This reverts commit 574823bf.

It turns out that my hope that we could just remove the code that
exposes the cache residency status from mincore() was too optimistic.

There are various random users that want it, and one example would be
the Netflix database cluster maintenance. To quote Josh Snyder:

 "For Netflix, losing accurate information from the mincore syscall
  would lengthen database cluster maintenance operations from days to
  months. We rely on cross-process mincore to migrate the contents of a
  page cache from machine to machine, and across reboots.

  To do this, I wrote and maintain happycache [1], a page cache
  dumper/loader tool. It is quite similar in architecture to pgfincore,
  except that it is agnostic to workload. The gist of happycache's
  operation is "produce a dump of residence status for each page, do
  some operation, then reload exactly the same pages which were present
  before." happycache is entirely dependent on accurate reporting of the
  in-core status of file-backed pages, as accessed by another process.

  We primarily use happycache with Cassandra, which (like Postgres +
  pgfincore) relies heavily on OS page cache to reduce disk accesses.
  Because our workloads never experience a cold page cache, we are able
  to provision hardware for a peak utilization level that is far lower
  than the hypothetical "every query is a cache miss" peak.

  A database warmed by happycache can be ready for service in seconds
  (bounded only by the performance of the drives and the I/O subsystem),
  with no period of in-service degradation. By contrast, putting a
  database in service without a page cache entails a potentially
  unbounded period of degradation (at Netflix, the time to populate a
  single node's cache via natural cache misses varies by workload from
  hours to weeks). If a single node upgrade were to take weeks, then
  upgrading an entire cluster would take months. Since we want to apply
  security upgrades (and other things) on a somewhat tighter schedule,
  we would have to develop more complex solutions to provide the same
  functionality already provided by mincore.

  At the bottom line, happycache is designed to benignly exploit the
  same information leak documented in the paper [2]. I think it makes
  perfect sense to remove cross-process mincore functionality from
  unprivileged users, but not to remove it entirely"

We do have an alternate approach that limits the cache residency
reporting only to processes that have write permissions to the file, so
we can fix the original information leak issue that way.  It involves
_adding_ code rather than removing it, which is sad, but hey, at least
we haven't found any users that would find the restrictions
unacceptable.

So revert the optimistic first approach to make room for that alternate
fix instead.
Reported-by: Josh Snyder <joshs@netflix.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Cyril Hrubis <chrubis@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Daniel Gruss <daniel@gruss.cc>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull IPMI fixes from Corey Minyard:
 "I missed the merge window, which wasn't really important at the time
  as there was nothing that critical that I had for 5.0.

  However, I say that,and then a number of critical fixes come in:

   - ipmi: fix use-after-free of user->release_barrier.rda
   - ipmi: Prevent use-after-free in deliver_response
   - ipmi: msghandler: Fix potential Spectre v1 vulnerabilities

  which are obvious candidates for 5.0.  Then there is:

   - ipmi:ssif: Fix handling of multi-part return messages

  which is less critical, but it still has some off-by-one things that
  are not great, so it seemed appropriate. Some machines are broken
  without it. Then:

   - ipmi: Don't initialize anything in the core until something uses it

  It turns out that using SRCU causes large chunks of memory to be used
  on big iron machines, even if IPMI is never used. This was causing
  some issues for people on those machines.

  Everything here is destined for stable"

* tag 'for-linus-5.0' of git://github.com/cminyard/linux-ipmi:
  ipmi: Don't initialize anything in the core until something uses it
  ipmi: fix use-after-free of user->release_barrier.rda
  ipmi: Prevent use-after-free in deliver_response
  ipmi: msghandler: Fix potential Spectre v1 vulnerabilities
  ipmi:ssif: Fix handling of multi-part return messages

Pull s390 fixes from Martin Schwidefsky:

 - Do not claim to run under z/VM if the hypervisor can not be
   identified

 - Fix crashes due to outdated ASCEs in CR1

 - Avoid a deadlock in regard to CPU hotplug

 - Really fix the vdso mapping issue for compat tasks

 - Avoid crash on restart due to an incorrect stack address

* tag 's390-5.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
  s390/vdso: correct vdso mapping for compat tasks
  s390/smp: fix CPU hotplug deadlock with CPU rescan
  s390/mm: always force a load of the primary ASCE on context switch
  s390/early: improve machine detection

The IPMI driver was recently modified to use SRCU, but it turns out
this uses a chunk of percpu memory, even if IPMI is never used.

