svcrdma's current SQ accounting algorithm takes sc_lock and disables
bottom-halves while posting all RDMA Read, Write, and Send WRs.

This is relatively heavyweight serialization. And note that Write and
Send are already fully serialized by the xpt_mutex.

Using a single atomic_t should be all that is necessary to guarantee
that ib_post_send() is called only when there is enough space on the
send queue. This is what the other RDMA-enabled storage targets do.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The current sendto code appears to support clients that provide only
one of a Read list, a Write list, or a Reply chunk. My reading of
that code is that it doesn't support the following cases:

 - Read list + Write list
 - Read list + Reply chunk
 - Write list + Reply chunk
 - Read list + Write list + Reply chunk

The protocol allows more than one Read or Write chunk in those
lists. Some clients do send a Read list and Reply chunk
simultaneously. NFSv4 WRITE uses a Read list for the data payload,
and a Reply chunk because the GETATTR result in the reply can
contain a large object like an ACL.

Generalize one of the sendto code paths needed to support all of
the above cases, and attempt to ensure that only one pass is done
through the RPC Call's transport header to gather chunk list
information for building the reply.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

S5.3.3.1 of RFC 2203 requires that an incoming GSS-wrapped message
whose sequence number lies outside the current window is dropped.
The rationale is:

  The reason for discarding requests silently is that the server
  is unable to determine if the duplicate or out of range request
  was due to a sequencing problem in the client, network, or the
  operating system, or due to some quirk in routing, or a replay
  attack by an intruder.  Discarding the request allows the client
  to recover after timing out, if indeed the duplication was
  unintentional or well intended.

However, clients may rely on the server dropping the connection to
indicate that a retransmit is needed. Without a connection reset, a
client can wait forever without retransmitting, and the workload
just stops dead. I've reproduced this behavior by running xfstests
generic/323 on an NFSv4.0 mount with proto=rdma and sec=krb5i.

To address this issue, have the server close the connection when it
silently discards an incoming message due to a GSS sequence number
problem.

There are a few other places where the server will never reply.
Change those spots in a similar fashion.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Logic copied from xs_setup_bc_tcp().

Fixes: 39a9beab ('rpc: share one xps between all backchannels')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

reply_cache_stats_operations, of type struct file_operations, is never
modified, so declare it as const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

No real change in functionality, but the old interface seems to be
deprecated.

We don't actually care about ordering necessarily, but we do depend on
running at most one work item at a time: nfsd4_process_cb_update()
assumes that no other thread is running it, and that no new callbacks
are starting while it's running.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Writes may depend on the auth_gss crypto code, so we shouldn't be
allocating with GFP_KERNEL there.

This still leaves some crypto_alloc_* calls which end up doing
GFP_KERNEL allocations in the crypto code.  Those could probably done at
crypto import time.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

3c8e0316 "NFSv4: do exact check about attribute specified" fixed
some handling of unsupported-attribute errors, but it also delayed
checking for unwriteable attributes till after we decode them.  This
could lead to odd behavior in the case a client attemps to set an
attribute we don't know about followed by one we try to parse.  In that
case the parser for the known attribute will attempt to parse the
unknown attribute.  It should fail in some safe way, but the error might
at least be incorrect (probably bad_xdr instead of inval).  So, it's
better to do that check at the start.

As far as I know this doesn't cause any problems with current clients
but it might be a minor issue e.g. if we encounter a future client that
supports a new attribute that we currently don't.

Cc: Yu Zhiguo <yuzg@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Minor cleanup, no change in behavior.

Provide helpers for some common attribute bitmap operations.  Drop some
comments that just echo the code.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Currently, when the client continually returns NFS4ERR_DELAY on a
CB_LAYOUTRECALL, we'll give up trying to retransmit after two lease
periods, but leave the layout in place.

What we really need to do here is fence the client in this case. Have it
fall through to that code in that case instead of into the
NFS4ERR_NOMATCHING_LAYOUT case.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Currently, we try to allocate the cache as a single, large chunk, which
can fail if no big chunks of memory are available. We _do_ try to size
it according to the amount of memory in the box, but if the server is
started well after boot time, then the allocation can fail due to memory
fragmentation.

