Impact: fix x86_32 stack protector

Brian Gerst found out that %gs was being initialized to stack_canary
instead of stack_canary - 20, which basically gave the same canary
value for all threads.  Fixing this also exposed the following bugs.

* cpu_idle() didn't call boot_init_stack_canary()

* stack canary switching in switch_to() was being done too late making
  the initial run of a new thread use the old stack canary value.

Fix all of them and while at it update comment in cpu_idle() about
calling boot_init_stack_canary().
Reported-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: stack protector for x86_32

Implement stack protector for x86_32.  GDT entry 28 is used for it.
It's set to point to stack_canary-20 and have the length of 24 bytes.
CONFIG_CC_STACKPROTECTOR turns off CONFIG_X86_32_LAZY_GS and sets %gs
to the stack canary segment on entry.  As %gs is otherwise unused by
the kernel, the canary can be anywhere.  It's defined as a percpu
variable.

x86_32 exception handlers take register frame on stack directly as
struct pt_regs.  With -fstack-protector turned on, gcc copies the
whole structure after the stack canary and (of course) doesn't copy
back on return thus losing all changed.  For now, -fno-stack-protector
is added to all files which contain those functions.  We definitely
need something better.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: pt_regs changed, lazy gs handling made optional, add slight
        overhead to SAVE_ALL, simplifies error_code path a bit

On x86_32, %gs hasn't been used by kernel and handled lazily.  pt_regs
doesn't have place for it and gs is saved/loaded only when necessary.
In preparation for stack protector support, this patch makes lazy %gs
handling optional by doing the followings.

* Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs.

* Save and restore %gs along with other registers in entry_32.S unless
  LAZY_GS.  Note that this unfortunately adds "pushl $0" on SAVE_ALL
  even when LAZY_GS.  However, it adds no overhead to common exit path
  and simplifies entry path with error code.

* Define different user_gs accessors depending on LAZY_GS and add
  lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS.  The
  lazy_*_gs() ops are used to save, load and clear %gs lazily.

* Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly.

xen and lguest changes need to be verified.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

On x86_32, %gs is handled lazily.  It's not saved and restored on
kernel entry/exit but only when necessary which usually is during task
switch but there are few other places.  Currently, it's done by
calling savesegment() and loadsegment() explicitly.  Define
get_user_gs(), set_user_gs() and task_user_gs() and use them instead.

While at it, clean up register access macros in signal.c.

This cleans up code a bit and will help future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

Use .macro instead of cpp #define where approriate.  This cleans up
code and will ease future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: avoid crash on vsyscall
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: no default -fno-stack-protector if stackp is enabled, cleanup

Stackprotector make rules had the following problems.

* cc support test and warning are scattered across makefile and
  kernel/panic.c.

* -fno-stack-protector was always added regardless of configuration.

Update such that cc support test and warning are contained in makefile
and -fno-stack-protector is added iff stackp is turned off.  While at
it, prepare for 32bit support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: misc udpate

* wrap content with CONFIG_CC_STACK_PROTECTOR so that other arch files
  can include it directly

* add missing includes

This will help future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

ELF core dump is used for both user land core dump and kernel crash
dump.  Depending on architecture, register might need to be accessed
differently for userland and kernel.  Allow architectures to define
ELF_CORE_COPY_KERNEL_REGS() and use different operation for kernel
register dump.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/kernel/acpi/boot.c

do_device_not_available() is the handler for #NM and it declares that
it takes a unsigned long and calls math_emu(), which takes a long
argument and surprisingly expects the stack frame starting at the zero
argument would match struct math_emu_info, which isn't true regardless
of configuration in the current code.

This patch makes do_device_not_available() take struct pt_regs like
other exception handlers and initialize struct math_emu_info with
pointer to it and pass pointer to the math_emu_info to math_emulate()
like normal C functions do.  This way, unless gcc makes a copy of
struct pt_regs in do_device_not_available(), the register frame is
correctly accessed regardless of kernel configuration or compiler
used.

This doesn't fix all math_emu problems but it at least gets it
somewhat working.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/mach-voyager/voyager_smp.c
	arch/x86/mm/fault.c

Impact: cleanup

* Come on, struct info?  s/struct info/struct math_emu_info/

* Use struct pt_regs and kernel_vm86_regs instead of defining its own
  register frame structure.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: dump the correct %gs into a.out core dump

aout_dump_thread() read %gs but didn't include it in core dump.  Fix
it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Commit 6194ba6f ("x86: don't special-case
pmd allocations as much") made changes to the way we handle pmd allocations,
and while doing that it dropped a call to  paravirt_release_pd on the
pgd page from the pgd_dtor code path.

As a result of this missing release, the hypervisor is now unaware of the
pgd page being freed, and as a result it ends up tracking this page as a
page table page.

