Impact: BIOS bug safety

For pre-ACPI 3 BIOSes, pre-initialize the end of the e820 buffer just
in case the BIOS returns an unchanged %ecx but without actually
touching the ACPI 3 extended flags field.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Impact: ACPI 3 spec compliance, BIOS bug workaround

The ACPI 3 spec added another field to the E820 buffer -- which is
backwards incompatible, since it contains a validity bit.
Furthermore, there has been at least one report of a BIOS which
assumes that the buffer it is pointed at is the same buffer as for the
previous E820 call.  Therefore, read the data into a temporary buffer
and copy the standard part of it if and only if the valid bit is set.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Impact: BIOS bugproofing

Since there are BIOSes known to clobber %ebx and %esi for INT 15 E820,
assume there is something out there clobbering %edi and/or %ebp too,
and don't wait for it to fail.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Jordan Hargrave diagnosed a BIOS clobbering %esi in the E820 call.
That particular BIOS has been fixed, but there is a possibility that
this is responsible for other occasional reports of early boot
failure, and it does not hurt to add %esi to the clobbers.

-stable candidate patch.

Cc: Justin Forbes <jmforbes@linuxtx.org>
Signed-off-by: Michael K Johnson <johnsonm@rpath.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org

Impact: section mismatch fix

Ingo reports these warnings:
> WARNING: vmlinux.o(.text+0x6a288e): Section mismatch in reference from
> the function dmi_alloc() to the function .init.text:extend_brk()
> The function dmi_alloc() references
> the function __init extend_brk().
> This is often because dmi_alloc lacks a __init annotation or the
> annotation of extend_brk is wrong.

dmi_alloc() is a static inline, and so should be immune to this
kind of error.  But force it to be inlined and make it __init
anyway, just to be extra sure.

All of dmi_alloc()'s callers are already __init.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49C6B23C.2040308@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The libaio test harness turned up a problem whereby lookup_ioctx on a
bogus io context was returning the 1 valid io context from the list
(harness/cases/3.p).

Because of that, an extra put_iocontext was done, and when the process
exited, it hit a BUG_ON in the put_iocontext macro called from exit_aio
(since we expect a users count of 1 and instead get 0).

The problem was introduced by "aio: make the lookup_ioctx() lockless"
(commit abf137dd).

Thanks to Zach for pointing out that hlist_for_each_entry_rcu will not
return with a NULL tpos at the end of the loop, even if the entry was
not found.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Remove a source of fput() call from inside IRQ context.  Myself, like Eric,
wasn't able to reproduce an fput() call from IRQ context, but Jeff said he was
able to, with the attached test program.  Independently from this, the bug is
conceptually there, so we might be better off fixing it.  This patch adds an
optimization similar to the one we already do on ->ki_filp, on ->ki_eventfd.
Playing with ->f_count directly is not pretty in general, but the alternative
here would be to add a brand new delayed fput() infrastructure, that I'm not
sure is worth it.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Sam Ravnborg says:
 "We have several architectures that plays strange games with $(CC) and
  $(CROSS_COMPILE).

  So we need to postpone any use of $(call cc-option..) until we have
  included the arch specific Makefile so we try with the correct $(CC)
  version."
Requested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] make page table upgrade work again
  [S390] make page table walking more robust
  [S390] Dont check for pfn_valid() in uaccess_pt.c
  [S390] ftrace/mcount: fix kernel stack backchain
  [S390] topology: define SD_MC_INIT to fix performance regression
  [S390] __div64_31 broken for CONFIG_MARCH_G5

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: fix waitqueue usage in hiddev
  HID: fix incorrect free in hiddev

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: Clear space_info full when adding new devices
  Btrfs: Fix locking around adding new space_info

Nick Piggin noticed this (very unlikely) race between setting a page
dirty and creating the buffers for it - we need to hold the mapping
private_lock until we've set the page dirty bit in order to make sure
that create_empty_buffers() might not build up a set of buffers without
the dirty bits set when the page is dirty.

