Lets provide the basic machine information for dump_stack on
s390. This enables the "Hardware name:" line and results in
output like

[...]
Oops: 0004 ilc:2 [#1] SMP
Modules linked in:
CPU: 1 PID: 74 Comm: sh Not tainted 4.5.0+ #205
Hardware name: IBM              2964 NC9              704	(KVM)
[...]
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NDaniel van Gerpen <daniel@vangerpen.de>
Acked-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Show the dynamic and static cpu mhz of each cpu. Since these values
are per cpu this requires a fundamental extension of the format of
/proc/cpuinfo.

Historically we had only a single line per cpu and a summary at the
top of the file. This format is hardly extendible if we want to add
more per cpu information.

Therefore this patch adds per cpu blocks at the end of /proc/cpuinfo:

cpu             : 0
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 1
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 2
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 3
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

Right now each block contains only the dynamic and static cpu mhz,
but it can be easily extended like on every other architecture.

This extension is supposed to be compatible with the old format.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NSascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Change the code to print all the current output during the first
iteration. This is a preparation patch for the upcoming per cpu block
extension to /proc/cpuinfo.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Ensure that we always have __stringify().
Signed-off-by: NJason Baron <jbaron@akamai.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add statistics that show how memory is mapped within the kernel
identity mapping. This is more or less the same like git
commit ce0c0e50 ("x86, generic: CPA add statistics about state
of direct mapping v4") for x86.

I also intentionally copied the lower case "k" within DirectMap4k vs
the upper case "M" and "G" within the two other lines. Let's have
consistent inconsistencies across architectures.

The output of /proc/meminfo now contains these additional lines:

DirectMap4k:        2048 kB
DirectMap1M:     3991552 kB
DirectMap2G:     4194304 kB

The implementation on s390 is lockless unlike the x86 version, since I
assume changes to the kernel mapping are a very rare event. Therefore
it really doesn't matter if these statistics could potentially be
inconsistent if read while kernel pages tables are being changed.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

For the kernel identity mapping map everything read-writeable and
subsequently call set_memory_ro() to make the ro section read-only.
This simplifies the code a lot.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

set_memory_ro() and set_memory_rw() currently only work on 4k
mappings, which is good enough for module code aka the vmalloc area.

However we stumbled already twice into the need to make this also work
on larger mappings:
- the ro after init patch set
- the crash kernel resize code

Therefore this patch implements automatic kernel page table splitting
if e.g. set_memory_ro() would be called on parts of a 2G mapping.
This works quite the same as the x86 code, but is much simpler.

In order to make this work and to be architecturally compliant we now
always use the csp, cspg or crdte instructions to replace valid page
table entries. This means that set_memory_ro() and set_memory_rw()
will be much more expensive than before. In order to avoid huge
latencies the code contains a couple of cond_resched() calls.

The current code only splits page tables, but does not merge them if
it would be possible.  The reason for this is that currently there is
no real life scenarion where this would really happen. All current use
cases that I know of only change access rights once during the life
time. If that should change we can still implement kernel page table
merging at a later time.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Make pmd_wrprotect() and pmd_mkwrite() available independently from
CONFIG_TRANSPARENT_HUGEPAGE and CONFIG_HUGETLB_PAGE so these can be
used on the kernel mapping.

Also introduce a couple of pud helper functions, namely pud_pfn(),
pud_wrprotect(), pud_mkwrite(), pud_mkdirty() and pud_mkclean()
which only work on the kernel mapping.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Always use PAGE_KERNEL when re-enabling pages within the kernel
mapping due to debug pagealloc. Without using this pgprot value
pte_mkwrite() and pte_wrprotect() won't work on such mappings after an
unmap -> map cycle anymore.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use pte_clear() instead of open-coding it.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

_REGION3_ENTRY_RO is a duplicate of _REGION_ENTRY_PROTECT.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Instead of open-coded SEGMENT_KERNEL and REGION3_KERNEL assignments use
defines.  Also to make e.g. pmd_wrprotect() work on the kernel mapping
a couple more flags must be set. Therefore add the missing flags also.

In order to make everything symmetrical this patch also adds software
dirty, young, read and write bits for region 3 table entries.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Usually segment and region tables are 16k aligned due to the way the
buddy allocator works.  This is not true for the vmem code which only
asks for a 4k alignment. In order to be consistent enforce a 16k
alignment here as well.

