Jesper Dangaard Brouer says:

====================
net: revert lib/percpu_counter API for fragmentation mem accounting

There is a bug in fragmentation codes use of the percpu_counter API,
that can cause issues on systems with many CPUs, above 24 CPUs.

After much consideration and different attempts at solving the API
usage.  The conclusion is to revert to the simple atomic_t API instead.

The ratio between batch size and threshold size make it a bad use-case
for the lib/percpu_counter API.  As using the correct API calls will
unfortunately cause systems with many CPUs to always execute an
expensive sum across all CPUs. Plus the added complexity is not worth it.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 1d6119ba.

After reverting commit 6d7b857d ("net: use lib/percpu_counter API
for fragmentation mem accounting") then here is no need for this
fix-up patch.  As percpu_counter is no longer used, it cannot
memory leak it any-longer.

Fixes: 6d7b857d ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119ba ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 6d7b857d.

There is a bug in fragmentation codes use of the percpu_counter API,
that can cause issues on systems with many CPUs.

The frag_mem_limit() just reads the global counter (fbc->count),
without considering other CPUs can have upto batch size (130K) that
haven't been subtracted yet.  Due to the 3MBytes lower thresh limit,
this become dangerous at >=24 CPUs (3*1024*1024/130000=24).

The correct API usage would be to use __percpu_counter_compare() which
does the right thing, and takes into account the number of (online)
CPUs and batch size, to account for this and call __percpu_counter_sum()
when needed.

We choose to revert the use of the lib/percpu_counter API for frag
memory accounting for several reasons:

1) On systems with CPUs > 24, the heavier fully locked
   __percpu_counter_sum() is always invoked, which will be more
   expensive than the atomic_t that is reverted to.

Given systems with more than 24 CPUs are becoming common this doesn't
seem like a good option.  To mitigate this, the batch size could be
decreased and thresh be increased.

2) The add_frag_mem_limit+sub_frag_mem_limit pairs happen on the RX
   CPU, before SKBs are pushed into sockets on remote CPUs.  Given
   NICs can only hash on L2 part of the IP-header, the NIC-RXq's will
   likely be limited.  Thus, a fair chance that atomic add+dec happen
   on the same CPU.

Revert note that commit 1d6119ba ("net: fix percpu memory leaks")
removed init_frag_mem_limit() and instead use inet_frags_init_net().
After this revert, inet_frags_uninit_net() becomes empty.

Fixes: 6d7b857d ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119ba ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

After ip_route_input() calls ip_route_input_noref(), another
check on skb_dst() is done, but if this fails, we shouldn't
override the return code from ip_route_input_noref(), as it
could have been more specific (i.e. -EHOSTUNREACH).

This also saves one call to skb_dst_force_safe() and one to
skb_dst() in case the ip_route_input_noref() check fails.
Reported-by: Sabrina Dubroca <sdubroca@redhat.com>
Fixes: 9df16efa ("ipv4: call dst_hold_safe() properly")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

The race was introduced by me in commit 971316f0 ("epoll:
ep_unregister_pollwait() can use the freed pwq->whead").  I did not
realize that nothing can protect eventpoll after ep_poll_callback() sets
->whead = NULL, only whead->lock can save us from the race with
ep_free() or ep_remove().

Move ->whead = NULL to the end of ep_poll_callback() and add the
necessary barriers.

TODO: cleanup the ewake/EPOLLEXCLUSIVE logic, it was confusing even
before this patch.

Hopefully this explains use-after-free reported by syzcaller:

	BUG: KASAN: use-after-free in debug_spin_lock_before
	...
	 _raw_spin_lock_irqsave+0x4a/0x60 kernel/locking/spinlock.c:159
	 ep_poll_callback+0x29f/0xff0 fs/eventpoll.c:1148

this is spin_lock(eventpoll->lock),

	...
	Freed by task 17774:
	...
	 kfree+0xe8/0x2c0 mm/slub.c:3883
	 ep_free+0x22c/0x2a0 fs/eventpoll.c:865

Fixes: 971316f0 ("epoll: ep_unregister_pollwait() can use the freed pwq->whead")
Reported-by: 范龙飞 <long7573@126.com>
Cc: stable@vger.kernel.org
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull networking fixes from David Miller:

 1) Fix handling of pinned BPF map nodes in hash of maps, from Daniel
    Borkmann.