Fall back to doing a vzalloc if the kcalloc fails, and switch the
shutdown code to do a kvfree to handle freeing correctly.
Reported-by: Olaf Hering <olaf@aepfle.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

When I push NFSv4.1 / RDMA hard, (xfstests generic/089, for example),
I get this crash on the server:

Oct 28 22:04:30 klimt kernel: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
Oct 28 22:04:30 klimt kernel: Modules linked in: cts rpcsec_gss_krb5 iTCO_wdt iTCO_vendor_support sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm btrfs irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd xor pcspkr raid6_pq i2c_i801 i2c_smbus lpc_ich mfd_core sg mei_me mei ioatdma shpchp wmi ipmi_si ipmi_msghandler rpcrdma ib_ipoib rdma_ucm acpi_power_meter acpi_pad ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb ahci libahci ptp mlx4_core pps_core dca libata i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod
Oct 28 22:04:30 klimt kernel: CPU: 7 PID: 1558 Comm: nfsd Not tainted 4.9.0-rc2-00005-g82cd754 #8
Oct 28 22:04:30 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Oct 28 22:04:30 klimt kernel: task: ffff880835c3a100 task.stack: ffff8808420d8000
Oct 28 22:04:30 klimt kernel: RIP: 0010:[<ffffffffa05a759f>]  [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP: 0018:ffff8808420dbce0  EFLAGS: 00010246
Oct 28 22:04:30 klimt kernel: RAX: ffff88084e6660f0 RBX: ffff88084e667020 RCX: 0000000000000000
Oct 28 22:04:30 klimt kernel: RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff88084e667020
Oct 28 22:04:30 klimt kernel: RBP: ffff8808420dbcf8 R08: 0000000000000001 R09: 0000000000000000
Oct 28 22:04:30 klimt kernel: R10: ffff880835c3a100 R11: ffff880835c3aca8 R12: 6b6b6b6b6b6b6b6b
Oct 28 22:04:30 klimt kernel: R13: ffff88084e6670d8 R14: ffff880835f546f0 R15: ffff880835f1c548
Oct 28 22:04:30 klimt kernel: FS:  0000000000000000(0000) GS:ffff88087bdc0000(0000) knlGS:0000000000000000
Oct 28 22:04:30 klimt kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 28 22:04:30 klimt kernel: CR2: 00007ff020389000 CR3: 0000000001c06000 CR4: 00000000001406e0
Oct 28 22:04:30 klimt kernel: Stack:
Oct 28 22:04:30 klimt kernel: ffff88084e667020 0000000000000000 ffff88084e6670d8 ffff8808420dbd20
Oct 28 22:04:30 klimt kernel: ffffffffa05ac80d ffff880835f54548 ffff88084e640008 ffff880835f545b0
Oct 28 22:04:30 klimt kernel: ffff8808420dbd70 ffffffffa059803d ffff880835f1c768 0000000000000870
Oct 28 22:04:30 klimt kernel: Call Trace:
Oct 28 22:04:30 klimt kernel: [<ffffffffa05ac80d>] nfsd4_free_stateid+0xfd/0x1b0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa059803d>] nfsd4_proc_compound+0x40d/0x690 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa0583114>] nfsd_dispatch+0xd4/0x1d0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa047bbf9>] svc_process_common+0x3d9/0x700 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<ffffffffa047ca64>] svc_process+0xf4/0x330 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<ffffffffa05827ca>] nfsd+0xfa/0x160 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa05826d0>] ? nfsd_destroy+0x170/0x170 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffff810b367b>] kthread+0x10b/0x120
Oct 28 22:04:30 klimt kernel: [<ffffffff810b3570>] ? kthread_stop+0x280/0x280
Oct 28 22:04:30 klimt kernel: [<ffffffff8174e8ba>] ret_from_fork+0x2a/0x40
Oct 28 22:04:30 klimt kernel: Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 48 8b 87 b0 00 00 00 48 89 fb 4c 8b a0 98 00 00 00 <49> 8b 44 24 20 48 8d b8 80 03 00 00 e8 10 66 1a e1 48 89 df e8
Oct 28 22:04:30 klimt kernel: RIP  [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP <ffff8808420dbce0>
Oct 28 22:04:30 klimt kernel: ---[ end trace cf5d0b371973e167 ]---

