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

However, it was overlooked that this introduced an new error path before
a reference is taken on the mm_struct's ->exe_file.  Since the
->exe_file of the new mm_struct was already set to the old ->exe_file by
the memcpy() in dup_mm(), it was possible for the mmput() in the error
path of dup_mm() to drop a reference to ->exe_file which was never
taken.

This caused the struct file to later be freed prematurely.

Fix it by updating mm_init() to NULL out the ->exe_file, in the same
place it clears other things like the list of mmaps.

This bug was found by syzkaller.  It can be reproduced using the
following C program:

    #define _GNU_SOURCE
    #include <pthread.h>
    #include <stdlib.h>
    #include <sys/mman.h>
    #include <sys/syscall.h>
    #include <sys/wait.h>
    #include <unistd.h>

    static void *mmap_thread(void *_arg)
    {
        for (;;) {
            mmap(NULL, 0x1000000, PROT_READ,
                 MAP_POPULATE|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
        }
    }

    static void *fork_thread(void *_arg)
    {
        usleep(rand() % 10000);
        fork();
    }

    int main(void)
    {
        fork();
        fork();
        fork();
        for (;;) {
            if (fork() == 0) {
                pthread_t t;

                pthread_create(&t, NULL, mmap_thread, NULL);
                pthread_create(&t, NULL, fork_thread, NULL);
                usleep(rand() % 10000);
                syscall(__NR_exit_group, 0);
            }
            wait(NULL);
        }
    }

No special kernel config options are needed.  It usually causes a NULL
pointer dereference in __remove_shared_vm_struct() during exit, or in
dup_mmap() (which is usually inlined into copy_process()) during fork.
Both are due to a vm_area_struct's ->vm_file being used after it's
already been freed.

Google Bug Id: 64772007

Link: http://lkml.kernel.org/r/20170823211408.31198-1-ebiggers3@gmail.com
Fixes: 7c051267 ("mm, fork: make dup_mmap wait for mmap_sem for write killable")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>	[v4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If madvise(..., MADV_FREE) split a transparent hugepage, it called
put_page() before unlock_page().

This was wrong because put_page() can free the page, e.g. if a
concurrent madvise(..., MADV_DONTNEED) has removed it from the memory
mapping. put_page() then rightfully complained about freeing a locked
page.

Fix this by moving the unlock_page() before put_page().

This bug was found by syzkaller, which encountered the following splat:

    BUG: Bad page state in process syzkaller412798  pfn:1bd800
    page:ffffea0006f60000 count:0 mapcount:0 mapping:          (null) index:0x20a00
    flags: 0x200000000040019(locked|uptodate|dirty|swapbacked)
    raw: 0200000000040019 0000000000000000 0000000000020a00 00000000ffffffff
    raw: ffffea0006f60020 ffffea0006f60020 0000000000000000 0000000000000000
    page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
    bad because of flags: 0x1(locked)
    Modules linked in:
    CPU: 1 PID: 3037 Comm: syzkaller412798 Not tainted 4.13.0-rc5+ #35
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
    Call Trace:
     __dump_stack lib/dump_stack.c:16 [inline]
     dump_stack+0x194/0x257 lib/dump_stack.c:52
     bad_page+0x230/0x2b0 mm/page_alloc.c:565
     free_pages_check_bad+0x1f0/0x2e0 mm/page_alloc.c:943
     free_pages_check mm/page_alloc.c:952 [inline]
     free_pages_prepare mm/page_alloc.c:1043 [inline]
     free_pcp_prepare mm/page_alloc.c:1068 [inline]
     free_hot_cold_page+0x8cf/0x12b0 mm/page_alloc.c:2584
     __put_single_page mm/swap.c:79 [inline]
     __put_page+0xfb/0x160 mm/swap.c:113
     put_page include/linux/mm.h:814 [inline]
     madvise_free_pte_range+0x137a/0x1ec0 mm/madvise.c:371
     walk_pmd_range mm/pagewalk.c:50 [inline]
     walk_pud_range mm/pagewalk.c:108 [inline]
     walk_p4d_range mm/pagewalk.c:134 [inline]
     walk_pgd_range mm/pagewalk.c:160 [inline]
     __walk_page_range+0xc3a/0x1450 mm/pagewalk.c:249
     walk_page_range+0x200/0x470 mm/pagewalk.c:326
     madvise_free_page_range.isra.9+0x17d/0x230 mm/madvise.c:444
     madvise_free_single_vma+0x353/0x580 mm/madvise.c:471
     madvise_dontneed_free mm/madvise.c:555 [inline]
     madvise_vma mm/madvise.c:664 [inline]
     SYSC_madvise mm/madvise.c:832 [inline]
     SyS_madvise+0x7d3/0x13c0 mm/madvise.c:760
     entry_SYSCALL_64_fastpath+0x1f/0xbe

