make use of F2FS_NAME_LEN for name length checking,
change return conditions at few places, by assigning
storing the errorvalue in 'error' and making a common
exit path.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Change f2fs so that a warning is emitted when an attempt is made to
mount a filesystem with the unsupported discard option.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The fsync call should be ended after flushing the in-device caches.
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The build_free_nid should not add free nids over nm_i->max_nid.
But, there was a hole that invalid free nid was added by the following scenario.

Let's suppose nm_i->max_nid = 150 and the last NAT page has 100 ~ 200 nids.

build_free_nids
  - get_current_nat_page loads the last NAT page
  - scan_nat_page can add 100 ~ 200 nids
    -> Bug here!
So, when scanning an NAT page, we should check each candidate whether it is
over max_nid or not.
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

If the return value of releasepage is equal to zero, the page cannot be reclaimed.
Instead, we should return 1 in order to reclaim clean pages.
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

When we build new free nids, let's scan the just next NAT page instead of
skipping a couple of previously scanned pages in order to reuse free nids in
there.
Otherwise, we can use too much wide range of nids even though several nids were
deallocated, and also their node pages can be cached in the node_inode's address
space.
This means that we can retain lots of clean pages in the main memory, which
induces mm's reclaiming overhead.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Currently, f2fs doesn't reclaim any node pages.
However, if we found that a node page was truncated by checking its block
address with zero during f2fs_write_node_page, we should not skip that node
page and return zero to reclaim it.
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

This patch reduces redundant locking and unlocking pages during read operations.
In f2fs_readpage, let's use wait_on_page_locked() instead of lock_page.
And then, when we need to modify any data finally, let's lock the page so that
we can avoid lock contention.

[readpage rule]
- The f2fs_readpage returns unlocked page, or released page too in error cases.
- Its caller should handle read error, -EIO, after locking the page, which
  indicates read completion.
- Its caller should check PageUptodate after grab_cache_page.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

In all the breaking conditions in get_node_path, 'n' is used to
track index in offset[] array, but while breaking out also, in all
paths n++ is done.
So, remove the ++ from breaking paths. Also, avoid
reset of 'level=0' in first case.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The maximum filename length supported in linux is 255 characters.
So let's follow that.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Optimize and change return path in lookup_free_nid_list
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

We can remove the call to find_get_page to get a page from the cache
and check for up-to-date, instead we can make use of grab_cache_page
part itself to fetch the page from the cache.
So, removing the call and moving the PageUptodate at proper place, also
taken care of moving the lock_page condition in the page_hit part.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The caller of get_nid should be careful not to put lower value than
NODE_DIR1_BLOCK in case of level is zero.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Previously, f2fs reads several node pages ahead when get_dnode_of_data is called
with RDONLY_NODE flag.
And, this flag is set by the following functions.
- get_data_block_ro
- get_lock_data_page
- do_write_data_page
- truncate_blocks
- truncate_hole

However, this readahead mechanism is initially introduced for the use of
get_data_block_ro to enhance the sequential read performance.

So, let's clarify all the cases with the additional modes as follows.

enum {
	ALLOC_NODE,	/* allocate a new node page if needed */
	LOOKUP_NODE,	/* look up a node without readahead */
	LOOKUP_NODE_RA,	/*
			 * look up a node with readahead called
			 * by get_datablock_ro.
			 */
}
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>

The get_node_page_ra tries to:
1. grab or read a target node page for the given nid,
2. then, call ra_node_page to read other adjacent node pages in advance.

So, when we try to read a target node page by #1, we should submit bio with
READ_SYNC instead of READA.
And, in #2, READA should be used.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>

If the node page was truncated, its block address became zero.
This means that we don't need to write the node page, but have to unlock
NODE_WRITE, decrease the number of dirty node pages, and then unlock_page
before returning the f2fs_write_node_page with zero.
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Use div_u64 to fix overflow when calculating utilization.
*long int* is 4-bytes on 32-bit so (user blocks * 100) might be
overflow if disk size is over e.g. 512GB.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Pull x86 fixes from Peter Anvin:
 "Several boot fixes (MacBook, legacy EFI bootloaders), another
  please-don't-brick fix, and some minor stuff."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Do not try to sync identity map for non-mapped pages
  x86, doc: Be explicit about what the x86 struct boot_params requires
  x86: Don't clear efi_info even if the sentinel hits
  x86, mm: Make sure to find a 2M free block for the first mapped area
  x86: Fix 32-bit *_cpu_data initializers
  efivarfs: return accurate error code in efivarfs_fill_super()
  efivars: efivarfs_valid_name() should handle pstore syntax
  efi: be more paranoid about available space when creating variables
  iommu, x86: Add DMA remap fault reason
  x86, smpboot: Remove unused variable

Pull drm fixes from Dave Airlie:
 "Misc radeon, nouveau, mgag200 and intel fixes.