 2) IPSEC ESP error paths leak memory, from Steffen Klassert.

 3) We need an RCU grace period before freeing fib6_node objects, from
    Wei Wang.

 4) Must check skb_put_padto() return value in HSR driver, from FLorian
    Fainelli.

 5) Fix oops on PHY probe failure in ftgmac100 driver, from Andrew
    Jeffery.

 6) Fix infinite loop in UDP queue when using SO_PEEK_OFF, from Eric
    Dumazet.

 7) Use after free when tcf_chain_destroy() called multiple times, from
    Jiri Pirko.

 8) Fix KSZ DSA tag layer multiple free of SKBS, from Florian Fainelli.

 9) Fix leak of uninitialized memory in sctp_get_sctp_info(),
    inet_diag_msg_sctpladdrs_fill() and inet_diag_msg_sctpaddrs_fill().
    From Stefano Brivio.

10) L2TP tunnel refcount fixes from Guillaume Nault.

11) Don't leak UDP secpath in udp_set_dev_scratch(), from Yossi
    Kauperman.

12) Revert a PHY layer change wrt. handling of PHY_HALTED state in
    phy_stop_machine(), it causes regressions for multiple people. From
    Florian Fainelli.

13) When packets are sent out of br0 we have to clear the
    offload_fwdq_mark value.

14) Several NULL pointer deref fixes in packet schedulers when their
    ->init() routine fails. From Nikolay Aleksandrov.

15) Aquantium devices cannot checksum offload correctly when the packet
    is <= 60 bytes. From Pavel Belous.

16) Fix vnet header access past end of buffer in AF_PACKET, from
    Benjamin Poirier.

17) Double free in probe error paths of nfp driver, from Dan Carpenter.

18) QOS capability not checked properly in DCB init paths of mlx5
    driver, from Huy Nguyen.

19) Fix conflicts between firmware load failure and health_care timer in
    mlx5, also from Huy Nguyen.

20) Fix dangling page pointer when DMA mapping errors occur in mlx5,
    from Eran Ben ELisha.

21) ->ndo_setup_tc() in bnxt_en driver doesn't count rings properly,
    from Michael Chan.

22) Missing MSIX vector free in bnxt_en, also from Michael Chan.

23) Refcount leak in xfrm layer when using sk_policy, from Lorenzo
    Colitti.

24) Fix copy of uninitialized data in qlge driver, from Arnd Bergmann.

25) bpf_setsockopts() erroneously always returns -EINVAL even on
    success. Fix from Yuchung Cheng.

26) tipc_rcv() needs to linearize the SKB before parsing the inner
    headers, from Parthasarathy Bhuvaragan.

27) Fix deadlock between link status updates and link removal in netvsc
    driver, from Stephen Hemminger.

28) Missed locking of page fragment handling in ESP output, from Steffen
    Klassert.

29) Fix refcnt leak in ebpf congestion control code, from Sabrina
    Dubroca.

30) sxgbe_probe_config_dt() doesn't check devm_kzalloc()'s return value,
    from Christophe Jaillet.

31) Fix missing ipv6 rx_dst_cookie update when rx_dst is updated during
    early demux, from Paolo Abeni.

32) Several info leaks in xfrm_user layer, from Mathias Krause.

33) Fix out of bounds read in cxgb4 driver, from Stefano Brivio.

34) Properly propagate obsolete state of route upwards in ipv6 so that
    upper holders like xfrm can see it. From Xin Long.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (118 commits)
  udp: fix secpath leak
  bridge: switchdev: Clear forward mark when transmitting packet
  mlxsw: spectrum: Forbid linking to devices that have uppers
  wl1251: add a missing spin_lock_init()
  Revert "net: phy: Correctly process PHY_HALTED in phy_stop_machine()"
  net: dsa: bcm_sf2: Fix number of CFP entries for BCM7278
  kcm: do not attach PF_KCM sockets to avoid deadlock
  sch_tbf: fix two null pointer dereferences on init failure
  sch_sfq: fix null pointer dereference on init failure
  sch_netem: avoid null pointer deref on init failure
  sch_fq_codel: avoid double free on init failure
  sch_cbq: fix null pointer dereferences on init failure
  sch_hfsc: fix null pointer deref and double free on init failure
  sch_hhf: fix null pointer dereference on init failure
  sch_multiq: fix double free on init failure
  sch_htb: fix crash on init failure
  net/mlx5e: Fix CQ moderation mode not set properly
  net/mlx5e: Fix inline header size for small packets
  net/mlx5: E-Switch, Unload the representors in the correct order
  net/mlx5e: Properly resolve TC offloaded ipv6 vxlan tunnel source address
  ...

