Those two functions have been unused since commit identified below.
Drop them.

Fixes: 31bfdb03 ("powerpc: Use instruction emulation infrastructure to handle alignment faults")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d5641ada199b8dd2af16ad00a66084cf974f2704.1596716418.git.christophe.leroy@csgroup.eu

Since the commit identified below, the forward declaration of
struct irqaction is useless. Drop it.

Fixes: b709c083 ("ppc64: move stack switching up in interrupt processing")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e0bcdabac45fcd26c02d7df273bd4a5827c6033d.1596716375.git.christophe.leroy@csgroup.eu

Since commit identified below, the forward declaration of
struct irq_chip is useless (was struct hw_interrupt_type at that time)

Remove it, together with the associated comment.

Fixes: c0ad90a3 ("[PATCH] genirq: add ->retrigger() irq op to consolidate hw_irq_resend()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fbe58d27cf128d5fe581e4510ded8701858f268e.1596716328.git.christophe.leroy@csgroup.eu

There are spelling mistakes in two debug messages. As recommended
by Wolfram Sang, these can be removed as there is plenty of debug
in the driver core.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200806102901.44988-1-colin.king@canonical.com

The assembler says:
  arch/powerpc/kernel/head_32.S:1095: Warning: invalid register expression

It's objecting to the use of r0 as the RA argument. That's because
when RA = 0 the literal value 0 is used, rather than the content of
r0, making the use of r0 in the source potentially confusing.

Fix it to use a literal 0, the generated code is identical.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2b69ac8e1cddff6f808fc7415907179eab4aae9e.1596693679.git.christophe.leroy@csgroup.eu

Building with W=1 results in the following warning:

In file included from arch/powerpc/platforms/powernv/vas-fault.c:16:
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
	coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
  159 | } __packed;
      | ^
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
	coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
	coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
	coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
cc1: all warnings being treated as errors

This happens because coprocessor_request_block includes several
sub-structures with an alignment specified using the __aligned(XX)
attribute. The problem comes from coprocessor_request_block having the
__packed attribute. Packing the structure causes the preferred alignment of
the nested structures to be ignored and we get the warnings as a result.

This isn't a problem in practice since the struct is defined with explicit
padding in the form of reserved fields, but we'd like to get rid of the
spurious warnings. The simplest solution is to remove the packed attribute
and use a BUILD_BUG_ON() to ensure the struct is the correct (expected by
HW) size compile time.

Also add a __aligned(128) to the request block structure since Book4 for P8
suggests the HW requires it to be aligned to a 128 byte boundary. There's a
similar requirement for P9 since the COPY and PASTE instructions used to
invoke VAS/NX accelerators operates on a cache line boundary.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804005410.146094-7-oohall@gmail.com

Comments opening with /** are parsed by kerneldoc and this causes the
following warning to be printed:

	arch/powerpc/platforms/powernv/opal-prd.c:31: warning: cannot understand
	function prototype: 'struct opal_prd_msg_queue_item '

opal_prd_mesg_queue_item is an internal data structure so there's no real
need for it to be documented at all. Fix up the comment to squash the
warning.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804005410.146094-5-oohall@gmail.com

There's a few scattered in the powernv platform.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804005410.146094-4-oohall@gmail.com

The asm/powernv.h header provides prototypes for functions which need to be
called by non-powernv platform code. Also include it in the powernv.h
that's local to the platform directory to squash some warnings about
non-static functions missing prototypes.

Also include powernv.h since from opal-memcons.c since it has the
prototypes for the memcons wrangling functions which are used for the opal
and ultravisor msglog.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804005410.146094-3-oohall@gmail.com

When building with W=1 we get the following warning:

 arch/powerpc/platforms/powernv/smp.c: In function ‘pnv_smp_cpu_kill_self’:
 arch/powerpc/platforms/powernv/smp.c:276:16: error: suggest braces around
 	empty body in an ‘if’ statement [-Werror=empty-body]
   276 |      cpu, srr1);
       |                ^
 cc1: all warnings being treated as errors

The full context is this block:

 if (srr1 && !generic_check_cpu_restart(cpu))
 	DBG("CPU%d Unexpected exit while offline srr1=%lx!\n",
 			cpu, srr1);

When building with DEBUG undefined DBG() expands to nothing and GCC emits
the warning due to the lack of braces around an empty statement.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804005410.146094-2-oohall@gmail.com

There is a spelling mistake in a pr_debug message. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804174316.402425-1-colin.king@canonical.com

Now that we are handling vmemmap list allocation failure correctly, don't
WARN in section deactivate when we don't find a mapping vmemmap list entry.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200731113500.248306-2-aneesh.kumar@linux.ibm.com

