Add support for drivers that implement static WEP internally, i.e.
expose connection keys to the driver in connect flow and don't
upload the keys after the connection.
Signed-off-by: NDavid Spinadel <david.spinadel@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Jouni reported that during (repeated) wext_pmf test runs (from the
wpa_supplicant hwsim test suite) the kernel crashes. The reason is
that after the key is set, the wext code still unnecessarily stores
it into the key cache. Despite smatch pointing out an overflow, I
failed to identify the possibility for this in the code and missed
it during development of the earlier patch series.

In order to fix this, simply check that we never store anything but
WEP keys into the cache, adding a comment as to why that's enough.

Also, since the cache is still allocated early even if it won't be
used in many cases, add a comment explaining why - otherwise we'd
have to roll back key settings to the driver in case of allocation
failures, which is far more difficult.

Fixes: 89b706fb ("cfg80211: reduce connect key caching struct size")
Reported-by: NJouni Malinen <j@w1.fi>
Bisected-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

After the previous patches, connect keys can only (correctly)
be used for storing static WEP keys. Therefore, remove all the
data for dealing with key index 4/5 and reduce the size of the
key material to the maximum for WEP keys.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When not connected, anything but WEP keys shouldn't be allowed to be
configured for later - only static WEP keys make sense at this point.
Change wext to reject anything else just like nl80211 does.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since a/b/g/n no longer exist as spec amendements and VHT (ex 802.11ac)
wasn't handled at all, it's better to just remove the amendment strings
to avoid confusion.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Reviewed-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This enum is already perfectly aliased to enum nl80211_band, and
the only reason for it is that we get IEEE80211_NUM_BANDS out of
it. There's no really good reason to not declare the number of
bands in nl80211 though, so do that and remove the cfg80211 one.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Until recently, mac80211 overwrote all the statistics it could
provide when getting called, but it now relies on the struct
having been zeroed by the caller. This was always the case in
nl80211, but wext used a static struct which could even cause
values from one device leak to another.

Using a static struct is OK (as even documented in a comment)
since the whole usage of this function and its return value is
always locked under RTNL. Not clearing the struct for calling
the driver has always been wrong though, since drivers were
free to only fill values they could report, so calling this
for one device and then for another would always have leaked
values from one to the other.

Fix this by initializing the structure in question before the
driver method call.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=99691

Cc: stable@vger.kernel.org
Reported-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Reported-by: NAlexander Kaltsas <alexkaltsas@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a fully converted cfg80211 driver needs cfg80211-wext for
userspace API purposes, the symbols need not be exported. When
other drivers (orinoco/hermes or ipw2200) are enabled, they do
need the symbols exported as they use them directly.

Make those drivers select a new CFG80211_WEXT_EXPORT Kconfig
symbol (instead of just CFG80211_WEXT) and export the functions
only if requested - this saves about 1/2k due to the size of
EXPORT_SYMBOL() itself.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is really just duplicating the list of information that's
already available in the nl80211 attribute, so remove the list.
Two small changes are needed:
 * remove STATION_INFO_ASSOC_REQ_IES complete, but the length
   (assoc_req_ies_len) can be used instead
 * add NL80211_STA_INFO_RX_DROP_MISC which exists internally
   but not in nl80211 yet

This gets rid of the duplicate maintenance of the two lists.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When freeing the keys stored for wireless extensions, clear the memory
to avoid having the key material stick around in memory "forever".
Similarly, when userspace overwrites a key, actually clear it instead
of just setting the key length to zero.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Name wiphy_to_rdev is more accurate to describe what the function
does, i.e., return a pointer pointing to struct
cfg80211_registered_device.
Signed-off-by: NZhao, Gang <gamerh2o@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

cfg80211_wext_freq() is declared in wext-compat.h, but its
parameter struct wiphy's declaration is not included there.
As the parameter isn't used, just remove it.
Signed-off-by: NZhao, Gang <gamerh2o@gmail.com>
[remove parameter instead of changing to netdev]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Block setting the wrong values through iwconfig retry
command. Add sanity checking before sending the retry
limit to the driver.
Signed-off-by: NUjjal Roy <royujjal@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

While getting the retry limit, wext-compat returns the value
without updating the flag for retry->flags is 0. Also in this
case, it updates long retry flag when short and long retry
value are unequal.

So, iwconfig never showing "Retry short limit" and showing
"Retry long limit" when both values are unequal.

Updated the flags and corrected the condition properly.
Signed-off-by: NUjjal Roy <royujjal@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Virtually all code paths in cfg80211 already (need to) hold
the RTNL. As such, there's little point in having another
four mutexes for various parts of the code, they just cause
lock ordering issues (and much of the time, the RTNL and a
few of the others need thus be held.)