Pull ceph fix from Ilya Dryomov:
 "ceph fscache page locking fix from Zheng, marked for stable"

* tag 'ceph-for-4.13-rc8' of git://github.com/ceph/ceph-client:
  ceph: fix readpage from fscache

Pull input fixes from Dmitry Torokhov:
 "Just a couple drivers fixes (Synaptics PS/2, Xpad)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: xpad - fix PowerA init quirk for some gamepad models
  Input: synaptics - fix device info appearing different on reconnect

Pull two more MMC fixes from Ulf Hansson:
 "MMC core:
   - Fix block status codes

  MMC host:
   - sdhci-xenon: Fix SD bus voltage select"

* tag 'mmc-v4.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: sdhci-xenon: add set_power callback
  mmc: block: Fix block status codes

Pull sound fixes from Takashi Iwai:
 "Three regression fixes that should be addressed before the final
  release: a missing mutex call in OSS PCM emulation ioctl, ASoC rt5670
  headset detection breakage, and a regression in simple-card parser
  code"

* tag 'sound-4.13-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ASoC: simple_card_utils: fix fallback when "label" property isn't present
  ALSA: pcm: Fix power lock unbalance via OSS emulation
  ASoC: rt5670: Fix GPIO headset detection regression

Pull s390 fixes from Martin Schwidefsky:
 "Three more bug fixes for v4.13.

  The two memory management related fixes are quite new, they fix kernel
  crashes that can be triggered by user space.

  The third commit fixes a bug in the vfio ccw translation code"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/mm: fix BUG_ON in crst_table_upgrade
  s390/mm: fork vs. 5 level page tabel
  vfio: ccw: fix bad ptr math for TIC cda translation

Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - Regression in chacha20 handling of chunked input

   - Crash in algif_skcipher when used with async io

   - Potential bogus pointer dereference in lib/mpi"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: algif_skcipher - only call put_page on referenced and used pages
  crypto: testmgr - add chunked test cases for chacha20
  crypto: chacha20 - fix handling of chunked input
  lib/mpi: kunmap after finishing accessing buffer

After commit dce4551c ("udp: preserve head state for IP_CMSG_PASSSEC")
we preserve the secpath for the whole skb lifecycle, but we also
end up leaking a reference to it.

We must clear the head state on skb reception, if secpath is
present.

Fixes: dce4551c ("udp: preserve head state for IP_CMSG_PASSSEC")
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 6bc506b4 ("bridge: switchdev: Add forward mark support for
stacked devices") added the 'offload_fwd_mark' bit to the skb in order
to allow drivers to indicate to the bridge driver that they already
forwarded the packet in L2.

In case the bit is set, before transmitting the packet from each port,
the port's mark is compared with the mark stored in the skb's control
block. If both marks are equal, we know the packet arrived from a switch
device that already forwarded the packet and it's not re-transmitted.

However, if the packet is transmitted from the bridge device itself
(e.g., br0), we should clear the 'offload_fwd_mark' bit as the mark
stored in the skb's control block isn't valid.

This scenario can happen in rare cases where a packet was trapped during
L3 forwarding and forwarded by the kernel to a bridge device.

Fixes: 6bc506b4 ("bridge: switchdev: Add forward mark support for stacked devices")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Yotam Gigi <yotamg@mellanox.com>
Tested-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mlxsw driver relies on NETDEV_CHANGEUPPER events to configure the
device in case a port is enslaved to a master netdev such as bridge or
bond.

Since the driver ignores events unrelated to its ports and their
uppers, it's possible to engineer situations in which the device's data
path differs from the kernel's.

