During the association, the regulatory is updated by country IE
that reaps the previously found beacons. The impact is that
after a STA disconnects *or* when for any reason a regulatory
domain change happens the beacon hint flag is not cleared
therefore preventing future beacon hints to be learned.
This is important as a regulatory domain change or a restore
of regulatory settings would set back the passive scan and no-ibss
flags on the channel. This is the right place to do this given that
it covers any regulatory domain change.

Cc: stable@kernel.org
Reviewed-by: NLuis R. Rodriguez <mcgrof@gmail.com>
Signed-off-by: NRajkumar Manoharan <rmanohar@qca.qualcomm.com>
Acked-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Reorder functions to remove the need for a forward declaration
introduced by the last commit.
Signed-off-by: NSven Neumann <s.neumann@raumfeld.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Luis R. Rodriguez <mcgrof@gmail.com>
Cc: Daniel Mack <daniel@zonque.org>
Cc: linux-wireless@vger.kernel.org
Acked-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The function wiphy_update_regulatory() uses the static variable
last_request and thus needs to be called with reg_mutex held.
This is the case for all users in reg.c, but the function was
exported for use by wiphy_register(), from where it is called
without the lock being held.

Fix this by making wiphy_update_regulatory() private and introducing
regulatory_update() as a wrapper that acquires and holds the lock.
Signed-off-by: NSven Neumann <s.neumann@raumfeld.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Luis R. Rodriguez <mcgrof@gmail.com>
Cc: Daniel Mack <daniel@zonque.org>
Cc: linux-wireless@vger.kernel.org
Acked-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Two spaces and the second "KHz" suggest that the code author meant to
print the bandwidth but forgot it.  The code appears in commit e702d3cf
already with two spaces and "KHz" in place of the bandwidth.
Signed-off-by: NPavel Roskin <proski@gnu.org>
Acked-by: NLuis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Several uses were missing terminating newlines.
Typo fix and macro neatening.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Just a typo fix changing regulaotry to regulatory.
Signed-off-by: NMihai Moldovan <ionic@ionic.de>
CC: John W. Linville <linville@tuxdriver.com>
CC: Mohammed Shafi <shafi.wireless@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

At the beginning of wiphy_update_regulatory() a check is performed
whether the request is to be ignored. Then the request is sent to
the driver nevertheless. This happens even if last_request points
to NULL, leading to a crash in the driver:

 [<bf01d864>] (lbs_set_11d_domain_info+0x28/0x1e4 [libertas]) from [<c03b714c>] (wiphy_update_regulatory+0x4d0/0x4f4)
 [<c03b714c>] (wiphy_update_regulatory+0x4d0/0x4f4) from [<c03b4008>] (wiphy_register+0x354/0x420)
 [<c03b4008>] (wiphy_register+0x354/0x420) from [<bf01b17c>] (lbs_cfg_register+0x80/0x164 [libertas])
 [<bf01b17c>] (lbs_cfg_register+0x80/0x164 [libertas]) from [<bf020e64>] (lbs_start_card+0x20/0x88 [libertas])
 [<bf020e64>] (lbs_start_card+0x20/0x88 [libertas]) from [<bf02cbd8>] (if_sdio_probe+0x898/0x9c0 [libertas_sdio])

Fix this by returning early. Also remove the out: label as it is
not any longer needed.
Signed-off-by: NSven Neumann <s.neumann@raumfeld.com>
Cc: linux-wireless@vger.kernel.org
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Daniel Mack <daniel@zonque.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

These warnings are exposed by gcc 4.6.
net/wireless/reg.c: In function 'freq_reg_info_regd':
net/wireless/reg.c:675:38: warning: variable 'pr' set but not used
[-Wunused-but-set-variable]
net/wireless/lib80211_crypt_wep.c: In function 'lib80211_wep_build_iv':
net/wireless/lib80211_crypt_wep.c:99:12: warning: variable 'len' set but
not used [-Wunused-but-set-variable]
Signed-off-by: NRajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The patch "cfg80211: add a timer for invalid user reg hints"
introduced a regression for the case where a secondary identical
regulatory hint from a user is sent. What would happen is the
second hint would schedule delayed work in to catch a timeout
but since we are never processing it given that the hint was already
applied we'd always hit the timeout and and restore regulatory
settings back to world regulatory domain. This is fixed by simply
avoiding sheduling work if the hint was already applied.
Tested-by: NFelix Fietkau <nbd@openwrt.org>
Reported-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We have no other option but to inform userspace that we
have queued up their regulatory hint request when we are
given one given that nl80211 operates atomically on user
requests. The best we can do is accept the request, and
add a delayed work item for processing failure and cancel it
if we succeeed. Upon failure we restore the regulatory
settings and ignore the user input.

