On Thu, Sep 11, 2008 at 10:27:10AM +0200, Ingo Molnar wrote:

> and it's working fine on most boxes. One testbox found this new locking
> scenario:
>
> PM: Adding info for No Bus:vcsa7
> EDAC DEBUG: MC0: i82860_check()
>
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.27-rc6-tip #1
> -------------------------------------------------------
> X/4873 is trying to acquire lock:
>  (&bb->mutex){--..}, at: [<c020ba20>] mmap+0x40/0xa0
>
> but task is already holding lock:
>  (&mm->mmap_sem){----}, at: [<c0125a1e>] sys_mmap2+0x8e/0xc0
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #1 (&mm->mmap_sem){----}:
>        [<c017dc96>] validate_chain+0xa96/0xf50
>        [<c017ef2b>] __lock_acquire+0x2cb/0x5b0
>        [<c017f299>] lock_acquire+0x89/0xc0
>        [<c01aa8fb>] might_fault+0x6b/0x90
>        [<c040b618>] copy_to_user+0x38/0x60
>        [<c020bcfb>] read+0xfb/0x170
>        [<c01c09a5>] vfs_read+0x95/0x110
>        [<c01c1443>] sys_pread64+0x63/0x80
>        [<c012146f>] sysenter_do_call+0x12/0x43
>        [<ffffffff>] 0xffffffff
>
> -> #0 (&bb->mutex){--..}:
>        [<c017d8b7>] validate_chain+0x6b7/0xf50
>        [<c017ef2b>] __lock_acquire+0x2cb/0x5b0
>        [<c017f299>] lock_acquire+0x89/0xc0
>        [<c0d6f2ab>] __mutex_lock_common+0xab/0x3c0
>        [<c0d6f698>] mutex_lock_nested+0x38/0x50
>        [<c020ba20>] mmap+0x40/0xa0
>        [<c01b111e>] mmap_region+0x14e/0x450
>        [<c01b170f>] do_mmap_pgoff+0x2ef/0x310
>        [<c0125a3d>] sys_mmap2+0xad/0xc0
>        [<c012146f>] sysenter_do_call+0x12/0x43
>        [<ffffffff>] 0xffffffff
>
> other info that might help us debug this:
>
> 1 lock held by X/4873:
>  #0:  (&mm->mmap_sem){----}, at: [<c0125a1e>] sys_mmap2+0x8e/0xc0
>
> stack backtrace:
> Pid: 4873, comm: X Not tainted 2.6.27-rc6-tip #1
>  [<c017cd09>] print_circular_bug_tail+0x79/0xc0
>  [<c017d8b7>] validate_chain+0x6b7/0xf50
>  [<c017a5b5>] ? trace_hardirqs_off_caller+0x15/0xb0
>  [<c017ef2b>] __lock_acquire+0x2cb/0x5b0
>  [<c017f299>] lock_acquire+0x89/0xc0
>  [<c020ba20>] ? mmap+0x40/0xa0
>  [<c0d6f2ab>] __mutex_lock_common+0xab/0x3c0
>  [<c020ba20>] ? mmap+0x40/0xa0
>  [<c0d6f698>] mutex_lock_nested+0x38/0x50
>  [<c020ba20>] ? mmap+0x40/0xa0
>  [<c020ba20>] mmap+0x40/0xa0
>  [<c01b111e>] mmap_region+0x14e/0x450
>  [<c01afb88>] ? arch_get_unmapped_area_topdown+0xf8/0x160
>  [<c01b170f>] do_mmap_pgoff+0x2ef/0x310
>  [<c0125a3d>] sys_mmap2+0xad/0xc0
>  [<c012146f>] sysenter_do_call+0x12/0x43
>  [<c0120000>] ? __switch_to+0x130/0x220
>  =======================
> evbug.c: Event. Dev: input3, Type: 20, Code: 0, Value: 500
> warning: `sudo' uses deprecated v2 capabilities in a way that may be insecure.
>
> i've attached the config.
>
> at first sight it looks like a genuine bug in fs/sysfs/bin.c?

Yes, it is a real bug by the looks. bin.c takes bb->mutex under mmap_sem
when it is mmapped, and then does its copy_*_user under bb->mutex too.

Here is a basic fix for the sysfs lor.


From: Nick Piggin <npiggin@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds a quick check for the driver<->device match before
taking the locks and doin gthe expensive checks. Taking the lock hurts
in asynchronous boot context where the device lock gets hit; one of the
init functions takes the lock and goes to do an expensive hardware init;
the other init functions walk the same PCI list and get stuck on the
lock as a result.

For the common case, we can know there's no chance whatsoever of a match
if the device isn't in the drivers ID table... so this patch does that
check as a best-effort-avoid-the-lock approach.