Simplify all this by getting rid of the extra four mutexes
and just use the RTNL throughout. Only a few code changes
were needed to do this and we can get rid of a work struct
for bonus points.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This doesn't generate any different code, but will
suppress a spurious smatch warning.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Change nl80211 to support specifying a VHT (or HT)
using the control channel frequency (as before) and
new attributes for the channel width and first and
second center frequency. The old channel type is of
course still supported for HT.

Also change the cfg80211 channel definition struct
to support these by adding the relevant fields to
it (and removing the _type field.)

This also adds new helper functions:
 - cfg80211_chandef_create to create a channel def
   struct given the control channel and channel type,
 - cfg80211_chandef_identical to check if two channel
   definitions are identical
 - cfg80211_chandef_compatible to check if the given
   channel definitions are compatible, and return the
   wider of the two

This isn't entirely complete, but that doesn't matter
until we have a driver using it. In particular, it's
missing
 - regulatory checks on the usable bandwidth (if that
   even makes sense)
 - regulatory TX power (database can't deal with it)
 - a proper channel compatibility calculation for the
   new channel types
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of passing a channel pointer and channel type
to all functions and driver methods, pass a new channel
definition struct. Right now, this struct contains just
the control channel and channel type, but for VHT this
will change.

Also, add a small inline cfg80211_get_chandef_type() so
that drivers don't need to use the _type field of the
new structure all the time, which will change.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The TX power setting is currently per wiphy (hardware
device) but with multi-channel capabilities that doesn't
make much sense any more.

Allow drivers (and mac80211) to advertise support for
per-interface TX power configuration. When the TX power
is configured for the wiphy, the wdev will be NULL and
the driver can still handle that, but when a wdev is
given the TX power can be set only for that wdev now.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This will allow adding central tracing like in mac80211.
Signed-off-by: NHila Gonen <hila.gonen@intel.com>
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This essentially reverts commit 2e165b81 but
introduces the get_channel operation with a new
wireless_dev argument so that you can retrieve
the channel per interface. This is necessary as
even though we can track all interface channels
(except monitor) we can't track the channel type
used.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

We do not need it anymore since cfg80211 tracks
monitor channel and monitor channel type.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Now that we've removed all uses of the set_channel
API except for the monitor channel and in libertas,
clarify this. Split the libertas mesh use into a
new libertas_set_mesh_channel() operation, just to
keep backward compatibility, and rename the normal
set_channel() to set_monitor_channel().

Also describe the desired set_monitor_channel()
semantics more clearly.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Just like the AP mode patch, instead of setting
the channel and then joining the mesh network,
provide the channel to join the network on to
the join_mesh() function.

Like in AP mode, you can also give the channel
to the join-mesh nl80211 command now.

Unlike AP mode, it picks a default channel if
none was given.

As libertas uses mesh mode interfaces but has
no join_mesh callback and we can't simply break
it, keep some compatibility code for that case
and configure the channel directly for it.

In the non-libertas case, where we store the
channel until join, allow setting it while the
interface is down.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If it worked (Felix says it doesn't right now), the
typical use-case for WDS interfaces would be to be
slaved to AP mode interfaces. Therefore, it isn't
necessary to set the channel on WDS interfaces. As
they don't support powersave or anything like that,
they also couldn't use a different channel anyway.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If the current channel is known, add frequency and channel type to
NL80211_CMD_GET_INTERFACE.
Signed-off-by: NPontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Just add API to get the channel & report it. Trivial really.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

A lot of code is dedicated to giving drivers the
ability to use cfg80211's wext handlers without
completely converting. However, only orinoco is
currently using this, and it is only partially
using it.

We reduce the size of both the source and binary
by removing those that nobody needs. If a driver
shows up that needs it during conversion, we can
add back those that are needed.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

A lot of drivers erroneously use wext constants
and don't notice since cfg80211.h includes them.
Make this more split up so drivers needing wext
compatibility from cfg80211 need to explicitly
include that from cfg80211-wext.h.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

I previously managed to reproduce a hang while scanning wireless
channels (reproducible with airodump-ng hopping channels); subsequent
lockdep instrumentation revealed a lock ordering issue.

Without knowing the design intent, it looks like the locks should be
taken in reverse order; please comment.