One example to such a situation is when a port is enslaved to a bond
that is already enslaved to a bridge. When the bond was enslaved the
driver ignored the event - as the bond wasn't one of its uppers - and
therefore a bridge port instance isn't created in the device.

Until such configurations are supported forbid them by checking that the
upper device doesn't have uppers of its own.

Fixes: 0d65fc13 ("mlxsw: spectrum: Implement LAG port join/leave")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Nogah Frankel <nogahf@mellanox.com>
Tested-by: Nogah Frankel <nogahf@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull cifs fixes from Steve French:
 "Two cifs bug fixes for stable"

* tag 'cifs-fixes-for-4.13-rc7-and-stable' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: remove endian related sparse warning
  CIFS: Fix maximum SMB2 header size

Pull block fixes from Jens Axboe:
 "Unfortunately a few issues that warrant sending another pull request,
  even if I had hoped to avoid it. This contains:

   - A fix for multiqueue xen-blkback, on tear down / disconnect.

   - A few fixups for NVMe, including a wrong bit definition, fix for
     host memory buffers, and an nvme rdma page size fix"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvme: fix the definition of the doorbell buffer config support bit
  nvme-pci: use dma memory for the host memory buffer descriptors
  nvme-rdma: default MR page size to 4k
  xen-blkback: stop blkback thread of every queue in xen_blkif_disconnect

Merge tag 'for-4.13/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - A couple fixes for bugs introduced as part of the blk_status_t block
   layer changes during the 4.13 merge window

 - A printk throttling fix to use discrete rate limiting state for each
   DM log level

 - A stable@ fix for DM multipath that delays request requeueing to
   avoid CPU lockup if/when the request queue is "dying"

* tag 'for-4.13/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: do not lock up a CPU with requeuing activity
  dm: fix printk() rate limiting code
  dm mpath: retry BLK_STS_RESOURCE errors
  dm: fix the second dec_pending() argument in __split_and_process_bio()

Merge more fixes from Andrew Morton:
 "6 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  scripts/dtc: fix '%zx' warning
  include/linux/compiler.h: don't perform compiletime_assert with -O0
  mm, madvise: ensure poisoned pages are removed from per-cpu lists
  mm, uprobes: fix multiple free of ->uprobes_state.xol_area
  kernel/kthread.c: kthread_worker: don't hog the cpu
  mm,page_alloc: don't call __node_reclaim() with oom_lock held.

Merge mmu_notifier fixes from Jérôme Glisse:
 "The invalidate_page callback suffered from 2 pitfalls. First it used
  to happen after page table lock was release and thus a new page might
  have been setup for the virtual address before the call to
  invalidate_page().

  This is in a weird way fixed by commit c7ab0d2f ("mm: convert
  try_to_unmap_one() to use page_vma_mapped_walk()") which moved the
  callback under the page table lock. Which also broke several existing
  user of the mmu_notifier API that assumed they could sleep inside this
  callback.

  The second pitfall was invalidate_page being the only callback not
  taking a range of address in respect to invalidation but was giving an
  address and a page. Lot of the callback implementer assumed this could
  never be THP and thus failed to invalidate the appropriate range for
  THP pages.

  By killing this callback we unify the mmu_notifier callback API to
  always take a virtual address range as input.

  There is now two clear API (I am not mentioning the youngess API which
  is seldomly used):

   - invalidate_range_start()/end() callback (which allow you to sleep)

   - invalidate_range() where you can not sleep but happen right after
     page table update under page table lock

  Note that a lot of existing user feels broken in respect to
  range_start/ range_end. Many user only have range_start() callback but
  there is nothing preventing them to undo what was invalidated in their
  range_start() callback after it returns but before any CPU page table
  update take place.

  The code pattern use in kvm or umem odp is an example on how to
  properly avoid such race. In a nutshell use some kind of sequence
  number and active range invalidation counter to block anything that
  might undo what the range_start() callback did.

  If you do not care about keeping fully in sync with CPU page table (ie
  you can live with CPU page table pointing to new different page for a
  given virtual address) then you can take a reference on the pages
  inside the range_start callback and drop it in range_end or when your
  driver is done with those pages.

