This should have been GPLv2 only, we cut and pasted from the wrong file
originally, sorry.

Also removed some unneeded boilerplate license code, we all know where
to find the GPLv2, and that there's no warranty as that is implicit from
the license.

Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
LKML-Reference: <20100507235541.GA15448@kroah.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

This patch integrates HyperV detection within the framework currently
used by VmWare. With this patch, we can avoid having to replicate the
HyperV detection code in each of the Microsoft HyperV drivers.

Reworked and tweaked by Greg K-H to build properly.
Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
LKML-Reference: <20100506190841.GA1605@kroah.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vadim Rozenfeld <vrozenfe@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

APERF/MPERF can be handled via the table like all the other scattered
CPU flags.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1270065406-1814-4-git-send-email-bp@amd64.org>

K8_NB depends on PCI and when the last is disabled (allnoconfig) we fail
at the final linking stage due to missing exported num_k8_northbridges.
Add a header stub for that.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100503183036.GJ26107@aftab>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

When disabling an L3 cache index, make sure we disable that index in
all four subcaches of the L3. Clarify nomenclature while at it, wrt to
disable slots versus disable index and rename accordingly.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1271945222-5283-6-git-send-email-bp@amd64.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Currently, we're allocating L3 cache info and calculating indices for
each online cpu which is clearly superfluous. Instead, we need to do
this per-node as is each L3 cache.

No functional change, only per-cpu memory savings.

-v2: Allocate L3 cache descriptors array dynamically.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1271945222-5283-5-git-send-email-bp@amd64.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Add a struct representing L3 cache attributes (subcache sizes and
indices count) and move the respective members out of _cpuid4_info.
Also, stash the struct pci_dev ptr into the struct simplifying the code
even more.

There should be no functionality change resulting from this patch except
slightly slimming the _cpuid4_info per-cpu vars.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1271945222-5283-4-git-send-email-bp@amd64.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

When running a quest kernel on xen we get:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: [<ffffffff8142f2fb>] cpuid4_cache_lookup_regs+0x2ca/0x3df
PGD 0
Oops: 0000 [#1] SMP
last sysfs file:
CPU 0
Modules linked in:

Pid: 0, comm: swapper Tainted: G        W  2.6.34-rc3 #1 /HVM domU
RIP: 0010:[<ffffffff8142f2fb>]  [<ffffffff8142f2fb>] cpuid4_cache_lookup_regs+0x
2ca/0x3df
RSP: 0018:ffff880002203e08  EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000060
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000000
RBP: ffff880002203ed8 R08: 00000000000017c0 R09: ffff880002203e38
R10: ffff8800023d5d40 R11: ffffffff81a01e28 R12: ffff880187e6f5c0
R13: ffff880002203e34 R14: ffff880002203e58 R15: ffff880002203e68
FS:  0000000000000000(0000) GS:ffff880002200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000038 CR3: 0000000001a3c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffffffff81a00000, task ffffffff81a44020)
Stack:
 ffffffff810d7ecb ffff880002203e20 ffffffff81059140 ffff880002203e30
<0> ffffffff810d7ec9 0000000002203e40 000000000050d140 ffff880002203e70
<0> 0000000002008140 0000000000000086 ffff880040020140 ffffffff81068b8b
Call Trace:
 <IRQ>
 [<ffffffff810d7ecb>] ? sync_supers_timer_fn+0x0/0x1c
 [<ffffffff81059140>] ? mod_timer+0x23/0x25
 [<ffffffff810d7ec9>] ? arm_supers_timer+0x34/0x36
 [<ffffffff81068b8b>] ? hrtimer_get_next_event+0xa7/0xc3
 [<ffffffff81058e85>] ? get_next_timer_interrupt+0x19a/0x20d
 [<ffffffff8142fa23>] get_cpu_leaves+0x5c/0x232
 [<ffffffff8106a7b1>] ? sched_clock_local+0x1c/0x82
 [<ffffffff8106a9a0>] ? sched_clock_tick+0x75/0x7a
 [<ffffffff8107748c>] generic_smp_call_function_single_interrupt+0xae/0xd0
 [<ffffffff8101f6ef>] smp_call_function_single_interrupt+0x18/0x27
 [<ffffffff8100a773>] call_function_single_interrupt+0x13/0x20
 <EOI>
 [<ffffffff8143c468>] ? notifier_call_chain+0x14/0x63
 [<ffffffff810295c6>] ? native_safe_halt+0xc/0xd
 [<ffffffff810114eb>] ? default_idle+0x36/0x53
 [<ffffffff81008c22>] cpu_idle+0xaa/0xe4
 [<ffffffff81423a9a>] rest_init+0x7e/0x80
 [<ffffffff81b10dd2>] start_kernel+0x40e/0x419
 [<ffffffff81b102c8>] x86_64_start_reservations+0xb3/0xb7
 [<ffffffff81b103c4>] x86_64_start_kernel+0xf8/0x107
Code: 14 d5 40 ff ae 81 8b 14 02 31 c0 3b 15 47 1c 8b 00 7d 0e 48 8b 05 36 1c 8b
 00 48 63 d2 48 8b 04 d0 c7 85 5c ff ff ff 00 00 00 00 <8b> 70 38 48 8d 8d 5c ff
 ff ff 48 8b 78 10 ba c4 01 00 00 e8 eb
RIP  [<ffffffff8142f2fb>] cpuid4_cache_lookup_regs+0x2ca/0x3df
 RSP <ffff880002203e08>
CR2: 0000000000000038
---[ end trace a7919e7f17c0a726 ]---

