Add a method to reset the audit_lost value.

An AUDIT_SET message with the AUDIT_STATUS_LOST flag set by itself
will return a positive value repesenting the current audit_lost value
and reset the counter to zero.  If AUDIT_STATUS_LOST is not the
only flag set, the reset command will be ignored.  The value sent with
the command is ignored.  The return value will be the +ve lost value at
reset time.

An AUDIT_CONFIG_CHANGE message will be queued to the listening audit
daemon.  The message will be a standard CONFIG_CHANGE message with the
fields "lost=0" and "old=" with the latter containing the value of
audit_lost at reset time.

See: https://github.com/linux-audit/audit-kernel/issues/3Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

The audit event specification asks for certain fields to exist in
all events. Running 'ausearch -m anom_abend -sv yes' returns no
events. This patch adds the result field so that the
AUDIT_ANOM_ABEND event conforms to the rules.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

The AUDIT_KERNEL event is not following name=value format. This causes
some information to get lost. The event has been reformatted to follow
the convention. Additionally the audit_enabled value was added for
troubleshooting purposes. The following is an example of the new event:

  type=KERNEL audit(1480621249.833:1): state=initialized
              audit_enabled=0 res=1
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
[PM: commit tweaks to make checkpatch.pl happy]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Resetting audit_sock appears to be racy.

audit_sock was being copied and dereferenced without using a refcount on
the source sock.

Bump the refcount on the underlying sock when we store a refrence in
audit_sock and release it when we reset audit_sock.  audit_sock
modification needs the audit_cmd_mutex.

See: https://lkml.org/lkml/2016/11/26/232

Thanks to Eric Dumazet <edumazet@google.com> and Cong Wang
<xiyou.wangcong@gmail.com> on ideas how to fix it.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
[PM: fixed the comment block text formatting for auditd_reset()]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Bring back commit bc51dddf ("netns: avoid disabling irq for netns
id") now that we've fixed some audit multicast issues that caused
problems with original attempt.  Additional information, and history,
can be found in the links below:

 * https://github.com/linux-audit/audit-kernel/issues/22
 * https://github.com/linux-audit/audit-kernel/issues/23Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Sleeping on a command record/message in audit_log_start() could slow
something, e.g. auditd, from doing something important, e.g. clean
shutdown, which could present problems on a heavily loaded system.
This patch allows tasks to bypass any queue restrictions if they are
logging a command record/message.
Signed-off-by: Paul Moore <paul@paul-moore.com>

When auditd stops cleanly it sets 'auditd_pid' to 0 with an
AUDIT_SET message, in this case we should reset our backlog
queues via the auditd_reset() function.  This patch also adds
a 'auditd_pid' check to the top of kauditd_send_unicast_skb()
so we can fail quicker.
Signed-off-by: Paul Moore <paul@paul-moore.com>

This patch was suggested by Richard Briggs back in 2015, see the link
to the mail archive below.  Unfortunately, that patch is no longer
even remotely valid due to other changes to the code.

* https://www.redhat.com/archives/linux-audit/2015-October/msg00075.htmlSuggested-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

The backlog queue handling in audit_log_start() is a little odd with
some questionable design decisions, this patch attempts to rectify
this with the following changes:

* Never make auditd wait, ignore any backlog limits as we need auditd
awake so it can drain the backlog queue.

* When we hit a backlog limit and start dropping records, don't wake
all the tasks sleeping on the backlog, that's silly.  Instead, let
kauditd_thread() take care of waking everyone once it has had a chance
to drain the backlog queue.

* Don't keep a global backlog timeout countdown, make it per-task.  A
per-task timer means we won't have all the sleeping tasks waking at
the same time and hammering on an already stressed backlog queue.
Signed-off-by: Paul Moore <paul@paul-moore.com>

The audit record backlog queue has always been a bit of a mess, and
the moving the multicast send into kauditd_thread() from
audit_log_end() only makes things worse.  This patch attempts to fix
the backlog queue with a better design that should hold up better
under load and have less of a performance impact at syscall
invocation time.

While it looks like there is a log going on in this patch, the main
change is the move from a single backlog queue to three queues:

* A queue for holding records generated from audit_log_end() that
haven't been consumed by kauditd_thread() (audit_queue).

* A queue for holding records that have been sent via multicast but
had a temporary failure when sending via unicast and need a resend
(audit_retry_queue).

* A queue for holding records that haven't been sent via unicast
because no one is listening (audit_hold_queue).

