There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Stop using kobject_register, as this way we can control the sending of
the uevent properly, after everything is properly initialized.

Cc: Jacob Shin <jacob.shin@amd.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make this kobject dynamic and convert it to not use kobject_register,
which is going away.

Cc: Jacob Shin <jacob.shin@amd.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Stop using kobject_register, as this way we can control the sending of
the uevent properly, after everything is properly initialized.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch reorganizes the way suspend and resume notifications are
sent to drivers.  The major changes are that now the PM core acquires
every device semaphore before calling the methods, and calls to
device_add() during suspends will fail, while calls to device_del()
during suspends will block.

It also provides a way to safely remove a suspended device with the
help of the PM core, by using the device_pm_schedule_removal() callback
introduced specifically for this purpose, and updates two drivers (msr
and cpuid) that need to use it.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When we set the MFGPT timer tick, there is a chance that we'll
immediately assert an event.  If for some reason the IRQ routing
for this clock has been setup for some other purpose, then we
could end up firing an interrupt into the SMM handler or worse.

This rearranges the timer tick init function to initalize the handler
before we set up the MFGPT clock to make sure that even if we get
an event, it will go to the handler.

Furthermore, in the handler we need to make sure that we clear the
event, even if the timer isn't running.
Signed-off-by: NJordan Crouse <jordan.crouse@amd.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Tested-by: NArnd Hannemann <hannemann@i4.informatik.rwth-aachen.de>

This reverts commit d4d25dec.

It tried to fix long standing bugzilla entries, but the solution was
reported to break other systems. The reporter of

http://bugzilla.kernel.org/show_bug.cgi?id=9791

tracked it down to this commit and confirmed that reverting the patch
restores the correct behaviour. It's too late in the release cycle to
find a better solution than reverting the commit to avoid regressions.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>

On Sat, 2007-12-29 at 18:06 +0100, Marcin Slusarz wrote:
> Hi
> Today I've got this (while i was upgrading my gentoo box):
>
> WARNING: at kernel/lockdep.c:2658 check_flags()
> Pid: 21680, comm: conftest Not tainted 2.6.24-rc6 #63
>
> Call Trace:
>  [<ffffffff80253457>] check_flags+0x1c7/0x1d0
>  [<ffffffff80257217>] lock_acquire+0x57/0xc0
>  [<ffffffff8024d5c0>] __atomic_notifier_call_chain+0x60/0xd0
>  [<ffffffff8024d641>] atomic_notifier_call_chain+0x11/0x20
>  [<ffffffff8024d67e>] notify_die+0x2e/0x30
>  [<ffffffff8020da0a>] do_divide_error+0x5a/0xa0
>  [<ffffffff80522bdd>] trace_hardirqs_on_thunk+0x35/0x3a
>  [<ffffffff80255b89>] trace_hardirqs_on+0xd9/0x180
>  [<ffffffff80522bdd>] trace_hardirqs_on_thunk+0x35/0x3a
>  [<ffffffff80523c2d>] error_exit+0x0/0xa9
>
> possible reason: unannotated irqs-off.
> irq event stamp: 4693
> hardirqs last  enabled at (4693): [<ffffffff80522bdd>] trace_hardirqs_on_thunk+0x35/0x3a
> hardirqs last disabled at (4692): [<ffffffff80522c17>] trace_hardirqs_off_thunk+0x35/0x37
> softirqs last  enabled at (3546): [<ffffffff80238343>] __do_softirq+0xb3/0xd0
> softirqs last disabled at (3521): [<ffffffff8020c97c>] call_softirq+0x1c/0x30

more early fixups for notify_die()..
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In the current code, RTC_AIE doesn't work if the RTC relies on
CONFIG_HPET_EMULATE_RTC because the code sets the RTC_AIE flag in
hpet_set_rtc_irq_bit().  The interrupt handles does accidentally check
for RTC_PIE and not RTC_AIE when comparing the time which was set in
hpet_set_alarm_time().

I now verified on a test system here that without the patch applied,
the attached test program fails on a system that has HPET with
2.6.24-rc7-default. That's not critical since I guess the problem has
been there for several kernel releases, but as the fix is quite
obvious.

Configuration is CONFIG_RTC=y and CONFIG_HPET_EMULATE_RTC=y.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Sometimes cpu_idle_wait gets stuck because it might miss CPUS that are
already in idle, have no tasks waiting to run and have no interrupts going
to them.  This is common on bootup when switching cpu idle governors.

