Allocate the rmap array during kvm_arch_prepare_memory_region() to pave
the way for removing kvm_arch_create_memslot() altogether.  Moving PPC's
memory allocation only changes the order of kernel memory allocations
between PPC and common KVM code.

No functional change intended.
Acked-by: NPaul Mackerras <paulus@ozlabs.org>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When CONFIG_PROVE_LOCKING is selected together with (now default)
CONFIG_VMAP_STACK, kernel enter deadlock during boot.

At the point of checking whether interrupts are enabled or not, the
value of MSR saved on stack is read using the physical address of the
stack. But at this point, when using VMAP stack the DATA MMU
translation has already been re-enabled, leading to deadlock.

Don't use the physical address of the stack when
CONFIG_VMAP_STACK is set.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Fixes: 02847487 ("powerpc/32: prepare for CONFIG_VMAP_STACK")
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/daeacdc0dec0416d1c587cc9f9e7191ad3068dc0.1581095957.git.christophe.leroy@c-s.fr

The early versions of our kernel user access prevention (KUAP) were
written by Russell and Christophe, and didn't have separate
read/write access.

At some point I picked up the series and added the read/write access,
but I failed to update the usages in futex.h to correctly allow read
and write.

However we didn't notice because of another bug which was causing the
low-level code to always enable read and write. That bug was fixed
recently in commit 1d8f739b ("powerpc/kuap: Fix set direction in
allow/prevent_user_access()").

futex_atomic_cmpxchg_inatomic() is passed the user address as %3 and
does:

  1:     lwarx   %1,  0, %3
         cmpw    0,  %1, %4
         bne-    3f
  2:     stwcx.  %5,  0, %3

Which clearly loads and stores from/to %3. The logic in
arch_futex_atomic_op_inuser() is similar, so fix both of them to use
allow_read_write_user().

Without this fix, and with PPC_KUAP_DEBUG=y, we see eg:

  Bug: Read fault blocked by AMR!
  WARNING: CPU: 94 PID: 149215 at arch/powerpc/include/asm/book3s/64/kup-radix.h:126 __do_page_fault+0x600/0xf30
  CPU: 94 PID: 149215 Comm: futex_requeue_p Tainted: G        W         5.5.0-rc7-gcc9x-g4c25df56 #1
  ...
  NIP [c000000000070680] __do_page_fault+0x600/0xf30
  LR [c00000000007067c] __do_page_fault+0x5fc/0xf30
  Call Trace:
  [c00020138e5637e0] [c00000000007067c] __do_page_fault+0x5fc/0xf30 (unreliable)
  [c00020138e5638c0] [c00000000000ada8] handle_page_fault+0x10/0x30
  --- interrupt: 301 at cmpxchg_futex_value_locked+0x68/0xd0
      LR = futex_lock_pi_atomic+0xe0/0x1f0
  [c00020138e563bc0] [c000000000217b50] futex_lock_pi_atomic+0x80/0x1f0 (unreliable)
  [c00020138e563c30] [c00000000021b668] futex_requeue+0x438/0xb60
  [c00020138e563d60] [c00000000021c6cc] do_futex+0x1ec/0x2b0
  [c00020138e563d90] [c00000000021c8b8] sys_futex+0x128/0x200
  [c00020138e563e20] [c00000000000b7ac] system_call+0x5c/0x68

Fixes: de78a9c4 ("powerpc: Add a framework for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: syzbot+e808452bad7c375cbee6@syzkaller-ppc64.appspotmail.com
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200207122145.11928-1-mpe@ellerman.id.au

The former contains nothing but a pointer to an array of the latter...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Unused now.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Since the need for a special flag to support SCSI passthrough on a
block device was added in May 2017 the SCSI passthrough support in
virtio-blk has been disabled.  It has always been a bad idea
(just ask the original author..) and we have virtio-scsi for proper
passthrough.  The feature also never made it into the virtio 1.0
or later specifications.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

	llseek		=> proc_lseek
	unlocked_ioctl	=> proc_ioctl

	xxx		=> proc_xxx

	delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
  Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Towards a more consistent naming scheme.

Link: http://lkml.kernel.org/r/20200116064531.483522-8-aneesh.kumar@linux.ibm.comSigned-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Towards a more consistent naming scheme.

[akpm@linux-foundation.org: fix sparc64 Kconfig]
Link: http://lkml.kernel.org/r/20200116064531.483522-7-aneesh.kumar@linux.ibm.comSigned-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Architectures for which we have hardware walkers of Linux page table
should flush TLB on mmu gather batch allocation failures and batch flush.
Some architectures like POWER supports multiple translation modes (hash
and radix) and in the case of POWER only radix translation mode needs the
above TLBI.  This is because for hash translation mode kernel wants to
avoid this extra flush since there are no hardware walkers of linux page
table.  With radix translation, the hardware also walks linux page table
and with that, kernel needs to make sure to TLB invalidate page walk cache
before page table pages are freed.