Special care is taken in this patch to ensure that the proper
record ordering is preserved, e.g. we send everything in the hold
queue first, then the retry queue, and finally the main queue.
Signed-off-by: Paul Moore <paul@paul-moore.com>

The audit queue names can be shortened and the record sending
helpers associated with the kauditd task could be named better, do
these small cleanups now to make life easier once we start reworking
the queues and kauditd code.
Signed-off-by: Paul Moore <paul@paul-moore.com>

Sending audit netlink multicast messages is bad for all the same
reasons that sending audit netlink unicast messages is bad, so this
patch reworks things so that we don't do the multicast send in
audit_log_end(), we do it from the dedicated kauditd_thread thread just
as we do for unicast messages.

See the GitHub issues below for more information/history:

 * https://github.com/linux-audit/audit-kernel/issues/23
 * https://github.com/linux-audit/audit-kernel/issues/22Signed-off-by: Paul Moore <paul@paul-moore.com>

Make sure everything is initialized before we start the kauditd_thread
and don't emit the "initialized" record until everything is finished.
We also panic with a descriptive message if we can't start the
kauditd_thread.
Signed-off-by: Paul Moore <paul@paul-moore.com>

Richard made this change some time ago but Eric backed it out because
the rest of the supporting code wasn't ready.  In order to move the
netlink multicast send to kauditd_thread we need to ensure the
kauditd_thread is always running, so restore commit 6ff5e459 ("audit:
move kaudit thread start from auditd registration to kaudit init").
Signed-off-by: Richard Guy Briggs <rbriggs@redhat.com>
[PM: brought forward and merged based on Richard's old patch]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Define AUDIT_SESSIONID in the uapi and add support for specifying user
filters based on the session ID.  Also add the new session ID filter
to the feature bitmap so userspace knows it is available.

https://github.com/linux-audit/audit-kernel/issues/4
RFE: add a session ID filter to the kernel's user filter
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: combine multiple patches from Richard into this one]
Signed-off-by: Paul Moore <paul@paul-moore.com>

The AUDIT_CONFIG_CHANGE events sometimes use a op= field. The current
code logs the value of the field with quotes. This field is documented
to not be encoded, so it should not have quotes.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
[PM: reformatted commit description to make checkpatch.pl happy]
Signed-off-by: Paul Moore <paul@paul-moore.com>

The value (unsigned int)-1 is used as a sentinel to indicate the
sessionID is unset.  Skip this value when the session_id value wraps.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Tame initialization warning of len_abuf in audit_log_execve_info even
though there isn't presently a bug introduced by commit 43761473
("audit: fix a double fetch in audit_log_single_execve_arg()").  Using
UNINITIALIZED_VAR instead may mask future bugs.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

%u requires 10 characters at most not 20.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Pull ARM fixes from Russell King:
 "Three relatively small fixes for ARM:

   - Roger noticed that dma_max_pfn() was calculating the upper limit
     wrongly, by adding the PFN offset of memory twice.

   - A fix from Robin to correct parsing of MPIDR values when the
     address size is larger than one BE32 unit.

   - A fix from Srinivas to ensure that we do not rely on the boot
     loader (or previous Linux kernel) setting the translation table
     base register a certain way in the decompressor, which can lead to
     crashes"

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7
  ARM: 8617/1: dma: fix dma_max_pfn()
  ARM: 8616/1: dt: Respect property size when parsing CPUs

If the bootloader uses the long descriptor format and jumps to
kernel decompressor code, TTBCR may not be in a right state.
Before enabling the MMU, it is required to clear the TTBCR.PD0
field to use TTBR0 for translation table walks.

The commit dbece458 ("ARM: 7501/1: decompressor:
reset ttbcr for VMSA ARMv7 cores") does the reset of TTBCR.N, but
doesn't consider all the bits for the size of TTBCR.N.

Clear TTBCR.PD0 field and reset all the three bits of TTBCR.N to
indicate the use of TTBR0 and the correct base address width.

Fixes: dbece458 ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull x86 fixes from Thomas Gleixner:
 "The last regression fixes for 4.8 final:

   - Two patches addressing the fallout of the CR4 optimizations which
     caused CR4-less machines to fail.