Jeff Layton says:
> Hm...now that I look though, this is a little suspicious:
>
>    struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner);
>
> I wonder if it's possible for the openstateid to have already been
> destroyed at this point.
>
> We might be better off doing something like this to get the client pointer:
>
>    stp->st_stid.sc_client;
>
> ...which should be more direct and less dependent on other stateids
> staying valid.

With the suggested change, I am no longer able to reproduce the above oops.

v2: Fix unhash_lock_stateid() as well
Fix-suggested-by: Jeff Layton <jlayton@redhat.com>
Fixes: 42691398 ('nfsd: Fix race between FREE_STATEID and LOCK')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The underlying transport releases the page pointed to by rq_buffer
during xprt_rdma_bc_send_request. When the backchannel reply arrives,
rq_rbuffer then points to freed memory.

Fixes: 68778945 ('SUNRPC: Separate buffer pointers for RPC ...')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We've been seeing some crashes in testing that look like this:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8135ce99>] memcpy_orig+0x29/0x110
PGD 212ca2067 PUD 212ca3067 PMD 0
Oops: 0002 [#1] SMP
Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ppdev parport_pc i2c_piix4 sg parport i2c_core virtio_balloon pcspkr acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod ata_generic pata_acpi virtio_scsi 8139too ata_piix libata 8139cp mii virtio_pci floppy virtio_ring serio_raw virtio
CPU: 1 PID: 1540 Comm: nfsd Not tainted 4.9.0-rc1 #39
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
task: ffff88020d7ed200 task.stack: ffff880211838000
RIP: 0010:[<ffffffff8135ce99>]  [<ffffffff8135ce99>] memcpy_orig+0x29/0x110
RSP: 0018:ffff88021183bdd0  EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffff88020d7fa000 RCX: 000000f400000000
RDX: 0000000000000014 RSI: ffff880212927020 RDI: 0000000000000000
RBP: ffff88021183be30 R08: 01000000ef896996 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff880211704ca8
R13: ffff88021473f000 R14: 00000000ef896996 R15: ffff880211704800
FS:  0000000000000000(0000) GS:ffff88021fc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000212ca1000 CR4: 00000000000006e0
Stack:
 ffffffffa01ea087 ffffffff63400001 ffff880215145e00 ffff880211bacd00
 ffff88021473f2b8 0000000000000004 00000000d0679d67 ffff880211bacd00
 ffff88020d7fa000 ffff88021473f000 0000000000000000 ffff88020d7faa30
Call Trace:
 [<ffffffffa01ea087>] ? svc_tcp_recvfrom+0x5a7/0x790 [sunrpc]
 [<ffffffffa01f84d8>] svc_recv+0xad8/0xbd0 [sunrpc]
 [<ffffffffa0262d5e>] nfsd+0xde/0x160 [nfsd]
 [<ffffffffa0262c80>] ? nfsd_destroy+0x60/0x60 [nfsd]
 [<ffffffff810a9418>] kthread+0xd8/0xf0
 [<ffffffff816dbdbf>] ret_from_fork+0x1f/0x40
 [<ffffffff810a9340>] ? kthread_park+0x60/0x60
Code: 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe 7c 35 48 83 ea 20 48 83 ea 20 4c 8b 06 4c 8b 4e 08 4c 8b 56 10 4c 8b 5e 18 48 8d 76 20 <4c> 89 07 4c 89 4f 08 4c 89 57 10 4c 89 5f 18 48 8d 7f 20 73 d4
RIP  [<ffffffff8135ce99>] memcpy_orig+0x29/0x110
 RSP <ffff88021183bdd0>
CR2: 0000000000000000

Both Bruce and Eryu ran a bisect here and found that the problematic
patch was 68778945 (SUNRPC: Separate buffer pointers for RPC Call and
Reply messages).

