I figured out another ACPI related regression today.

randconfig testing triggered an early boot-time hang on a laptop of mine
(32-bit x86, config attached) - the screen was scrolling ACPI AML
exceptions [with no serial port and no early debugging available].

v2.6.24 works fine on that laptop with the same .config, so after a few
hours of bisection (had to restart it 3 times - other regressions
interacted), it honed in on this commit:

| 10270d48 is first bad commit
|
| Author: Linus Torvalds <torvalds@woody.linux-foundation.org>
| Date:   Wed Feb 13 09:56:14 2008 -0800
|
|     acpi: fix acpi_os_read_pci_configuration() misuse of raw_pci_read()

reverting this commit ontop of -rc5 gave a correctly booting kernel.

But this commit fixes a real bug so the real question is, why did it
break the bootup?

After quite some head-scratching, the following change stood out:

-                               pci_id->bus = tu8;
+                               pci_id->bus = val;

pci_id->bus is defined as u16:

   struct acpi_pci_id {
           u16 segment;
           u16 bus;
   ...

and 'tu8' changed from u8 to u32. So previously we'd unconditionally
mask the return value of acpi_os_read_pci_configuration()
(raw_pci_read()) to 8 bits, but now we just trust whatever comes back
from the PCI access routines and only crop it to 16 bits.

But if the high 8 bits of that result contains any noise then we'll
write that into ACPI's PCI ID descriptor and confuse the heck out of the
rest of ACPI.

So lets check the PCI-BIOS code on that theory. We have this codepath
for 8-bit accesses (arch/x86/pci/pcbios.c:pci_bios_read()):

        switch (len) {
        case 1:
                __asm__("lcall *(%%esi); cld\n\t"
                        "jc 1f\n\t"
                        "xor %%ah, %%ah\n"
                        "1:"
                        : "=c" (*value),
                          "=a" (result)
                        : "1" (PCIBIOS_READ_CONFIG_BYTE),
                          "b" (bx),
                          "D" ((long)reg),
                          "S" (&pci_indirect));

Aha! The "=a" output constraint puts the full 32 bits of EAX into
*value. But if the BIOS's routines set any of the high bits to nonzero,
we'll return a value with more set in it than intended.

The other, more common PCI access methods (v1 and v2 PCI reads) clear
out the high bits already, for example pci_conf1_read() does:

        switch (len) {
        case 1:
                *value = inb(0xCFC + (reg & 3));

which explicitly converts the return byte up to 32 bits and zero-extends
it.

So zero-extending the result in the PCI-BIOS read routine fixes the
regression on my laptop. ( It might fix some other long-standing issues
we had with PCI-BIOS during the past decade ... ) Both 8-bit and 16-bit
accesses were buggy.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6:
  PCI Hotplug: Fix small mem leak in IBM Hot Plug Controller Driver
  PCI: rename DECLARE_PCI_DEVICE_TABLE to DEFINE_PCI_DEVICE_TABLE

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6:
  drivers: fix dma_get_required_mask
  firmware: provide stubs for the FW_LOADER=n case
  nozomi: fix initialization and early flow control access
  sysdev: fix problem with sysdev_class being re-registered

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: Do not append space to guests kernel command line
  lguest: Revert 1ce70c4f, fix real problem.
  lguest: Sanitize the lguest clock.
  lguest: fix __get_vm_area usage.
  lguest: make sure cpu is initialized before accessing it

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
  ocfs2: Fix NULL pointer dereferences in o2net
  ocfs2/dlm: dlm_thread should not sleep while holding the dlm_spinlock
  ocfs2/dlm: Print message showing the recovery master
  ocfs2/dlm: Add missing dlm_lockres_put()s
  ocfs2/dlm: Add missing dlm_lockres_put()s in migration path
  ocfs2/dlm: Add missing dlm_lock_put()s
  ocfs2: Fix an endian bug in online resize.
  [PATCH] [OCFS2]: constify function pointer tables
  ocfs2: Fix endian bug in o2dlm protocol negotiation.
  ocfs2: Use dlm_print_one_lock_resource for lock resource print
  [PATCH] fs/ocfs2/dlm/dlmdomain.c: fix printk warning