   - Fix the VDSO build on big endian machines

   - Take care of FPU initialization if no CPUID is available otherwise
     task struct size ends up being zero

   - Fix up context tracking in case load_gs_index fails"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Fix context tracking state warning when load_gs_index fails
  x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
  x86/vdso: Fix building on big endian host
  x86/boot: Fix another __read_cr4() case on 486
  x86/init: Fix cr4_init_shadow() on CR4-less machines

Pull MIPS fixes from Ralf Baechle:
 "Another round of fixes:

   - CM: Fix mips_cm_max_vp_width for non-MT kernels on MT systems
   - CPS: Avoid BUG() when offlining pre-r6 CPUs
   - DEC: Avoid gas warnings due to suspicious instruction scheduling by
     manually expanding assembler macros.
   - FTLB: Fix configuration by moving confiuguratoin after probing
   - FTLB: clear execution hazard after changing FTLB enable
   - Highmem: Fix detection of unsupported highmem with cache aliases
   - I6400: Don't touch FTLBP chicken bits
   - microMIPS: Fix BUILD_ROLLBACK_PROLOGUE
   - Malta: Fix IOCU disable switch read for MIPS64
   - Octeon: Fix probing of devices attached to GPIO lines
   - uprobes: Misc small fixes"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: CM: Fix mips_cm_max_vp_width for non-MT kernels on MT systems
  MIPS: Fix detection of unsupported highmem with cache aliases
  MIPS: Malta: Fix IOCU disable switch read for MIPS64
  MIPS: Fix BUILD_ROLLBACK_PROLOGUE for microMIPS
  MIPS: clear execution hazard after changing FTLB enable
  MIPS: Configure FTLB after probing TLB sizes from config4
  MIPS: Stop setting I6400 FTLBP
  MIPS: DEC: Avoid la pseudo-instruction in delay slots
  MIPS: Octeon: mark GPIO controller node not populated after IRQ init.
  MIPS: uprobes: fix use of uninitialised variable
  MIPS: uprobes: remove incorrect set_orig_insn
  MIPS: fix uretprobe implementation
  MIPS: smp-cps: Avoid BUG() when offlining pre-r6 CPUs

Pull sparc fixes from David Miller:

 1) Fix section mismatches in some builds, from Paul Gortmaker.

 2) Need to count huge zero page mappings when doing TSB sizing, from
    Mike Kravetz.

 3) Fix handing of cpu_possible_mask when nr_cpus module option is
    specified, from Atish Patra.

 4) Don't allocate irq stacks until nr_irqs has been processed, also
    from Atish Patra.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix non-SMP build.
  sparc64: Fix irq stack bootmem allocation.
  sparc64: Fix cpu_possible_mask if nr_cpus is set
  sparc64 mm: Fix more TSB sizing issues
  sparc64: fix section mismatch in find_numa_latencies_for_group

Pull networking fixes from David Miller:

 1) Fix wrong TCP checksums on MTU probing when checksum offloading is
    disabled, from Douglas Caetano dos Santos.

 2) Fix qdisc backlog updates in qfq and sfb schedulers, from Cong Wang.

 3) Route lookup flow key protocol value is wrong in ip6gre_xmit_other(),
    fix from Lance Richardson.

 4) Scheduling while atomic in multicast routing code of ipv4 and ipv6,
    fix from Nikolay Aleksandrov.

 5) Fix packet alignment in fec driver, from Eric Nelson.

 6) Fix perf regression in sctp due to struct layout and cache misses,
    from Xin Long.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock
  sctp: change to check peer prsctp_capable when using prsctp polices
  sctp: remove prsctp_param from sctp_chunk
  sctp: move sent_count to the memory hole in sctp_chunk
  tg3: Avoid NULL pointer dereference in tg3_io_error_detected()
  act_ife: Fix false encoding
  act_ife: Fix external mac header on encode
  VSOCK: Don't dec ack backlog twice for rejected connections
  Revert "net: ethernet: bcmgenet: use phydev from struct net_device"
  net: fec: align IP header in hardware
  net: fec: remove QUIRK_HAS_RACC from i.mx27
  net: fec: remove QUIRK_HAS_RACC from i.mx25
  ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route
  ip6_gre: fix flowi6_proto value in ip6gre_xmit_other()
  tcp: fix a compile error in DBGUNDO()
  tcp: fix wrong checksum calculation on MTU probing
  sch_sfb: keep backlog updated with qlen
  sch_qfq: keep backlog updated with qlen
  can: dev: fix deadlock reported after bus-off

When discovering the number of VPEs per core, smp_num_siblings will be
incorrect for kernels built without support for the MIPS MultiThreading
(MT) ASE running on systems which implement said ASE. This leads to
accesses to VPEs in secondary cores being performed incorrectly since
mips_cm_vp_id calculates the wrong ID to write to the local "other"
registers. Fix this by examining the number of VPEs in the core as
reported by the CM.