The L3 cache index disable feature of AMD CPUs has to be disabled if the
kernel is running as guest on top of a hypervisor because northbridge
devices are not available to the guest. Currently, this fixes a boot
crash on top of Xen. In the future this will become an issue on KVM as
well.

Check if northbridge devices are present and do not enable the feature
if there are none.
Signed-off-by: Frank Arnold <frank.arnold@amd.com>
LKML-Reference: <1271945222-5283-3-git-send-email-bp@amd64.org>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

All F10h CPUs starting with model 8 resp. 9, stepping 1, support L3
cache index disable. Concentrate the family, model, stepping checking at
one place and enable the feature implicitly on upcoming Fam10h models.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1271945222-5283-2-git-send-email-bp@amd64.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Multiple modules used to define those which are with identical
functionality and were needlessly replicated among the different cpufreq
drivers. Push them into the header and remove duplication.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1270065406-1814-7-git-send-email-bp@amd64.org>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

With F10, model 10, all valid frequencies are in the ACPI _PST table.

Cc: <stable@kernel.org> # 33.x 32.x
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
LKML-Reference: <1270065406-1814-6-git-send-email-bp@amd64.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Starting with model 10 of Family 0x10, AMD processors may have
support for APERF/MPERF.  Add support for identifying it and using
it within cpufreq.  Move the APERF/MPERF functions out of the
acpi-cpufreq code and into their own file so they can easily be
shared.
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
LKML-Reference: <20100401141956.GA1930@aftab>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Initialize this CPUID flag feature in common code. It could be made a
standalone function later, maybe, if more functionality is duplicated.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1270065406-1814-4-git-send-email-bp@amd64.org>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Starting with F10h, revE, AMD processors add support for a dynamic
core boosting feature called Core Performance Boost. When a specific
condition is present, a subset of the cores on a system are boosted
beyond their P0 operating frequency to speed up the performance of
single-threaded applications.

In the normal case, the system comes out of reset with core boosting
enabled. This patch adds a sysfs knob with which core boosting can be
switched on or off for benchmarking purposes.

While at it, make the CPB code hotplug-aware so that taking cores
offline wouldn't interfere with boosting the remaining online cores.
Furthermore, add cpu_online_mask hotplug protection as suggested by
Andrew.

Finally, cleanup the driver init codepath and update copyrights.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1270065406-1814-3-git-send-email-bp@amd64.org>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

By semi-popular demand, this adds the Core Performance Boost feature
flag to /proc/cpuinfo. Possible use case for this is userspace tools
like cpufreq-aperf, for example, so that they don't have to jump through
hoops of accessing "/dev/cpu/%d/cpuid" in order to check for CPB hw
support, or call cpuid from userspace.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1270065406-1814-2-git-send-email-bp@amd64.org>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Add a MAINTAINERS record for the key management facility.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  CRED: Fix memory leak in error handling

* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
  [LogFS] Erase new journal segments
  [LogFS] Move reserved segments with journal
  [LogFS] Clear PagePrivate when moving journal
  Simplify and fix pad_wbuf
  Prevent data corruption in logfs_rewrite_block()
  Use deactivate_locked_super
  Fix logfs_get_sb_final error path
  Write out both superblocks on mismatch
  Prevent schedule while atomic in __logfs_readdir
  Plug memory leak in writeseg_end_io
  Limit max_pages for insane devices
  Open segment file before using it

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Do not free zero sized per cpu areas
  x86: Make sure free_init_pages() frees pages on page boundary
  x86: Make smp_locks end with page alignment