This alignment will be assumed and therefore is required by the
pageattr code.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We have already two inline assemblies which make use of the csp
instruction. Since I need a third instance let's introduce a generic
inline assmebly which can be used by everyone.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use memdup_user_nul to duplicate a memory region from user-space
to kernel-space and terminate with a NULL, instead of open coding
using kmalloc + copy_from_user and explicitly NULL terminating.
Signed-off-by: NMuhammad Falak R Wani <falakreyaz@gmail.com>
[heiko.carstens@de.ibm.com: remove comment]
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

commit 1e133ab2 ("s390/mm: split arch/s390/mm/pgtable.c") factored
out the page table handling code from __gmap_zap and  __s390_reset_cmma
into ptep_zap_unused and added a simple flag that tells which one of the
function (reset or not) is to be made. This also changed the behaviour,
as it also zaps unused page table entries on reset.
Turns out that this is wrong as s390_reset_cmma uses the page walker,
which DOES NOT take the ptl lock.

The most simple fix is to not do the zapping part on reset (which uses
the walker)
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Fixes: 1e133ab2 ("s390/mm: split arch/s390/mm/pgtable.c")
Cc: stable@vger.kernel.org # 4.6+
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Pull thermal management fixes from Zhang Rui:

 - fix an ordering issue in cpu cooling that cooling device is
   registered before it's ready (freq_table being populated).
   (Lukasz Luba)

 - fix a missing comment update (Caesar Wang)

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: add the note for set_trip_temp
  thermal: cpu_cooling: fix improper order during initialization

Pull block layer fixes from Jens Axboe:
 "A small collection of fixes for the current series.  This contains:

   - Two fixes for xen-blkfront, from Bob Liu.

   - A bug fix for NVMe, releasing only the specific resources we
     requested.

   - Fix for a debugfs flags entry for nbd, from Josef.

   - Plug fix from Omar, fixing up a case of code being switched between
     two functions.

   - A missing bio_put() for the new discard callers of
     submit_bio_wait(), fixing a regression causing a leak of the bio.
     From Shaun.

   - Improve dirty limit calculation precision in the writeback code,
     fixing a case where setting a limit lower than 1% of memory would
     end up being zero.  From Tejun"

* 'for-linus' of git://git.kernel.dk/linux-block:
  NVMe: Only release requested regions
  xen-blkfront: fix resume issues after a migration
  xen-blkfront: don't call talk_to_blkback when already connected to blkback
  nbd: pass the nbd pointer for flags debugfs
  block: missing bio_put following submit_bio_wait
  blk-mq: really fix plug list flushing for nomerge queues
  writeback: use higher precision calculation in domain_dirty_limits()

Pull GPIO fixes from Linus Walleij:
 "A new bunch of GPIO fixes for v4.7.

  This time I am very grateful that Ricardo Ribalda Delgado went in and
  fixed my stupid refcounting mistakes in the removal path for GPIO
  chips.  I had a feeling something was wrong here and so it was.  It
  exploded on OMAP and it fixes their problem.  Now it should be (more)
  solid.

  The rest i compilation, Kconfig and driver fixes.  Some tagged for
  stable.

  Summary:

   - Fix a NULL pointer dereference when we are searching the GPIO
     device list but one of the devices have been removed (struct
     gpio_chip pointer is NULL).

   - Fix unaligned reference counters: we were ending on +3 after all
     said and done.  It should be 0.  Remove an extraneous get_device(),
     and call cdev_del() followed by device_del() in gpiochip_remove()
     instead and the count goes to zero and calls the release() function
     properly.

   - Fix a compile warning due to a missing #include in the OF/device
     tree portions.

   - Select ANON_INODES for GPIOLIB, we're using that for our character
     device.  Some randconfig tests disclosed the problem.

   - Make sure the Zynq driver clock runs also without CONFIG_PM enabled

   - Fix an off-by-one error in the 104-DIO-48E driver

   - Fix warnings in bcm_kona_gpio_reset()"

* tag 'gpio-v4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: bcm-kona: fix bcm_kona_gpio_reset() warnings
  gpio: select ANON_INODES
  gpio: include <linux/io-mapping.h> in gpiolib-of
  gpiolib: Fix unaligned used of reference counters
  gpiolib: Fix NULL pointer deference
  gpio: zynq: initialize clock even without CONFIG_PM
  gpio: 104-dio-48e: Fix control port offset computation off-by-one error

Pull SCSI fixes from James Bottomley:
 "Two current fixes:

   - one affects Qemu CD ROM emulation, which stopped working after the
     updates in SCSI to require VPD pages from all conformant devices.

     Fix temporarily by blacklisting Qemu (we can relax later when they
     come into compliance).

   - The other is a fix to the optimal transfer size.  We set up a
     minefield for ourselves by being confused about whether the limits
     are in bytes or sectors (SCSI optimal is in blocks and the queue
     parameter is in bytes).