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [WATCHDOG] make watchdog/hpwdt.c:asminline_call() static
  [WATCHDOG] Remove volatiles from watchdog device structures
  [WATCHDOG] replace remaining __FUNCTION__ occurrences
  [WATCHDOG] hpwdt: Use dmi_walk() instead of own copy
  [WATCHDOG] Fix return value warning in hpwdt
  [WATCHDOG] Fix declaration of struct smbios_entry_point in hpwdt
  [WATCHDOG] it8712f_wdt support for 16-bit timeout values, WDIOC_GETSTATUS

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix kernel crash when stifb driver is used with a A1439A CRX (Rattler)
graphics card.  (Reference:
http://thread.gmane.org/gmane.linux.ports.hppa/1834)
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix wrong pointer type passed into the dev_dbg() function.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Acked-by: Mike Rapoport <mike@compulab.co.il>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iov_iter_advance() skips over zero-length iovecs, however it does not properly
terminate at the end of the iovec array.  Fix this by checking against
i->count before we skip a zero-length iov.

The bug was reproduced with a test program that continually randomly creates
iovs to writev.  The fix was also verified with the same program and also it
could verify that the correct data was contained in the file after each
writev.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Tested-by: "Kevin Coffman" <kwc@citi.umich.edu>
Cc: "Alexey Dobriyan" <adobriyan@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The original preemptible-RCU patch put the choice between classic and
preemptible RCU into kernel/Kconfig.preempt, which resulted in build failures
on machines not supporting CONFIG_PREEMPT.  This choice was therefore moved to
init/Kconfig, which worked, but placed the choice between classic and
preemptible RCU at the top level, a very obtuse choice indeed.

This patch changes from the Kconfig "choice" mechanism to a pair of booleans,
only one of which (CONFIG_PREEMPT_RCU) is user-visible, and is located in
kernel/Kconfig.preempt, where one would expect it to be.  The other
(CONFIG_CLASSIC_RCU) is in init/Kconfig so that it is available to all
architectures, hopefully avoiding build breakage.  Thanks to Roman Zippel for
suggesting this approach.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Josh Triplett <josh@freedesktop.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use SGI_HAS_I8042 to select SGI i8042 handling
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Return value convention of module's init functions is 0/-E.  Sometimes,
e.g.  during forward-porting mistakes happen and buggy module created,
where result of comparison "workqueue != NULL" is propagated all the way up
to sys_init_module.  What happens is that some other module created
workqueue in question, our module created it again and module was
successfully loaded.

Or it could be some other bug.

Let's make such mistakes much more visible.  In retrospective, such
messages would noticeably shorten some of my head-scratching sessions.

Note, that dump_stack() is just a way to get attention from user.  Sample
message:

sys_init_module: 'foo'->init suspiciously returned 1, it should follow 0/-E convention
sys_init_module: loading module anyway...
Pid: 4223, comm: modprobe Not tainted 2.6.24-25f66630 #5

Call Trace:
 [<ffffffff80254b05>] sys_init_module+0xe5/0x1d0
 [<ffffffff8020b39b>] system_call_after_swapgs+0x7b/0x80
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit c9a3ba55 (module: wait for dependent modules doing init.) didn't quite
work because the waiter holds the module lock, meaning that the state of the
module it's waiting for cannot change.

Fortunately, it's fairly simple to update the state outside the lock and do
the wakeup.

Thanks to Jan Glauber for tracking this down and testing (qdio and qeth).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Free pages in the hugetlb pool are free and as such have a reference count of
zero.  Regular allocations into the pool from the buddy are "freed" into the
pool which results in their page_count dropping to zero.  However, surplus
pages can be directly utilized by the caller without first being freed to the
pool.  Therefore, a call to put_page_testzero() is in order so that such a
page will be handed to the caller with a correct count.

This has not affected end users because the bad page count is reset before the
page is handed off.  However, under CONFIG_DEBUG_VM this triggers a BUG when
the page count is validated.

Thanks go to Mel for first spotting this issue and providing an initial fix.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The pca953x driver is an I2C driver so gpio_chip->can_sleep should be set.
This lets upper layers know they should use the gpio_*_cansleep() calls to
access values, and may not access them from nonsleeping contexts.
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: "eric miao" <eric.y.miao@gmail.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Recent patch titled
  Reduce CPU wastage on idle md array with a write-intent bitmap.

would sometimes leave the array with dirty bitmap bits that stay dirty.  A
subsequent write would sort things out so it isn't a big problem, but should
be fixed nonetheless.