So modify thing to on initialize on the first use.  There was already
code to sort of handle this for handling init races, so piggy back
on top of that, and simplify it in the process.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reported-by: Tejun Heo <tj@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.18

When we do the following test, we got oops in ipmi_msghandler driver
while((1))
do
	service ipmievd restart & service ipmievd restart
done

---------------------------------------------------------------
[  294.230186] Unable to handle kernel paging request at virtual address 0000803fea6ea008
[  294.230188] Mem abort info:
[  294.230190]   ESR = 0x96000004
[  294.230191]   Exception class = DABT (current EL), IL = 32 bits
[  294.230193]   SET = 0, FnV = 0
[  294.230194]   EA = 0, S1PTW = 0
[  294.230195] Data abort info:
[  294.230196]   ISV = 0, ISS = 0x00000004
[  294.230197]   CM = 0, WnR = 0
[  294.230199] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000a1c1b75a
[  294.230201] [0000803fea6ea008] pgd=0000000000000000
[  294.230204] Internal error: Oops: 96000004 [#1] SMP
[  294.235211] Modules linked in: nls_utf8 isofs rpcrdma ib_iser ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_umad rdma_cm ib_cm iw_cm dm_mirror dm_region_hash dm_log dm_mod aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce sha2_ce ses sha256_arm64 sha1_ce hibmc_drm hisi_sas_v2_hw enclosure sg hisi_sas_main sbsa_gwdt ip_tables mlx5_ib ib_uverbs marvell ib_core mlx5_core ixgbe ipmi_si mdio hns_dsaf ipmi_devintf ipmi_msghandler hns_enet_drv hns_mdio
[  294.277745] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Not tainted 5.0.0-rc2+ #113
[  294.285511] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.37 11/21/2017
[  294.292835] pstate: 80000005 (Nzcv daif -PAN -UAO)
[  294.297695] pc : __srcu_read_lock+0x38/0x58
[  294.301940] lr : acquire_ipmi_user+0x2c/0x70 [ipmi_msghandler]
[  294.307853] sp : ffff00001001bc80
[  294.311208] x29: ffff00001001bc80 x28: ffff0000117e5000
[  294.316594] x27: 0000000000000000 x26: dead000000000100
[  294.321980] x25: dead000000000200 x24: ffff803f6bd06800
[  294.327366] x23: 0000000000000000 x22: 0000000000000000
[  294.332752] x21: ffff00001001bd04 x20: ffff80df33d19018
[  294.338137] x19: ffff80df33d19018 x18: 0000000000000000
[  294.343523] x17: 0000000000000000 x16: 0000000000000000
[  294.348908] x15: 0000000000000000 x14: 0000000000000002
[  294.354293] x13: 0000000000000000 x12: 0000000000000000
[  294.359679] x11: 0000000000000000 x10: 0000000000100000
[  294.365065] x9 : 0000000000000000 x8 : 0000000000000004
[  294.370451] x7 : 0000000000000000 x6 : ffff80df34558678
[  294.375836] x5 : 000000000000000c x4 : 0000000000000000
[  294.381221] x3 : 0000000000000001 x2 : 0000803fea6ea000
[  294.386607] x1 : 0000803fea6ea008 x0 : 0000000000000001
[  294.391994] Process swapper/3 (pid: 0, stack limit = 0x0000000083087293)
[  294.398791] Call trace:
[  294.401266]  __srcu_read_lock+0x38/0x58
[  294.405154]  acquire_ipmi_user+0x2c/0x70 [ipmi_msghandler]
[  294.410716]  deliver_response+0x80/0xf8 [ipmi_msghandler]
[  294.416189]  deliver_local_response+0x28/0x68 [ipmi_msghandler]
[  294.422193]  handle_one_recv_msg+0x158/0xcf8 [ipmi_msghandler]
[  294.432050]  handle_new_recv_msgs+0xc0/0x210 [ipmi_msghandler]
[  294.441984]  smi_recv_tasklet+0x8c/0x158 [ipmi_msghandler]
[  294.451618]  tasklet_action_common.isra.5+0x88/0x138
[  294.460661]  tasklet_action+0x2c/0x38
[  294.468191]  __do_softirq+0x120/0x2f8
[  294.475561]  irq_exit+0x134/0x140
[  294.482445]  __handle_domain_irq+0x6c/0xc0
[  294.489954]  gic_handle_irq+0xb8/0x178
[  294.497037]  el1_irq+0xb0/0x140
[  294.503381]  arch_cpu_idle+0x34/0x1a8
[  294.510096]  do_idle+0x1d4/0x290
[  294.516322]  cpu_startup_entry+0x28/0x30
[  294.523230]  secondary_start_kernel+0x184/0x1d0
[  294.530657] Code: d538d082 d2800023 8b010c81 8b020021 (c85f7c25)
[  294.539746] ---[ end trace 8a7a880dee570b29 ]---
[  294.547341] Kernel panic - not syncing: Fatal exception in interrupt
[  294.556837] SMP: stopping secondary CPUs
[  294.563996] Kernel Offset: disabled
[  294.570515] CPU features: 0x002,21006008
[  294.577638] Memory Limit: none
[  294.587178] Starting crashdump kernel...
[  294.594314] Bye!