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.38-rc5-341cd #4
-------------------------------------------------------
airodump-ng/15445 is trying to acquire lock:
 (&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff816b1266>]
cfg80211_wext_siwfreq+0xc6/0x100

but task is already holding lock:
 (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] cfg80211_wext_siwfreq+0xbc/0x100

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&wdev->mtx){+.+.+.}:
       [<ffffffff810a79d6>] lock_acquire+0xc6/0x280
       [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0
       [<ffffffff81696080>] cfg80211_netdev_notifier_call+0x430/0x5f0
       [<ffffffff8109351b>] notifier_call_chain+0x8b/0x100
       [<ffffffff810935b1>] raw_notifier_call_chain+0x11/0x20
       [<ffffffff81576d92>] call_netdevice_notifiers+0x32/0x60
       [<ffffffff815771a4>] __dev_notify_flags+0x34/0x80
       [<ffffffff81577230>] dev_change_flags+0x40/0x70
       [<ffffffff8158587c>] do_setlink+0x1fc/0x8d0
       [<ffffffff81586042>] rtnl_setlink+0xf2/0x140
       [<ffffffff81586923>] rtnetlink_rcv_msg+0x163/0x270
       [<ffffffff8159d741>] netlink_rcv_skb+0xa1/0xd0
       [<ffffffff815867b0>] rtnetlink_rcv+0x20/0x30
       [<ffffffff8159d39a>] netlink_unicast+0x2ba/0x300
       [<ffffffff8159dd57>] netlink_sendmsg+0x267/0x3e0
       [<ffffffff8155e364>] sock_sendmsg+0xe4/0x110
       [<ffffffff8155f3a3>] sys_sendmsg+0x253/0x3b0
       [<ffffffff81003192>] system_call_fastpath+0x16/0x1b

-> #0 (&rdev->devlist_mtx){+.+.+.}:
       [<ffffffff810a7222>] __lock_acquire+0x1622/0x1d10
       [<ffffffff810a79d6>] lock_acquire+0xc6/0x280
       [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0
       [<ffffffff816b1266>] cfg80211_wext_siwfreq+0xc6/0x100
       [<ffffffff816b2fad>] ioctl_standard_call+0x5d/0xd0
       [<ffffffff816b3223>] T.808+0x163/0x170
       [<ffffffff816b326a>] wext_handle_ioctl+0x3a/0x90
       [<ffffffff815798d2>] dev_ioctl+0x6f2/0x830
       [<ffffffff8155cf3d>] sock_ioctl+0xfd/0x290
       [<ffffffff8117dffd>] do_vfs_ioctl+0x9d/0x590
       [<ffffffff8117e53a>] sys_ioctl+0x4a/0x80
       [<ffffffff81003192>] system_call_fastpath+0x16/0x1b

other info that might help us debug this:

2 locks held by airodump-ng/15445:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff81586782>] rtnl_lock+0x12/0x20
 #1:  (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>]
cfg80211_wext_siwfreq+0xbc/0x100

stack backtrace:
Pid: 15445, comm: airodump-ng Not tainted 2.6.38-rc5-341cd #4
Call Trace:
 [<ffffffff810a3f0a>] ? print_circular_bug+0xfa/0x100
 [<ffffffff810a7222>] ? __lock_acquire+0x1622/0x1d10
 [<ffffffff810a1f99>] ? trace_hardirqs_off_caller+0x29/0xc0
 [<ffffffff810a79d6>] ? lock_acquire+0xc6/0x280
 [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
 [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90
 [<ffffffff816d6bce>] ? mutex_lock_nested+0x6e/0x4b0
 [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
 [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90
 [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
 [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
 [<ffffffff816b2fad>] ? ioctl_standard_call+0x5d/0xd0
 [<ffffffff8157818b>] ? __dev_get_by_name+0x9b/0xc0
 [<ffffffff816b2f50>] ? ioctl_standard_call+0x0/0xd0
 [<ffffffff816b3223>] ? T.808+0x163/0x170
 [<ffffffff8112ddf2>] ? might_fault+0x72/0xd0
 [<ffffffff816b326a>] ? wext_handle_ioctl+0x3a/0x90
 [<ffffffff8112de3b>] ? might_fault+0xbb/0xd0
 [<ffffffff815798d2>] ? dev_ioctl+0x6f2/0x830
 [<ffffffff810a1bae>] ? put_lock_stats+0xe/0x40
 [<ffffffff810a1c8c>] ? lock_release_holdtime+0xac/0x150
 [<ffffffff8155cf3d>] ? sock_ioctl+0xfd/0x290
 [<ffffffff8117dffd>] ? do_vfs_ioctl+0x9d/0x590
 [<ffffffff8116c8ff>] ? fget_light+0x1df/0x3c0
 [<ffffffff8117e53a>] ? sys_ioctl+0x4a/0x80
 [<ffffffff81003192>] ? system_call_fastpath+0x16/0x1b
Signed-off-by: NDaniel J Blueman <daniel.blueman@gmail.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Extend channel to frequency mapping for 802.11j Japan 4.9GHz band, according to
IEEE802.11 section 17.3.8.3.2 and Annex J. Because there are now overlapping
channel numbers in the 2GHz and 5GHz band we can't map from channel to
frequency without knowing the band. This is no problem as in most contexts we
know the band. In places where we don't know the band (and WEXT compatibility)
we assume the 2GHz band for channels below 14.