This patch gives those CPUS that don't check in an IPI kick.

 Background:
 -----------
I notice this while developing the mcount patches, that every once in a
while the system would hang. Looking deeper, the hang was always at boot
up when registering init_menu of the cpu_idle menu governor. Talking
with Thomas Gliexner, we discovered that one of the CPUS had no timer
events scheduled for it and it was in idle (running with NO_HZ). So the
CPU would not set the cpu_idle_state bit.

Hitting sysrq-t a few times would eventually route the interrupt to the
stuck CPU and the system would continue.

Note, I would have used the PDA isidle but that is set after the
cpu_idle_state bit is cleared, and would leave a window open where we
may miss being kicked.

hmm, looking closer at this, we still have a small race window between
clearing the cpu_idle_state and disabling interrupts (hence the RFC).

    CPU0:                          CPU 1:
  ---------                       ---------
 cpu_idle_wait():                 cpu_idle():
      |                           __cpu_cpu_var(is_idle) = 1;
      |                           if (__get_cpu_var(cpu_idle_state)) /* == 0 */
 per_cpu(cpu_idle_state, 1) = 1;         |
 if (per_cpu(is_idle, 1)) /* == 1 */     |
 smp_call_function(1)                    |
      |                             receives ipi and runs do_nothing.
 wait on map == empty               idle();
   /* waits forever */

So really we need interrupts off for most of this then. One might think
that we could simply clear the cpu_idle_state from do_nothing, but I'm
assuming that cpu_idle governors can be removed, and this might cause a
race that a governor might be used after the module was removed.

Venki said:

  I think your RFC patch is the right solution here.  As I see it, there is
  no race with your RFC patch.  As long as you call a dummy smp_call_function
  on all CPUs, we should be OK.  We can get rid of cpu_idle_state and the
  current wait forever logic altogether with dummy smp_call_function.  And so
  there wont be any wait forever scenario.

  The whole point of cpu_idle_wait() is to make all CPUs come out of idle
  loop atleast once.  The caller will use cpu_idle_wait something like this.

  // Want to change idle handler

  - Switch global idle handler to always present default_idle

  - call cpu_idle_wait so that all cpus come out of idle for an instant
    and stop using old idle pointer and start using default idle

  - Change the idle handler to a new handler

  - optional cpu_idle_wait if you want all cpus to start using the new
    handler immediately.

Maybe the below 1s patch is safe bet for .24.  But for .25, I would say we
just replace all complicated logic by simple dummy smp_call_function and
remove cpu_idle_state altogether.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ACPI and APM used "pm_active" to guarantee that
they would not be simultaneously active.

But pm_active was recently moved under CONFIG_PM_LEGACY,
so that without CONFIG_PM_LEGACY, pm_active became a NOP --
allowing ACPI and APM to both be simultaneously enabled.
This caused unpredictable results, including boot hangs.

Further, the code under CONFIG_PM_LEGACY is scheduled
for removal.

So replace pm_active with pm_flags.
pm_flags depends only on CONFIG_PM,
which is present for both CONFIG_APM and CONFIG_ACPI.

http://bugzilla.kernel.org/show_bug.cgi?id=9194Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

With CPU_HOTPLUG=n:

WARNING: vmlinux.o(.text+0x104f8): Section mismatch: reference to .init.text:fork_idle (between
'do_fork_idle' and 'lapic_timer_broadcast')

do_fork_idle() needs to be __cpuinit. It can be static as well.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After 17d57a92 ("x86: fix x86-32 early
fixmap initialization.") removing lg.ko caused a printk from vunmap:

	mm/memory.c:115: bad pgd 004b3027.

On the second use after module load, the kernel crashes.

This fixes the immediate problem (accessed and dirty bits not set as
expected in pmd_none_or_clear_bad).  I can't see why this would cause
a crash, but I haven't been able to reproduce it once this is applied.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit fbdcf18d.