Because the user->release_barrier.rda is freed in ipmi_destroy_user(), but
the refcount is not zero, when acquire_ipmi_user() uses user->release_barrier.rda
in __srcu_read_lock(), it causes oops.
Fix this by calling cleanup_srcu_struct() when the refcount is zero.

Fixes: e86ee2d4 ("ipmi: Rework locking and shutdown for hot remove")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

Some IPMI modules (e.g. ibmpex_msg_handler()) will have ipmi_usr_hdlr
handlers that call ipmi_free_recv_msg() directly. This will essentially
kfree(msg), leading to use-after-free.

This does not happen in the ipmi_devintf module, which will queue the
message and run ipmi_free_recv_msg() later.

BUG: KASAN: use-after-free in deliver_response+0x12f/0x1b0
Read of size 8 at addr ffff888a7bf20018 by task ksoftirqd/3/27
CPU: 3 PID: 27 Comm: ksoftirqd/3 Tainted: G           O      4.19.11-amd64-ani99-debug #12.0.1.601133+pv
Hardware name: AppNeta r1000/X11SPW-TF, BIOS 2.1a-AP 09/17/2018
Call Trace:
dump_stack+0x92/0xeb
print_address_description+0x73/0x290
kasan_report+0x258/0x380
deliver_response+0x12f/0x1b0
? ipmi_free_recv_msg+0x50/0x50
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
...

Allocated by task 9885:
kasan_kmalloc+0xa0/0xd0
kmem_cache_alloc_trace+0x116/0x290
ipmi_alloc_recv_msg+0x28/0x70
i_ipmi_request+0xb4a/0x1640
ipmi_request_settime+0x1b8/0x1e0
...

Freed by task 27:
__kasan_slab_free+0x12e/0x180
kfree+0xe9/0x280
deliver_response+0x122/0x1b0
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
tasklet_action_common.isra.19+0xc4/0x250
__do_softirq+0x11f/0x51f

Fixes: e86ee2d4 ("ipmi: Rework locking and shutdown for hot remove")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

channel and addr->channel are indirectly controlled by user-space,
hence leading to a potential exploitation of the Spectre variant 1
vulnerability.

These issues were detected with the help of Smatch:

drivers/char/ipmi/ipmi_msghandler.c:1381 ipmi_set_my_address() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1401 ipmi_get_my_address() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1421 ipmi_set_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1441 ipmi_get_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:2260 check_addr() warn: potential spectre issue 'intf->addrinfo' [r] (local cap)

Fix this by sanitizing channel and addr->channel before using them to
index user->intf->addrinfo and intf->addrinfo, correspondingly.

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

The block number was not being compared right, it was off by one
when checking the response.

Some statistics wouldn't be incremented properly in some cases.

Check to see if that middle-part messages always have 31 bytes of
data.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org # 4.4

Pull thermal management fixes from Zhang Rui:

 - Fix a race condition that sysfs could be accessed before necessary
   initialization in int340x thermal driver. (Aaron Hill)

 - Fix a NULL vs IS_ERR() check in int340x thermal driver. (Dan
   Carpenter)

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  drivers: thermal: int340x_thermal: Fix sysfs race condition
  thermal: int340x_thermal: Fix a NULL vs IS_ERR() check

Pull clk fixes from Stephen Boyd:
 "This is a sort of random collection of clk fixes that have come in
  since the merge window:

   - Handful of memory allocation and potentially bad pointer usage
     fixes

   - JSON format was incorrect for clk_dump because it missed a comma

   - Two Kconfig fixes, one duplicate and one missing select line

   - Compiler warning fix for the VC5 clk driver

   - Name and rate fixes for PLLs in the stratix10 driver so it can
     properly detect PLL rates and parents"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: socfpga: stratix10: fix naming convention for the fixed-clocks
  clk: socfpga: stratix10: fix rate calculation for pll clocks
  clk: qcom: Select QCOM_GDSC with MSM_GCC_8998
  clk: vc5: Abort clock configuration without upstream clock
  clk: sysfs: fix invalid JSON in clk_dump
  clk: imx: Remove Kconfig duplicate include
  clk: zynqmp: Fix memory allocation in zynqmp_clk_setup
  clk: tegra: dfll: Fix a potential Oop in remove()
  clk: imx: fix potential NULL dereference in imx8qxp_lpcg_clk_probe()