If we fail to allocate vmemmap list, we don't keep track of allocated
vmemmap block buf. Hence on section deactivate we skip vmemmap block
buf free. This results in memory leak.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200731113500.248306-1-aneesh.kumar@linux.ibm.com

Fix gcc '-Wunused-but-set-variable' warning:

arch/powerpc/platforms/powernv/pci-ioda.c: In function pnv_ioda_configure_pe:
arch/powerpc/platforms/powernv/pci-ioda.c:867:18: warning: variable parent set but not used [-Wunused-but-set-variable]

It is not used since commit b131a842 ("powerpc/powernv:
Set PELTV for compound PEs")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1574144074-142032-6-git-send-email-zhengbin13@huawei.com

Fix gcc '-Wunused-but-set-variable' warning:

arch/powerpc/perf/imc-pmu.c: In function trace_imc_event_init:
arch/powerpc/perf/imc-pmu.c:1292:22: warning: variable target set but not used [-Wunused-but-set-variable]

It is introduced by commit 012ae244 ("powerpc/perf:
Trace imc PMU functions"), but never used, so remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1574144074-142032-3-git-send-email-zhengbin13@huawei.com

Fix gcc '-Wunused-but-set-variable' warning:

arch/powerpc/kernel/fadump.c: In function fadump_update_elfcore_header:
arch/powerpc/kernel/fadump.c:790:17: warning: variable elf set but not used [-Wunused-but-set-variable]

It is introduced by commit ebaeb5ae ("fadump:
Convert firmware-assisted cpu state dump data into elf notes."),
but never used, so remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1574144074-142032-2-git-send-email-zhengbin13@huawei.com

Since the interrupt pin for RTC DS1339 is not connected
to the CPU on T1024RDB, remove the interrupt property
from the device tree.

This also fix the following warning for hwclock.util-linux:
$ hwclock.util-linux
hwclock.util-linux: select() to /dev/rtc0
to wait for clock tick timed out
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Acked-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527034228.23793-2-biwen.li@oss.nxp.com

Since the interrupt pin for RTC DS1374 is not connected
to the CPU on T4240RDB, remove the interrupt property
from the device tree.

This also fix the following warning for hwclock.util-linux:
$ hwclock.util-linux
hwclock.util-linux: select() to /dev/rtc0
to wait for clock tick timed out
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Acked-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527034228.23793-1-biwen.li@oss.nxp.com

Improve the error message shown if a capi adapter is plugged on a
capi-incompatible slot directly under the PHB (no intermediate switch).

Fixes: 56328743 ("cxl: Add support for POWER9 DD2")
Cc: stable@vger.kernel.org # 4.14+
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200407115601.25453-1-fbarrat@linux.ibm.com

We now allocate interrupts through xive directly.
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200403153838.29224-5-fbarrat@linux.ibm.com

Existing users of ocxl_link_irq_alloc() have been converted to obtain
the trigger page of an interrupt through xive directly, we therefore
have no need to return the trigger page when allocating an interrupt.

It also allows ocxl to use the xive native interface to allocate
interrupts, instead of its custom service.
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200403153838.29224-4-fbarrat@linux.ibm.com

We can access the trigger page through standard APIs so let's use it
and avoid saving it when allocating the interrupt. It will also allow
to simplify allocation in a later patch.
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200403153838.29224-3-fbarrat@linux.ibm.com

xive is already mapping the trigger page in kernel space and it can be
accessed through standard APIs, so let's reuse it and simplify the code.
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Matthew R. Ochs <mrochs@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200403153838.29224-2-fbarrat@linux.ibm.com

Both of_find_compatible_node() and of_find_node_by_type() will return
a refcounted node on success - thus for the success path the node must
be explicitly released with a of_node_put().

Fixes: 0b05ac6e ("powerpc/xics: Rewrite XICS driver")
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1530691407-3991-1-git-send-email-hofrat@osadl.org

The call to of_find_compatible_node() returns a node pointer with
refcount incremented thus it must be explicitly decremented here
before returning.

Fixes: a489043f ("powerpc/pseries: Implement arch_get_random_long() based on H_RANDOM")
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1530522496-14816-1-git-send-email-hofrat@osadl.org

Pull powerpc fixes from Michael Ellerman:

 - Add perf support for emitting extended registers for power10.

 - A fix for CPU hotplug on pseries, where on large/loaded systems we
   may not wait long enough for the CPU to be offlined, leading to
   crashes.

 - Addition of a raw cputable entry for Power10, which is not required
   to boot, but is required to make our PMU setup work correctly in
   guests.