This fixes this reported bug:

https://bugzilla.kernel.org/show_bug.cgi?id=28112

Reported-by: gregoryx.alagnou@intel.com
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When we restore regulatory settings its possible CRDA
will not reply because of a bogus user entry. In this
case the bogus entry will prevent any further processing
on cfg80211 for regulatory domains even if we restore
regulatory settings.

To prevent this we suck out all pending requests when
restoring regulatory settings and add them back into the
queue after we have queued up the reset work.

The impact of not having this applied is that a user
with privileges can issue a userspace regulatory hint
while we are disasocciating and this would prevent any
further processing of regulatory domains.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Regulatory devices issue change uevents to inform userspace of a need
to call the crda tool; however these can often be sent before udevd is
running, and were not previously included in the results of
udevadm trigger (which requests a new change event using the /uevent
attribute of the sysfs object).

Add a uevent function to the device type which includes the COUNTRY
information from the last request if it has yet to be processed, the
case of multiple requests is already handled in the code by checking
whether an unprocessed one is queued in the same manner and refusing
to queue a new one.

The existing udev rule continues to work as before.
Signed-off-by: NScott James Remnant <keybuk@google.com>
Acked-By: NKay Sievers <kay.sievers@vrfy.org>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
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>

Fixes the misplaced article in the following:

"cfg80211: Updating information on frequency 5785 MHz for
    20 a MHz width channel with regulatory rule:"
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Once we moved the core regulatory request to the queue and let
the scheduler process it last_request will have been left NULL
until the schedular decides to process the first request. When
this happens and we are loading a driver with a custom regulatory
request like all Atheros drivers we end up with a NULL pointer
dereference. We fix this by checking if the request was a
custom one.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
IP: [<ffffffffa016de87>] freq_reg_info_regd.clone.2+0x27/0x130 [cfg80211]
PGD 71f91067 PUD 712b2067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:1d.7/usb2/2-1/firmware/2-1/loading
CPU 0
Modules linked in: ath9k_htc(+) ath9k_common ath9k_hw ath <etc>
Pid: 3094, comm: insmod Tainted: G        W   2.6.37-rc5-wl #16 INVALID/28427ZQ
RIP: 0010:[<ffffffffa016de87>]  [<ffffffffa016de87>] freq_reg_info_regd.clone.2+0x27/0x130 [cfg80211]
RSP: 0018:ffff88007045db78  EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffffffa047d9a0 RCX: ffff88007045dbd0
RDX: 0000000000004e20 RSI: 000000000024cde0 RDI: ffff8800700483e0
RBP: ffff88007045db98 R08: ffffffffa02f5b40 R09: 0000000000000001
R10: 000000000000000e R11: 0000000000000001 R12: 0000000000000000
R13: ffff88007004e3b0 R14: 0000000000000000 R15: ffff880070048340
FS:  00007f635a707700(0000) GS:ffff880077400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000004 CR3: 00000000708a9000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process insmod (pid: 3094, threadinfo ffff88007045c000, task ffff8800713e3ec0)
Stack:
 ffffffffa047d9a0 0000000000000000 ffff88007004e3b0 0000000000000000
 ffff88007045dc08 ffffffffa016e147 000000007045dc08 0000000000000002
 ffff8800700483e0 ffffffffa02f5b40 ffff88007045dbd8 0000000000000000
Call Trace:
 [<ffffffffa016e147>] wiphy_apply_custom_regulatory+0x137/0x1d0 [cfg80211]
 [<ffffffffa047a690>] ? ath9k_reg_notifier+0x0/0x50 [ath9k_htc]
 [<ffffffffa02f47f7>] ath_regd_init+0x347/0x430 [ath]
 [<ffffffffa047b1f5>] ath9k_htc_probe_device+0x6c5/0x960 [ath9k_htc]
 [<ffffffffa0472a2c>] ath9k_htc_hw_init+0xc/0x30 [ath9k_htc]
 [<ffffffffa04747e6>] ath9k_hif_usb_probe+0x216/0x3b0 [ath9k_htc]
 [<ffffffffa03bb6bc>] usb_probe_interface+0x10c/0x210 [usbcore]
 [<ffffffff812aec26>] driver_probe_device+0x96/0x1c0
 [<ffffffff812aedf3>] __driver_attach+0xa3/0xb0
 [<ffffffff812aed50>] ? __driver_attach+0x0/0xb0
 [<ffffffff812adaae>] bus_for_each_dev+0x5e/0x90
 [<ffffffff812ae8c9>] driver_attach+0x19/0x20
 [<ffffffff812ae438>] bus_add_driver+0x168/0x320
 [<ffffffff812af071>] driver_register+0x71/0x140
 [<ffffffff811fc4a8>] ? __raw_spin_lock_init+0x38/0x70
 [<ffffffffa03ba39c>] usb_register_driver+0xdc/0x190 [usbcore]
 [<ffffffffa03a2000>] ? ath9k_htc_init+0x0/0x4f [ath9k_htc]
 [<ffffffffa047499e>] ath9k_hif_usb_init+0x1e/0x20 [ath9k_htc]
 [<ffffffffa03a202b>] ath9k_htc_init+0x2b/0x4f [ath9k_htc]
 [<ffffffff8100212f>] do_one_initcall+0x3f/0x180
 [<ffffffff8109ef5b>] sys_init_module+0xbb/0x200
 [<ffffffff8100bf52>] system_call_fastpath+0x16/0x1b
Code: <etc, who cares>
RIP  [<ffffffffa016de87>] freq_reg_info_regd.clone.2+0x27/0x130 [cfg80211]
 RSP <ffff88007045db78>
CR2: 0000000000000004
---[ end trace 79e4193601c8b713 ]---
Reported-by: NSujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