Merge tag 'linux-kselftest-5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:
 "Fixes to rtc, seccomp and other tests"

* tag 'linux-kselftest-5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/seccomp: Abort without user notification support
  selftests: gpio-mockup-chardev: Check asprintf() for error
  selftests: seccomp: use LDLIBS instead of LDFLAGS
  selftests/vm/gup_benchmark.c: match gup struct to kernel
  tools/testing/selftests/x86/unwind_vdso.c: Remove duplicate header
  x86/mpx/selftests: fix spelling mistake "succeded" -> "succeeded"
  selftests: rtc: rtctest: add alarm test on minute boundary
  selftests: rtc: rtctest: fix alarm tests

Pull HID fixes from Jiri Kosina:

 - descriptor parsing regression fix for devices that have more than 16
   collections, from Peter Hutterer (and followup cleanup from Philipp
   Zabel)

 - quirk for Goodix touchpad

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  HID: core: simplify active collection tracking
  HID: i2c-hid: Disable runtime PM on Goodix touchpad
  HID: core: replace the collection tree pointers with indices

Pull XArray fixes from Matthew Wilcox:
 "Fix some oversights in the XArray porcelain API:

   - support for m68k's two-byte aligned pointers

   - reserving entries using xa_insert()

   - missing xa_insert_bh() and xa_insert_irq() functions

   - simplify using xa_for_each()

   - use lockdep correctly

   - a few other minor fixes and improvements"

* tag 'xarray-5.0-rc3' of git://git.infradead.org/users/willy/linux-dax:
  XArray: Fix an arithmetic error in xa_is_err
  XArray tests: Check mark 2 gets squashed
  XArray: Fix typo in comment
  XArray: Honour reserved entries in xa_insert
  XArray: Permit storing 2-byte-aligned pointers
  XArray: Change xa_for_each iterator
  XArray: Turn xa_init_flags into a static inline
  XArray tests: Add RCU locking

Fixes: ec7d9c9c ("ide: replace ->proc_fops with ->proc_show")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull IOMMU fix from Joerg Roedel:
 "One fix only for now: Fix probe deferral in iommu/of code (broke with
  recent changes to iommu_ops->add_device invocation)"

* tag 'iommu-fixes-v5.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/of: Fix probe-deferral

Pull ARC architecture updates from Vineet Gupta:

 - Perf support for raw events

 - boot log printing: return stack, action points

 - fix memset to avoid prefetchw bleeding past end of buffer

 - do_page_fault fix for mmap_sem held while returning to userspace

 - other misc fixes

* tag 'arc-5.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: lib: memeset: fix doing prefetchw outside of buffer
  ARC: mm: do_page_fault fixes #1: relinquish mmap_sem if signal arrives while handle_mm_fault
  ARC: show_regs: lockdep: re-enable preemption
  ARC: show_regs: lockdep: avoid page allocator...
  ARC: perf: avoid kernel killing where it is possible
  ARC: perf: move HW events mapping to separate function
  ARC: perf: introduce Kernel PMU events support
  ARC: perf: trivial code cleanup
  ARC: perf: map generic branches to correct hardware condition
  ARC: adjust memblock_reserve of kernel memory
  arc: remove redundant kernel-space generic-y
  ARC: fix __ffs return value to avoid build warnings
  ARC: boot log: print Action point details
  ARCv2: boot log: BPU return stack depth

Pull pstore fixes from Kees Cook:

 - Fix console ramoops to show the previous boot logs (Sai Prakash
   Ranjan)

 - Avoid allocation and leak of platform data

* tag 'pstore-v5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Avoid allocation and leak of platform data
  pstore/ram: Fix console ramoops to show the previous boot logs

Pull gcc-plugins fixes from Kees Cook:
 "Fix ARM per-task stack protector plugin under GCC 9 (Ard Biesheuvel)"

* tag 'gcc-plugins-v5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  gcc-plugins: arm_ssp_per_task_plugin: fix for GCC 9+
  gcc-plugins: arm_ssp_per_task_plugin: sign extend the SP mask

Pull networking fixes from David Miller:

 1) Fix endless loop in nf_tables, from Phil Sutter.