After this the guest may start using the same page for other purposes, and
depending on what use the page is put to, it may result in various performance
and/or functional issues ( hangs, reboots).

Since this release is only required for VMI, I now release the pgd page from
the (vmi)_pgd_free hook.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>

Impact: find right nr_irqs_gsi on some systems.

One test-system has gap between gsi's:

[    0.000000] ACPI: IOAPIC (id[0x04] address[0xfec00000] gsi_base[0])
[    0.000000] IOAPIC[0]: apic_id 4, version 0, address 0xfec00000, GSI 0-23
[    0.000000] ACPI: IOAPIC (id[0x05] address[0xfeafd000] gsi_base[48])
[    0.000000] IOAPIC[1]: apic_id 5, version 0, address 0xfeafd000, GSI 48-54
[    0.000000] ACPI: IOAPIC (id[0x06] address[0xfeafc000] gsi_base[56])
[    0.000000] IOAPIC[2]: apic_id 6, version 0, address 0xfeafc000, GSI 56-62
...
[    0.000000] nr_irqs_gsi: 38

So nr_irqs_gsi is not right. some irq for MSI will overwrite with io_apic.

need to get that with acpi_probe_gsi when acpi io_apic is used
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

For Intel 7400 series CPUs, the recommendation is to use a clflush on the
monitored address just before monitor and mwait pair [1].

This clflush makes sure that there are no false wakeups from mwait when the
monitored address was recently written to.

[1] "MONITOR/MWAIT Recommendations for Intel Xeon Processor 7400 series"
    section in specification update document of 7400 series
    http://download.intel.com/design/xeon/specupdt/32033601.pdfSigned-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: bug fix

Don't use per_cpu_offset() to determine if it valid to access a
per-cpu variable for a given cpu number.  It is not a valid assumption
on x86-64 anymore. Use cpu_possible() instead.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup and bug fix

Use the linker to create symbols for certain per-cpu variables
that are offset by __per_cpu_load.  This allows the removal of
the runtime fixup of the GDT pointer, which fixes a bug with
resume reported by Jiri Slaby.
Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: bug fix

IA-64 needs to put percpu data in the seperate section even on UP.
Fixes regression caused by "percpu: refactor percpu.h"
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async-update:
  async: use list_move_tail
  async: Rename _special -> _domain for clarity.
  async: Add some documentation.
  async: Handle kthread_run() return codes.
  async: Fix running list handling.

For historical reason, this driver used its own saving/restoring
of the PCI config space, and used the state of it on resume as
an indication as to whether it needed to re-POST the chip or not.

This methods breaks with the later core changes since the core will
have restored things for us.

This patch fixes it by removing that custom code, using standard
core methods to save/restore state, and testing for the need to
re-POST by comparing the content of a few key PLL registers.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This fixes aty128fb to properly save the PCI config space -before- it
potentially switches the PM state of the chip. This avoids a
warning with the new PM core and is the right thing to do anyway.

I also replaced the hand-coded switch to D2 with a call to the
genericc pci_set_power_state() and removed the code that switches it
back to D0 since the generic code is doing that for us nowadays.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This fixes atyfb to properly save the PCI config space -before- it
potentially switches the PM state of the chip. This avoids a
warning with the new PM core and is the right thing to do anyway.

I also slightly cleaned up the code that checks whether we are
running on a PowerMac to do a runtime check instead of a compile
check only, and replaced a deprecated number with the proper
symbolic constant.

Finally, I removed the useless switch to D0 from resume since
the core does it for us.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

list.h provides a dedicated primitive for
"list_del followed by list_add_tail"... list_move_tail.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Rename the async_*_special() functions to async_*_domain(), which
describes the purpose of these functions much better.
[Broke up long lines to silence checkpatch]
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

Add some kerneldoc to the async interface.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

If we fail to create the manager thread, fall back to non-fastboot.
If we fail to create an async thread, try again after waiting for
a bit.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

async_schedule() should pass in async_running as the running
list, and run_one_entry() should put the entry to be run on
the provided running list instead of always on the generic one.
Reported-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI PM: make the PM core more careful with drivers using the new PM framework
  PCI PM: Read power state from device after trying to change it on resume
  PCI PM: Do not disable and enable bridges during suspend-resume
  PCI: PCIe portdrv: Simplify suspend and resume
  PCI PM: Fix saving of device state in pci_legacy_suspend
  PCI PM: Check if the state has been saved before trying to restore it
  PCI PM: Fix handling of devices without drivers
  PCI: return error on failure to read PCI ROMs
  PCI: properly clean up ASPM link state on device remove

Impact: fix spurious BUG_ON() triggered under load

module_refcount() isn't reliable outside stop_machine(), as demonstrated
by Karsten Keil <kkeil@suse.de>, networking can trigger it under load
(an inc on one cpu and dec on another while module_refcount() is tallying
 can give false results, for example).