Here is a C reproducer:

    #define _GNU_SOURCE
    #include <pthread.h>
    #include <sys/mman.h>
    #include <unistd.h>

    #define MADV_FREE	8
    #define PAGE_SIZE	4096

    static void *mapping;
    static const size_t mapping_size = 0x1000000;

    static void *madvise_thrproc(void *arg)
    {
        madvise(mapping, mapping_size, (long)arg);
    }

    int main(void)
    {
        pthread_t t[2];

        for (;;) {
            mapping = mmap(NULL, mapping_size, PROT_WRITE,
                           MAP_POPULATE|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);

            munmap(mapping + mapping_size / 2, PAGE_SIZE);

            pthread_create(&t[0], 0, madvise_thrproc, (void*)MADV_DONTNEED);
            pthread_create(&t[1], 0, madvise_thrproc, (void*)MADV_FREE);
            pthread_join(t[0], NULL);
            pthread_join(t[1], NULL);
            munmap(mapping, mapping_size);
        }
    }

Note: to see the splat, CONFIG_TRANSPARENT_HUGEPAGE=y and
CONFIG_DEBUG_VM=y are needed.

Google Bug Id: 64696096

Link: http://lkml.kernel.org/r/20170823205235.132061-1-ebiggers3@gmail.com
Fixes: 854e9ed0 ("mm: support madvise(MADV_FREE)")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>	[v4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In DAX there are two separate places where the 2MiB range of a PMD is
defined.

The first is in the page tables, where a PMD mapping inserted for a
given address spans from (vmf->address & PMD_MASK) to ((vmf->address &
PMD_MASK) + PMD_SIZE - 1).  That is, from the 2MiB boundary below the
address to the 2MiB boundary above the address.

So, for example, a fault at address 3MiB (0x30 0000) falls within the
PMD that ranges from 2MiB (0x20 0000) to 4MiB (0x40 0000).

The second PMD range is in the mapping->page_tree, where a given file
offset is covered by a radix tree entry that spans from one 2MiB aligned
file offset to another 2MiB aligned file offset.

So, for example, the file offset for 3MiB (pgoff 768) falls within the
PMD range for the order 9 radix tree entry that ranges from 2MiB (pgoff
512) to 4MiB (pgoff 1024).

This system works so long as the addresses and file offsets for a given
mapping both have the same offsets relative to the start of each PMD.

Consider the case where the starting address for a given file isn't 2MiB
aligned - say our faulting address is 3 MiB (0x30 0000), but that
corresponds to the beginning of our file (pgoff 0).  Now all the PMDs in
the mapping are misaligned so that the 2MiB range defined in the page
tables never matches up with the 2MiB range defined in the radix tree.

The current code notices this case for DAX faults to storage with the
following test in dax_pmd_insert_mapping():

	if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR)
		goto unlock_fallback;

This test makes sure that the pfn we get from the driver is 2MiB
aligned, and relies on the assumption that the 2MiB alignment of the pfn
we get back from the driver matches the 2MiB alignment of the faulting
address.

However, faults to holes were not checked and we could hit the problem
described above.