I doubt anybody has ever hit this race (and it didn't solve the issue
Nick was looking at), but as Nick says: "Still, it does appear to solve
a real race, which we should close."
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This makes sure that gcc doesn't try to optimize away wrapping
arithmetic, which the kernel occasionally uses for overflow testing, ie
things like

	if (ptr + offset < ptr)

which technically is undefined for non-unsigned types. See

	http://bugzilla.kernel.org/show_bug.cgi?id=12597

for details.

Not all versions of gcc support it, so we need to make it conditional
(it looks like it was introduced in gcc-3.4).
Reminded-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Impact: cleanup

set_pte_present() is no longer used, directly or indirectly,
so remove it.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
LKML-Reference: <1237406613-2929-2-git-send-email-jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup, remove last user of set_pte_present

set_pte_vaddr() is only used to install ptes in fixmaps, and
should never be used to overwrite a present mapping.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
LKML-Reference: <1237406613-2929-1-git-send-email-jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix boot crash

This fixes commit a6830278.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1237403503.22438.21.camel@ht.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix rarely-used feature

The VGA Miscellaneous Output Register is read from address 0x3CC but
written to address 0x3C2.  This was missed when this code was
converted from assembly to C.  While we're at it, clean up the code by
making the overflow bits and the math used to set the bits explicit.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
  Staging: benet: remove driver now that it is merged in drivers/net/

* 'for-2.6.29' of git://linux-nfs.org/~bfields/linux:
  nfsd: nfsd should drop CAP_MKNOD for non-root
  NFSD: provide encode routine for OP_OPENATTR

The benet driver is now in the proper place in drivers/net/benet, so we
can remove the staging version.
Acked-by: Sathya Perla <sathyap@serverengines.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Impact: cleanup

Refactor the MP-table parsing code via the introduction of the
following helper functions:

  skip_entry()
  smp_reserve_bootmem()
  check_irq_src()
  check_slot()

To simplify the code flow and to reduce the size of the
following oversized functions: smp_read_mpc(), smp_scan_config().

There should be no impact to functionality.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/ps3: ps3_defconfig updates
  powerpc/mm: Respect _PAGE_COHERENT on classic ppc32 SW
  powerpc/5200: Enable CPU_FTR_NEED_COHERENT for MPC52xx
  ps3/block: Replace mtd/ps3vram by block/ps3vram

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  module: fix refptr allocation and release order

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
  USB: storage: Unusual USB device Prolific 2507 variation added
  USB: Add device id for Option GTM380 to option driver
  USB: Add Vendor/Product ID for new CDMA U727 to option driver
  USB: Updated unusual-devs entry for USB mass storage on Nokia 6233
  USB: Option: let cdc-acm handle Sony Ericsson F3507g / Dell 5530
  USB: EHCI: expedite unlinks when the root hub is suspended
  USB: EHCI: Fix isochronous URB leak
  USB: option.c: add ZTE 622 modem device
  USB: wusbcore/wa-xfer, fix lock imbalance
  USB: misc/vstusb, fix lock imbalance
  USB: misc/adutux, fix lock imbalance
  USB: image/mdc800, fix lock imbalance
  USB: atm/cxacru, fix lock imbalance
  USB: unusual_devs: Add support for GI 0431 SD-Card interface
  USB: serial: new cp2101 device id
  USB: serial: ftdi: enable UART detection on gnICE JTAG adaptors blacklist interface0
  USB: serial: add FTDI USB/Serial converter devices
  USB: usbfs: keep async URBs until the device file is closed
  USB: usbtmc: add protocol 1 support
  USB: usbtmc: fix stupid bug in open()

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: Fix vunmap and free order in snd_free_sgbuf_pages()
  ALSA: mixart, fix lock imbalance
  ALSA: pcm_oss, fix locking typo
  ALSA: oss-mixer - Fixes recording gain control
  ALSA: hda - Workaround for buggy DMA position on ATI controllers
  ALSA: hda - Fix DMA mask for ATI controllers
  ALSA: opl3sa2 - Fix NULL dereference when suspending snd_opl3sa2