As pointed out by Yanmin Zhang, the problem was already fixed
differently (and correctly), and rather than fix anything, it actually
causes us to create a sub-optimal sched-domains hierarchy (not setting
up the domain belonging to the core) when CONFIG_X86_HT=y.
Requested-by: NYanmin Zhang <yanmin_zhang@linux.intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds a cpu cache info entry for the Intel Tolapai cpu.
Signed-off-by: NJason Gaston <jason.d.gaston@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Andrew "Eagle Eye" Morton noticed that we use raw_local_save_flags()
instead of raw_local_irq_save(flags) in die(). This allows the
preemption of oopsing contexts - which is highly undesirable. It also
causes CONFIG_DEBUG_PREEMPT to complain, as reported by Miles Lane.

this bug was introduced via:

  commit 39743c9e
  Author: Andi Kleen <ak@suse.de>
  Date:   Fri Oct 19 20:35:03 2007 +0200

      x86: use raw locks during oopses

-               spin_lock_irqsave(&die.lock, flags);
+               __raw_spin_lock(&die.lock);
+               raw_local_save_flags(flags);

that is not a correct open-coding of spin_lock_irqsave(): both the
ordering is wrong (irqs should be disabled _first_), and the wrong
flags-saving API was used.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

when called by setup_arch) after smp_store_cpu_info() had set it to the
correct value.

The error shows up in 'cat /proc/cpuinfo' will all cpus = 0.
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Suresh B Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

CONFIG_HOTPLUG_CPU=y:

WARNING: vmlinux.o(.text+0xfa52): Section mismatch: reference to .init.data:disable_pse (between 'identify_cpu' and 'identify_secondary_cpu')

[ akpm@linux-foundation.org: initializer fix. ]
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

CONFIG_HOTPLUG_CPU=y:

WARNING: vmlinux.o(.text+0x1199a): Section mismatch: reference to .init.text.5:select_idle_routine (between 'init_intel' and 'init_nexgen')
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

CONFIG_HOTPLUG_CPU=y:

WARNING: vmlinux.o(.text+0x22c60): Section mismatch: reference to .init.data:cpu_idle_tasks (between 'do_boot_cpu' and 'do_warm_boot_cpu')
WARNING: vmlinux.o(.text+0x22c99): Section mismatch: reference to .init.data:cpu_idle_tasks (between 'do_boot_cpu' and 'do_warm_boot_cpu')
WARNING: vmlinux.o(.text+0x2359b): Section mismatch: reference to .init.data:smp_b_stepping (between 'smp_store_cpu_info' and 'cpu_exit_clear')
WARNING: vmlinux.o(.text+0x235a0): Section mismatch: reference to .init.data:smp_b_stepping (between 'smp_store_cpu_info' and 'cpu_exit_clear')
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

CONFIG_HOTPLUG_CPU=y:

WARNING: vmlinux.o(.text+0x2390d): Section mismatch: reference to .init.text.5:setup_local_APIC (between 'start_secondary' and 'check_tsc_warp')
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

this is the tale of a full day spent debugging an ancient but elusive bug.

after booting up thousands of random .config kernels, i finally happened
to generate a .config that produced the following rare bootup failure
on 32-bit x86:

| ..TIMER: vector=0x31 apic1=0 pin1=2 apic2=-1 pin2=-1
| ..MP-BIOS bug: 8254 timer not connected to IO-APIC
| ...trying to set up timer (IRQ0) through the 8259A ...  failed.
| ...trying to set up timer as Virtual Wire IRQ... failed.
| ...trying to set up timer as ExtINT IRQ... failed :(.
| Kernel panic - not syncing: IO-APIC + timer doesn't work!  Boot with apic=debug
| and send a report.  Then try booting with the 'noapic' option

this bug has been reported many times during the years, but it was never
reproduced nor fixed.

the bug that i hit was extremely sensitive to .config details.

First i did a .config-bisection - suspecting some .config detail.
That led to CONFIG_X86_MCE: enabling X86_MCE magically made the bug disappear
and the system would boot up just fine.

Debugging my way through the MCE code ended up identifying two unlikely
candidates: the thing that made a real difference to the hang was that
X86_MCE did two printks:

 Intel machine check architecture supported.
 Intel machine check reporting enabled on CPU#1.

Adding the same printks to a !CONFIG_X86_MCE kernel made the bug go away!

this left timing as the main suspect: i experimented with adding various
udelay()s to the arch/x86/kernel/io_apic_32.c:check_timer() function, and
the race window turned out to be narrower than 30 microseconds (!).