No change in output for pr_<level> prefixes.
netdev_<level> output is different, arguably improved.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When two cards are connected with the same regulatory domain
if CRDA had a delayed response then cfg80211's own set regulatory
domain would still be the world regulatory domain. There was a bug
on cfg80211's logic such that it assumed that once you pegged a
request as the last request it was already the currently set
regulatory domain. This would mean we would race setting a stale
regulatory domain to secondary cards which had the same regulatory
domain since the alpha2 would match.

We fix this by processing each regulatory request atomically,
and only move on to the next one once we get it fully processed.
In the case CRDA is not present we will simply world roam.

This issue is only present when you have a slow system and the
CRDA processing is delayed. Because of this it is not a known
regression.

Without this fix when a delay is present with CRDA the second card
would end up with an intersected regulatory domain and not allow it
to use the channels it really is designed for. When two cards with
two different regulatory domains were inserted you'd end up
rejecting the second card's regulatory domain request.
This fails with mac80211_hswim's regtest=2 (two requests, same alpha2)
and regtest=3 (two requests, different alpha2) module parameter
options.

This was reproduced and tested against mac80211_hwsim using this
CRDA delayer:

       #!/bin/bash
       echo $COUNTRY >> /tmp/log
       sleep 2
       /sbin/crda.orig

And these regulatory tests:

       modprobe mac80211_hwsim regtest=2
       modprobe mac80211_hwsim regtest=3
Reported-by: NMark Mentovai <mark@moxienet.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: NMark Mentovai <mark@moxienet.com>
Tested-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This will be required in the next patch and it makes the
next patch easier to review.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: NMark Mentovai <mark@moxienet.com>
Tested-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

These will be used earlier in the next few patches.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: NMark Mentovai <mark@moxienet.com>
Tested-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This will simplify the synchronization for pending requests.
Without this we have a race between the core and when we
restore regulatory settings, although this is unlikely
its best to just avoid that race altogether.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: NMark Mentovai <mark@moxienet.com>
Tested-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Everyone's doing it, its the cool thing.

Cc: Easwar Krishnan <easwar.krishnan@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In the worst case you are seeing really odd things you want
more information than what is provided right now, for those
that insist and want debug info through CONFIG_CFG80211_REG_DEBUG
provide a print of when we are processing a channel and with what
regulatory rule.