This was reported in response to the NVML nvml/src/test/pmempool_sync
TEST5:

	$ cd nvml/src/test/pmempool_sync
	$ make TEST5

You can grab NVML here:

	https://github.com/pmem/nvml/

The dmesg warning you see when you hit this error is:

  WARNING: CPU: 13 PID: 2900 at fs/dax.c:641 dax_insert_mapping_entry+0x2df/0x310

Where we notice in dax_insert_mapping_entry() that the radix tree entry
we are about to replace doesn't match the locked entry that we had
previously inserted into the tree.  This happens because the initial
insertion was done in grab_mapping_entry() using a pgoff calculated from
the faulting address (vmf->address), and the replacement in
dax_pmd_load_hole() => dax_insert_mapping_entry() is done using
vmf->pgoff.

In our failure case those two page offsets (one calculated from
vmf->address, one using vmf->pgoff) point to different order 9 radix
tree entries.

This failure case can result in a deadlock because the radix tree unlock
also happens on the pgoff calculated from vmf->address.  This means that
the locked radix tree entry that we swapped in to the tree in
dax_insert_mapping_entry() using vmf->pgoff is never unlocked, so all
future faults to that 2MiB range will block forever.

Fix this by validating that the faulting address's PMD offset matches
the PMD offset from the start of the file.  This check is done at the
very beginning of the fault and covers faults that would have mapped to
storage as well as faults to holes.  I left the COLOUR check in
dax_pmd_insert_mapping() in place in case we ever hit the insanity
condition where the alignment of the pfn we get from the driver doesn't
match the alignment of the userspace address.

Link: http://lkml.kernel.org/r/20170822222436.18926-1-ross.zwisler@linux.intel.comSigned-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: "Slusarz, Marcin" <marcin.slusarz@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

/sys/kernel/mm/transparent_hugepage/shmem_enabled controls if we want
to allocate huge pages when allocate pages for private in-kernel shmem
mount.

Unfortunately, as Dan noticed, I've screwed it up and the only way to
make kernel allocate huge page for the mount is to use "force" there.
All other values will be effectively ignored.

Link: http://lkml.kernel.org/r/20170822144254.66431-1-kirill.shutemov@linux.intel.com
Fixes: 5a6e75f8 ("shmem: prepare huge= mount option and sysfs knob")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org> [4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is a problem that when counting the pages for creating the
hibernation snapshot will take significant amount of time, especially on
system with large memory.  Since the counting job is performed with irq
disabled, this might lead to NMI lockup.  The following warning were
found on a system with 1.5TB DRAM:

  Freezing user space processes ... (elapsed 0.002 seconds) done.
  OOM killer disabled.
  PM: Preallocating image memory...
  NMI watchdog: Watchdog detected hard LOCKUP on cpu 27
  CPU: 27 PID: 3128 Comm: systemd-sleep Not tainted 4.13.0-0.rc2.git0.1.fc27.x86_64 #1
  task: ffff9f01971ac000 task.stack: ffffb1a3f325c000
  RIP: 0010:memory_bm_find_bit+0xf4/0x100
  Call Trace:
   swsusp_set_page_free+0x2b/0x30
   mark_free_pages+0x147/0x1c0
   count_data_pages+0x41/0xa0
   hibernate_preallocate_memory+0x80/0x450
   hibernation_snapshot+0x58/0x410
   hibernate+0x17c/0x310
   state_store+0xdf/0xf0
   kobj_attr_store+0xf/0x20
   sysfs_kf_write+0x37/0x40
   kernfs_fop_write+0x11c/0x1a0
   __vfs_write+0x37/0x170
   vfs_write+0xb1/0x1a0
   SyS_write+0x55/0xc0
   entry_SYSCALL_64_fastpath+0x1a/0xa5
  ...
  done (allocated 6590003 pages)
  PM: Allocated 26360012 kbytes in 19.89 seconds (1325.28 MB/s)

It has taken nearly 20 seconds(2.10GHz CPU) thus the NMI lockup was
triggered.  In case the timeout of the NMI watch dog has been set to 1
second, a safe interval should be 6590003/20 = 320k pages in theory.
However there might also be some platforms running at a lower frequency,
so feed the watchdog every 100k pages.

[yu.c.chen@intel.com: simplification]
  Link: http://lkml.kernel.org/r/1503460079-29721-1-git-send-email-yu.c.chen@intel.com
[yu.c.chen@intel.com: use interval of 128k instead of 100k to avoid modulus]
Link: http://lkml.kernel.org/r/1503328098-5120-1-git-send-email-yu.c.chen@intel.comSigned-off-by: Chen Yu <yu.c.chen@intel.com>
Reported-by: Jan Filipcewicz <jan.filipcewicz@intel.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull more rdma fixes from Doug Ledford:
 "Well, I thought we were going to be done for this -rc cycle. I should
  have known better than to say so though.