That made debugging especially funny, debugging without having printk
ability before the bug hits is ... interesting ;-)

eventually i started suspecting IRQ activities - those are pretty much the
only thing that happen this early during bootup and have the timescale of
a few dozen microseconds. Also, check_timer() changes the IRQ hardware
in various creative ways, so the main candidate became IRQ0 interaction.

i've added a counter to track timer irqs (on which core they arrived, at
what exact time, etc.) and found that no timer IRQ would arrive after the
bug condition hits - even if we re-enable IRQ0 and re-initialize the i8259A,
but that we'd get a small number of timer irqs right around the time when we
call the check_timer() function.

Eventually i got the following backtrace triggered from debug code in the
timer interrupt:

...trying to set up timer as Virtual Wire IRQ... failed.
...trying to set up timer as ExtINT IRQ...
Pid: 1, comm: swapper Not tainted (2.6.24-rc5 #57)
EIP: 0060:[<c044d57e>] EFLAGS: 00000246 CPU: 0
EIP is at _spin_unlock_irqrestore+0x5/0x1c
EAX: c0634178 EBX: 00000000 ECX: c4947d63 EDX: 00000246
ESI: 00000002 EDI: 00010031 EBP: c04e0f2e ESP: f7c41df4
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
 CR0: 8005003b CR2: ffe04000 CR3: 00630000 CR4: 000006d0
 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
 DR6: ffff0ff0 DR7: 00000400
  [<c05f5784>] setup_IO_APIC+0x9c3/0xc5c

the spin_unlock() was called from init_8259A(). Wait ... we have an IRQ0
entry while we are in the middle of setting up the local APIC, the i8259A
and the PIT??

That is certainly not how it's supposed to work! check_timer() was supposed
to be called with irqs turned off - but this eroded away sometime in the
past. This code would still work most of the time because this code runs
very quickly, but just the right timing conditions are present and IRQ0
hits in this small, ~30 usecs window, timer irqs stop and the system does
not boot up. Also, given how early this is during bootup, the hang is
very deterministic - but it would only occur on certain machines (and
certain configs).

The fix was quite simple: disable/restore interrupts properly in this
function. With that in place the test-system now boots up just fine.

(64-bit x86 io_apic_64.c had the same bug.)

Phew! One down, only 1500 other kernel bugs are left ;-)
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Kprobes for x86-64 may cause a kernel crash if it inserted on "iret"
instruction. "call absolute" is invalid on x86-64, so we don't need
treat it.

 - Change the processing order as same as x86-32.
 - Add "iret"(0xcf) case.
 - Remove next_rip local variable.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

jprobe for x86-64 may cause kernel page fault when the jprobe_return()
is called from incorrect function.

- Use jprobe_saved_regs instead getting it from stack.
  (Especially on x86-64, it may get incorrect data, because
   pt_regs can not be get by using container_of(rsp))
- Change the type of stack pointer to unsigned long *.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Revert commit efa4d2fb ("Hibernation:
Use temporary page tables for kernel text mapping on x86_64") because it
causes my t61p to reboot right at the end of resume-from-disk.  For
reasons unknown at this time.

Cc: Pavel Machek <pavel@ucw.cz>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Old debugging hack sneaked back during x86 merge, this removes it.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLen Brown <len.brown@intel.com>

fix this on i386 allnoconfig:

 WARNING: vmlinux.o(.text+0x6f2e): Section mismatch: reference to .init.text:register_cpu (between 'arch_register_cpu' and 'text_poke')
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

free_cache_attributes() must be __cpuinit since it calls the
__cpuinit cache_remove_shared_cpu_map().

This patch fixes the following section mismatch reported by
Chris Clayton:

 ...
 WARNING: vmlinux.o(.text+0x90b6): Section mismatch: reference to .init.text:cache_remove_shared_cpu_map (between 'free_cache_attributes' and 'show_level')
 ...
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Our automated test suite looks for keywords like error, fail, warning in
the boot log.  In the case when the nmi watchdog is determined to be
stuck in check_nmi_watchdog(), none of those keywords are displayed.

This patch adds a keyword, "WARNING:", so it makes it easier to notice
when the nmi watchdog isn't working correctly. Also add a proper
KERN_WARNING mark to this printout.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

pageexec@freemail.hu writes:

> i've just noticed that the chunk in i386/kernel/head.S ended up in a
> weird place, namely, it's not going to be executed as it's just after
> a 'jmp 3f' and before startup_32_smp, probably not what you intended.
> on a sidenote, the whole thing can be done in a single insn, like:
>
> movl $(swapper_pg_pmd - __PAGE_OFFSET + 0x067), (swapper_pg_dir -
> __PAGE_OFFSET+ 4092)

Thanks for the reminder I thought we had fixed this problem a while ago.