Almost noone should be using __module_get, but that's another issue.

Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (30 commits)
  ACPI: Kconfig text - Fix the ACPI_CONTAINER module name according to the real module name.
  eeepc-laptop: fix oops when changing backlight brightness during eeepc-laptop init
  ACPICA: Fix table entry truncation calculation
  ACPI: Enable bit 11 in _PDC to advertise hw coord
  ACPI: struct device - replace bus_id with dev_name(), dev_set_name()
  ACPI: add missing KERN_* constants to printks
  ACPI: dock: Don't eval _STA on every show_docked sysfs read
  ACPI: disable ACPI cleanly when bad RSDP found
  ACPI: delete CPU_IDLE=n code
  ACPI: cpufreq: Remove deprecated /proc/acpi/processor/../performance proc entries
  ACPI: make some IO ports off-limits to AML
  ACPICA: add debug dump of BIOS _OSI strings
  ACPI: proc_dir_entry 'video/VGA' already registered
  ACPI: Skip the first two elements in the _BCL package
  ACPI: remove BM_RLD access from idle entry path
  ACPI: remove locking from PM1x_STS register reads
  eeepc-laptop: use netlink interface
  eeepc-laptop: Implement rfkill hotplugging in eeepc-laptop
  eeepc-laptop: Check return values from rfkill_register
  eeepc-laptop: Add support for extended hotkeys
  ...

Merge branches 'release', 'asus', 'bugzilla-12450', 'cpuidle', 'debug', 'ec', 'misc', 'printk' and 'processor' into release

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

I got the following oops while changing the backlight brightness during
startup.  When it happens, it prevents use of the hotkeys, Fn-Fx, and the
lid button.

It's a clear use-before-init, as I verified by testing with an
appropriately-placed "else printk".

BUG: unable to handle kernel NULL pointer dereference at 00000000
*pde = 00000000
Oops: 0002 [#1] PREEMPT SMP
Pid: 160, comm: kacpi_notify Not tainted (2.6.28.1-eee901 #4) 901
EIP: 0060:[<c0264e68>]  [<c0264e68>] eeepc_hotk_notify+26/da
EFLAGS: 00010246 CPU: 1
Using defaults from ksymoops -t elf32-i386 -a i386
EAX: 00000009 EBX: 00000000 ECX: 00000009 EDX: f70dbf64
ESI: 00000029 EDI: f7335188 EBP: c02112c9 ESP: f70dbf80
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
 f70731e0 f73acd50 c02164ac f7335180 f70aa040 c02112e6 f733518c c012b62f
 f70aa044 f70aa040 c012bdba f70aa04c 00000000 c012be6e 00000000 f70bdf80
 c012e198 f70dbfc4 f70dbfc4 f70aa040 c012bdba 00000000 c012e0c9 c012e091
Call Trace:
 [<c02164ac>] ? acpi_ev_notify_dispatch+4c/55
 [<c02112e6>] ? acpi_os_execute_deferred+1d/25
 [<c012b62f>] ? run_workqueue+71/f1
 [<c012bdba>] ? worker_thread+0/bf
 [<c012be6e>] ? worker_thread+b4/bf
 [<c012e198>] ? autoremove_wake_function+0/2b
 [<c012bdba>] ? worker_thread+0/bf
 [<c012e0c9>] ? kthread+38/5f
 [<c012e091>] ? kthread+0/5f
 [<c0103abf>] ? kernel_thread_helper+7/10
Code: 00 00 00 00 c3 83 3d 60 5c 50 c0 00 56 89 d6 53 0f 84 c4 00 00 00 8d 42
e0 83 f8 0f 77 0f 8b 1d 68 5c 50 c0 89 d8 e8 a9 fa ff ff <89> 03 8b 1d 60 5c
50 c0 89 f2 83 e2 7f 0f b7 4c 53 10 8d 41 01
Signed-off-by: Darren Salt <linux@youmustbejoking.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

During early boot, ACPI RSDT/XSDT table entries are gathered into the
'initial_tables[]' array.  This array is currently statically defined (see
./drivers/acpi/tables.c).  When there are more table entries than can be
held in the 'initial_tables[]' array, the message "Truncating N table
entries!" is output.  As currently implemented, this message will always
erroneously calculate N as 0.

This patch fixes the calculation that determines how many table entries
will be missing (truncated).

This modification may be used under either the GPL or the BSD-style
license used for Intel ACPI CA code.
Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

Bit 11 in intel PDC definitions is meant for OS capability to handle
hardware coordination of P-states. In Linux we have always supported
hwardware coordination of P-states. Just let the BIOSes know that we
support it, by setting this bit.

Some BIOSes use this bit to choose between hardware or software coordination
and without this change below, BIOSes switch to software coordination, which
is not very optimal in terms of power consumption and extra wakeups from idle.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>