  The intel fixes should contain the fix for the touchpad on the
  Chromebook - hey I'm an input maintainer now!"

Hate to pee on your parade, Dave, but I don't think being an input
maintainer is necessarily something to strive for..

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (25 commits)
  drm/tegra: drop "select DRM_HDMI"
  drm: Documentation typo fixes
  drm/mgag200: Bug fix: Renesas board now selects native resolution.
  drm/mgag200: Reject modes that are too big for VRAM
  drm/mgag200: 'fbdev_list' in 'struct mga_fbdev' is not used
  drm/radeon: don't check mipmap alignment if MIP_ADDRESS is FMASK
  drm/radeon: skip MC reset as it's probably not hung
  drm/radeon: add primary dac adj quirk for R200 board
  drm/radeon: don't set hpd, afmt interrupts when interrupts are disabled
  drm/i915: Turn off hsync and vsync on ADPA when disabling crt
  drm/i915: Fix incorrect definition of ADPA HSYNC and VSYNC bits
  drm/i915: also disable south interrupts when handling them
  drm/i915: enable irqs earlier when resuming
  drm/i915: Increase the RC6p threshold.
  DRM/i915: On G45 enable cursor plane briefly after enabling the display plane.
  drm/nv50-: prevent some races between modesetting and page flipping
  drm/nouveau/i2c: drop parent refcount when creating ports
  drm/nv84: fix regression in page flipping
  drm/nouveau: Fix typo in init_idx_addr_latched().
  drm/nouveau: Disable AGP on PowerPC again.
  ...

Pull ACPI and power management fixes from Rafael J Wysocki:

 - Two fixes for the new intel_pstate driver from Dirk Brandewie.

 - Fix for incorrect usage of the .find_bridge() callback from struct
   acpi_bus_type in the USB core and subsequent removal of that callback
   from Rafael J Wysocki.

 - ACPI processor driver cleanups from Chen Gang and Syam Sidhardhan.

 - ACPI initialization and error messages fix from Joe Perches.

 - Operating Performance Points documentation improvement from Nishanth
   Menon.

 - Fixes for memory leaks and potential concurrency issues and sysfs
  attributes leaks during device removal in the core device PM QoS code
  from Rafael J Wysocki.

 - Calxeda Highbank cpufreq driver simplification from Emilio López.

 - cpufreq comment cleanup from Namhyung Kim.

 - Fix for a section mismatch in Calxeda Highbank interprocessor
   communication code from Mark Langsdorf (this is not a PM fix strictly
   speaking, but the code in question went in through the PM tree).

* tag 'pm+acpi-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq / intel_pstate: Do not load on VM that does not report max P state.
  cpufreq / intel_pstate: Fix intel_pstate_init() error path
  ACPI / glue: Drop .find_bridge() callback from struct acpi_bus_type
  ACPI / glue: Add .match() callback to struct acpi_bus_type
  ACPI / porocessor: Beautify code, pr->id is u32 which is never < 0
  ACPI / processor: Remove redundant NULL check before kfree
  ACPI / Sleep: Avoid interleaved message on errors
  PM / QoS: Remove device PM QoS sysfs attributes at the right place
  PM / QoS: Fix concurrency issues and memory leaks in device PM QoS
  cpufreq: highbank: do not initialize array with a loop
  PM / OPP: improve introductory documentation
  cpufreq: Fix a typo in comment
  mailbox, pl320-ipc: remove __init from probe function

Commit ac24c220 ("drm/tegra: Use generic
HDMI infoframe helpers") added "select DRM_HDMI" to the DRM_TEGRA
Kconfig entry. But there is no Kconfig symbol named DRM_HDMI. The select
statement for that symbol is a nop. Drop it.

What was needed to use HDMI functionality was to select HDMI (which this
entry already did through depending on DRM) and to include linux/hdmi.h
(which this commit also did).
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: Christopher Harvey <charvey@matrox.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Renesas boards were consistently defaulting to the 1024x768 resolution,
regardless of the native resolution of the monitor plugged in.  It was
determined that the EDID of the monitor was not being read.  Since the
DAC is a shared line, in order to read from or write to it we must take
control of the DAC clock.  This can be done by setting the proper
register to one.

