Hulbert <jaredeh@gmail.com>
Acked-by: Carsten Otte <cotte@freenet.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 15:40:32 -07:00