tlclk calls register_chrdev() and permits register_chrdev() to allocate the
major, but it promptly forgets what that major was.  So if there's no hardware
present you still get "telco_clock" appearing in /proc/devices and, I assume,
an oops reading /proc/devices if tlclk was a module.

Fix.

Mark, I'd suggest that that we not call register_chrdev() until _after_ we've
established that the hardware is present.

Cc: Mark Gross <mgross@linux.intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Check that kernel_thread() succeeded, so we don't wait for something which
cannot happen.
Signed-off-by: NHerbert Poetzl <herbert@13thfloor.at>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Change proc_dir_entry->size to be loff_t to represent files like
/proc/vmcore for 32bit systems with more than 4G memory.

Needed for seeing correct size for /proc/vmcore for 32-bit systems with >
4G RAM.
Signed-off-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Create compat_sys_adjtimex and use it an all appropriate places.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We had a copy of the compatibility version of struct timex in each 64 bit
architecture.  This patch just creates a global one and replaces all the
usages of the old ones.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NKyle McMartin <kyle@parisc-linux.org>
Acked-by: NTony Luck <tony.luck@intel.com>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update the NFSv4 server to use the new posix_lock_file_conf() interface.
Remove unnecessary (and race-prone) posix_test_file() calls.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Lockd and the NFSv4 server both exercise a race condition where
posix_test_lock() is called either before or after posix_lock_file() to
deal with a denied lock request due to a conflicting lock.

Remove the race condition for the NFSv4 server by adding a new conflicting
lock parameter to __posix_lock_file() , changing the name to
__posix_lock_file_conf().

Keep posix_lock_file() interface, add posix_lock_conf() interface, both
call __posix_lock_file_conf().

[akpm@osdl.org: Put the EXPORT_SYMBOL() where it belongs]
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

BUG instead of handling a case that should never happen.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I discovered on oprofile hunting on a SMP platform that dentry lookups were
slowed down because d_hash_mask, d_hash_shift and dentry_hashtable were in
a cache line that contained inodes_stat.  So each time inodes_stats is
changed by a cpu, other cpus have to refill their cache line.

This patch moves some variables to the __read_mostly section, in order to
avoid false sharing.  RCU dentry lookups can go full speed.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add __KERNEL__ block.
Use __KERNEL__ to allow ioctl interface to be usable.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Need to increment the version number because of the new PCI and sysfs
capabilities of the driver.  People maintaining things for distros have
asked that I do this after interface or major functional changes.
Signed-off-by: NCorey Minyard <minyard@acm.org>
Acked-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add full driver model support for the IPMI driver.  It links in the proper
bus and device support.

It adds an "ipmi" driver interface that has each BMC discovered by the
driver (as a device).  These BMCs appear in the devices/platform directory.
 If there are multiple interfaces to the same BMC, the driver should
discover this and will only have one BMC entry.  The BMC entry will have
pointers to each interface device that connects to it.

The device information (statistics and config information) has not yet been
ported over to the driver model from proc, that will come later.

This work was based on work by Yani Ioannou.  I basically rewrote it using
that code as a guide, but he still deserves credit :).

[bunk@stusta.de: make ipmi_find_bmc_guid() static]
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NYani Ioannou <yani.ioannou@gmail.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Modify the PCI hanling code for the IPMI driver to use the new method of
tables and registering, and adds more generic PCI handling for IPMI.
Unfortunately, this required a rather large rework of the way the driver
did detection so it would be more event-driven.

[bunk@stusta.de: make a struct static]
Signed-off-by: NCorey Minyard <minyard@acm.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

net/core/flow.c: In function 'flow_cache_flush':
net/core/flow.c:299: warning: statement with no effect
Signed-off-by: NCon Kolivas <kernel@kolivas.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The return value of this function is never used, so let's be honest and
declare it as void.

Some places where invalidatepage returned 0, I have inserted comments
suggesting a BUG_ON.