  We have four additional items that trickled in.

  One was a simple mistake on my part. I took a patch into my for-next
  thinking that the issue was less severe than it was. I was then
  notified that it needed to be in my -rc area instead.

  The other three were just found late in testing.

  Summary:

   - One core fix accidentally applied first to for-next and then cherry
     picked back because it needed to be in the -rc cycles instead

   - Another core fix

   - Two mlx5 fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/mlx5: Always return success for RoCE modify port
  IB/mlx5: Fix Raw Packet QP event handler assignment
  IB/core: Avoid accessing non-allocated memory when inferring port type
  RDMA/uverbs: Initialize cq_context appropriately

Pull ACPI fixes from Rafael Wysocki:
 "These fix two recent regressions (in ACPICA and in the ACPI EC driver)
  and one bug in code introduced during the 4.12 cycle (ACPI device
  properties library routine).

  Specifics:

   - Fix a regression in the ACPI EC driver causing a kernel to crash
     during initialization on some systems due to a code ordering issue
     exposed by a recent change (Lv Zheng).

   - Fix a recent regression in ACPICA due to a change of the behavior
     of a library function in a way that is not backwards compatible
     with some existing callers of it (Rafael Wysocki).

   - Fix a coding mistake in a library function related to the handling
     of ACPI device properties introduced during the 4.12 cycle (Sakari
     Ailus)"

* tag 'acpi-4.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: device property: Fix node lookup in acpi_graph_get_child_prop_value()
  ACPICA: Fix acpi_evaluate_object_typed()
  ACPI: EC: Fix regression related to wrong ECDT initialization order

Merge tag 'kbuild-fixes-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - fix linker script regression caused by dead code elimination support

 - fix typos and outdated comments

 - specify kselftest-clean as a PHONY target

 - fix "make dtbs_install" when $(srctree) includes shell special
   characters like '~'

 - Move -fshort-wchar to the global option list because defining it
   partially emits warnings

* tag 'kbuild-fixes-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: update comments of Makefile.asm-generic
  kbuild: Do not use hyphen in exported variable name
  Makefile: add kselftest-clean to PHONY target list
  Kbuild: use -fshort-wchar globally
  fixdep: trivial: typo fix and correction
  kbuild: trivial cleanups on the comments
  kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured

Pull btrfs fix from David Sterba:
 "We have one more fixup that stems from the blk_status_t conversion
  that did not quite cover everything.

  The normal cases were not affected because the code is 0, but any
  error and retries could mix up new and old values"

* 'for-4.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix blk_status_t/errno confusion

Pull tracing fixes from Steven Rostedt:
 "Various bug fixes:

   - Two small memory leaks in error paths.

   - A missed return error code on an error path.

   - A fix to check the tracing ring buffer CPU when it doesn't exist
     (caused by setting maxcpus on the command line that is less than
     the actual number of CPUs, and then onlining them manually).

   - A fix to have the reset of boot tracers called by lateinit_sync()
     instead of just lateinit(). As some of the tracers register via
     lateinit(), and if the clear happens before the tracer is
     registered, it will never start even though it was told to via the
     kernel command line"

* tag 'trace-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix freeing of filter in create_filter() when set_str is false
  tracing: Fix kmemleak in tracing_map_array_free()
  ftrace: Check for null ret_stack on profile function graph entry function
  ring-buffer: Have ring_buffer_alloc_read_page() return error on offline CPU
  tracing: Missing error code in tracer_alloc_buffers()
  tracing: Call clear_boot_tracer() at lateinit_sync

Pull ARM SoC fixes from Arnd Bergmann:
 "A small number of bugfixes, again nothing serious.