  Last alternative is to use invalidate_range() if you can do
  invalidation without sleeping as invalidate_range() callback happens
  under the CPU page table spinlock right after the page table is
  updated.

  The first two patches convert existing mmu_notifier_invalidate_page()
  calls to mmu_notifier_invalidate_range() and bracket those call with
  call to mmu_notifier_invalidate_range_start()/end().

  The next ten patches remove existing invalidate_page() callback as it
  can no longer happen.

  Finally the last page remove the invalidate_page() callback completely
  so it can RIP.

  Changes since v1:
   - remove more dead code in kvm (no testing impact)
   - more accurate end address computation (patch 2) in page_mkclean_one
     and try_to_unmap_one
   - added tested-by/reviewed-by gotten so far"

* emailed patches from Jérôme Glisse <jglisse@redhat.com>:
  mm/mmu_notifier: kill invalidate_page
  KVM: update to new mmu_notifier semantic v2
  xen/gntdev: update to new mmu_notifier semantic
  sgi-gru: update to new mmu_notifier semantic
  misc/mic/scif: update to new mmu_notifier semantic
  iommu/intel: update to new mmu_notifier semantic
  iommu/amd: update to new mmu_notifier semantic
  IB/hfi1: update to new mmu_notifier semantic
  IB/umem: update to new mmu_notifier semantic
  drm/amdgpu: update to new mmu_notifier semantic
  powerpc/powernv: update to new mmu_notifier semantic
  mm/rmap: update to new mmu_notifier semantic v2
  dax: update to new mmu_notifier semantic

jfs had previously avoided the use of MAX_LFS_FILESIZE because it hadn't
accounted for the whole 32-bit index range on 32-bit systems.  That has
been fixed by commit 0cc3b0ec ("Clarify (and fix) MAX_LFS_FILESIZE
macros"), so we can simplify the code now.

Suggested by Andreas Dilger.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: jfs-discussion@lists.sourceforge.net
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dtc uses an incorrect format specifier for printing a uint64_t value.
uint64_t may be either 'unsigned long' or 'unsigned long long' depending
on the host architecture.

Fix this by using %llx and casting to unsigned long long, which ensures
that we always have a wide enough variable to print 64 bits of hex.

    HOSTCC  scripts/dtc/checks.o
  scripts/dtc/checks.c: In function 'check_simple_bus_reg':
  scripts/dtc/checks.c:876:2: warning: format '%zx' expects argument of type 'size_t', but argument 4 has type 'uint64_t' [-Wformat=]
    snprintf(unit_addr, sizeof(unit_addr), "%zx", reg);
    ^
  scripts/dtc/checks.c:876:2: warning: format '%zx' expects argument of type 'size_t', but argument 4 has type 'uint64_t' [-Wformat=]

Link: http://lkml.kernel.org/r/20170829222034.GJ20805@n2100.armlinux.org.uk
Fixes: 828d4cdd ("dtc: check.c fix compile error")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit c7acec71 ("kernel.h: handle pointers to arrays better in
container_of()") made use of __compiletime_assert() from container_of()
thus increasing the usage of this macro, allowing developers to notice
type conflicts in usage of container_of() at compile time.

However, the implementation of __compiletime_assert relies on compiler
optimizations to report an error.  This means that if a developer uses
"-O0" with any code that performs container_of(), the compiler will always
report an error regardless of whether there is an actual problem in the
code.

This patch disables compile_time_assert when optimizations are disabled to
allow such code to compile with CFLAGS="-O0".

Example compilation failure:

./include/linux/compiler.h:547:38: error: call to `__compiletime_assert_94' declared with attribute error: pointer type mismatch in container_of()
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
                                      ^
./include/linux/compiler.h:530:4: note: in definition of macro `__compiletime_assert'
    prefix ## suffix();    \
    ^~~~~~
./include/linux/compiler.h:547:2: note: in expansion of macro `_compiletime_assert'
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
  ^~~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:46:37: note: in expansion of macro `compiletime_assert'
 #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                     ^~~~~~~~~~~~~~~~~~
./include/linux/kernel.h:860:2: note: in expansion of macro `BUILD_BUG_ON_MSG'
  BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
  ^~~~~~~~~~~~~~~~

[akpm@linux-foundation.org: use do{}while(0), per Michal]
Link: http://lkml.kernel.org/r/20170829230114.11662-1-joe@ovn.org
Fixes: c7acec71 ("kernel.h: handle pointers to arrays better in container_of()")
Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Wendy Wang reported off-list that a RAS HWPOISON-SOFT test case failed
and bisected it to the commit 479f854a ("mm, page_alloc: defer
debugging checks of pages allocated from the PCP").