 - Three fixes for the recent changes on 32-bit Book3S to move modules
   into their own segment for strict RWX.

 - A fix for a recent change in our powernv PCI code that could lead to
   crashes.

 - A change to our perf interrupt accounting to avoid soft lockups when
   using some events, found by syzkaller.

 - A change in the way we handle power loss events from the hypervisor
   on pseries. We no longer immediately shut down if we're told we're
   running on a UPS.

 - A few other minor fixes.

Thanks to Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T
Sudhakar, Athira Rajeev, Christophe Leroy, Frederic Barrat, Greg Kurz,
Kajol Jain, Madhavan Srinivasan, Michael Neuling, Michael Roth,
Nageswara R Sastry, Oliver O'Halloran, Thiago Jung Bauermann,
Vaidyanathan Srinivasan, Vasant Hegde.

* tag 'powerpc-5.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/perf/hv-24x7: Move cpumask file to top folder of hv-24x7 driver
  powerpc/32s: Fix module loading failure when VMALLOC_END is over 0xf0000000
  powerpc/pseries: Do not initiate shutdown when system is running on UPS
  powerpc/perf: Fix soft lockups due to missed interrupt accounting
  powerpc/powernv/pci: Fix possible crash when releasing DMA resources
  powerpc/pseries/hotplug-cpu: wait indefinitely for vCPU death
  powerpc/32s: Fix is_module_segment() when MODULES_VADDR is defined
  powerpc/kasan: Fix KASAN_SHADOW_START on BOOK3S_32
  powerpc/fixmap: Fix the size of the early debug area
  powerpc/pkeys: Fix build error with PPC_MEM_KEYS disabled
  powerpc/kernel: Cleanup machine check function declarations
  powerpc: Add POWER10 raw mode cputable entry
  powerpc/perf: Add extended regs support for power10 platform
  powerpc/perf: Add support for outputting extended regs in perf intr_regs
  powerpc: Fix P10 PVR revision in /proc/cpuinfo for SMT4 cores

Pull x86 fix from Thomas Gleixner:
 "A single fix for x86 which removes the RDPID usage from the paranoid
  entry path and unconditionally uses LSL to retrieve the CPU number.

  RDPID depends on MSR_TSX_AUX. KVM has an optmization to avoid
  expensive MRS read/writes on VMENTER/EXIT. It caches the MSR values
  and restores them either when leaving the run loop, on preemption or
  when going out to user space. MSR_TSX_AUX is part of that lazy MSR
  set, so after writing the guest value and before the lazy restore any
  exception using the paranoid entry will read the guest value and use
  it as CPU number to retrieve the GSBASE value for the current CPU when
  FSGSBASE is enabled. As RDPID is only used in that particular entry
  path, there is no reason to burden VMENTER/EXIT with two extra MSR
  writes. Remove the RDPID optimization, which is not even backed by
  numbers from the paranoid entry path instead"

* tag 'x86-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Do not use RDPID in paranoid entry to accomodate KVM

Pull x86 perf fix from Thomas Gleixner:
 "A single update for perf on x86 which has support for the broken down
  bandwith counters"

* tag 'perf-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Add BW counters for GT, IA and IO breakdown

Pull EFI fixes from Thomas Gleixner:

 - Enforce NX on RO data in mixed EFI mode

 - Destroy workqueue in an error handling path to prevent UAF

 - Stop argument parser at '--' which is the delimiter for init

 - Treat a NULL command line pointer as empty instead of dereferncing it
   unconditionally.

 - Handle an unterminated command line correctly

 - Cleanup the 32bit code leftovers and remove obsolete documentation

* tag 'efi-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation: efi: remove description of efi=old_map
  efi/x86: Move 32-bit code into efi_32.c
  efi/libstub: Handle unterminated cmdline
  efi/libstub: Handle NULL cmdline
  efi/libstub: Stop parsing arguments at "--"
  efi: add missed destroy_workqueue when efisubsys_init fails
  efi/x86: Mark kernel rodata non-executable for mixed mode

Pull entry fix from Thomas Gleixner:
 "A single bug fix for the common entry code.

  The transcription of the x86 version messed up the reload of the
  syscall number from pt_regs after ptrace and seccomp which breaks
  syscall number rewriting"

* tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  core/entry: Respect syscall number rewrites

Pull EDAC fix from Borislav Petkov:
 "A single fix correcting a reversed error severity determination check
  which lead to a recoverable error getting marked as fatal, by Tony
  Luck"

* tag 'edac_urgent_for_v5.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/{i7core,sb,pnd2,skx}: Fix error event severity

Pull networking fixes from David Miller:
 "Nothing earth shattering here, lots of small fixes (f.e. missing RCU
  protection, bad ref counting, missing memset(), etc.) all over the
  place:

   1) Use get_file_rcu() in task_file iterator, from Yonghong Song.