Cc: Easwar Krishnan <easwar.krishnan@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NSenthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Cc: Easwar Krishnan <easwar.krishnan@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This can help with debugging issues. You will only see
these with CONFIG_CFG80211_REG_DEBUG enabled.

Cc: Easwar Krishnan <easwar.krishnan@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NSenthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

After a module loads you will have loaded the world roaming regulatory
domain or a custom regulatory domain. Further regulatory hints are
welcomed and should be respected unless the regulatory hint is coming
from a country IE as the IEEE spec allows for a country IE to be a subset
of what is allowed by the local regulatory agencies.

So disable all channels that do not fit a regulatory domain sent
from a unless the hint is from a country IE and the country IE had
no information about the band we are currently processing.

This fixes a few regulatory issues, for example for drivers that depend
on CRDA and had no 5 GHz freqencies allowed were not properly disabling
5 GHz at all, furthermore it also allows users to restrict devices
further as was intended.

If you recieve a country IE upon association we will also disable the
channels that are not allowed if the country IE had at least one
channel on the respective band we are procesing.

This was the original intention behind this design but it was
completely overlooked...

Cc: David Quan <david.quan@atheros.com>
Cc: Jouni Malinen <jouni.malinen@atheros.com>
cc: Easwar Krishnan <easwar.krishnan@atheros.com>
Cc: stable@kernel.org
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We should be enabling country IE hints for WIPHY_FLAG_STRICT_REGULATORY
even if we haven't yet recieved regulatory domain hint for the driver
if it needed one. Without this Country IEs are not passed on to drivers
that have set WIPHY_FLAG_STRICT_REGULATORY, today this is just all
Atheros chipset drivers: ath5k, ath9k, ar9170, carl9170.

This was part of the original design, however it was completely
overlooked...

Cc: Easwar Krishnan <easwar.krishnan@atheros.com>
Cc: stable@kernel.org
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This is required later.

Cc: Easwar Krishnan <easwar.krishnan@atheros.com>
Cc: stable@kernel.org
signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The patch 4f366c5d:

	wireless: only use alpha2 regulatory information from country IE

removed some complex intersection we were always doing between the AP's
country IE info and what we got from CRDA. When CRDA sent us back a
regulatory domain we would do some sanity checks on that regulatory
domain response we just got. Part of these sanity checks included
checking that we already had performed an intersection for the
request of NL80211_REGDOM_SET_BY_COUNTRY_IE type.

This mean that cfg80211 was only processing country IEs for cases
where we already had an intersection, but since we removed enforcing
this this is no longer required, we should just apply the country
IE country hint with the data received from CRDA.

This patch has fixes intended for kernels >= 2.6.36.

Cc: stable@kernel.org
Reported-by: NEaswar Krishnan <easwar.krishnan@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead of using a WARN_ON(!mutex_is_locked())
use lockdep_assert_held() which compiles away
completely when lockdep isn't enabled, and
also is a more accurate assertion since it
checks that the current thread is holding the
mutex.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This provides a little more flexibility for human users, and it allows
us to use isalpha rather than the custom is_alpha_upper.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In some cases there could be possible dereferencing freed pointer. The
update is intended to avoid this issue.
Signed-off-by: NYuri Ershov <ext-yuri.ershov@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The "rd" variable isn't needed any more since 4f366c5d
"wireless: only use alpha2 regulatory information from country IE"
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

"Might as well remove  reg_same_country_ie_hint() completely since we
already dealt with suspend/resume through the regulatory hint
disconnect." -- Luis
Reported-by: NLuis R. Rodriguez <mcgrof@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The meaning and/or usage of the country IE is somewhat poorly defined.
In practice, this means that regulatory rulesets in a country IE are
often incomplete and might be untrustworthy.  This removes the code
associated with interpreting those rulesets while preserving respect
for country "alpha2" codes also contained in the country IE.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

regulatory_init is only called by cfg80211_init which is in .init.text,
too.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Also correct indentation in net/wireless/reg.c.
Signed-off-by: NFrans Pop <elendil@planet.nl>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Stanse discovered that kmalloc is being called with GFP_KERNEL while
holding this spinlock.  The spinlock can be a mutex instead, which also
enables the removal of the unlock/lock around the lock/unlock of
cfg80211_mutex and the call to set_regdom.
Reported-by: NJiri Slaby <jirislaby@gmail.com>
Cc: stable@kernel.org
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>