 2) Fix cross namespace ip6_gre tunnel hash list corruption, from
    Olivier Matz.

 3) Don't be too strict in phy_start_aneg() otherwise we might not allow
    restarting auto negotiation. From Heiner Kallweit.

 4) Fix various KMSAN uninitialized value cases in tipc, from Ying Xue.

 5) Memory leak in act_tunnel_key, from Davide Caratti.

 6) Handle chip errata of mv88e6390 PHY, from Andrew Lunn.

 7) Remove linear SKB assumption in fou/fou6, from Eric Dumazet.

 8) Missing udplite rehash callbacks, from Alexey Kodanev.

 9) Log dirty pages properly in vhost, from Jason Wang.

10) Use consume_skb() in neigh_probe() as this is a normal free not a
    drop, from Yang Wei. Likewise in macvlan_process_broadcast().

11) Missing device_del() in mdiobus_register() error paths, from Thomas
    Petazzoni.

12) Fix checksum handling of short packets in mlx5, from Cong Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (96 commits)
  bpf: in __bpf_redirect_no_mac pull mac only if present
  virtio_net: bulk free tx skbs
  net: phy: phy driver features are mandatory
  isdn: avm: Fix string plus integer warning from Clang
  net/mlx5e: Fix cb_ident duplicate in indirect block register
  net/mlx5e: Fix wrong (zero) TX drop counter indication for representor
  net/mlx5e: Fix wrong error code return on FEC query failure
  net/mlx5e: Force CHECKSUM_UNNECESSARY for short ethernet frames
  tools: bpftool: Cleanup license mess
  bpf: fix inner map masking to prevent oob under speculation
  bpf: pull in pkt_sched.h header for tooling to fix bpftool build
  selftests: forwarding: Add a test case for externally learned FDB entries
  selftests: mlxsw: Test FDB offload indication
  mlxsw: spectrum_switchdev: Do not treat static FDB entries as sticky
  net: bridge: Mark FDB entries that were added by user as such
  mlxsw: spectrum_fid: Update dummy FID index
  mlxsw: pci: Return error on PCI reset timeout
  mlxsw: pci: Increase PCI SW reset timeout
  mlxsw: pci: Ring CQ's doorbell before RDQ's
  MAINTAINERS: update email addresses of liquidio driver maintainers
  ...

Yue Hu noticed that when parsing device tree the allocated platform data
was never freed. Since it's not used beyond the function scope, this
switches to using a stack variable instead.
Reported-by: Yue Hu <huyue2@yulong.com>
Fixes: 35da6094 ("pstore/ram: add Device Tree bindings")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

GCC 9 reworks the way the references to the stack canary are
emitted, to prevent the value from being spilled to the stack
before the final comparison in the epilogue, defeating the
purpose, given that the spill slot is under control of the
attacker that we are protecting ourselves from.

Since our canary value address is obtained without accessing
memory (as opposed to pre-v7 code that will obtain it from a
literal pool), it is unlikely (although not guaranteed) that
the compiler will spill the canary value in the same way, so
let's just disable this improvement when building with GCC9+.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

The ARM per-task stack protector GCC plugin hits an assert in
the compiler in some case, due to the fact the the SP mask
expression is not sign-extended as it should be. So fix that.
Suggested-by: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

Pull virtio/vhost fixes and cleanups from Michael Tsirkin:
 "Fixes and cleanups all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost/scsi: Use copy_to_iter() to send control queue response
  vhost: return EINVAL if iovecs size does not match the message size
  virtio-balloon: tweak config_changed implementation
  virtio: don't allocate vqs when names[i] = NULL
  virtio_pci: use queue idx instead of array idx to set up the vq
  virtio: document virtio_config_ops restrictions
  virtio: fix virtio_config_ops description

Pull btrfs fixes from David Sterba:
 "A handful of fixes (some of them in testing for a long time):

   - fix some test failures regarding cleanup after transaction abort

   - revert of a patch that could cause a deadlock

   - delayed iput fixes, that can help in ENOSPC situation when there's
     low space and a lot data to write"

* tag 'for-5.0-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: wakeup cleaner thread when adding delayed iput
  btrfs: run delayed iputs before committing
  btrfs: wait on ordered extents on abort cleanup
  btrfs: handle delayed ref head accounting cleanup in abort
  Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"

Merge tags 'compiler-attributes-for-linus-v5.0-rc3' and 'clang-format-for-linus-v5.0-rc3' of git://github.com/ojeda/linux

Pull misc clang fixes from Miguel Ojeda:

  - A fix for OPTIMIZER_HIDE_VAR from Michael S Tsirkin

  - Update clang-format with the latest for_each macro list from Jason
    Gunthorpe

* tag 'compiler-attributes-for-linus-v5.0-rc3' of git://github.com/ojeda/linux:
  include/linux/compiler*.h: fix OPTIMIZER_HIDE_VAR

* tag 'clang-format-for-linus-v5.0-rc3' of git://github.com/ojeda/linux:
  clang-format: Update .clang-format with the latest for_each macro list

If an input number x for int_sqrt64() has the highest bit set, then
fls64(x) is 64.  (1UL << 64) is an overflow and breaks the algorithm.

