Oleg Nesterov reported an SMP deadlock.  If there is a running timer
tracking a different process's CPU time clock when the process owning
the timer exits, we deadlock on tasklist_lock in posix_cpu_timer_del via
exit_itimers.

That code was using tasklist_lock to check for a race with __exit_signal
being called on the timer-target task and clearing its ->signal.
However, there is actually no such race.  __exit_signal will have called
posix_cpu_timers_exit and posix_cpu_timers_exit_group before it does
that.  Those will clear those k_itimer's association with the dying
task, so posix_cpu_timer_del will return early and never reach the code
in question.

In addition, posix_cpu_timer_del called from exit_itimers during execve
or directly from timer_delete in the process owning the timer can race
with an exiting timer-target task to cause a double put on timer-target
task struct.  Make sure we always access cpu_timers lists with sighand
lock held.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The hugetlb pages are currently pre-faulted.  At the time of mmap of
hugepages, we populate the new PTEs.  It is possible that HW has already
cached some of the unused PTEs internally.  These stale entries never
get a chance to be purged in existing control flow.

This patch extends the check in page fault code for hugepages.  Check if
a faulted address falls with in size for the hugetlb file backing it.
We return VM_FAULT_MINOR for these cases (assuming that the arch
specific page-faulting code purges the stale entry for the archs that
need it).
Signed-off-by: Rohit Seth <rohit.seth@intel.com>

[ This is apparently arguably an ia64 port bug. But the code won't
  hurt, and for now it fixes a real problem on some ia64 machines ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Reported by: Bob Tracy <rct@gherkin.frus.com>

 "...I've got a Toshiba notebook (730XCDT -- Pentium 150MMX) for which
  I'm using the Vesa FB driver.  When the machine has been idle for some
  time and the driver attempts to powerdown the display, rather than the
  display going blank, it goes gray with several strange lines.  When I
  hit the "shift" key or other-wise wake up the display, the old video
  state is not fully restored..."

vesafb recently added a blank method which has only 2 states, powerup and
powerdown.  The powerdown state is used for all blanking levels, but in his
case, powerdown does not work correctly for higher levels of display
powersaving. Thus, for intermediate power levels, use software blanking,
and use only hardware blanking for an explicit powerdown.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This still leaves driver and architecture-specific subdirectories alone,
but gets rid of the bulk of the "generic" generated files that we should
ignore.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Patch from Kenneth Tan

The get_irqnr_and_base subroutine of ixp4xx does not take interrupt 0 condition into account properly. We should not perform "subs" here. The Z flag will be set when interrupt 0 occur, which resulting "movne r1, sp" in the caller routine (irq_handler) not being executed.

When interrupt 0 occur:
o if CONFIG_CPU_IXP46X is not set, "subs" will set the Z flag and return
o if CONFIG_CPU_IXP46X is set, codes in upper interrupt handling will be trigerred. But since this is not supper interrupt, the "cmp" in the upper interrupt handling portion will set the Z flag and return
Signed-off-by: Kenneth Tan <chong.yin.tan@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Patch from Kenneth Tan

The cpu_is_ixp465 macro in include/asm-arm/arch-ixp4xx/hardware.h is always returning 0 because #ifdef CONFIG_CPU_IXP465 is always false.
Signed-off-by: Kenneth Tan <chong.yin.tan@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Patch from Ben Dooks

Check that the device we are looking at is really
a platform device before trying to cast it to one
to find out the platform bus number.

Thanks to RMK for pointing this out.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The following build error happens with 2.6.14-rc4 when CONFIG_KALLSYMS is
not defined.  The error message in a fragment of the output was:

  CC      arch/i386/lib/usercopy.o
  AR      arch/i386/lib/lib.a
/bin/sh: line 1: +@: command not found
make[3]: warning: jobserver unavailable: using -j1.  Add `+' to parent make rule.
  CHK     include/linux/compile.h
Signed-off-by: Mark Rustad <mrustad@mac.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

lock_kiocb() was introduced to serialize retrying and cancellation.  In the
process of doing so it tried to sleep waiting for KIF_LOCKED while holding
the ctx_lock spinlock.  Recent fixes have ensured that multiple concurrent
retries won't be attempted for a given iocb.  Cancel has other problems and
has no significant in-tree users that have been complaining about it.  So
for the immediate future we'll revert sleeping with the lock held and will
address proper cancellation and retry serialization in the future.
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Only signal completion after marking request slot as free, otherwise other
processor can free request structure before we finish using it.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix -EIO on /proc/acpi/events after suspends.  This actually breaks
suspending by power button in many setups.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Since Revision 1.10 was released the n_r3964 module wasn't able to receive any
data.  The reason for that behavior is because there were some wrong calls of
mod_timer(...) in the function receive_char (...).  This patch should fix this
problem and was successfully tested with talking to some kuka industrial
robots.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Currently you do not get all the map entries on nommu systems because the
start function doesn't index into the list using the value of "pos".
Signed-off-by: David McCullough <davidm@snapgear.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This makes call_rcu() keep track of how many events there are on the RCU
list, and cause a reschedule event when the list gets too long.