Fix a memory leak on an OOM condition in prepare_usermodehelper_creds().
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
  ocfs2: Fix a race in o2dlm lockres mastery
  Ocfs2: Handle deletion of reflinked oprhan inodes correctly.
  Ocfs2: Journaling i_flags and i_orphaned_slot when adding inode to orphan dir.
  ocfs2: Clear undo bits when local alloc is freed
  ocfs2: Init meta_ac properly in ocfs2_create_empty_xattr_block.
  ocfs2: Fix the update of name_offset when removing xattrs
  ocfs2: Always try for maximum bits with new local alloc windows
  ocfs2: set i_mode on disk during acl operations
  ocfs2: Update i_blocks in reflink operations.
  ocfs2: Change bg_chain check for ocfs2_validate_gd_parent.
  [PATCH] Skip check for mandatory locks when unlocking

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (28 commits)
  ceph: update discussion list address in MAINTAINERS
  ceph: some documentations fixes
  ceph: fix use after free on mds __unregister_request
  ceph: avoid loaded term 'OSD' in documention
  ceph: fix possible double-free of mds request reference
  ceph: fix session check on mds reply
  ceph: handle kmalloc() failure
  ceph: propagate mds session allocation failures to caller
  ceph: make write_begin wait propagate ERESTARTSYS
  ceph: fix snap rebuild condition
  ceph: avoid reopening osd connections when address hasn't changed
  ceph: rename r_sent_stamp r_stamp
  ceph: fix connection fault con_work reentrancy problem
  ceph: prevent dup stale messages to console for restarting mds
  ceph: fix pg pool decoding from incremental osdmap update
  ceph: fix mds sync() race with completing requests
  ceph: only release unused caps with mds requests
  ceph: clean up handle_cap_grant, handle_caps wrt session mutex
  ceph: fix session locking in handle_caps, ceph_check_caps
  ceph: drop unnecessary WARN_ON in caps migration
  ...

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  hwmon: (asc7621) Add X58 entry in Kconfig
  hwmon: (w83793) Saving negative errors in unsigned
  hwmon: (coretemp) Add missing newline to dev_warn() message
  hwmon: (coretemp) Fix cpu model output

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  pata_via: fix VT6410/6415/6330 detection issue

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (33 commits)
  r8169: offical fix for CVE-2009-4537 (overlength frame DMAs)
  ipv6: Don't drop cache route entry unless timer actually expired.
  tulip: Add missing parens.
  r8169: fix broken register writes
  pcnet_cs: add new id
  bonding: fix broken multicast with round-robin mode
  drivers/net: Fix continuation lines
  e1000: do not modify tx_queue_len on link speed change
  net: ipmr/ip6mr: prevent out-of-bounds vif_table access
  ixgbe: Do not run all Diagnostic offline tests when VFs are active
  igb: use correct bits to identify if managability is enabled
  benet: Fix compile warnnings in drivers/net/benet/be_ethtool.c
  net: Add MSG_WAITFORONE flag to recvmmsg
  e1000e: do not modify tx_queue_len on link speed change
  igbvf: do not modify tx_queue_len on link speed change
  ipv4: Restart rt_intern_hash after emergency rebuild (v2)
  ipv4: Cleanup struct net dereference in rt_intern_hash
  net: fix netlink address dumping in IPv4/IPv6
  tulip: Fix null dereference in uli526x_rx_packet()
  gianfar: fix undo of reserve()
  ...

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc64: Properly truncate pt_regs framepointer in perf callback.
  arch/sparc/kernel: Use set_cpus_allowed_ptr
  sparc: Fix use of uid16_t and gid16_t in asm/stat.h

In commit 9df93939 ("ext3: Use bitops to read/modify
EXT3_I(inode)->i_state") ext3 changed its internal 'i_state' variable to
use bitops for its state handling.  However, unline the same ext4
change, it didn't actually change the name of the field when it changed
the semantics of it.

As a result, an old use of 'i_state' remained in fs/ext3/ialloc.c that
initialized the field to EXT3_STATE_NEW.  And that does not work
_at_all_ when we're now working with individually named bits rather than
values that get masked.  So the code tried to mark the state to be new,
but in actual fact set the field to EXT3_STATE_JDATA.  Which makes no
sense at all, and screws up all the code that checks whether the inode
was newly allocated.

In particular, it made the xattr code unhappy, and caused various random
behavior, like apparently

	https://bugzilla.redhat.com/show_bug.cgi?id=577911

So fix the initialization, and rename the field to match ext4 so that we
don't have this happen again.

Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Daniel J Walsh <dwalsh@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Official patch to fix the r8169 frame length check error.

Based on this initial thread:
http://marc.info/?l=linux-netdev&m=126202972828626&w=1
This is the official patch to fix the frame length problems in the r8169
driver.  As noted in the previous thread, while this patch incurs a performance
hit on the driver, its possible to improve performance dynamically by updating
the mtu and rx_copybreak values at runtime to return performance to what it was
for those NICS which are unaffected by the ideosyncracy (if there are any).