Subtracting 1 is a better guess for the initial value of m anyway and
that's what also done in int_sqrt() implicitly [*].

[*] Note how int_sqrt() uses __fls() with two underscores, which already
    returns the proper raw bit number.

    In contrast, int_sqrt64() used fls64(), and that returns bit numbers
    illogically starting at 1, because of error handling for the "no
    bits set" case. Will points out that he bug probably is due to a
    copy-and-paste error from the regular int_sqrt() case.
Signed-off-by: Florian La Roche <Florian.LaRoche@googlemail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 594cc251 ("make 'user_access_begin()' do 'access_ok()'")
makes the access_ok() check part of the user_access_begin() preceding a
series of 'unsafe' accesses.  This has the desirable effect of ensuring
that all 'unsafe' accesses have been range-checked, without having to
pick through all of the callsites to verify whether the appropriate
checking has been made.

However, the consolidated range check does not inhibit speculation, so
it is still up to the caller to ensure that they are not susceptible to
any speculative side-channel attacks for user addresses that ultimately
fail the access_ok() check.

This is an oversight, so use __uaccess_begin_nospec() to ensure that
speculation is inhibited until the access_ok() check has passed.
Reported-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull arm64 fixes from Will Deacon:
 "Three arm64 fixes for -rc3.

  We've plugged a couple of nasty issues involving KASLR-enabled
  kernels, and removed a redundant #define that was introduced as part
  of the KHWASAN fixes from akpm at -rc2.

   - Fix broken kpti page-table rewrite in bizarre KASLR configuration

   - Fix module loading with KASLR

   - Remove redundant definition of ARCH_SLAB_MINALIGN"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  kasan, arm64: remove redundant ARCH_SLAB_MINALIGN define
  arm64: kaslr: ensure randomized quantities are clean to the PoC
  arm64: kpti: Update arm64_kernel_use_ng_mappings() when forced on

Daniel Borkmann says:

====================
pull-request: bpf 2019-01-20

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix a out-of-bounds access in __bpf_redirect_no_mac, from Willem.

2) Fix bpf_setsockopt to reset sock dst on SO_MARK changes, from Peter.

3) Fix map in map masking to prevent out-of-bounds access under
   speculative execution, from Daniel.

4) Fix bpf_setsockopt's SO_MAX_PACING_RATE to support TCP internal
   pacing, from Yuchung.

5) Fix json writer license in bpftool, from Thomas.

6) Fix AF_XDP to check if an actually queue exists during umem
   setup, from Krzysztof.

7) Several fixes to BPF stackmap's build id handling. Another fix
   for bpftool build to account for libbfd variations wrt linking
   requirements, from Stanislav.

8) Fix BPF samples build with clang by working around missing asm
   goto, from Yonghong.

9) Fix libbpf to retry program load on signal interrupt, from Lorenz.

10) Various minor compile warning fixes in BPF code, from Mathieu.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Syzkaller was able to construct a packet of negative length by
redirecting from bpf_prog_test_run_skb with BPF_PROG_TYPE_LWT_XMIT:

    BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:345 [inline]
    BUG: KASAN: slab-out-of-bounds in skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline]
    BUG: KASAN: slab-out-of-bounds in __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
    Read of size 4294967282 at addr ffff8801d798009c by task syz-executor2/12942

    kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
    check_memory_region_inline mm/kasan/kasan.c:260 [inline]
    check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
    memcpy+0x23/0x50 mm/kasan/kasan.c:302
    memcpy include/linux/string.h:345 [inline]
    skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline]
    __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
    __pskb_copy include/linux/skbuff.h:1053 [inline]
    pskb_copy include/linux/skbuff.h:2904 [inline]
    skb_realloc_headroom+0xe7/0x120 net/core/skbuff.c:1539
    ipip6_tunnel_xmit net/ipv6/sit.c:965 [inline]
    sit_tunnel_xmit+0xe1b/0x30d0 net/ipv6/sit.c:1029
    __netdev_start_xmit include/linux/netdevice.h:4325 [inline]
    netdev_start_xmit include/linux/netdevice.h:4334 [inline]
    xmit_one net/core/dev.c:3219 [inline]
    dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3235
    __dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3805
    dev_queue_xmit+0x17/0x20 net/core/dev.c:3838
    __bpf_tx_skb net/core/filter.c:2016 [inline]
    __bpf_redirect_common net/core/filter.c:2054 [inline]
    __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2061
    ____bpf_clone_redirect net/core/filter.c:2094 [inline]
    bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2066
    bpf_prog_41f2bcae09cd4ac3+0xb25/0x1000

The generated test constructs a packet with mac header, network
header, skb->data pointing to network header and skb->len 0.

Redirecting to a sit0 through __bpf_redirect_no_mac pulls the
mac length, even though skb->data already is at skb->network_header.
bpf_prog_test_run_skb has already pulled it as LWT_XMIT !is_l2.

Update the offset calculation to pull only if skb->data differs
from skb->network_header, which is not true in this case.

The test itself can be run only from commit 1cf1cae9 ("bpf:
introduce BPF_PROG_TEST_RUN command"), but the same type of packets
with skb at network header could already be built from lwt xmit hooks,
so this fix is more relevant to that commit.

Also set the mac header on redirect from LWT_XMIT, as even after this
change to __bpf_redirect_no_mac that field is expected to be set, but
is not yet in ip_finish_output2.

Fixes: 3a0af8fd ("bpf: BPF for lightweight tunnel infrastructure")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Use napi_consume_skb() to get bulk free.  Note that napi_consume_skb is
safe to call in a non-napi context as long as the napi_budget flag is
correct.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull MIPS fixes from Paul Burton:

 - Fix IPI handling for Lantiq SoCs, which was broken by changes made
   back in v4.12.

 - Enable OF/DT serial support in ath79_defconfig to give us working
   serial by default.

 - Fix 64b builds for the Jazz platform.

 - Set up a struct device for the BCM47xx SoC to allow BCM47xx drivers
   to perform DMA again following the major DMA mapping changes made in
   v4.19.

 - Disable MSI on Cavium Octeon systems when the pcie_disable command
   line parameter introduced in v3.3 is used, in order to avoid
   inadvetently accessing PCIe controller registers despite the command
   line.

 - Fix a build failure for Cavium Octeon kernels with kexec enabled,
   introduced in v4.20.

 - Fix a regression in the behaviour of semctl/shmctl/msgctl IPC
   syscalls for kernels including n32 support but not o32 support caused
   by some cleanup in v3.19.

* tag 'mips_fixes_5.0_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: OCTEON: fix kexec support
  mips: fix n32 compat_ipc_parse_version
  Disable MSI also when pcie-octeon.pcie_disable on
  MIPS: BCM47XX: Setup struct device for the SoC
  MIPS: jazz: fix 64bit build
  MIPS: ath79: Enable OF serial ports in the default config
  MIPS: lantiq: Use CP0_LEGACY_COMPARE_IRQ
  MIPS: lantiq: Fix IPI interrupt handling

Pull Devicetree fix from Rob Herring:
 "A single build fix for powerpc due to device_node.type removal"

* tag 'devicetree-fixes-for-5.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  powerpc: chrp: Use of_node_is_type to access device_type

Pull libnvdimm fixes from Dan Williams:
 "A crash fix, a build warning fix, a miscellaneous small cleanups.

  In case anyone is looking for them, there was a regression caught by
  testing that caused two patches to be dropped from this update.  Those
  patches have been reworked and will soak for another week / re-target
  5.0-rc4.

   - Fix driver initialization crash due to the inability to report an
     'error' state for a DIMM's security capability.

   - Build warning fix for little-endian ARM64 builds

   - Fix a potential race between the EDAC driver's usage of the NFIT
     SMBIOS id for a DIMM and the driver shutdown path.