That patch changed rpc_xdr_encode to use a new rq_rbuffer pointer to
set up the receive buffer, but didn't change all of the necessary
codepaths to set it properly. In particular the backchannel setup was
missing.

We need to set rq_rbuffer whenever rq_buffer is set. Ensure that it is.
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Reported-by: Eryu Guan <guaneryu@gmail.com>
Tested-by: Eryu Guan <guaneryu@gmail.com>
Fixes: 68778945 "SUNRPC: Separate buffer pointers..."
Reported-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

As of ac4e97ab "scatterlist: sg_set_buf() argument must be in linear
mapping", sg_set_buf hits a BUG when make_checksum_v2->xdr_process_buf,
among other callers, passes it memory on the stack.

We only need a scatterlist to pass this to the crypto code, and it seems
like overkill to require kmalloc'd memory just to encrypt a few bytes,
but for now this seems the best fix.

Many of these callers are in the NFS write paths, so we allocate with
GFP_NOFS.  It might be possible to do without allocations here entirely,
but that would probably be a bigger project.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Bruce was hitting some lockdep warnings in testing, showing that we
could hit a deadlock with the new CB_NOTIFY_LOCK handling, involving a
rather complex situation involving four different spinlocks.

The crux of the matter is that we end up taking the nn->client_lock in
the lm_notify handler. The simplest fix is to just declare a new
per-nfsd_net spinlock to protect the new CB_NOTIFY_LOCK structures.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Pull UBI[FS] fixes from Richard Weinberger:
 "This contains fixes for issues in both UBI and UBIFS:

   - Fallout from the merge window, refactoring UBI code introduced some
     issues.

   - Fixes for an UBIFS readdir bug which can cause getdents() to busy
     loop for ever and a bug in the UBIFS xattr code"

* tag 'upstream-4.9-rc2' of git://git.infradead.org/linux-ubifs:
  ubifs: Abort readdir upon error
  UBI: Fix crash in try_recover_peb()
  ubi: fix swapped arguments to call to ubi_alloc_aeb
  ubifs: Fix xattr_names length in exit paths
  ubifs: Rename ubifs_rename2

Pull ext4 fixes from Ted Ts'o:
 "A few bug fixes and add some missing KERN_CONT annotations"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: add missing KERN_CONT to a few more debugging uses
  fscrypto: lock inode while setting encryption policy
  ext4: correct endianness conversion in __xattr_check_inode()
  fscrypto: make XTS tweak initialization endian-independent
  ext4: do not advertise encryption support when disabled
  jbd2: fix incorrect unlock on j_list_lock
  ext4: super.c: Update logging style using KERN_CONT

Pull SCSI target fixes from Nicholas Bellinger:
 "Here are the outstanding target-pending fixes for v4.9-rc2.

  This includes:

   - Fix v4.1.y+ reference leak regression with concurrent TMR
     ABORT_TASK + session shutdown. (Vaibhav Tandon)

   - Enable tcm_fc w/ SCF_USE_CPUID to avoid host exchange timeouts
     (Hannes)

   - target/user error sense handling fixes. (Andy + MNC + HCH)

   - Fix iscsi-target NOP_OUT error path iscsi_cmd descriptor leak
     (Varun)

   - Two EXTENDED_COPY SCSI status fixes for ESX VAAI (Dinesh Israni +
     Nixon Vincent)

   - Revert a v4.8 residual overflow change, that breaks sg_inq with
     small allocation lengths.

  There are a number of folks stress testing the v4.1.y regression fix
  in their environments, and more folks doing iser-target I/O stress
  testing atop recent v4.x.y code.