     This tries to fix the problem (wrong setting for queue limits
     max_sectors) and make the problem more obvious by introducing a
     wrapper function"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sd: Fix rw_max for devices that report an optimal xfer size
  scsi: Add QEMU CD-ROM to VPD Inquiry Blacklist

Pull i2c fixes from Wolfram Sang:

 - a bigger fix for i801 to finally be able to be loaded on some
   machines again

 - smaller driver fixes

 - documentation update because of a renamed file

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: mux: reg: Provide of_match_table
  i2c: mux: refer to i2c-mux.txt
  i2c: octeon: Avoid printk after too long SMBUS message
  i2c: octeon: Missing AAK flag in case of I2C_M_RECV_LEN
  i2c: i801: Allow ACPI SystemIO OpRegion to conflict with PCI BAR

Pull DeviceTree fixes from Rob Herring:

 - fix unflatten_dt_nodes when dad parameter is set.

 - add vendor prefixes for TechNexion and UniWest

 - documentation fix for Marvell BT

 - OF IRQ kerneldoc fixes

 - restrict CMA alignment adjustments to non dma-coherent

 - a couple of warning fixes in reserved-memory code

 - DT maintainers updates

* tag 'devicetree-fixes-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  drivers: of: add definition of early_init_dt_alloc_reserved_memory_arch
  drivers/of: Fix depth for sub-tree blob in unflatten_dt_nodes()
  drivers: of: Fix of_pci.h header guard
  dt-bindings: Add vendor prefix for TechNexion
  of: add vendor prefix for UniWest
  dt: bindings: fix documentation for MARVELL's bt-sd8xxx wireless device
  of: add missing const for of_parse_phandle_with_args() in !CONFIG_OF
  of: silence warnings due to max() usage
  drivers: of: of_reserved_mem: fixup the CMA alignment not to affect dma-coherent
  of: irq: fix of_irq_get[_byname]() kernel-doc
  MAINTAINERS: DeviceTree maintainer updates

Merge tag '20160610_uvc_compat_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux

Pull uvc compat XU ioctl fixes from Andy Lutomirski:
 "uvc's compat XU ioctls go through tons of potentially buggy
  indirection.  The first patch removes the indirection.  The second one
  cleans up the code.

  Compile-tested only.  I have the hardware, but I have absolutely no
  idea what XU does, how to use it, what software to recompile as
  32-bit, or what to test in that software"

* tag '20160610_uvc_compat_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux:
  uvc_v4l2: Simplify compat ioctl implementation
  uvc: Forward compat ioctls to their handlers directly

The uvc compat ioctl implementation seems to have copied user data
for no good reason.  Remove a bunch of copies.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>

The current code goes through a lot of indirection just to call a
known handler.  Simplify it: just call the handlers directly.

Cc: stable@vger.kernel.org
Signed-off-by: NAndy Lutomirski <luto@kernel.org>

Pull btrfs fixes from Chris Mason:
 "Has some fixes and some new self tests for btrfs.  The self tests are
  usually disabled in the .config file (unless you're doing btrfs dev
  work), and this bunch is meant to find problems with the 64K page size
  patches.

  Jeff has a patch to help people see if they are using the hardware
  assist crc32c module, which really helps us nail down problems when
  people ask why crcs are using so much CPU.

  Otherwise, it's small fixes"

* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: self-tests: Fix extent buffer bitmap test fail on BE system
  Btrfs: self-tests: Fix test_bitmaps fail on 64k sectorsize
  Btrfs: self-tests: Use macros instead of constants and add missing newline
  Btrfs: self-tests: Support testing all possible sectorsizes and nodesizes
  Btrfs: self-tests: Execute page straddling test only when nodesize < PAGE_SIZE
  btrfs: advertise which crc32c implementation is being used at module load
  Btrfs: add validadtion checks for chunk loading
  Btrfs: add more validation checks for superblock
  Btrfs: clear uptodate flags of pages in sys_array eb
  Btrfs: self-tests: Support non-4k page size
  Btrfs: Fix integer overflow when calculating bytes_per_bitmap
  Btrfs: test_check_exists: Fix infinite loop when searching for free space entries
  Btrfs: end transaction if we abort when creating uuid root
  btrfs: Use __u64 in exported linux/btrfs.h.