   - A small collection of one-line benign cleanups for duplicate
     variable assignments, a duplicate header include and a mis-typed
     function argument"

* tag 'libnvdimm-fixes-5.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/security: Fix nvdimm_security_state() state request selection
  acpi/nfit: Remove duplicate set nd_set in acpi_nfit_init_interleave_set()
  acpi/nfit: Fix race accessing memdev in nfit_get_smbios_id()
  libnvdimm/dimm: Fix security capability detection for non-Intel NVDIMMs
  nfit: Mark some functions as __maybe_unused
  ACPI/nfit: delete the function to_acpi_nfit_desc
  ACPI/nfit: delete the redundant header file

Pull watchdog fixes from Wim Van Sebroeck:

 - mt7621_wdt/rt2880_wdt: Fix compilation problem

 - tqmx86: Fix a couple IS_ERR() vs NULL bugs

* tag 'linux-watchdog-5.0-rc-fixes' of git://www.linux-watchdog.org/linux-watchdog:
  watchdog: tqmx86: Fix a couple IS_ERR() vs NULL bugs
  watchdog: mt7621_wdt/rt2880_wdt: Fix compilation problem

Pull NFS client fixes from Anna Schumaker:
 "These are mostly fixes for SUNRPC bugs, with a single v4.2
  copy_file_range() fix mixed in.

  Stable bugfixes:
   - Fix TCP receive code on archs with flush_dcache_page()

  Other bugfixes:
   - Fix error code in rpcrdma_buffer_create()
   - Fix a double free in rpcrdma_send_ctxs_create()
   - Fix kernel BUG at kernel/cred.c:825
   - Fix unnecessary retry in nfs42_proc_copy_file_range()
   - Ensure rq_bytes_sent is reset before request transmission
   - Ensure we respect the RPCSEC_GSS sequence number limit
   - Address Kerberos performance/behavior regression"

* tag 'nfs-for-5.0-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  SUNRPC: Address Kerberos performance/behavior regression
  SUNRPC: Ensure we respect the RPCSEC_GSS sequence number limit
  SUNRPC: Ensure rq_bytes_sent is reset before request transmission
  NFSv4.2 fix unnecessary retry in nfs4_copy_file_range
  sunrpc: kernel BUG at kernel/cred.c:825!
  SUNRPC: Fix TCP receive code on archs with flush_dcache_page()
  xprtrdma: Double free in rpcrdma_sendctxs_create()
  xprtrdma: Fix error code in rpcrdma_buffer_create()

Pull SCSI fixes from James Bottomley:
 "A set of 17 fixes. Most of these are minor or trivial.

  The one fix that may be serious is the isci one: the bug can cause hba
  parameters to be set from uninitialized memory. I don't think it's
  exploitable, but you never know"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: cxgb4i: add wait_for_completion()
  scsi: qla1280: set 64bit coherent mask
  scsi: ufs: Fix geometry descriptor size
  scsi: megaraid_sas: Retry reads of outbound_intr_status reg
  scsi: qedi: Add ep_state for login completion on un-reachable targets
  scsi: ufs: Fix system suspend status
  scsi: qla2xxx: Use correct number of vectors for online CPUs
  scsi: hisi_sas: Set protection parameters prior to adding SCSI host
  scsi: tcmu: avoid cmd/qfull timers updated whenever a new cmd comes
  scsi: isci: initialize shost fully before calling scsi_add_host()
  scsi: lpfc: lpfc_sli: Mark expected switch fall-throughs
  scsi: smartpqi_init: fix boolean expression in pqi_device_remove_start
  scsi: core: Synchronize request queue PM status only on successful resume
  scsi: pm80xx: reduce indentation
  scsi: qla4xxx: check return code of qla4xxx_copy_from_fwddb_param
  scsi: megaraid_sas: correct an info message
  scsi: target/iscsi: fix error msg typo when create lio_qr_cache failed
  scsi: sd: Fix cache_type_store()

Pull block fixes from Jens Axboe:

 - block size setting fixes for loop/nbd (Jan Kara)

 - md bio_alloc_mddev() cleanup (Marcos)

 - Ensure we don't lose the REQ_INTEGRITY flag (Ming)

 - Two NVMe fixes by way of Christoph:
    - Fix NVMe IRQ calculation (Ming)
    - Uninitialized variable in nvmet-tcp (Sagi)

 - BFQ comment fix (Paolo)

 - License cleanup for recently added blk-mq-debugfs-zoned (Thomas)

* tag 'for-linus-20190118' of git://git.kernel.dk/linux-block:
  block: Cleanup license notice
  nvme-pci: fix nvme_setup_irqs()
  nvmet-tcp: fix uninitialized variable access
  block: don't lose track of REQ_INTEGRITY flag
  blockdev: Fix livelocks on loop device
  nbd: Use set_blocksize() to set device blocksize
  md: Make bio_alloc_mddev use bio_alloc_bioset
  block, bfq: fix comments on __bfq_deactivate_entity

Re-run the shell fragment that generated the original list. In particular
this adds the missing xarray related functions.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>