Summary:

    A while back Eric submitted a patch for r8169 in which the proper
allocated frame size was written to RXMaxSize to prevent the NIC from dmaing too
much data.  This was done in commit fdd7b4c3.  A
long time prior to that however, Francois posted
126fa4b9, which expiclitly disabled the MaxSize
setting due to the fact that the hardware behaved in odd ways when overlong
frames were received on NIC's supported by this driver.  This was mentioned in a
security conference recently:
http://events.ccc.de/congress/2009/Fahrplan//events/3596.en.html

It seems that if we can't enable frame size filtering, then, as Eric correctly
noticed, we can find ourselves DMA-ing too much data to a buffer, causing
corruption.  As a result is seems that we are forced to allocate a frame which
is ready to handle a maximally sized receive.

This obviously has performance issues with it, so to mitigate that issue, this
patch does two things:

1) Raises the copybreak value to the frame allocation size, which should force
appropriately sized packets to get allocated on rx, rather than a full new 16k
buffer.

2) This patch only disables frame filtering initially (i.e., during the NIC
open), changing the MTU results in ring buffer allocation of a size in relation
to the new mtu (along with a warning indicating that this is dangerous).

Because of item (2), individuals who can't cope with the performance hit (or can
otherwise filter frames to prevent the bug), or who have hardware they are sure
is unaffected by this issue, can manually lower the copybreak and reset the mtu
such that performance is restored easily.
Signed-off-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For 32-bit processes, we save the full 64-bits of the regs in pt_regs.

But unlike when the userspace actually does load and store
instructions, the top 32-bits don't get automatically truncated by the
cpu in kernel mode (because the kernel doesn't execute with PSTATE_AM
address masking enabled).

So we have to do it by hand.
Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Intel X58 have asc7621a chip. So added X58 entry in Kconfig for asc7621.
Also arranged existing models in ascending order.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

"ret" is used to store the return value for watchdog_trigger() and it
should be signed for the error handling to work.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Add missing newline to dev_warn() message string. This is more of an issue
with older kernels that don't automatically add a newline if it was missing
from the end of the previous line.
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Avoid hex and decimal confusion when printing out the cpu model.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

If the device contains on old logfs image and the journal is moved to
segment that have never been used by the current logfs and not all
journal segments are erased before the next mount, the old content can
confuse mount code.  To prevent this, always erase the new journal
segments.
Signed-off-by: Joern Engel <joern@logfs.org>

Fixes a GC livelock.
Signed-off-by: Joern Engel <joern@logfs.org>

This avoids an infinite loop in free_early_partial().

Add a warning to free_early_partial() to catch future problems.

-v5: put back start > end back into WARN_ONCE()
-v6: use one line for warning, suggested by Linus
-v7: more tests
-v8: remove the function name as suggested by Johannes
     WARN_ONCE() will print out that function name.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Joel Becker <joel.becker@oracle.com>
Tested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-4-git-send-email-yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or
in a more compact fashion.

Example:

 Allocated new RAMDISK: 00ec2000 - 0248ce57
 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56

The new RAMDISK's end is not page aligned.
Last page could be shared with other users.

When free_init_pages are called for initrd or .init, the page
could be freed and we could corrupt other data.

code segment in free_init_pages():

 |        for (; addr < end; addr += PAGE_SIZE) {
 |                ClearPageReserved(virt_to_page(addr));
 |                init_page_count(virt_to_page(addr));
 |                memset((void *)(addr & ~(PAGE_SIZE-1)),
 |                        POISON_FREE_INITMEM, PAGE_SIZE);
 |                free_page(addr);
 |                totalram_pages++;
 |        }

last half page could be used as one whole free page.

So page align the boundaries.

-v2: make the original initramdisk to be aligned, according to
     Johannes, otherwise we have the chance to lose one page.
     we still need to keep initrd_end not aligned, otherwise it could
     confuse decompressor.
-v3: change to WARN_ON instead, suggested by Johannes.
-v4: use PAGE_ALIGN, suggested by Johannes.
     We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN
     Add comments about assuming ramdisk start is aligned
     in relocate_initrd(), change to re get ramdisk_image instead of save it
     to make diff smaller. Add warning for wrong range, suggested by Johannes.
-v6: remove one WARN()
     We need to align beginning in free_init_pages()
     do not copy more than ramdisk_size, noticed by Johannes
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Signed-off-by: Sage Weil <sage@newdream.net>

New documentation should have an entry in the 00-INDEX.  Correct git
urls.
Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>