Bootcharts for before and after can be seen at
http://www.fenrus.org/before.svg
http://www.fenrus.org/after.svg

Note the long time "agp_ali_init" takes in the first graph; my laptop
doesn't even have an ALI chip in it!  (the bootgraphs look a bit
dissimilar, but that's the point, the first one has a bunch of arbitrary
delays in it that cause it to look very different)

This reduces my kernel boot time by about 20%
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

If device_register() in device_create_vargs() fails, the device
must be cleaned up with put_device() (which is also fine on NULL)
instead of kfree().
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make the comments on how to use device_initialize(), device_add()
and device_register() a bit clearer - in particular, explicitly
note that put_device() must be used once we tried to add the device
to the hierarchy.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch makes the following needlessly global functions static:
- ibft_attr_show_initiator()
- ibft_attr_show_nic()
- ibft_attr_show_target()
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NKonrad Rzeszutek <ketuzsezr@darnok.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Support sysfs_notify from atomic context with new sysfs_notify_dirent

sysfs_notify currently takes sysfs_mutex.
This means that it cannot be called in atomic context.
sysfs_mutex  is sometimes held over a malloc (sysfs_rename_dir)
so it can block on low memory.

In md I want to be able to notify on a sysfs attribute from
atomic context, and I don't want to block on low memory because I
could be in the writeout path for freeing memory.

So:
 - export the "sysfs_dirent" structure along with sysfs_get, sysfs_put
   and sysfs_get_dirent so I can get the sysfs_dirent that I want to
   notify on and hold it in an md structure.
 - split sysfs_notify_dirent out of sysfs_notify so the sysfs_dirent
   can be notified on with no blocking (just a spinlock).
Signed-off-by: NNeil Brown <neilb@suse.de>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch makes the needlessly global struct platform_pm_ops static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Base infrastructure to enable per-module debug messages.

I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.

The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.

Future plans include extending this functionality to subsystems, that define 
their own debug levels and flags.

Usage:

Dynamic debugging is controlled by the debugfs file, 
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:

	<module_name> <enabled=0/1>
		.
		.
		.

	<module_name> : Name of the module in which the debug call resides
	<enabled=0/1> : whether the messages are enabled or not

For example:

	snd_hda_intel enabled=0
	fixup enabled=1
	driver enabled=0

Enable a module:

	$echo "set enabled=1 <module_name>" > dynamic_printk/modules

Disable a module:

	$echo "set enabled=0 <module_name>" > dynamic_printk/modules

Enable all modules:

	$echo "set enabled=1 all" > dynamic_printk/modules

Disable all modules:

	$echo "set enabled=0 all" > dynamic_printk/modules

Finally, passing "dynamic_printk" at the command line enables
debugging for all modules. This mode can be turned off via the above
disable command.

[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change how the Ethernet/RNDIS gadget driver builds:  don't
use separate compilation, since it works poorly when key
parts are library code (with init sections etc).  Instead
be as close as we can to "gcc --combine ...".

This is a bit more complicated than most of the others
because it had to resolve a few symbol collisions.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change how the CDC Composite gadget driver builds:  don't
use separate compilation, since it works poorly when key
parts are library code (with init sections etc).  Instead
be as close as we can to "gcc --combine ...".
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change how the file storage gadget driver builds:  don't
use separate compilation, since it works poorly when key
parts are library code (with init sections etc).  Instead
be as close as we can to "gcc --combine ...".
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change how the printer gadget driver builds:  don't use
separate compilation, since it works poorly when key parts
are library code (with init sections etc).  Instead be as
close as we can to "gcc --combine ...".
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change how the MIDI gadget driver builds:  don't use separate
compilation, since it works poorly when key parts are library
code (with init sections etc).  Instead be as close as we can
to "gcc --combine ...".
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change how the Gadget Zero driver builds:  don't use
separate compilation, since it works poorly when key
parts are library code (with init sections etc).
Instead be as close as we can to "gcc --combine ...".
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change how the serial gadget driver builds:  don't use
separate compilation, since it works poorly when key parts
are library code (with init sections etc).  Instead be as
close as we can to "gcc --combine ...".
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that the tree is cleaned up, device_create_drvdata can be safely
removed.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.

Cc: Ben Collins <ben.collins@ubuntu.com>
Acked-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that device_create() has been audited, rename things back to the
original call to be sane.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Print the name of the last-accessed sysfs file when we oops, to help track
down oopses which occur in sysfs store/read handlers.  Because these oopses
tend to not leave any trace of the offending code in the stack traces.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix "notes" kobject leak

It happens every rmmod if KALLSYMS=y and SYSFS=y.