This bug fix sets the register MGA1064_GEN_IO_CTL2 to one.  The DAC
control line can be used to determine whether or not a new monitor has
been plugged in.  But since the hotplug feature is not one we will
support, it has been decided to simply leave the register set to one.
Signed-off-by: Julia Lemire <jlemire@matrox.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

A monitor or a user could request a resolution greater than the
available VRAM for the backing framebuffer. This change checks the
required framebuffer size against the max VRAM size and rejects modes
if they are too big. This change can also remove a mode request passed
in via the video= parameter.
Signed-off-by: Christopher Harvey <charvey@matrox.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: Christopher Harvey <charvey@matrox.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Alex writes:
  Radeon fixes pull.  Not much to it.
  - fix some splatter if the interrupt handler isn't registered
  - Add a quirk for an old R200 board to fix washed out colors on the DAC
  - Don't try and soft reset the MC when we reset the GPU.  It usually doesn't
    need it and doesn't always work reliably.
  - A CS checker fix from Marek

* 'drm-fixes-3.9' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon: don't check mipmap alignment if MIP_ADDRESS is FMASK
  drm/radeon: skip MC reset as it's probably not hung
  drm/radeon: add primary dac adj quirk for R200 board
  drm/radeon: don't set hpd, afmt interrupts when interrupts are disabled

Pull ARM fixes from Russell King:
 "Mainly a group of fixes, the only exception is the wiring up of the
  kcmp syscall now that those patches went in during the last merge
  window."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations
  ARM: 7667/1: perf: Fix section mismatch on armpmu_init()
  ARM: 7666/1: decompressor: add -mno-single-pic-base for building the decompressor
  ARM: 7665/1: Wire up kcmp syscall
  ARM: 7664/1: perf: remove erroneous semicolon from event initialisation
  ARM: 7663/1: perf: fix ARMv7 EVTYPE_MASK to include NSH bit
  ARM: 7662/1: hw_breakpoint: reset debug logic on secondary CPUs in s2ram resume
  ARM: 7661/1: mm: perform explicit branch predictor maintenance when required
  ARM: 7660/1: tlb: add branch predictor maintenance operations
  ARM: 7659/1: mm: make mm->context.id an atomic64_t variable
  ARM: 7658/1: mm: fix race updating mm->context.id on ASID rollover
  ARM: 7657/1: head: fix swapper and idmap population with LPAE and big-endian
  ARM: 7655/1: smp_twd: make twd_local_timer_of_register() no-op for nosmp
  ARM: 7652/1: mm: fix missing use of 'asid' to get asid value from mm->context.id
  ARM: 7642/1: netx: bump IRQ offset to 64

EFI changes for v3.9-rc2,

  * Make the EFI variable code more paranoid about running out of
    space in NVRAM, since this is the root cause of the recent issue
    where machines refuse to boot - from Matthew Garrett.

  * Some efivarfs patches that fix regressions introduced in v3.9-rc1.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

kernel_map_sync_memtype() is called from a variety of contexts.  The
pat.c code that calls it seems to ensure that it is not called for
non-ram areas by checking via pat_pagerange_is_ram().  It is important
that it only be called on the actual identity map because there *IS*
no map to sync for highmem pages, or for memory holes.

The ioremap.c uses are not as careful as those from pat.c, and call
kernel_map_sync_memtype() on PCI space which is in the middle of the
kernel identity map _range_, but is not actually mapped.

This patch adds a check to kernel_map_sync_memtype() which probably
duplicates some of the checks already in pat.c.  But, it is necessary
for the ioremap.c uses and shouldn't hurt other callers.

I have reproduced this bug and this patch fixes it for me and the
original bug reporter:

	https://lkml.org/lkml/2013/2/5/396Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130307163151.D9B58C4E@kernel.stglabs.ibm.comSigned-off-by: Dave Hansen <dave@sr71.net>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Pull regulator fixes from Mark Brown:
 "A few small things here and there, nothing major here really.  The
  conversion of twl4030ldo_ops to get_voltage_sel is a fix, as covered
  in the commit log it fixes inconsistency in handling of the IS_UNSUP()
  feature in the driver."