Merge tag 'powerpc-4.7-3Michael Ellerman:' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from
 - ptrace: Fix out of bounds array access warning from Khem Raj
 - pseries: Fix PCI config address for DDW from Gavin Shan
 - pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
   from Michael Ellerman
 - of: fix autoloading due to broken modalias with no 'compatible' from
   Wolfram Sang
 - radix: Fix always false comparison against MMU_NO_CONTEXT from Aneesh
   Kumar K.V
 - hash: Compute the segment size correctly for ISA 3.0 from Aneesh
   Kumar K.V
 - nohash: Fix build break with 64K pages from Michael Ellerman

* tag 'powerpc-4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/nohash: Fix build break with 64K pages
  powerpc/mm/hash: Compute the segment size correctly for ISA 3.0
  powerpc/mm/radix: Fix always false comparison against MMU_NO_CONTEXT
  of: fix autoloading due to broken modalias with no 'compatible'
  powerpc/pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
  powerpc/pseries: Fix PCI config address for DDW
  powerpc/ptrace: Fix out of bounds array access warning

Merge tag 'hwmon-for-linus-v4.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - fix regression in fam15h_power driver

 - minor variable type fix in lm90 driver

 - document compatible statement for ina2xx driver

* tag 'hwmon-for-linus-v4.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (lm90) use proper type for update_interval
  hwmon: (ina2xx) Document compatible for INA231
  hwmon: (fam15h_power) Disable preemption when reading registers

Merge filesystem stacking fixes from Jann Horn.

* emailed patches from Jann Horn <jannh@google.com>:
  sched: panic on corrupted stack end
  ecryptfs: forbid opening files without mmap handler
  proc: prevent stacking filesystems on top

Until now, hitting this BUG_ON caused a recursive oops (because oops
handling involves do_exit(), which calls into the scheduler, which in
turn raises an oops), which caused stuff below the stack to be
overwritten until a panic happened (e.g.  via an oops in interrupt
context, caused by the overwritten CPU index in the thread_info).

Just panic directly.
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This prevents users from triggering a stack overflow through a recursive
invocation of pagefault handling that involves mapping procfs files into
virtual memory.
Signed-off-by: NJann Horn <jannh@google.com>
Acked-by: NTyler Hicks <tyhicks@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This prevents stacking filesystems (ecryptfs and overlayfs) from using
procfs as lower filesystem.  There is too much magic going on inside
procfs, and there is no good reason to stack stuff on top of procfs.

(For example, procfs does access checks in VFS open handlers, and
ecryptfs by design calls open handlers from a kernel thread that doesn't
drop privileges or so.)
Signed-off-by: NJann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull arm64 fix from Will Deacon:
 "A fix for an issue that Alex saw whilst swapping with hardware
  access/dirty bit support enabled in the kernel: Fix a failure to fault
  in old pages on a write when CONFIG_ARM64_HW_AFDBM is enabled"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: always take dirty state from new pte in ptep_set_access_flags

Pull x86 fixes from Ingo Molnar:
 "Misc fixes from all around the map, plus a commit that introduces a
  new header of Intel model name symbols (unused) that will make the
  next merge window easier"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioapic: Fix incorrect pointers in ioapic_setup_resources()
  x86/entry/traps: Don't force in_interrupt() to return true in IST handlers
  x86/cpu/AMD: Extend X86_FEATURE_TOPOEXT workaround to newer models
  x86/cpu/intel: Introduce macros for Intel family numbers
  x86, build: copy ldlinux.c32 to image.iso
  x86/msr: Use the proper trace point conditional for writes

Pull scheduler fixes from Ingo Molnar:
 "Two scheduler debugging fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Fix 'schedstats=enable' cmdline option
  sched/debug: Fix /proc/sched_debug regression

Pull perf fixes from Ingo Molnar:
 "A handful of tooling fixes, two PMU driver fixes and a cleanup of
  redundant code that addresses a security analyzer false positive"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Remove a redundant check
  perf/x86/intel/uncore: Remove SBOX support for Broadwell server
  perf ctf: Convert invalid chars in a string before set value
  perf record: Fix crash when kptr is restricted
  perf symbols: Check kptr_restrict for root
  perf/x86/intel/rapl: Fix pmus free during cleanup

Pull locking fixes from Ingo Molnar:
 "Misc fixes:

   - a file-based futex fix
   - one more spin_unlock_wait() fix
   - a ww-mutex deadlock detection improvement/fix
   - and a raw_read_seqcount_latch() barrier fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Calculate the futex key based on a tail page for file-based futexes
  locking/qspinlock: Fix spin_unlock_wait() some more
  locking/ww_mutex: Report recursive ww_mutex locking early
  locking/seqcount: Re-fix raw_read_seqcount_latch()

Pull EFI fixes from Ingo Molnar:
 "Two fixes: a regression/crash fix, and a message output fix"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/arm: Fix the format of EFI debug messages
  efi: Fix for_each_efi_memory_desc_in_map() for empty memmaps