	# modprobe foo

kobject: 'foo' (ffffffffa00743d0): kobject_add_internal: parent: 'module', set: 'module'
kobject: 'holders' (ffff88017e7c5770): kobject_add_internal: parent: 'foo', set: '<NULL>'
kobject: 'foo' (ffffffffa00743d0): kobject_uevent_env
kobject: 'foo' (ffffffffa00743d0): fill_kobj_path: path = '/module/foo'
kobject: 'notes' (ffff88017fa9b668): kobject_add_internal: parent: 'foo', set: '<NULL>'
	  ^^^^^

	# rmmod foo

kobject: 'holders' (ffff88017e7c5770): kobject_cleanup
kobject: 'holders' (ffff88017e7c5770): auto cleanup kobject_del
kobject: 'holders' (ffff88017e7c5770): calling ktype release
kobject: (ffff88017e7c5770): dynamic_kobj_release
kobject: 'holders': free name
kobject: 'foo' (ffffffffa00743d0): kobject_cleanup
kobject: 'foo' (ffffffffa00743d0): does not have a release() function, it is broken and must be fixed.
kobject: 'foo' (ffffffffa00743d0): auto cleanup 'remove' event
kobject: 'foo' (ffffffffa00743d0): kobject_uevent_env
kobject: 'foo' (ffffffffa00743d0): fill_kobj_path: path = '/module/foo'
kobject: 'foo' (ffffffffa00743d0): auto cleanup kobject_del
kobject: 'foo': free name

	[whooops]
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  MIPS: Kill unused <asm/debug.h> inclusions
  MIPS: IP32: Add platform device for CMOS RTC; remove dead code
  RTC: M48T35: new RTC driver
  MIPS: IP27: Switch over to RTC class driver
  MIPS: DS1286: New RTC driver
  MIPS: IP22/28: Switch over to RTC class driver
  MIPS: PCI: Scan busses when they are registered
  MIPS: WGT634U: Add reset button support
  MIPS: BCM47xx: Use the new SSB GPIO API
  MIPS: BCM47xx: Remove references to BCM947XX
  MIPS: WGT634U: Add machine detection message
  MIPS: Align .data.cacheline_aligned based on CONFIG_MIPS_L1_CACHE_SHIFT
  MIPS: show_cpuinfo prints the type of the calling CPU
  MIPS: Fix wrong branch target in new spin_lock code.
  MIPS: Have a heart for a lonely, lost header file ...

proc_clear_tty() gets called with interrupts off (while holding the task list
lock) from sys_setid. This means that it needs the _irqsave version of the
locking primitives.
Reported-by: NMarcin Slusarz <marcin.slusarz@gmail.com>
Tested-by: NMarcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The metronome driver produces warnings when built on x86-64 as it assumes that
size_t is an int. Use %Zd instead.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When we skip unrecognized options in xfs_fs_remount we should just break
out of the switch and not return because otherwise we may skip clearing
the xfs-internal read-only flag.  This will only show up on some
operations like touch because most read-only checks are done by the VFS
which thinks this filesystem is r/w.  Eventually we should replace the
XFS read-only flag with a helper that always checks the VFS flag to make
sure they can never get out of sync.

Bug reported and fix verified by Marcel Beister on #xfs.
Bug fix verified by updated xfstests/189.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NTimothy Shimmin <tes@sgi.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'build_fix' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
  ocfs2: fix build error

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (158 commits)
  powerpc: Fix CHRP PCI config access for indirect_pci
  powerpc/chrp: Fix detection of Python PCI host bridge on IBM CHRPs
  powerpc: Fix 32-bit SMP boot on CHRP
  powerpc: Fix link errors on 32-bit machines using legacy DMA
  powerpc/pci: Improve detection of unassigned bridge resources
  hvc_console: Fix free_irq in spinlocked section
  powerpc: Get USE_STRICT_MM_TYPECHECKS working again
  powerpc: Reflect the used arguments in machine_init() prototype
  powerpc: Fix DMA offset for non-coherent DMA
  powerpc: fix fsl_upm nand driver modular build
  powerpc/83xx: add NAND support for the MPC8360E-RDK boards
  powerpc: FPGA support for GE Fanuc SBC610
  i2c: MPC8349E-mITX Power Management and GPIO expander driver
  powerpc: reserve two DMA channels for audio in MPC8610 HPCD device tree
  powerpc: document the "fsl,ssi-dma-channel" compatible property
  powerpc: disable CHRP and PMAC support in various defconfigs
  OF: add fsl,mcu-mpc8349emitx to the exception list
  powerpc/83xx: add DS1374 RTC support for the MPC837xE-MDS boards
  powerpc: remove support for bootmem-allocated memory for the DIU driver
  powerpc: remove non-dependent load fsl_booke PTE_64BIT
  ...

Signed-off-by: NShinya Kuribayashi <skuribay@ruby.dti.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This driver replaces the broken ip27-rtc driver in drivers/char and
gives back RTC support for SGI IP27 machines.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: NAlessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patchset removes some dead code and creates a platform device
for the RTC class driver.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>