More details in commit d86564a2 ("mm/tlb, x86/mm: Support invalidating
TLB caches for RCU_TABLE_FREE")

The changes to sparc are to make sure we keep the old behavior since we
are now removing HAVE_RCU_TABLE_NO_INVALIDATE.  The default value for
tlb_needs_table_invalidate is to always force an invalidate and sparc can
avoid the table invalidate.  Hence we define tlb_needs_table_invalidate to
false for sparc architecture.

Link: http://lkml.kernel.org/r/20200116064531.483522-3-aneesh.kumar@linux.ibm.com
Fixes: a46cc7a9 ("powerpc/mm/radix: Improve TLB/PWC flushes")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Cc: <stable@vger.kernel.org>	[4.14+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "Fixup page directory freeing", v4.

This is a repost of patch series from Peter with the arch specific changes
except ppc64 dropped.  ppc64 changes are added here because we are redoing
the patch series on top of ppc64 changes.  This makes it easy to backport
these changes.  Only the first 2 patches need to be backported to stable.

The thing is, on anything SMP, freeing page directories should observe the
exact same order as normal page freeing:

 1) unhook page/directory
 2) TLB invalidate
 3) free page/directory

Without this, any concurrent page-table walk could end up with a
Use-after-Free.  This is esp.  trivial for anything that has software
page-table walkers (HAVE_FAST_GUP / software TLB fill) or the hardware
caches partial page-walks (ie.  caches page directories).

Even on UP this might give issues since mmu_gather is preemptible these
days.  An interrupt or preempted task accessing user pages might stumble
into the free page if the hardware caches page directories.

This patch series fixes ppc64 and add generic MMU_GATHER changes to
support the conversion of other architectures.  I haven't added patches
w.r.t other architecture because they are yet to be acked.

This patch (of 9):

A followup patch is going to make sure we correctly invalidate page walk
cache before we free page table pages.  In order to keep things simple
enable RCU_TABLE_FREE even for !SMP so that we don't have to fixup the
!SMP case differently in the followup patch

!SMP case is right now broken for radix translation w.r.t page walk
cache flush.  We can get interrupted in between page table free and
that would imply we have page walk cache entries pointing to tables
which got freed already.  Michael said "both our platforms that run on
Power9 force SMP on in Kconfig, so the !SMP case is unlikely to be a
problem for anyone in practice, unless they've hacked their kernel to
build it !SMP."

Link: http://lkml.kernel.org/r/20200116064531.483522-2-aneesh.kumar@linux.ibm.comSigned-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

walk_page_range() is going to be allowed to walk page tables other than
those of user space.  For this it needs to know when it has reached a
'leaf' entry in the page tables.  This information is provided by the
p?d_leaf() functions/macros.

For powerpc p?d_is_leaf() functions already exist.  Export them using the
new p?d_leaf() name.

Link: http://lkml.kernel.org/r/20191218162402.45610-7-steven.price@arm.comSigned-off-by: NSteven Price <steven.price@arm.com>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.

It is typically useful in scripts/Makefile because it allows Kbuild to
selectively compile host programs based on the kernel configuration.

This commit renames like follows:

  always       ->  always-y
  hostprogs-y  ->  hostprogs

So, scripts/Makefile will look like this:

  always-$(CONFIG_BUILD_BIN2C) += ...
  always-$(CONFIG_KALLSYMS)    += ...
      ...
  hostprogs := $(always-y) $(always-m)

I think this makes more sense because a host program is always a host
program, irrespective of the kernel configuration. We want to specify
which ones to compile by CONFIG options, so always-y will be handier.

The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
compatibility for a while.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

In order to provide a clearer, more symmetric API for pinning and
unpinning DMA pages.  This way, pin_user_pages*() calls match up with
unpin_user_pages*() calls, and the API is a lot closer to being
self-explanatory.

Link: http://lkml.kernel.org/r/20200107224558.2362728-23-jhubbard@nvidia.comSigned-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1. Convert from get_user_pages() to pin_user_pages().

2. As required by pin_user_pages(), release these pages via
   put_user_page().

Link: http://lkml.kernel.org/r/20200107224558.2362728-21-jhubbard@nvidia.comSigned-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_ENABLE_WARN_DEPRECATED is gone since
commit 771c0353 ("deprecate the '__deprecated' attribute warnings
entirely and for good").