This patch does not implement all channel to frequency mappings defined in
802.11, it's just an extension for 802.11j 20MHz channels. 5MHz and 10MHz
channels as well as 802.11y channels have been omitted.

The following drivers have been updated to reflect the API changes:
iwl-3945, iwl-agn, iwmc3200wifi, libertas, mwl8k, rt2x00, wl1251, wl12xx.
The drivers have been compile-tested only.
Signed-off-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NBrian Prodoehl <bprodoehl@gmail.com>
Acked-by: NLuciano Coelho <coelho@ti.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Allow userspace to specify that a given key
is default only for unicast and/or multicast
transmissions. Only WEP keys are for both,
WPA/RSN keys set here are GTKs for multicast
only. For more future flexibility, allow to
specify all combiations.

Wireless extensions can only set both so use
nl80211; WEP keys (connect keys) must be set
as default for both (but 802.1X WEP is still
possible).
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Some stats for /proc/net/wireless (and wext in general) are not
being set.  This patch addresses a few of those with values easily
obtained from mac80211 core.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This adds API to allow adding per-station GTKs,
updates mac80211 to support it, and also allows
drivers to remove a key from hwaccel again when
this may be necessary due to multiple GTKs.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Wireless extensions have an unfortunate, undocumented
requirement which requires drivers to always fill
iwp->length when returning a successful status. When
a driver doesn't do this, it leads to a kernel heap
content leak when userspace offers a larger buffer
than would have been necessary.

Arguably, this is a driver bug, as it should, if it
returns 0, fill iwp->length, even if it separately
indicated that the buffer contents was not valid.

However, we can also at least avoid the memory content
leak if the driver doesn't do this by setting the iwp
length to max_tokens, which then reflects how big the
buffer is that the driver may fill, regardless of how
big the userspace buffer is.

To illustrate the point, this patch also fixes a
corresponding cfg80211 bug (since this requirement
isn't documented nor was ever pointed out by anyone
during code review, I don't trust all drivers nor
all cfg80211 handlers to implement it correctly).

Cc: stable@kernel.org [all the way back]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

  CHECK   net/wireless/wext-compat.c
net/wireless/wext-compat.c:1434:5: warning: symbol 'cfg80211_wext_siwpmksa' was not declared. Should it be static?

Add declaration in cfg80211.h.  Also add an EXPORT_SYMBOL_GPL, since all
the peer functions have it.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In preparation for a TX power setting interface in the nl80211, change the
.set_tx_power function to use mBm units instead of dBm for greater accuracy and
smaller power levels.

Also, already in advance move the tx_power_setting enumeration to nl80211.

This change affects the .tx_set_power function prototype. As a result, the
corresponding changes are needed to modules using it. These are mac80211,
iwmc3200wifi and rndis_wlan.

Cc: Samuel Ortiz <samuel.ortiz@intel.com>
Cc: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NJuuso Oikarinen <juuso.oikarinen@nokia.com>
Acked-by: NSamuel Ortiz <samuel.ortiz@intel.com>
Acked-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently (all tested with hwsim) you can do stupid
things like setting up an AP on a certain channel,
then adding another virtual interface and making
that associate on another channel -- this will make
the beaconing to move channel but obviously without
the necessary IEs data update.

In order to improve this situation, first make the
configuration APIs (cfg80211 and nl80211) aware of
multi-channel operation -- we'll eventually need
that in the future anyway. There's one userland API
change and one API addition. The API change is that
now SET_WIPHY must be called with virtual interface
index rather than only wiphy index in order to take
effect for that interface -- luckily all current
users (hostapd) do that. For monitor interfaces, the
old setting is preserved, but monitors are always
slaved to other devices anyway so no guarantees.

The second userland API change is the introduction
of a per virtual interface SET_CHANNEL command, that
hostapd should use going forward to make it easier
to understand what's going on (it can automatically
detect a kernel with this command).

Other than mac80211, no existing cfg80211 drivers
are affected by this change because they only allow
a single virtual interface.

mac80211, however, now needs to be aware that the
channel settings are per interface now, and needs
to disallow (for now) real multi-channel operation,
which is another important part of this patch.

One of the immediate benefits is that you can now
start hostapd to operate on a hardware that already
has a connection on another virtual interface, as
long as you specify the same channel.

Note that two things are left unhandled (this is an
improvement -- not a complete fix):

 * different HT/no-HT modes

   currently you could start an HT AP and then
   connect to a non-HT network on the same channel
   which would configure the hardware for no HT;
   that can be fixed fairly easily

 * CSA

   An AP we're connected to on a virtual interface
   might indicate switching channels, and in that
   case we would follow it, regardless of how many
   other interfaces are operating; this requires
   more effort to fix but is pretty rare after all
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>