We need to make sure that when the bitmap becomes not "allclean", the
daemon_sleep really does get set to a sensible value.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If an md array is "auto-read-only", then this appears in /proc/mdstat as

   /dev/md0: active(auto-read-only)

whereas if it is truely readonly, it appears as

   /dev/md0: active (read-only)

The difference being a space.

One program known to parse this file expects the space and gets badly
confused.  It will be fixed, but it would be best if what the kernel generates
is more consistent too.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Address 3 known bugs in the current memory policy reference counting method.
I have a series of patches to rework the reference counting to reduce overhead
in the allocation path.  However, that series will require testing in -mm once
I repost it.

1) alloc_page_vma() does not release the extra reference taken for
   vma/shared mempolicy when the mode == MPOL_INTERLEAVE.  This can result in
   leaking mempolicy structures.  This is probably occurring, but not being
   noticed.

   Fix:  add the conditional release of the reference.

2) hugezonelist unconditionally releases a reference on the mempolicy when
   mode == MPOL_INTERLEAVE.  This can result in decrementing the reference
   count for system default policy [should have no ill effect] or premature
   freeing of task policy.  If this occurred, the next allocation using task
   mempolicy would use the freed structure and probably BUG out.

   Fix:  add the necessary check to the release.

3) The current reference counting method assumes that vma 'get_policy()'
   methods automatically add an extra reference a non-NULL returned mempolicy.
    This is true for shmem_get_policy() used by tmpfs mappings, including
   regular page shm segments.  However, SHM_HUGETLB shm's, backed by
   hugetlbfs, just use the vma policy without the extra reference.  This
   results in freeing of the vma policy on the first allocation, with reuse of
   the freed mempolicy structure on subsequent allocations.

   Fix: Rather than add another condition to the conditional reference
   release, which occur in the allocation path, just add a reference when
   returning the vma policy in shm_get_policy() to match the assumptions.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Rientjes <rientjes@google.com>
Cc: <eric.whitney@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I have found a very small typo in Documentation/scheduler/sched-stats.txt.
See the end of this mail.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This should improve reliability of detection of cards already in socket on
driver load.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Instead of assuming that host is powered on only once at card insertion, allow
for the possibility that memstick layer may need to cycle card's power to get
it out from some unhealthy states.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Additional input received from JMicron on MemoryStick host interfaces showed
that some assumtions in fifo handling code were incorrect.  This patch also
fixes data corruption used to occure during PIO transfers.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bus driver may need to be informed that host is being suspended/resumed.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Thanks to some input from kind people at JMicron it is now possible to have
more correct definitions of protocol structures and bit field semantics.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix memory size multiplier during detection.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Remove locking registers after they are unlocked during switch to/from MMIO
mode.  This fixes regression on the Blade3D (Trident 9880) caused by the
previous patch (probe fixes).
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix the following section mismatches:

WARNING: drivers/built-in.o(.exit.text+0x5a): Section mismatch in reference from the function of_platform_serial_exit() to the variable .devinit.data:of_platform_serial_driver
The function __exit of_platform_serial_exit() references
a variable __devinitdata of_platform_serial_driver.
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This macro is used to define tables, not to declare them.

Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In drivers/pci/hotplug/ibmphp_ebda.c::ebda_rsrc_controller(), storage is
allocated with kzalloc() and assigned to 'tmp_slot'.  Then lots of
stuff, like ->flag, ->supported_speed etc is set in tmp_slot.  A bit
further down there's then this test :

  if (!bus_info_ptr1) {
    rc = -ENODEV;
    goto error;
  }

At this point, tmp_slot has not been assigned to anything, so when
erroring-out we want to free it, but nothing at the 'error:' label
free's 'tmp_slot' - and we can't really free 'tmp_slot' at 'error:'
since we may jump to that label later when 'tmp_slot' *has* been used
and we do not want it freed. So, the only sane option left seems to be
to kfree(tmp_slot) just before jumping to the 'error:' label in the one
place where this is what actually makes sense. The following patch does
just that and thus kills off a tiny potential memory leak.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

a) DECLARE_PCI_DEVICE_TABLE is misnamed.  It is used to *define* tables,
   not to declare them.  It should be called DEFINE_PCI_DEVICE_TABLE.

b) It's lame, anyway.  We could implement any number of such helper
   thingies, but we choose not to.


So I wouldn't go adding code which uses this thing until it has a correct
name, and until we've decided that we actually want to live with it.


From: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>