CONFIG_IOSCHED_DEADLINE and CONFIG_IOSCHED_CFQ are gone since
commit f382fb0b ("block: remove legacy IO schedulers").

The IOSCHED_DEADLINE was replaced by MQ_IOSCHED_DEADLINE and it will be
now enabled by default (along with MQ_IOSCHED_KYBER).
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200130195223.3843-1-krzk@kernel.org

Enable more hardening options.

Note BUG_ON_DATA_CORRUPTION selects DEBUG_LIST and is essentially just
a synonym for it.

DEBUG_SG, DEBUG_NOTIFIERS, DEBUG_LIST, DEBUG_CREDENTIALS and
SCHED_STACK_END_CHECK should all be low overhead and just add a few
extra checks.

SLAB_FREELIST_RANDOM, and SLUB_DEBUG_ON will add some overhead to the
SLAB allocator, but nothing that should be meaningful for skiroot.

Unselecting SLAB_MERGE_DEFAULT causes the SLAB to use more memory, but
the skiroot kernel shouldn't be memory constrained on any of our
systems, all it does is run a small bootloader.

Disabling merging has some security/robustness benefit as it means a
user-after-free or overflow will be limited to the objects in that
slab, rather than potentially affecting objects from unrelated slabs
that have been merged.

Note also that slab merging is disabled anyway by enabling
SLUB_DEBUG_ON, because of the SLAB_NEVER_MERGE mask.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-9-mpe@ellerman.id.au

If the skiroot kernel crashes we don't want it sitting at an xmon
prompt forever. Instead it's more helpful to reboot and bring the
boot loader back up, and if the crash was transient we can then boot
successfully.

Similarly if we panic we should reboot, with a short timeout in case
someone is watching the console.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-8-mpe@ellerman.id.au

This turns on HARDENED_USERCOPY with HARDENED_USERCOPY_PAGESPAN, and
FORTIFY_SOURCE.

It also enables SECURITY_LOCKDOWN_LSM with _EARLY and
LOCK_DOWN_KERNEL_FORCE_INTEGRITY options enabled. This still allows
xmon to be used in read-only mode.

MODULE_SIG is selected by lockdown, so it is still enabled.

Because we're setting LOCK_DOWN_KERNELFORCE_INTEGRITY=y we also need
to enable KEXEC_FILE=y so that kexec continues to work.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
[mpe: Switch to lockdown integrity mode per oohal, enable KEXEC_FILE
      as reported by jms]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-7-mpe@ellerman.id.au

Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-6-mpe@ellerman.id.au

It's default n so we don't need to disable it.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-5-mpe@ellerman.id.au

Commit bdd08fff ("HID: logitech: Add depends on LEDS_CLASS to
Logitech Kconfig entry") made HID_LOGITECH depend on LEDS_CLASS which
we do not enable, meaning we are not actually enabling those drivers
any more.

The Kconfig help text suggests USB HID compliant Logictech devices
will continue to work without HID_LOGITECH, so just drop it.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-4-mpe@ellerman.id.au

The HP network driver moved to staging in commit 52340b82 ("hp100:
Move 100BaseVG AnyLAN driver to staging") meaning we don't need to
disable it any more in our defconfigs.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-3-mpe@ellerman.id.au

The NET_CADENCE symbol was renamed to NET_VENDOR_CADENCE, so we don't
need to disable the former, see commit 0df5f81c ("net: ethernet:
Add missing VENDOR to Cadence and Packet Engines symbols").
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-2-mpe@ellerman.id.au

The QLGE driver moved to staging in commit 955315b0 ("qlge: Move
drivers/net/ethernet/qlogic/qlge/ to drivers/staging/qlge/"), meaning
our defconfigs that enable it have no effect as we don't enable
CONFIG_STAGING.

It sounds like the device is obsolete, so drop the driver.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200121043000.16212-1-mpe@ellerman.id.au

Commit 8580ac94 ("bpf: Process in-kernel BTF") introduced two weak
symbols that may be unresolved at link time which result in an absolute
relocation to 0. relocs_check.sh emits the following warning:

"WARNING: 2 bad relocations
c000000001a41478 R_PPC64_ADDR64    _binary__btf_vmlinux_bin_start
c000000001a41480 R_PPC64_ADDR64    _binary__btf_vmlinux_bin_end"

whereas those relocations are legitimate even for a relocatable kernel
compiled with -pie option.

relocs_check.sh already excluded some weak unresolved symbols explicitly:
remove those hardcoded symbols and add some logic that parses the symbols
using nm, retrieves all the weak unresolved symbols and excludes those from
the list of the potential bad relocations.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAlexandre Ghiti <alex@ghiti.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200118170335.21440-1-alex@ghiti.fr

On book3s/32 CPUs that are handling MMU through a hash table,
MMU_init_hw() function was adapted for VMAP_STACK in order to
handle virtual addresses instead of physical addresses in the
low level hash functions.