[akpm@osdl.org: JBD BUG fix]
[akpm@osdl.org: rework for git-nfs]
[akpm@osdl.org: don't go BUG in block_invalidate_page()]
Signed-off-by: NNeil Brown <neilb@suse.de>
Acked-by: NDave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The only user ignores the return value, and the only instanace
(block_sync_page) always returns 0...
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jens Axboe <axboe@suse.de>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Acked-by: NAlasdair G Kergon <agk@redhat.com>
Cc: Greg KH <greg@kroah.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Cc: Robert Love <rml@tech9.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If there's an error in load_image() we should return that without checking
snapshot_image_loaded.
Signed-off-by: NCon Kolivas <kernel@kolivas.org>
Acked-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ia64 ioremap is now smart enough to use the correct memory attributes, so
remove the EFI checks from osl.c.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: N"Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Here's a patch that fixes EFI boot for x86 on 2.6.16-rc5-mm3.  The
off-by-one is admittedly my fault, but the other two fix up the rest.

Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Almost all users of the table addresses from the EFI system table want
physical addresses.  So rather than doing the pa->va->pa conversion, just keep
physical addresses in struct efi.

This fixes a DMI bug: the efi structure contained the physical SMBIOS address
on x86 but the virtual address on ia64, so dmi_scan_machine() used ioremap()
on a virtual address on ia64.

This is essentially the same as an earlier patch by Matt Tolentino:
	http://marc.theaimsgroup.com/?l=linux-kernel&m=112130292316281&w=2
except that this changes all table addresses, not just ACPI addresses.

Matt's original patch was backed out because it caused MCAs on HP sx1000
systems.  That problem is resolved by the ioremap() attribute checking added
for ia64.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: N"Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

dmi_scan_machine() tries to ioremap 0x10000 (64K) bytes, even though it only
looks at the first 32 bytes or so.  If the SMBIOS table is near the end of a
memory region, the ioremap() may fail when it shouldn't.

This is in the efi_enabled path, so it really only affects ia64 at the moment.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: N"Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Check the EFI memory map so we can use the correct memory attributes for
ioremap().  Previously, we always used uncacheable access, which blows up on
some machines for regular system memory.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: N"Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Pass the size, not a pointer to the size, to efi_mem_attribute_range().

This function validates memory regions for the /dev/mem read/write/mmap paths.
The pointer allows arches to reduce the size of the range, but I think that's
unnecessary complexity.  Simplifying it will let me use
efi_mem_attribute_range() to improve the ia64 ioremap() implementation.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: N"Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Enable DMI table parsing on ia64.

Andi Kleen has a patch in his x86_64 tree which enables the use of i386
dmi_scan.c on x86_64.  dmi_scan.c functions are being used by the
drivers/char/ipmi/ipmi_si_intf.c driver for autodetecting the ports or
memory spaces where the IPMI controllers may be found.

This patch adds equivalent changes for ia64 as to what is in the x86_64
tree.  In addition, I reworked the DMI detection, such that on EFI-capable
systems, it uses the efi.smbios pointer to find the table, rather than
brute-force searching from 0xF0000.  On non-EFI systems, it continues the
brute-force search.

My test system, an Intel S870BN4 'Tiger4', aka Dell PowerEdge 7250, with
latest BIOS, does not list the IPMI controller in the ACPI namespace, nor
does it have an ACPI SPMI table.  Also note, currently shipping Dell x8xx
EM64T servers don't have these either, so DMI is the only method for
obtaining the address of the IPMI controller.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Acked-by: N"Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently /proc/iomem exports physical memory also apart from io device
memory.  But on i386, it truncates any memory more than 4GB.  This leads to
problems for kexec/kdump.

Kexec reads /proc/iomem to determine the system memory layout and prepares a
memory map based on that and passes it to the kernel being kexeced.  Given the
fact that memory more than 4GB has been truncated, new kernel never gets to
see and use that memory.

Kdump also reads /proc/iomem to determine the physical memory layout of the
system and encodes this informaiton in ELF headers.  After a crash new kernel
parses these ELF headers being used by previous kernel and vmcore is prepared
accordingly.  As memory more than 4GB has been truncated, kdump never sees
that memory and never prepares ELF headers for it.  Hence vmcore is truncated
and limited to 4GB even if there is more physical memory in the system.