   2) There are two ways to set remote source MAC addresses in macvlan
      driver, but only one of which validates things properly. Fix this.
      From Alvin Šipraga.

   3) Missing of_node_put() in gianfar probing, from Sumera
      Priyadarsini.

   4) Preserve device wanted feature bits across multiple netlink
      ethtool requests, from Maxim Mikityanskiy.

   5) Fix rcu_sched stall in task and task_file bpf iterators, from
      Yonghong Song.

   6) Avoid reset after device destroy in ena driver, from Shay
      Agroskin.

   7) Missing memset() in netlink policy export reallocation path, from
      Johannes Berg.

   8) Fix info leak in __smc_diag_dump(), from Peilin Ye.

   9) Decapsulate ECN properly for ipv6 in ipv4 tunnels, from Mark
      Tomlinson.

  10) Fix number of data stream negotiation in SCTP, from David Laight.

  11) Fix double free in connection tracker action module, from Alaa
      Hleihel.

  12) Don't allow empty NHA_GROUP attributes, from Nikolay Aleksandrov"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (46 commits)
  net: nexthop: don't allow empty NHA_GROUP
  bpf: Fix two typos in uapi/linux/bpf.h
  net: dsa: b53: check for timeout
  tipc: call rcu_read_lock() in tipc_aead_encrypt_done()
  net/sched: act_ct: Fix skb double-free in tcf_ct_handle_fragments() error flow
  net: sctp: Fix negotiation of the number of data streams.
  dt-bindings: net: renesas, ether: Improve schema validation
  gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY
  hv_netvsc: Fix the queue_mapping in netvsc_vf_xmit()
  hv_netvsc: Remove "unlikely" from netvsc_select_queue
  bpf: selftests: global_funcs: Check err_str before strstr
  bpf: xdp: Fix XDP mode when no mode flags specified
  selftests/bpf: Remove test_align leftovers
  tools/resolve_btfids: Fix sections with wrong alignment
  net/smc: Prevent kernel-infoleak in __smc_diag_dump()
  sfc: fix build warnings on 32-bit
  net: phy: mscc: Fix a couple of spelling mistakes "spcified" -> "specified"
  libbpf: Fix map index used in error message
  net: gemini: Fix missing free_netdev() in error path of gemini_ethernet_port_probe()
  net: atlantic: Use readx_poll_timeout() for large timeout
  ...

Pull epoll fixes from Al Viro:
 "Fix reference counting and clean up exit paths"

* 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  do_epoll_ctl(): clean the failure exits up a bit
  epoll: Keep a reference on files added to the check list

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

When adding a new fd to an epoll, and that this new fd is an
epoll fd itself, we recursively scan the fds attached to it
to detect cycles, and add non-epool files to a "check list"
that gets subsequently parsed.

However, this check list isn't completely safe when deletions
can happen concurrently. To sidestep the issue, make sure that
a struct file placed on the check list sees its f_count increased,
ensuring that a concurrent deletion won't result in the file
disapearing from under our feet.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Currently the nexthop code will use an empty NHA_GROUP attribute, but it
requires at least 1 entry in order to function properly. Otherwise we
end up derefencing null or random pointers all over the place due to not
having any nh_grp_entry members allocated, nexthop code relies on having at
least the first member present. Empty NHA_GROUP doesn't make any sense so
just disallow it.
Also add a WARN_ON for any future users of nexthop_create_group().