When using KASAN, the same adaptations are required for the
early hash table set up by kasan_early_hash_table() function.

Fixes: cd08f109 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fc8390a33c2a470105f01abbcbdc7916c30c0a54.1580301269.git.christophe.leroy@c-s.fr

Indent a Kconfig continuation line to improve readability.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ff8729c1-3a4b-c720-48ba-a1a42b0ef892@infradead.org

This doc patch provides an initial description of the hcall op-codes
that are used by Linux kernel running as a guest (LPAR) on top of
PowerVM or any other sPAPR compliant hyper-visor (e.g qemu).

Apart from documenting the hcalls the doc-patch also provides a
rudimentary overview of how hcall ABI, how they are issued with the
Linux kernel and how information/control flows between the guest and
hypervisor.
Signed-off-by: NVaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: NLaurent Dufour <ldufour@linux.ibm.com>
Acked-by: NNicholas Piggin <npiggin@gmail.com>
[mpe: Add SPDX tag, add it to index.rst]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190828082729.16695-1-vaibhav@linux.ibm.com

Fixes: 3a167bea ("kvm: powerpc: Add kvmppc_ops callback")
Signed-off-by: NDavid Michael <fedora.dm0@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

When migrate_vma_setup() fails in kvmppc_svm_page_out(),
release kvm->arch.uvmem_lock before returning.

Fixes: ca9f4942 ("KVM: PPC: Book3S HV: Support for running secure guests")
Signed-off-by: NBharata B Rao <bharata@linux.ibm.com>
Reviewed-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

There's an OF helper called of_dma_is_coherent(), which checks if a
device has a "dma-coherent" property to see if the device is coherent
for DMA.

But on some platforms devices are coherent by default, and on some
platforms it's not possible to update existing device trees to add the
"dma-coherent" property.

So add a Kconfig symbol to allow arch code to tell
of_dma_is_coherent() that devices are coherent by default, regardless
of the presence of the property.

Select that symbol on powerpc when NOT_COHERENT_CACHE is not set, ie.
when the system has a coherent cache.

Fixes: 92ea637e ("of: introduce of_dma_is_coherent() helper")
Cc: stable@vger.kernel.org # v3.16+
Reported-by: NChristian Zigotzky <chzigotzky@xenosoft.de>
Tested-by: NChristian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRob Herring <robh@kernel.org>

Implement user_access_save() and user_access_restore()

On 8xx and radix:
  - On save, get the value of the associated special register then
    prevent user access.
  - On restore, set back the saved value to the associated special
    register.

On book3s/32:
  - On save, get the value stored in current->thread.kuap and prevent
    user access.
  - On restore, regenerate address range from the stored value and
    reopen read/write access for that range.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/54f2f74938006b33c55a416674807b42ef222068.1579866752.git.christophe.leroy@c-s.fr

Today, when a function like strncpy_from_user() is called,
the userspace access protection is de-activated and re-activated
for every word read.

By implementing user_access_begin and friends, the protection
is de-activated at the beginning of the copy and re-activated at the
end.

Implement user_access_begin(), user_access_end() and
unsafe_get_user(), unsafe_put_user() and unsafe_copy_to_user()

For the time being, we keep user_access_save() and
user_access_restore() as nops.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/36d4fbf9e56a75994aca4ee2214c77b26a5a8d35.1579866752.git.christophe.leroy@c-s.fr

In preparation of implementing user_access_begin and friends
on powerpc, the book3s/32 version of prevent_user_access() need
to be prepared for user_access_end().

user_access_end() doesn't provide the address and size which
were passed to user_access_begin(), required by prevent_user_access()
to know which segment to modify.

The list of segments which where unprotected by allow_user_access()
are available in current->kuap. But we don't want prevent_user_access()
to read this all the time, especially everytime it is 0 (for instance
because the access was not a write access).

Implement a special direction named KUAP_CURRENT. In this case only,
the addr and end are retrieved from current->kuap.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/55bcc1f25d8200892a31f67a0b024ff3b816c3cc.1579866752.git.christophe.leroy@c-s.fr

NULL addr is a user address. Don't waste time checking it. If
someone tries to access it, it will SIGFAULT the same way as for
address 1, so no need to make it special.