Needed to get fixed virtual address for USB debug and earlycon with mmio.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

we should also add hpet_disable() for kdump.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

If HPET was enabled by pci quirks, we use i8253 as initial clockevent
because pci quirks doesn't run until pci is initialized.

The above means the kernel (or something) is assuming HPET legacy
replacement is disabled and can use i8253 at boot.

If we used kexec, it isn't true. So, this patch disables HPET legacy
replacement for kexec in machine_shutdown().
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Subdividing the paravirt_ops structure caused a regression in certain
non-GPL modules which try to use mmu_ops and cpu_ops.  This restores the
old behaviour, and makes it consistent with the non-CONFIG_PARAVIRT case.

Takashi Iwai <tiwai@suse.de> adds:
> I took at this problem (as I have an nvidia card on one of my
> workstations), and found out that the following suffer from
> EXPORT_SYMBOL_GPL changes:
>
> * local_disable_irq(), local_irq_save*(), etc.
> * MSR-related macros like rdmsr(), wrmsr(), read_cr0(), etc.
>   wbinvd(), too.
> * pmd_val(), pgd_val(), etc are all involved with pv_mm_ops.
>   pmd_large() and pmd_bad() is also indirectly involved.
>   __flush_tlb() and friends suffer, too.

Christoph Hellwig objects to this patch on the grounds that modules
shouldn't be using these operations anyway.  I don't think this is a
particularly good reason to reject the patch, for several reasons:

1. These operations are still available to modules when not using
   CONFIG_PARAVIRT, since they are implicitly exported as inline
   functions via the kernel headers.  Exporting the same functionality as
   GPL-only symbols just adds a gratuitious difference between
   CONFIG_PARAVIRT and non-CONFIG_PARAVIRT configurations.  If we really
   think these operations are not for module use (or non-GPL module use),
   then we should solve the problem in a general way.

2. It's a regression from previous kernels, which would work these
   modules even with CONFIG_PARAVIRT enabled.

3. The operations in question seem pretty reasonable for modules to
   use.  The control registers/MSRs can be accessed directly anyway, so there's
   no benefit in preventing modules from using standard interfaces.  And it seems
   reasonable to allow a graphics driver to create its own mappings if it wants.

Therefore, I think this patch should go in for 2.6.24.  If people
really think that these operations should not be available to modules,
then we can address that separately.
Signed-off-by: NJeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Cc: Tobias Powalowski <t.powa@gmx.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

warmbloodedcreature@gmail.com reported that an APIC-enabled
Asus a7v8x-x with an Athlon XP reboots early in the bootup:

   http://bugzilla.kernel.org/show_bug.cgi?id=8723

after a long marathon of spontaneous-reboot debugging, it turns
out to be caused by sync_Arb_ids(). AMD CPUs never really needed
this sequence anyway, so just return early if we meet an AMD CPU.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The latest KVM driver wants to use the empty_zero_page symbol, and it's
not exported in 32-bit x86 (although it is exported by x86_64, s390, and
uml architectures).
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: tglx@linutronix.de
Cc: linux-kernel@vger.kernel.com
Cc: kvm-devel@lists.sourceforge.net
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix:

arch/x86/kernel/kprobes_64.c: In function 'set_current_kprobe':
arch/x86/kernel/kprobes_64.c:152: sorry, unimplemented: inlining failed in call to 'is_IF_modifier': recursive inlining
arch/x86/kernel/kprobes_64.c:166: sorry, unimplemented: called from here

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: mingo@elte.hu
Cc: akpm@linux-foundation.org
Cc: tglx@linutronix.de
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ensure the hardirq state is consistent before using locks. Use the rare
trace_hardirqs_fixup() because the trap can happen in any context.

resolves this rare lockdep warning:

WARNING: at kernel/lockdep.c:2658 check_flags()
 [<c013571e>] check_flags+0x90/0x140
 [<c0138a69>] lock_release+0x4b/0x1d0
 [<c0507fea>] notifier_call_chain+0x2a/0x47
 [<c050806b>] __atomic_notifier_call_chain+0x64/0x6d
 [<c0508007>] __atomic_notifier_call_chain+0x0/0x6d
 [<c050808b>] atomic_notifier_call_chain+0x17/0x1a
 [<c0131802>] notify_die+0x30/0x34
 [<c0506b09>] do_debug+0x3e/0xd4
 [<c050658f>] debug_stack_correct+0x27/0x2c
 [<c04be389>] tcp_rcv_established+0x1/0x620
 [<c04c38c2>] tcp_v4_do_rcv+0x2b/0x313
 [<c04c56b6>] tcp_v4_rcv+0x467/0x85d
 [<c0505ff2>] _spin_lock_nested+0x27/0x32
 [<c04c5a4d>] tcp_v4_rcv+0x7fe/0x85d
 [<c04c560e>] tcp_v4_rcv+0x3bf/0x85d
 [<c04adbb5>] ip_local_deliver_finish+0x11b/0x1b0
 [<c04adac8>] ip_local_deliver_finish+0x2e/0x1b0
 [<c04ada7b>] ip_rcv_finish+0x27b/0x29a
 [<c04961e5>] netif_receive_skb+0xfb/0x2a6
 [<c04add0f>] ip_rcv+0x0/0x1fb
 [<c0496354>] netif_receive_skb+0x26a/0x2a6
 [<c04961e5>] netif_receive_skb+0xfb/0x2a6
 [<c049872e>] process_backlog+0x7f/0xc6
 [<c04983ba>] net_rx_action+0xb9/0x1ac
 [<c0498348>] net_rx_action+0x47/0x1ac
 [<c01376cb>] trace_hardirqs_on+0x118/0x16b
 [<c01225e2>] __do_softirq+0x49/0xa2
 [<c010595f>] do_softirq+0x60/0xdd
 [<c0506300>] _spin_unlock_irq+0x20/0x2c
 [<c0103e4f>] restore_nocheck+0x12/0x15
 [<c01440e1>] handle_fasteoi_irq+0x0/0x9b
 [<c0105a70>] do_IRQ+0x94/0xaa
 [<c0506300>] _spin_unlock_irq+0x20/0x2c
 [<c0104832>] common_interrupt+0x2e/0x34
 [<c0114703>] native_safe_halt+0x2/0x3
 [<c0102c01>] default_idle+0x44/0x65
 [<c010257f>] cpu_idle+0x42/0x50
 [<c076ea09>] start_kernel+0x26b/0x270
 [<c076e317>] unknown_bootoption+0x0/0x196
 =======================
irq event stamp: 559190
hardirqs last  enabled at (559190): [<c0507316>] kprobe_exceptions_notify+0x299/0x305
hardirqs last disabled at (559189): [<c05067bf>] do_int3+0x1d/0x95
softirqs last  enabled at (559172): [<c010595f>] do_softirq+0x60/0xdd
softirqs last disabled at (559181): [<c010595f>] do_softirq+0x60/0xdd
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

revert this commit for now:

    commit 94806268
    Author: Andi Kleen <ak@suse.de>
    Date:   Fri Oct 19 20:35:03 2007 +0200

        x86: enable iommu_merge by default

it's causing regressions:

    http://bugzilla.kernel.org/show_bug.cgi?id=9412Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

today, all oopses contain a version number of the kernel, which is nice
because the people who actually do bother to read the oops get this
vital bit of information always without having to ask the reporter in
another round trip.

However, WARN_ON() and many other dump_stack() users right now lack this
information; the patch below adds this. This information is essential
for getting people to use their time effectively when looking at these
things; in addition, it's essential for tools that try to collect
statistics about defects.

Please consider, since its so simple and important for long term kernel
quality processes.

The code is identical between 32/64 bit; a lot of this code should be
unified over time, the patch keeps the identical-ness intact.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

More than 3 years ago Niclas Gustafsson reported a 'stopped time'
problem:

> Watching the /proc/interrupts with 10s apart after the "stop".
>
> [root@s151 root]# more /proc/interrupts
>            CPU0
>   0:   66413955  local-APIC-edge  timer
[...]
> LOC:   67355837
> ERR:          0
> MIS:          0
> [root@s151 root]# more /proc/interrupts
>            CPU0
>   0:   66413955  local-APIC-edge  timer
[...]
> LOC:   67379568
> ERR:          0
> MIS:          0

This may be because buggy SMM firmware messes with the 8259A (configured
for a transparent mode -- yes that rare "local-APIC-edge" mode is tricky
;-) ) insanely.

this should resolve:

  http://bugzilla.kernel.org/show_bug.cgi?id=2544
  http://bugzilla.kernel.org/show_bug.cgi?id=6296Patch-dusted-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>