The problem is that a page that was poisoned with madvise() is reused.
The commit removed a check that would trigger if DEBUG_VM was enabled
but re-enabling the check only fixes the problem as a side-effect by
printing a bad_page warning and recovering.

The root of the problem is that an madvise() can leave a poisoned page
on the per-cpu list.  This patch drains all per-cpu lists after pages
are poisoned so that they will not be reused.  Wendy reports that the
test case in question passes with this patch applied.  While this could
be done in a targeted fashion, it is over-complicated for such a rare
operation.

Link: http://lkml.kernel.org/r/20170828133414.7qro57jbepdcyz5x@techsingularity.net
Fixes: 479f854a ("mm, page_alloc: defer debugging checks of pages allocated from the PCP")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Wang, Wendy <wendy.wang@intel.com>
Tested-by: Wang, Wendy <wendy.wang@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Hansen, Dave" <dave.hansen@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 7c051267 ("mm, fork: make dup_mmap wait for mmap_sem for
write killable") made it possible to kill a forking task while it is
waiting to acquire its ->mmap_sem for write, in dup_mmap().

However, it was overlooked that this introduced an new error path before
the new mm_struct's ->uprobes_state.xol_area has been set to NULL after
being copied from the old mm_struct by the memcpy in dup_mm().  For a
task that has previously hit a uprobe tracepoint, this resulted in the
'struct xol_area' being freed multiple times if the task was killed at
just the right time while forking.

Fix it by setting ->uprobes_state.xol_area to NULL in mm_init() rather
than in uprobe_dup_mmap().

With CONFIG_UPROBE_EVENTS=y, the bug can be reproduced by the same C
program given by commit 2b7e8665 ("fork: fix incorrect fput of
->exe_file causing use-after-free"), provided that a uprobe tracepoint
has been set on the fork_thread() function.  For example:

    $ gcc reproducer.c -o reproducer -lpthread
    $ nm reproducer | grep fork_thread
    0000000000400719 t fork_thread
    $ echo "p $PWD/reproducer:0x719" > /sys/kernel/debug/tracing/uprobe_events
    $ echo 1 > /sys/kernel/debug/tracing/events/uprobes/enable
    $ ./reproducer

Here is the use-after-free reported by KASAN:

    BUG: KASAN: use-after-free in uprobe_clear_state+0x1c4/0x200
    Read of size 8 at addr ffff8800320a8b88 by task reproducer/198

    CPU: 1 PID: 198 Comm: reproducer Not tainted 4.13.0-rc7-00015-g36fde05f #255
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
    Call Trace:
     dump_stack+0xdb/0x185
     print_address_description+0x7e/0x290
     kasan_report+0x23b/0x350
     __asan_report_load8_noabort+0x19/0x20
     uprobe_clear_state+0x1c4/0x200
     mmput+0xd6/0x360
     do_exit+0x740/0x1670
     do_group_exit+0x13f/0x380
     get_signal+0x597/0x17d0
     do_signal+0x99/0x1df0
     exit_to_usermode_loop+0x166/0x1e0
     syscall_return_slowpath+0x258/0x2c0
     entry_SYSCALL_64_fastpath+0xbc/0xbe

    ...

    Allocated by task 199:
     save_stack_trace+0x1b/0x20
     kasan_kmalloc+0xfc/0x180
     kmem_cache_alloc_trace+0xf3/0x330
     __create_xol_area+0x10f/0x780
     uprobe_notify_resume+0x1674/0x2210
     exit_to_usermode_loop+0x150/0x1e0
     prepare_exit_to_usermode+0x14b/0x180
     retint_user+0x8/0x20

    Freed by task 199:
     save_stack_trace+0x1b/0x20
     kasan_slab_free+0xa8/0x1a0
     kfree+0xba/0x210
     uprobe_clear_state+0x151/0x200
     mmput+0xd6/0x360
     copy_process.part.8+0x605f/0x65d0
     _do_fork+0x1a5/0xbd0
     SyS_clone+0x19/0x20
     do_syscall_64+0x22f/0x660
     return_from_SYSCALL_64+0x0/0x7a

Note: without KASAN, you may instead see a "Bad page state" message, or
simply a general protection fault.