This patch presumes that the number of VPEs will be the same in each
core of the system. As this path only applies to systems with CM version
2.5 or lower, and this property is true of all such known systems, this
is likely to be fine but is described in a comment for good measure.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14338/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Pull SCSI fix from James Bottomley:
 "One final fix before 4.8.

  There was a memory leak triggered by turning scsi mq off due to the
  fact that we assume on host release that the already running hosts
  weren't mq based because that's the state of the global flag (even
  though they were).

  Fix it by tracking this on a per host host basis"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Avoid that toggling use_blk_mq triggers a memory leak

Pull input fix from Dmitry Torokhov:
 "One small change to make joydev (which is used by older games) to bind
  to devices that export Z axis but not X or Y (such as TRC rudder)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: joydev - recognize devices with Z axis as joysticks

Merge more fixes from Andrew Morton:
 "Three fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/linux/property.h: fix typo/compile error
  ocfs2: fix deadlock on mmapped page in ocfs2_write_begin_nolock()
  mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()

This fixes commit d76eebfa ("include/linux/property.h: fix build
issues with gcc-4.4.4").

With that commit we get the following compile error when using the
PROPERTY_ENTRY_INTEGER_ARRAY macro.

 include/linux/property.h:201:39: error: `u32_data' undeclared (first
                 use in this function)
  PROPERTY_ENTRY_INTEGER_ARRAY(_name_, u32, _val_)
                                       ^
 include/linux/property.h:193:17: note: in definition of macro
                 `PROPERTY_ENTRY_INTEGER_ARRAY'
  { .pointer = { _type_##_data = _val_ } },  \
                 ^

This needs a '.' to reference the union member.  It seems this was just
overlooked here since it is done correctly in similar constructs in
other parts of the original commit.

This fix is in preparation of upcoming commits that will use this macro.

Fixes: commit d76eebfa ("include/linux/property.h: fix build issues with gcc-4.4.4")
Link: http://lkml.kernel.org/r/2de3b929290d88a723ed829a3e3cbd02044714df.1475114627.git.johnyoun@synopsys.comSigned-off-by: John Youn <johnyoun@synopsys.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The testcase "mmaptruncate" of ocfs2-test deadlocks occasionally.

In this testcase, we create a 2*CLUSTER_SIZE file and mmap() on it;
there are 2 process repeatedly performing the following operations
respectively: one is doing memset(mmaped_addr + 2*CLUSTER_SIZE - 1, 'a',
1), while the another is playing ftruncate(fd, 2*CLUSTER_SIZE) and then
ftruncate(fd, CLUSTER_SIZE) again and again.

This is the backtrace when the deadlock happens:

   __wait_on_bit_lock+0x50/0xa0
   __lock_page+0xb7/0xc0
   ocfs2_write_begin_nolock+0x163f/0x1790 [ocfs2]
   ocfs2_page_mkwrite+0x1c7/0x2a0 [ocfs2]
   do_page_mkwrite+0x66/0xc0
   handle_mm_fault+0x685/0x1350
   __do_page_fault+0x1d8/0x4d0
   trace_do_page_fault+0x37/0xf0
   do_async_page_fault+0x19/0x70
   async_page_fault+0x28/0x30

In ocfs2_write_begin_nolock(), we first grab the pages and then allocate
disk space for this write; ocfs2_try_to_free_truncate_log() will be
called if -ENOSPC is returned; if we're lucky to get enough clusters,
which is usually the case, we start over again.

But in ocfs2_free_write_ctxt() the target page isn't unlocked, so we
will deadlock when trying to grab the target page again.

Also, -ENOMEM might be returned in ocfs2_grab_pages_for_write().
Another deadlock will happen in __do_page_mkwrite() if
ocfs2_page_mkwrite() returns non-VM_FAULT_LOCKED, and along with a
locked target page.

These two errors fail on the same path, so fix them by unlocking the
target page manually before ocfs2_free_write_ctxt().

Jan Kara helps me clear out the JBD2 part, and suggest the hint for root
cause.

Changes since v1:
1. Also put ENOMEM error case into consideration.