  There is also one v4.2.y+ RCU conversion regression related to
  explicit NodeACL configfs changes, that is still being tracked down"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target/tcm_fc: use CPU affinity for responses
  target/tcm_fc: Update debugging statements to match libfc usage
  target/tcm_fc: return detailed error in ft_sess_create()
  target/tcm_fc: print command pointer in debug message
  target: fix potential race window in target_sess_cmd_list_waiting()
  Revert "target: Fix residual overflow handling in target_complete_cmd_with_length"
  target: Don't override EXTENDED_COPY xcopy_pt_cmd SCSI status code
  target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE
  target: Re-add missing SCF_ACK_KREF assignment in v4.1.y
  iscsi-target: fix iscsi cmd leak
  iscsi-target: fix spelling mistake "Unsolicitied" -> "Unsolicited"
  target/user: Fix comments to not refer to data ring
  target/user: Return an error if cmd data size is too large
  target/user: Use sense_reason_t in tcmu_queue_cmd_ring

Merge tag 'hwmon-for-linus-v4.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Couple of hwmon fixes:

  Fix a potential ERR_PTR dereference in max31790 driver, and handle
  temperature readings below 0 in adm9240 driver"

* tag 'hwmon-for-linus-v4.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (max31790) potential ERR_PTR dereference
  hwmon: (adm9240) handle temperature readings below 0

Pull IPMI updates from Corey Minyard:
 "A small bug fix and a new driver for acting as an IPMI device.

  I was on vacation during the merge window (a long vacation) but this
  is a bug fix that should go in and a new driver that shouldn't hurt
  anything.

  This has been in linux-next for a month or so"

* tag 'for-linus-4.9-2' of git://git.code.sf.net/p/openipmi/linux-ipmi:
  ipmi: fix crash on reading version from proc after unregisted bmc
  ipmi/bt-bmc: remove redundant return value check of platform_get_resource()
  ipmi/bt-bmc: add a dependency on ARCH_ASPEED
  ipmi: Fix ioremap error handling in bt-bmc
  ipmi: add an Aspeed BT IPMI BMC driver

Pull timer updates from Thomas Gleixner:
 "This updates contains:

   - A revert which addresses a boot failure on ARM Sun5i platforms

   - A new clocksource driver, which has been delayed beyond rc1 due to
     an interrupt driver issue which was unearthed by this driver. The
     debugging of that issue and the discussion about the proper
     solution made this driver miss the merge window. There is no point
     in delaying it for a full cycle as it completes the basic mainline
     support for the new JCore platform and does not create any risk
     outside of that platform"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "clocksource/drivers/timer_sun5i: Replace code by clocksource_mmio_init"
  clocksource: Add J-Core timer/clocksource driver
  of: Add J-Core timer bindings

Pull x86 fixes from Ingo Molnar:
 "Three fixes, a hw-enablement and a cross-arch fix/enablement change:

   - SGI/UV fix for older platforms

   - x32 signal handling fix

   - older x86 platform bootup APIC fix

   - AVX512-4VNNIW (Neural Network Instructions) and AVX512-4FMAPS
     (Multiply Accumulation Single precision instructions) enablement.

   - move thread_info back into x86 specific code, to make life easier
     for other architectures trying to make use of
     CONFIG_THREAD_INFO_IN_TASK_STRUCT=y"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/smp: Don't try to poke disabled/non-existent APIC
  sched/core, x86: Make struct thread_info arch specific again
  x86/signal: Remove bogus user_64bit_mode() check from sigaction_compat_abi()
  x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates
  x86/cpufeature: Add AVX512_4VNNIW and AVX512_4FMAPS features
  x86/vmware: Skip timer_irq_works() check on VMware

Pull vmap stack fixes from Ingo Molnar:
 "This is fallout from CONFIG_HAVE_ARCH_VMAP_STACK=y on x86: stack
  accesses that used to be just somewhat questionable are now totally
  buggy.