This helps keep RCU event lists down.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This change makes quirk_intel_ide_combined() dependent on the precise
conditions under which it is needed:

* IDE is built in
* IDE SATA option is not set
* ata_piix or ahci drivers are enabled

This fixes an issue where some modular configurations would not cause
the quirk to be enabled.
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Linus torvalds <torvalds@osdl.org>

Make sure we release the task struct properly when releasing pending
timers.

release_task() does write_lock_irq(&tasklist_lock), so it can't race
with run_posix_cpu_timers() on any cpu.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Oopsable since nfs_wait_on_inode() can get called as part of iput_final().

Unnecessary since the caller had better be damned sure that the inode won't
disappear from underneath it anyway.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

If the data cache has been marked as potentially invalid by nfs_refresh_inode,
we should invalidate it rather than assume that changes are due to our own
activity.

Also ensure that we always start with a valid cache before declaring it
to be protected by a delegation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

During the development of an USB device I found a bug in the handling of
Highspeed HID devices in the kernel.

What happened?

Highspeed HID devices are correctly recognized and enumerated by the
kernel. But even if usbhid kernel module is loaded, no HID reports are
received by the kernel.

The output of the hardware USB analyzer told me that the host doesn't
even poll for interrupt IN transfers (even the "interrupt in" USB
transfer are polled by the host).

After some debugging in hid-core.c I've found the reason.

In case of a highspeed device, the endpoint interval is re-calculated in
driver/usb/input/hid-core.c:

line 1669:
             /* handle potential highspeed HID correctly */
             interval = endpoint->bInterval;
             if (dev->speed == USB_SPEED_HIGH)
                   interval = 1 << (interval - 1);

Basically this calculation is correct (refer to USB 2.0 spec, 9.6.6).
This new calculated value of "interval" is used as input for
usb_fill_int_urb:

line 1685:

            usb_fill_int_urb(hid->urbin, dev, pipe, hid->inbuf, 0,
                   hid_irq_in, hid, interval);

Unfortunately the same calculation as above is done a second time in
usb_fill_int_urb in the file include/linux/usb.h:

line 933:
        if (dev->speed == USB_SPEED_HIGH)
                urb->interval = 1 << (interval - 1);
        else
                urb->interval = interval;

This means, that if the endpoint descriptor (of a high speed device)
specifies e.g. bInterval = 7, the urb->interval gets the value:

hid-core.c: interval = 1 << (7-1) = 0x40 = 64
urb->interval = 1 << (interval -1) = 1 << (63) = integer overflow

Because of this the value of urb->interval is sometimes negative and is
rejected in core/urb.c:
line 353:
                /* too small? */
                if (urb->interval <= 0)
                        return -EINVAL;

The conclusion is, that the recalculaton of the interval (which is
necessary for highspeed) should not be made twice, because this is
simply wrong. ;-)

Re-calculation in usb_fill_int_urb makes more sense, because it is the
most general approach. So it would make sense to remove it from
hid-core.c.

Because in hid-core.c the interval variable is only used for calling
usb_fill_int_urb, it is no problem to remove the highspeed
re-calculation in this file.
Signed-off-by: Christian Krause <chkr@plauener.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Increased use of scatter-gather by usb-storage driver after 2.6.13 has
exposed a buggy codepath in isp116x-hcd, which was probably never
visited before: bug happened only for those urbs, for which
URB_SHORT_NOT_OK was set AND short transfer occurred.

The fix attached was tested in 2 ways: (a) it fixed failing
initialization of a flash drive with an embedded hub; (b) the fix was
tested with 'usbtest' against a modified g_zero driver (on top of
net2280), which generated short bulk IN transfers of various lengths
including multiples and non-multiples of max_packet_length.
Signed-off-by: Olav Kongas <ok@artecdesign.ee>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Dipankar made RCU limit the batch size to improve latency, but that
approach is unworkable: it can cause the RCU queues to grow without
bounds, since the batch limiter ended up limiting the callbacks.