Link: http://lkml.kernel.org/r/20170830033303.17927-1-ebiggers3@gmail.com
Fixes: 7c051267 ("mm, fork: make dup_mmap wait for mmap_sem for write killable")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>    [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If the worker thread continues getting work, it will hog the cpu and rcu
stall complains.  Make it a good citizen.  This is triggered in a loop
block device test.

Link: http://lkml.kernel.org/r/5de0a179b3184e1a2183fc503448b0269f24d75b.1503697127.git.shli@fb.comSigned-off-by: Shaohua Li <shli@fb.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We are doing a last second memory allocation attempt before calling
out_of_memory().  But since slab shrinker functions might indirectly
wait for other thread's __GFP_DIRECT_RECLAIM && !__GFP_NORETRY memory
allocations via sleeping locks, calling slab shrinker functions from
node_reclaim() from get_page_from_freelist() with oom_lock held has
possibility of deadlock.  Therefore, make sure that last second memory
allocation attempt does not call slab shrinker functions.

Link: http://lkml.kernel.org/r/1503577106-9196-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jpSigned-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The invalidate_page callback suffered from two pitfalls.  First it used
to happen after the page table lock was release and thus a new page
might have setup before the call to invalidate_page() happened.

This is in a weird way fixed by commit c7ab0d2f ("mm: convert
try_to_unmap_one() to use page_vma_mapped_walk()") that moved the
callback under the page table lock but this also broke several existing
users of the mmu_notifier API that assumed they could sleep inside this
callback.

The second pitfall was invalidate_page() being the only callback not
taking a range of address in respect to invalidation but was giving an
address and a page.  Lots of the callback implementers assumed this
could never be THP and thus failed to invalidate the appropriate range
for THP.

By killing this callback we unify the mmu_notifier callback API to
always take a virtual address range as input.

Finally this also simplifies the end user life as there is now two clear
choices:
  - invalidate_range_start()/end() callback (which allow you to sleep)
  - invalidate_range() where you can not sleep but happen right after
    page table update under page table lock
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Bernhard Held <berny156@gmx.de>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: axie <axie@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.

Changed since v1 (Linus Torvalds)
    - remove now useless kvm_arch_mmu_notifier_invalidate_page()
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Tested-by: Adam Borowski <kilobyte@angband.pl>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: xen-devel@lists.xenproject.org (moderated for non-subscribers)
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: iommu@lists.linux-foundation.org
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: linux-rdma@vger.kernel.org
Cc: Dean Luick <dean.luick@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Cc: linux-rdma@vger.kernel.org
Cc: Artemy Kovalyov <artemyko@mellanox.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and are now bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Calls to mmu_notifier_invalidate_page() were replaced by calls to
mmu_notifier_invalidate_range() and now are bracketed by calls to
mmu_notifier_invalidate_range_start()/end()

Remove now useless invalidate_page callback.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Replace all mmu_notifier_invalidate_page() calls by *_invalidate_range()
and make sure it is bracketed by calls to *_invalidate_range_start()/end().

Note that because we can not presume the pmd value or pte value we have
to assume the worst and unconditionaly report an invalidation as
happening.

Changed since v2:
  - try_to_unmap_one() only one call to mmu_notifier_invalidate_range()
  - compute end with PAGE_SIZE << compound_order(page)
  - fix PageHuge() case in try_to_unmap_one()
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Bernhard Held <berny156@gmx.de>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: axie <axie@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Replace all mmu_notifier_invalidate_page() calls by *_invalidate_range()
and make sure it is bracketed by calls to *_invalidate_range_start()/end().

Note that because we can not presume the pmd value or pte value we have
to assume the worst and unconditionaly report an invalidation as
happening.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Bernhard Held <berny156@gmx.de>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: axie <axie@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>