The special case is when not doing a write, in that case we want
to drop the entire function. This is now handled by 'dir' param
and not by the nulity of 'to' anymore.

Also make beginning of prevent_user_access() similar
to beginning of allow_user_access(), and tell the compiler
that writing in kernel space or with a 0 length is unlikely
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/85e971223dfe6ace734637db1841678939a76155.1579866752.git.christophe.leroy@c-s.fr

__builtin_constant_p() always return 0 for pointers, so on RADIX
we always end up opening both direction (by writing 0 in SPR29):

  0000000000000170 <._copy_to_user>:
  ...
   1b0:	4c 00 01 2c 	isync
   1b4:	39 20 00 00 	li      r9,0
   1b8:	7d 3d 03 a6 	mtspr   29,r9
   1bc:	4c 00 01 2c 	isync
   1c0:	48 00 00 01 	bl      1c0 <._copy_to_user+0x50>
  			1c0: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000220 <._copy_from_user>:
  ...
   2ac:	4c 00 01 2c 	isync
   2b0:	39 20 00 00 	li      r9,0
   2b4:	7d 3d 03 a6 	mtspr   29,r9
   2b8:	4c 00 01 2c 	isync
   2bc:	7f c5 f3 78 	mr      r5,r30
   2c0:	7f 83 e3 78 	mr      r3,r28
   2c4:	48 00 00 01 	bl      2c4 <._copy_from_user+0xa4>
  			2c4: R_PPC64_REL24	.__copy_tofrom_user
  ...

Use an explicit parameter for direction selection, so that GCC
is able to see it is a constant:

  00000000000001b0 <._copy_to_user>:
  ...
   1f0:	4c 00 01 2c 	isync
   1f4:	3d 20 40 00 	lis     r9,16384
   1f8:	79 29 07 c6 	rldicr  r9,r9,32,31
   1fc:	7d 3d 03 a6 	mtspr   29,r9
   200:	4c 00 01 2c 	isync
   204:	48 00 00 01 	bl      204 <._copy_to_user+0x54>
  			204: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000260 <._copy_from_user>:
  ...
   2ec:	4c 00 01 2c 	isync
   2f0:	39 20 ff ff 	li      r9,-1
   2f4:	79 29 00 04 	rldicr  r9,r9,0,0
   2f8:	7d 3d 03 a6 	mtspr   29,r9
   2fc:	4c 00 01 2c 	isync
   300:	7f c5 f3 78 	mr      r5,r30
   304:	7f 83 e3 78 	mr      r3,r28
   308:	48 00 00 01 	bl      308 <._copy_from_user+0xa8>
  			308: R_PPC64_REL24	.__copy_tofrom_user
  ...
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
[mpe: Spell out the directions, s/KUAP_R/KUAP_READ/ etc.]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f4e88ec4941d5facb35ce75026b0112f980086c3.1579866752.git.christophe.leroy@c-s.fr

At the moment, bad_kuap_fault() reports a fault only if a bad access
to userspace occurred while access to userspace was not granted.

But if a fault occurs for a write outside the allowed userspace
segment(s) that have been unlocked, bad_kuap_fault() fails to
detect it and the kernel loops forever in do_page_fault().

Fix it by checking that the accessed address is within the allowed
range.

Fixes: a68c31fc ("powerpc/32s: Implement Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f48244e9485ada0a304ed33ccbb8da271180c80d.1579866752.git.christophe.leroy@c-s.fr

Commit f7354cca ("powerpc/32: Remove CURRENT_THREAD_INFO and
rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when
_TLF_SLEEPING is set) by delaying the tovirt(r2, r2).

This is because r2 is not restored by fast_exception_return. It used
to work (by chance ?) because CPU wake-up interrupt never comes from
user, so r2 is expected to point to 'current' on return.

Commit e2fb9f54 ("powerpc/32: Prepare for Kernel Userspace Access
Protection") broke it even more by clobbering r0 which is not
restored by fast_exception_return either.

Use r6 instead of r0. This is possible because r3-r6 are restored by
fast_exception_return and only r3-r5 are used for exception arguments.

For r2 it could be converted back to virtual address, but stay on the
safe side and restore it from the stack instead. It should be live
in the cache at that moment, so loading from the stack should make
no difference compared to converting it from phys to virt.

Fixes: f7354cca ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU")
Fixes: e2fb9f54 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr

Use kvm_vcpu_gfn_to_hva() when retrieving the host page size so that the
correct set of memslots is used when handling x86 page faults in SMM.

Fixes: 54bf36aa ("KVM: x86: use vcpu-specific functions to read/write/translate GFNs")
Cc: stable@vger.kernel.org
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>