So make the limit much higher, and start planning on instead limiting
the batch size by doing RCU callbacks more often if the queue looks like
it might be growing too long.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix the fact that the svideo input will only give input in black/white in
some circumstances.  Reason is that in the PCI controller driver (zr36067),
after setting input, we reset norm, which overwrites the input register
with the default.  This patch makes it always set the correct value for the
input when changing norm.
Signed-off-by: Ronald S. Bultje <rbultje@ronald.bitfreak.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix bug #5404 in kernel bugzilla.

It basically updates the vpx3220 initialization tables with some newer
values that we've had in CVS for a while (and that, for some reason, never
ended up in the kernel...  must've gotten lost).  Those fix a ~16 pixels
noise at the top of the picture in at least SECAM, although (now that I
think about it) PAL was probably affected, also.
Signed-off-by: Ronald S. Bultje <rbultje@ronald.bitfreak.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix bug 5441.

I didn't know about messy programs like svgatextmode...  Couldn't this be
integrated in some linux/drivers/video/console/svgacon.c ?...  So because
of the existence of the svgatextmode program, the kernel is not supposed to
touch to CRT_OVERFLOW/SYNC_END/DISP/DISP_END/OFFSET ?

Disabling the check in vgacon_resize() might help indeed, but I'm really
not sure whether it will work for any chipset: in my patch, CRT registers
are set at each console switch, since stty rows/cols apply to consoles
separately...

The attached solution is to keep the test, but if it fails, we assume that
the caller knows what it does (i.e.  it is svgatextmode) and then disable
any further call to vgacon_doresize.  Svgatextmode is usually used to
_expand_ the display, not to shrink it.  And it is harmless in the case of
a too big stty rows/cols: the display will just be cropped.  I tested it on
my laptop, and it works fine with svgatextmode.

A better solution would be that svgatextmode explicitely tells the kernel
not to care about video timing, but for this an interface needs be defined
and svgatextmode be patched.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

It seems that all the list_*_rcu primitives are missing a memory barrier
on the very first dereference.  For example,

#define list_for_each_rcu(pos, head) \
	for (pos = (head)->next; prefetch(pos->next), pos != (head); \
		pos = rcu_dereference(pos->next))

It will go something like:

	pos = (head)->next

	prefetch(pos->next)

	pos != (head)

	do stuff

We're missing a barrier here.

	pos = rcu_dereference(pos->next)

		fetch pos->next

		barrier given by rcu_dereference(pos->next)

		store pos

Without the missing barrier, the pos->next value may turn out to be stale.
In fact, if "do stuff" were also dereferencing pos and relying on
list_for_each_rcu to provide the barrier then it may also break.

So here is a patch to make sure that we have a barrier for the first
element in the list.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

As noticed by Nick Piggin, we need to make sure that we check the page
count before we check for PageDirty, since the dirty check is only valid
if the count implies that we're the only possible ones holding the page.

We always did do this, but the code needs a read-memory-barrier to make
sure that the orderign is also honored by the CPU.

(The writer side is ordered due to the atomic decrement and test on the
page count, see the discussion on linux-kernel)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

	... otherwise, things like alpha and sparc64 break and break
badly.  They define cpu_possible_map to something else in smp.h
*AFTER* having included cpumask.h.

	If that puppy is a macro, expansion will happen at the actual
caller, when we'd already seen #define cpu_possible_map ... and we will
get the right thing used.

	As an inline helper it will be tokenized before we get to that
define and that's it; no matter what we define later, it won't affect
anything.  We get modules with dependency on cpu_possible_map instead
of the right symbol (phys_cpu_present_map in case of sparc64), or outright
link errors if they are built-in.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The modem is said to work with belows addition to pnp_dev_table[]:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=296011Signed-off-by: maximilian attems <janitor@sternwelten.at>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Kernel version 2.6.13 introduced a regression in the generic USB
serial converter driver (usbserial.o, drivers/usb/serial/generic.c).
The bug manifests, as far as I can tell, whenever you attempt to write
to the device -- the write will never complete (write() returns 0, or
blocks).
Signed-off-by: Randall Nortman <oss@wonderclown.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

I am taking over all Megaraid SCSI drivers.  Here is the patch for the
MAINTENERS file.
Signed-off-by: Neela Syam Kolli <Neela.Kolli@engenio.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Argument does not agree.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

"proc_smaps_operations" is not defined in case of "CONFIG_MMU=n".
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/built-in.o: In function `w1_alloc_dev': undefined reference to `netlink_kernel_create'
drivers/built-in.o: In function `w1_alloc_dev': undefined reference to `sock_release'
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>