* tag 'regulator-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: fixed regulator_bulk_enable unwinding code
  regulator: twl: Convert twl4030ldo_ops to get_voltage_sel
  regulator: palmas: fix number of SMPS voltages
  regulator: core: fix documentation error in regulator_allow_bypass
  regulator: core: update kernel documentation for regulator_desc
  regulator: db8500-prcmu - remove incorrect __exit markup

Pull regmap PM fix from Mark Brown:
 "A simple fix to stop us leaking a runtime PM reference in the case
  where we fail to enable a device."

* tag 'regmap-v3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: irq: call pm_runtime_put in pm_runtime_get_sync failed case

Merge tag 'ecryptfs-3.9-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

Pull ecryptfs fixes from Tyler Hicks:
 "Minor code cleanups and new Kconfig option to disable /dev/ecryptfs

  The code cleanups fix up W=1 compiler warnings and some unnecessary
  checks.  The new Kconfig option, defaulting to N, allows the rarely
  used eCryptfs kernel to userspace communication channel to be compiled
  out.  This may be the first step in it being eventually removed."

Hmm.  I'm not sure whether these should be called "fixes", and it
probably should have gone in the merge window.  But I'll let it slide.

* tag 'ecryptfs-3.9-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  eCryptfs: allow userspace messaging to be disabled
  eCryptfs: Fix redundant error check on ecryptfs_find_daemon_by_euid()
  ecryptfs: ecryptfs_msg_ctx_alloc_to_free(): remove kfree() redundant null check
  eCryptfs: decrypt_pki_encrypted_session_key(): remove kfree() redundant null check
  eCryptfs: remove unneeded checks in virt_to_scatterlist()
  eCryptfs: Fix -Wmissing-prototypes warnings
  eCryptfs: Fix -Wunused-but-set-variable warnings
  eCryptfs: initialize payload_len in keystore.c

Pull hwmon patches from Guenter Roeck:
 "Bug fixes for sht15 and ltc2978 driver plus some documentation
  updates"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (sht15) Check return value of regulator_enable()
  hwmon: (adt7410) Document ADT7420 support
  hwmon: (pmbus/ltc2978) Use detected chip ID to select supported functionality
  hwmon: (pmbus/ltc2978) Fix peak attribute handling
  hwmon: (pmbus/ltc2978) Update datasheet links
  hwmon: Update my e-mail address in driver documentation

The MIP_ADDRESS state has 2 meanings. If the texture has one sample
per pixel, it's a pointer to the mipmap chain. If the texture has
multiple samples per pixel, it's a pointer to FMASK, a metadata buffer
needed for reading compressed MSAA textures. The mipmap
alignment rules do not apply to FMASK.
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

The MC is mostly likely busy (e.g., display requests), not hung
so no need to reset it.  Doing an MC reset is tricky and not
particularly reliable.  Fixes hangs in certain cases.
Reported-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

vbios values are wrong leading to colors that are
too bright.  Use the default values instead.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Avoids splatter if the interrupt handler is not registered due
to acceleration being disabled.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Cc: stable@vger.kernel.org

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, #16 ; 0x10
800554dc:       e3a01011        mov     r1, #17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, #12]
800554ec:       e5830000        str     r0, [r3]
800554f0:       e5830004        str     r0, [r3, #4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, #16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], #4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, #16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".
Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

If the sentinel triggers, we do not want the boot loader authors to
just poke it and make the error go away, we want them to actually fix
the problem.

This should help avoid making the incorrect change in non-compliant
bootloaders.

[ hpa: dropped the Documentation/x86/boot.txt hunk pending
  clarifications ]
Signed-off-by: Peter Jones <pjones@redhat.com>
Link: http://lkml.kernel.org/r/1362592823-28967-1-git-send-email-pjones@redhat.comSigned-off-by: H. Peter Anvin <hpa@zytor.com>

When boot_params->sentinel is set, all we really know is that some
undefined set of fields in struct boot_params contain garbage.  In the
particular case of efi_info, however, there is a private magic for
that substructure, so it is generally safe to leave it even if the
bootloader is broken.

kexec (for which we did the initial analysis) did not initialize this
field, but of course all the EFI bootloaders do, and most EFI
bootloaders are broken in this respect (and should be fixed.)
Reported-by: Robin Holt <holt@sgi.com>
Link: http://lkml.kernel.org/r/CA%2B5PVA51-FT14p4CRYKbicykugVb=PiaEycdQ57CK2km_OQuRQ@mail.gmail.comTested-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>