  These changes try to do it without breaking the ABI: the fields are
  left there, they are just reporting zero, or reporting narrower
  information (the maps file change)"

* 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mm: Change vm_is_stack_for_task() to vm_is_stack_for_current()
  fs/proc: Stop trying to report thread stacks
  fs/proc: Stop reporting eip and esp in /proc/PID/stat
  mm/numa: Remove duplicated include from mprotect.c

Pull irq fixes from Ingo Molnar:
 "Mostly irqchip driver fixes, plus a symbol export"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kernel/irq: Export irq_set_parent()
  irqchip/gic: Add missing \n to CPU IF adjustment message
  irqchip/jcore: Don't show Kconfig menu item for driver
  irqchip/eznps: Drop pointless static qualifier in nps400_of_init()
  irqchip/gic-v3-its: Fix entry size mask for GITS_BASER
  irqchip/gic-v3-its: Fix 64bit GIC{R,ITS}_TYPER accesses

Pull EFI fixes from Ingo Molnar:
 "Add Ard Biesheuvel as EFI co-maintainer, plus fix an ARM build bug
  with older toolchains"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/arm: Fix absolute relocation detection for older toolchains
  MAINTAINERS: Add myself as EFI maintainer

Apparently trying to poke a disabled or non-existent APIC
leads to a box that doesn't even boot. Let's not do that.

No real clue if this is the right fix, but at least my
P3 machine boots again.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: dyoung@redhat.com
Cc: kexec@lists.infradead.org
Cc: stable@vger.kernel.org
Fixes: 2a51fe08 ("arch/x86: Handle non enumerated CPU after physical hotplug")
Link: http://lkml.kernel.org/r/1477102684-5092-1-git-send-email-ville.syrjala@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Pull powerpc fixes from Michael Ellerman:
 "Fixes marked for stable:
   - Prevent unlikely crash in copro_calculate_slb() (Frederic Barrat)
   - cxl: Prevent adapter reset if an active context exists (Vaibhav Jain)

  Fixes for code merged this cycle:
   - Fix boot on systems with uncompressed kernel image (Heiner Kallweit)
   - Drop dump_numa_memory_topology() (Michael Ellerman)
   - Fix numa topology console print (Aneesh Kumar K.V)
   - Ignore the pkey system calls for now (Stephen Rothwell)"

* tag 'powerpc-4.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Ignore the pkey system calls for now
  powerpc: Fix numa topology console print
  powerpc/mm: Drop dump_numa_memory_topology()
  cxl: Prevent adapter reset if an active context exists
  powerpc/boot: Fix boot on systems with uncompressed kernel image
  powerpc/mm: Prevent unlikely crash in copro_calculate_slb()

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - avoid livelock when walking guest page tables
   - fix HYP mode static keys without CC_HAVE_ASM_GOTO

  MIPS:
   - fix a build error without TRACEPOINTS_ENABLED

  s390:
   - reject a malformed userspace configuration

  x86:
   - suppress a warning without CONFIG_CPU_FREQ
   - initialize whole irq_eoi array"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  arm/arm64: KVM: Map the BSS at HYP
  arm64: KVM: Take S1 walks into account when determining S2 write faults
  KVM: s390: reject invalid modes for runtime instrumentation
  kvm: x86: memset whole irq_eoi
  kvm/x86: Fix unused variable warning in kvm_timer_init()
  KVM: MIPS: Add missing uaccess.h include

Pull NFS client bugfixes from Anna Schumaker:
 "Just two bugfixes this time:

  Stable bugfix:
   - Fix last_write_offset incorrectly set to page boundary

  Other bugfix:
   - Fix missing-braces warning"

* tag 'nfs-for-4.9-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  nfs4: fix missing-braces warning
  pnfs/blocklayout: fix last_write_offset incorrectly set to page boundary

Pull ACPI fixes from Rafael Wysocki:
 "These fix an issue related to system resume in the new WDAT-based
  watchdog driver and a return value of a stub function in the ACPI CPPC
  framework.

  Specifics:

   - Update the ACPI WDAT-based watchdog driver to ping the hardware
     during system resume to prevent a reset from occurring after the
     resume is complete (Mika Westerberg).