After TASK_SIZE now gives the current size of the address space the
upgrade of a 64 bit process from 3 to 4 levels of page table  needs
to use the arch_mmap_check hook to catch large mmap lengths. The
get_unmapped_area* functions need to check for -ENOMEM from the
arch_get_unmapped_area*, upgrade the page table and retry.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Make page table walking on s390 more robust. The current code requires
that the pgd/pud/pmd/pte loop is only done for address ranges that are
below the end address of the last vma of the address space. But this
is not always true, e.g. the generic page table walker does not guarantee
this. Change TASK_SIZE/TASK_SIZE_OF to reflect the current size of the
address space. This makes the generic page table walker happy but it
breaks the upgrade of a 3 level page table to a 4 level page table.
To make the upgrade work again another fix is required.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

pfn_valid() actually checks for a valid struct page and not for a
valid pfn. Using xip mappings w/o struct pages, this will result in
-EFAULT returned by the (page table walk) user copy functions,
even though there is valid memory. Those user copy functions don't
need a struct page, so this patch just removes the pfn_valid() check.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

With packed stack the backchain is at a different location.
Just use __SF_BACKCHAIN as an offset to store the backchain.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The default values for SD_MC_INIT cause an additional cpu usage of up
to 40% on some network benchmarks compared to the plain SD_CPU_INIT
values. So just define SD_MC_INIT to SD_CPU_INIT.
More tuning needs to be done.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The implementation of __div64_31 for G5 machines is broken. The comments
in __div64_31 are correct, only the code does not do what the comments
say. The part "If the remainder has overflown subtract base and increase
the quotient" is only partially realized, the base is subtracted correctly
but the quotient is only increased if the dividend had the last bit set.
Using the correct instruction fixes the problem.

Cc: stable@kernel.org
Reported-by: Frans Pop <elendil@planet.nl>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/x86/kernel/kprobes.c:196: warning: passing argument 1 of ‘search_exception_tables’ makes integer from pointer without a cast
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference:<49BED952.2050809@redhat.com>
LKML-Reference: <1237378065.13488.2.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branches 'x86/cleanups', 'x86/cpu', 'x86/debug', 'x86/mce2', 'x86/mm', 'x86/mtrr', 'x86/setup', 'x86/setup-memory', 'x86/urgent', 'x86/uv', 'x86/x2apic' and 'linus' into x86/core

Conflicts:
	arch/parisc/kernel/irq.c

arch/x86/kernel/cpu/mtrr/cleanup.c:197: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1237378015.13488.1.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix boot crash on UV systems

Commit 76ba0ecd "cpumask: use
cpumask_var_t in uv_flush_tlb_others" used cur_cpu as an iterator;
it was supposed to be zero for the code below it.
Reported-by: Cliff Wickman <cpw@sgi.com>
Original-From: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: steiner@sgi.com
Cc: <stable@kernel.org>
LKML-Reference: <200903180822.31196.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: optimize APIC IPI related barriers

Uncached MMIO accesses for xapic are inherently serializing and hence
we don't need explicit barriers for xapic IPI paths.

x2apic MSR writes/reads don't have serializing semantics and hence need
a serializing instruction or mfence, to make all the previous memory
stores globally visisble before the x2apic msr write for IPI.

Add x2apic_wrmsr_fence() in flush tlb path to x2apic specific paths.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "steiner@sgi.com" <steiner@sgi.com>
Cc: Nick Piggin <npiggin@suse.de>
LKML-Reference: <1237313814.27006.203.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

In snd_free_sgbuf_pags(), vunmap() is called after releasing the SG
pages, and it causes errors on Xen as Xen manages the pages
differently.  Although no significant errors have been reported on
the actual hardware, this order should be fixed other way round,
first vunmap() then free pages.

Cc: Jan Beulich <jbeulich@novell.com>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>