This patch exports memory more than 4GB through /proc/iomem on i386.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Pass the trap number causing the call to notify_die() to the die
notification handler chain in a number of instances.  Also, honor the
return value from the handler chain invocation in die() as, through a
debugger, the fault may have been fixed.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Acked-By: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a "make isoimage" to i386 and x86-64, which allows the automatic
creation of a bootable CD image.  It also adds an option FDINITRD= to
include an initrd of the user's choice in generated floppy- or CD boot
images.  Finally, some minor cleanups of the image generation code.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We have a problem in a lot of emulated storage in that it takes a page from
get_user_pages() and does something like

kmap_atomic(page)
modify page
kunmap_atomic(page)

However, nothing has flushed the kernel cache view of the page before the
kunmap.  We need a lightweight API to do this, so this new API would
specifically be for flushing the kernel cache view of a user page which the
kernel has modified.  The driver would need to add
flush_kernel_dcache_page(page) before the final kunmap.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently, get_user_pages() returns fully coherent pages to the kernel for
anything other than anonymous pages.  This is a problem for things like
fuse and the SCSI generic ioctl SG_IO which can potentially wish to do DMA
to anonymous pages passed in by users.

The fix is to add a new memory management API: flush_anon_page() which
is used in get_user_pages() to make anonymous pages coherent.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It has been discovered that the remove_proc_entry has a race in the removing
of entries in the proc file system that are siblings.  There's no protection
around the traversing and removing of elements that belong in the same
subdirectory.

This subdirectory list is protected in other areas by the BKL.  So the BKL was
at first used to protect this area too, but unfortunately, remove_proc_entry
may be called with spinlocks held.  The BKL may schedule, so this was not a
solution.

The final solution was to add a new global spin lock to protect this list,
called proc_subdir_lock.  This lock now protects the list in
remove_proc_entry, and I also went around looking for other areas that this
list is modified and added this protection there too.  Care must be taken
since these locations call several functions that may also schedule.

Since I don't see any location that these functions that modify the
subdirectory list are called by interrupts, the irqsave/restore versions of
the spin lock was _not_ used.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Warn if free_irq() is called in IRQ context - free_irq() can execute /proc
VFS work, which must not be done in IRQ context.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

free_irq() should not be executed from softirq context.

Found by the lock validator.  The fix is to push fd_free_irq() into
keventd.  The code validates fine with this patch applied.

(akpm: this is revolting, but so is floppy.c)

[akpm@osdl.org: added flush_scheduled_work()]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* master.kernel.org:/home/rmk/linux-2.6-serial:
  [ARM] 3383/3: ixp2000: ixdp2x01 platform serial conversion
  [SERIAL] amba-pl010: Remove accessor macros
  [SERIAL] remove 8250_acpi (replaced by 8250_pnp and PNPACPI)
  [SERIAL] icom: select FW_LOADER

* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] 3030/2: fix permission check in the obscur cmpxchg syscall
  [ARM] nommu: rename compressed/head.S symbols to a new style
  [ARM] select TLS_REG_EMUL and NEEDS_SYSCALL_FOR_CMPXCHG
  [ARM] nommu: Move hardware page table definitions to pgtable-hwdef.h
  [ARM] Move read of processor ID out of lookup_processor_type()
  [ARM] Fix typo in tlbflush.h
  [ARM] noMMU: removes TLB codes in nommu mode
  [ARM] noMMU: block sys_fork in nommu mode
  [ARM] 3399/1: Fix link problem when CONFIG_PRINTK is disabled
  [ARM] 3398/1: Fix the VFP registers loading/storing base address
  [ARM] 3397/1: AT91RM9200 Header update
  [ARM] 3385/1: Battery support for sharp zaurus sl-5500 (collie)
  [ARM] SMP: don't set cpu_*_map in smp_prepare_boot_cpu
  include/linux/clk.h is betraying its ARM origins
  [ARM] Move enable_irq and disable_irq to assembler.h
  [ARM] 3391/1: use PLAT8250_DEV_PLATFORM{,1} for platform device id instead of 0/1

Broken earlier by me by a x86-64 patch.

The code was optimized away, but the compiler still complained about an
undeclared function.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Patch from Lennert Buytenhek

Add a PLAT8250_DEV_PLATFORM2, and convert the two ixdp2x01 CPLD serial
ports to use platform serial devices with ids PLAT8250_DEV_PLATFORM[12].
(The on-chip xscale UART is PLAT8250_DEV_PLATFORM, id #0.)
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

Quoting RMK:

|pte_write() just says that the page _may_ be writable. It doesn't say
|that the MMU is programmed to allow writes. If pte_dirty() doesn't
|return true, that means that the page is _not_ writable from userspace.
|If you write to it from kernel mode (without using put_user) you'll
|bypass the MMU read-only protection and may end up writing to a page
|owned by two separate processes.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>