   - Fix the return value of the pcc_mbox_request_channel() stub for
     CONFIG_PCC unset (Hoan Tran)"

* tag 'acpi-4.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  watchdog: wdat_wdt: Ping the watchdog on resume
  mailbox: PCC: Fix return value of pcc_mbox_request_channel()

* acpi-wdat:
  watchdog: wdat_wdt: Ping the watchdog on resume

* acpi-cppc:
  mailbox: PCC: Fix return value of pcc_mbox_request_channel()

Merge tag 'gic-fixes-for-4.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull GIC updates from Marc Zyngier:

 - Fix for 32bit accesses that should be 64bit on 64bit machines
 - Fix for a field decoding macro
 - Beautify a warning message

Pull SCSI fixes from James Bottomley:
 "Five small fixes.

  Some of these, like the nested spinlock overwriting saved flags and
  the Kasan use after free look serious, but they seem not to have been
  picked up in testing or seen in the field.

  The biggest user visible issue is probably the wrong device handler
  for Clariion, which means that alua doesn't bind to the array like it
  should"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ipr: Fix async error WARN_ON
  scsi: zfcp: spin_lock_irqsave() is not nestable
  scsi: Remove one useless stack variable
  scsi: Fix use-after-free
  scsi: Replace wrong device handler name for CLARiiON arrays

Pull block fixes from Jens Axboe:
 "A set of fixes that missed the merge window, mostly due to me being
  away around that time.

  Nothing major here, a mix of nvme cleanups and fixes, and one fix for
  the badblocks handling"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvmet: use symbolic constants for CNS values
  nvme: use symbolic constants for CNS values
  nvme.h: add an enum for cns values
  nvme.h: don't use uuid_be
  nvme.h: resync with nvme-cli
  nvme: Add tertiary number to NVME_VS
  nvme : Add sysfs entry for NVMe CMBs when appropriate
  nvme: don't schedule multiple resets
  nvme: Delete created IO queues on reset
  nvme: Stop probing a removed device
  badblocks: fix overlapping check for clearing

Pull PCI fixes from Bjorn Helgaas:
 "This includes:

   - Fix for a Layerscape driver issue that causes a use-before-set
     crash

   - Maintainer update for the Synopsis prototyping device driver"

* tag 'pci-v4.9-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: designware-plat: Update author email address
  PCI: layerscape: Fix drvdata usage before assignment
  PCI: designware-plat: Change maintainer to Jose Abreu

KVM/ARM updates for 4.9-rc2

- Handle faults generated by the page table walker as being writes
- Map the BSS at EL2

When used with a compiler that doesn't implement "asm goto"
(such as the AArch64 port of GCC 4.8), jump labels generate a
memory access to find out about the value of the key (instead
of just patching the code). The key itself is likely to be
stored in the BSS.

This is perfectly fine, except that we don't map the BSS at HYP,
leading to an exploding kernel at the first access. The obvious
fix is simply to map the BSS there (which should have been done
a long while ago, but hey...).
Reported-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

The WnR bit in the HSR/ESR_EL2 indicates whether a data abort was
generated by a read or a write instruction. For stage 2 data aborts
generated by a stage 1 translation table walk (i.e. the actual page
table access faults at EL2), the WnR bit therefore reports whether the
instruction generating the walk was a load or a store, *not* whether the
page table walker was reading or writing the entry.

For page tables marked as read-only at stage 2 (e.g. due to KSM merging
them with the tables from another guest), this could result in livelock,
where a page table walk generated by a load instruction attempts to
set the access flag in the stage 1 descriptor, but fails to trigger
CoW in the host since only a read fault is reported.

This patch modifies the arm64 kvm_vcpu_dabt_iswrite function to
take into account stage 2 faults in stage 1 walks. Since DBM cannot be
disabled at EL2 for CPUs that implement it, we assume that these faults
are always causes by writes, avoiding the livelock situation at the
expense of occasional, spurious CoWs.

We could, in theory, do a bit better by checking the guest TCR
configuration and inspecting the page table to see why the PTE faulted.
However, I doubt this is measurable in practice, and the threat of
livelock is real.

Cc: <stable@vger.kernel.org>
Cc: Julien Grall <julien.grall@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>