 BUG: kernel NULL pointer dereference, address: 0000000000000080
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP
 CPU: 0 PID: 558 Comm: ip Not tainted 5.9.0-rc1+ #93
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
 RIP: 0010:fib_check_nexthop+0x4a/0xaa
 Code: 0f 84 83 00 00 00 48 c7 02 80 03 f7 81 c3 40 80 fe fe 75 12 b8 ea ff ff ff 48 85 d2 74 6b 48 c7 02 40 03 f7 81 c3 48 8b 40 10 <48> 8b 80 80 00 00 00 eb 36 80 78 1a 00 74 12 b8 ea ff ff ff 48 85
 RSP: 0018:ffff88807983ba00 EFLAGS: 00010213
 RAX: 0000000000000000 RBX: ffff88807983bc00 RCX: 0000000000000000
 RDX: ffff88807983bc00 RSI: 0000000000000000 RDI: ffff88807bdd0a80
 RBP: ffff88807983baf8 R08: 0000000000000dc0 R09: 000000000000040a
 R10: 0000000000000000 R11: ffff88807bdd0ae8 R12: 0000000000000000
 R13: 0000000000000000 R14: ffff88807bea3100 R15: 0000000000000001
 FS:  00007f10db393700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000080 CR3: 000000007bd0f004 CR4: 00000000003706f0
 Call Trace:
  fib_create_info+0x64d/0xaf7
  fib_table_insert+0xf6/0x581
  ? __vma_adjust+0x3b6/0x4d4
  inet_rtm_newroute+0x56/0x70
  rtnetlink_rcv_msg+0x1e3/0x20d
  ? rtnl_calcit.isra.0+0xb8/0xb8
  netlink_rcv_skb+0x5b/0xac
  netlink_unicast+0xfa/0x17b
  netlink_sendmsg+0x334/0x353
  sock_sendmsg_nosec+0xf/0x3f
  ____sys_sendmsg+0x1a0/0x1fc
  ? copy_msghdr_from_user+0x4c/0x61
  ___sys_sendmsg+0x63/0x84
  ? handle_mm_fault+0xa39/0x11b5
  ? sockfd_lookup_light+0x72/0x9a
  __sys_sendmsg+0x50/0x6e
  do_syscall_64+0x54/0xbe
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f10dacc0bb7
 Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb cd 66 0f 1f 44 00 00 8b 05 9a 4b 2b 00 85 c0 75 2e 48 63 ff 48 63 d2 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 b1 f2 2a 00 f7 d8 64 89 02 48
 RSP: 002b:00007ffcbe628bf8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 00007ffcbe628f80 RCX: 00007f10dacc0bb7
 RDX: 0000000000000000 RSI: 00007ffcbe628c60 RDI: 0000000000000003
 RBP: 000000005f41099c R08: 0000000000000001 R09: 0000000000000008
 R10: 00000000000005e9 R11: 0000000000000246 R12: 0000000000000000
 R13: 0000000000000000 R14: 00007ffcbe628d70 R15: 0000563a86c6e440
 Modules linked in:
 CR2: 0000000000000080

CC: David Ahern <dsahern@gmail.com>
Fixes: 430a0491 ("nexthop: Add support for nexthop groups")
Reported-by: syzbot+a61aa19b0c14c8770bd9@syzkaller.appspotmail.com
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'kbuild-fixes-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - move -Wsign-compare warning from W=2 to W=3

 - fix the keyword _restrict to __restrict in genksyms

 - fix more bugs in qconf

* tag 'kbuild-fixes-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: qconf: replace deprecated QString::sprintf() with QTextStream
  kconfig: qconf: remove redundant help in the info view
  kconfig: qconf: remove qInfo() to get back Qt4 support
  kconfig: qconf: remove unused colNr
  kconfig: qconf: fix the popup menu in the ConfigInfoView window
  kconfig: qconf: fix signal connection to invalid slots
  genksyms: keywords: Use __restrict not _restrict
  kbuild: remove redundant patterns in filter/filter-out
  extract-cert: add static to local data
  Makefile.extrawarn: Move sign-compare from W=2 to W=3

Pull arm64 fixes from Catalin Marinas:

 - Allow booting of late secondary CPUs affected by erratum 1418040
   (currently they are parked if none of the early CPUs are affected by
   this erratum).

 - Add the 32-bit vdso Makefile to the vdso_install rule so that 'make
   vdso_install' installs the 32-bit compat vdso when it is compiled.

 - Print a warning that untrusted guests without a CPU erratum
   workaround (Cortex-A57 832075) may deadlock the affected system.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  ARM64: vdso32: Install vdso32 from vdso_install
  KVM: arm64: Print warning when cpu erratum can cause guests to deadlock
  arm64: Allow booting of late CPUs affected by erratum 1418040
  arm64: Move handling of erratum 1418040 into C code

Pull s390 fixes from Vasily Gorbik:

 - a couple of fixes for storage key handling relevant for debugging

 - add cond_resched into potentially slow subchannels scanning loop

 - fixes for PF/VF linking and to ignore stale PCI configuration request
   events

* tag 's390-5.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: fix PF/VF linking on hot plug
  s390/pci: re-introduce zpci_remove_device()
  s390/pci: fix zpci_bus_link_virtfn()
  s390/ptrace: fix storage key handling
  s390/runtime_instrumentation: fix storage key handling
  s390/pci: ignore stale configuration request event
  s390/cio: add cond_resched() in the slow_eval_known_fn() loop