Link: http://lkml.kernel.org/r/1474173902-32075-1-git-send-email-zren@suse.comSigned-off-by: Eric Ren <zren@suse.com>
Reviewed-by: He Gang <ghe@suse.com>
Acked-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Antonio reports the following crash when using fuse under memory pressure:

  kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: all of them
  CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
  RIP: shadow_lru_isolate+0x181/0x190
  Call Trace:
    __list_lru_walk_one.isra.3+0x8f/0x130
    list_lru_walk_one+0x23/0x30
    scan_shadow_nodes+0x34/0x50
    shrink_slab.part.40+0x1ed/0x3d0
    shrink_zone+0x2ca/0x2e0
    kswapd+0x51e/0x990
    kthread+0xd8/0xf0
    ret_from_fork+0x3f/0x70

which corresponds to the following sanity check in the shadow node
tracking:

  BUG_ON(node->count & RADIX_TREE_COUNT_MASK);

The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.

While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page.  Eventually the page count bits in node->count underflow while
leaving the node incorrectly linked to the shadow node LRU.

To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert().  This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.

Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.

Fixes: 449dd698 ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.orgSigned-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Antonio SJ Musumeci <trapexit@spawn.link>
Debugged-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>	[3.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Change my email address to my kernel.org account instead of the ARM one.
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This warning:

 WARNING: CPU: 0 PID: 3331 at arch/x86/entry/common.c:45 enter_from_user_mode+0x32/0x50
 CPU: 0 PID: 3331 Comm: ldt_gdt_64 Not tainted 4.8.0-rc7+ #13
 Call Trace:
  dump_stack+0x99/0xd0
  __warn+0xd1/0xf0
  warn_slowpath_null+0x1d/0x20
  enter_from_user_mode+0x32/0x50
  error_entry+0x6d/0xc0
  ? general_protection+0x12/0x30
  ? native_load_gs_index+0xd/0x20
  ? do_set_thread_area+0x19c/0x1f0
  SyS_set_thread_area+0x24/0x30
  do_int80_syscall_32+0x7c/0x220
  entry_INT80_compat+0x38/0x50

... can be reproduced by running the GS testcase of the ldt_gdt test unit in
the x86 selftests.

do_int80_syscall_32() will call enter_form_user_mode() to convert context
tracking state from user state to kernel state. The load_gs_index() call
can fail with user gsbase, gsbase will be fixed up and proceed if this
happen.

However, enter_from_user_mode() will be called again in the fixed up path
though it is context tracking kernel state currently.

This patch fixes it by just fixing up gsbase and telling lockdep that IRQs
are off once load_gs_index() failed with user gsbase.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1475197266-3440-1-git-send-email-wanpeng.li@hotmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Otherwise arch_task_struct_size == 0 and we die.  While we're at it,
set X86_FEATURE_ALWAYS, too.
Reported-by: David Saggiorato <david@saggiorato.net>
Tested-by: David Saggiorato <david@saggiorato.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
Link: http://lkml.kernel.org/r/8de723afbf0811071185039f9088733188b606c9.1475103911.git.luto@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

We need to call GET_LE to read hdr->e_type.

Fixes: 57f90c3d ("x86/vdso: Error out if the vDSO isn't a valid DSO")
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-next@vger.kernel.org
Link: http://lkml.kernel.org/r/20160929193442.GA16617@gate.crashing.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

The condition for reading CR4 was wrong: there are some CPUs with
CPUID but not CR4.  Rather than trying to make the condition exact,
use __read_cr4_safe().

Fixes: 18bc7bd5 ("x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly")
Reported-by: david@saggiorato.net
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Link: http://lkml.kernel.org/r/8c453a61c4f44ab6ff43c29780ba04835234d2e5.1475178369.git.luto@kernel.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

When sctp dumps all the ep->assocs, it needs to lock_sock first,
but now it locks sock in rcu_read_lock, and lock_sock may sleep,
which would break rcu_read_lock.

This patch is to get and hold one sock when traversing the list.
After that and get out of rcu_read_lock, lock and dump it. Then
it will traverse the list again to get the next one until all
sctp socks are dumped.

For sctp_diag_dump_one, it fixes this issue by holding asoc and
moving cb() out of rcu_read_lock in sctp_transport_lookup_process.

Fixes: 8f840e47 ("sctp: add the sctp_diag.c file")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Xin Long says:

====================
sctp: a bunch of fixes for prsctp polices

This patchset is to fix 2 issues for prsctp polices:

  1. patch 1 and 2 fix "netperf-Throughput_Mbps -37.2% regression" issue
     when overloading the CPU.

  2. patch 3 fix "prsctp polices should check both sides' prsctp_capable,
     instead of only local side".
====================
Signed-off-by: David S. Miller <davem@davemloft.net>