   - Alexander Dahl found multiple bugs in the Atmel memory interface
     driver

   - A randconfig build fix for at91 was incomplete, the second attempt
     fixes the remaining corner case

   - One fix for the TI Keystone queue handler

   - The Odroid XU4 HDMI port (added in 4.13) needs a small DT fix"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: exynos: add needs-hpd for Odroid-XU3/4
  ARM: at91: don't select CONFIG_ARM_CPU_SUSPEND for old platforms
  soc: ti: knav: Add a NULL pointer check for kdev in knav_pool_create
  memory: atmel-ebi: Fix smc cycle xlate converter
  memory: atmel-ebi: Allow t_DF timings of zero ns
  memory: atmel-ebi: Fix smc timing return value evaluation

The implementation of TIOCGPTPEER has two issues.

When /dev/ptmx (as opposed to /dev/pts/ptmx) is opened the wrong
vfsmount is passed to dentry_open.  Which results in the kernel displaying
the wrong pathname for the peer.

The second is simply by caching the vfsmount and dentry of the peer it leaves
them open, in a way they were not previously Which because of the inreased
reference counts can cause unnecessary behaviour differences resulting in
regressions.

To fix these move the ioctl into tty_io.c at a generic level allowing
the ioctl to have access to the struct file on which the ioctl is
being called.  This allows the path of the slave to be derived when
opening the slave through TIOCGPTPEER instead of requiring the path to
the slave be cached.  Thus removing the need for caching the path.

A new function devpts_ptmx_path is factored out of devpts_acquire and
used to implement a function devpts_mntget.   The new function devpts_mntget
takes a filp to perform the lookup on and fsi so that it can confirm
that the superblock that is found by devpts_ptmx_path is the proper superblock.

v2: Lots of fixes to make the code actually work
v3: Suggestions by Linus
    - Removed the unnecessary initialization of filp in ptm_open_peer
    - Simplified devpts_ptmx_path as gotos are no longer required

[ This is the fix for the issue that was reverted in commit
  143c97cc, but this time without breaking 'pbuilder' due to
  increased reference counts   - Linus ]

Fixes: 54ebbfb1 ("tty: add TIOCGPTPEER ioctl")
Reported-by: Christian Brauner <christian.brauner@canonical.com>
Reported-and-tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* acpica-fix:
  ACPICA: Fix acpi_evaluate_object_typed()

* acpi-ec-fix:
  ACPI: EC: Fix regression related to wrong ECDT initialization order

* acpi-properties-fix:
  ACPI: device property: Fix node lookup in acpi_graph_get_child_prop_value()

CM layer calls ib_modify_port() regardless of the link layer.

For the Ethernet ports, qkey violation and Port capabilities
are meaningless. Therefore, always return success for ib_modify_port
calls on the Ethernet ports.

Cc: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

In case we have SQ and RQ for Raw Packet QP, the SQ's event handler
wasn't assigned.

Fixing this by assigning event handler for each WQ after creation.

[ 1877.145243] Call Trace:
[ 1877.148644] <IRQ>
[ 1877.150580] [<ffffffffa07987c5>] ? mlx5_rsc_event+0x105/0x210 [mlx5_core]
[ 1877.159581] [<ffffffffa0795bd7>] ? mlx5_cq_event+0x57/0xd0 [mlx5_core]
[ 1877.167137] [<ffffffffa079208e>] mlx5_eq_int+0x53e/0x6c0 [mlx5_core]
[ 1877.174526] [<ffffffff8101a679>] ? sched_clock+0x9/0x10
[ 1877.180753] [<ffffffff810f717e>] handle_irq_event_percpu+0x3e/0x1e0
[ 1877.188014] [<ffffffff810f735d>] handle_irq_event+0x3d/0x60
[ 1877.194567] [<ffffffff810f9fe7>] handle_edge_irq+0x77/0x130
[ 1877.201129] [<ffffffff81014c3f>] handle_irq+0xbf/0x150
[ 1877.207244] [<ffffffff815ed78a>] ? atomic_notifier_call_chain+0x1a/0x20
[ 1877.214829] [<ffffffff815f434f>] do_IRQ+0x4f/0xf0
[ 1877.220498] [<ffffffff815e94ad>] common_interrupt+0x6d/0x6d
[ 1877.227025] <EOI>
[ 1877.228967] [<ffffffff814834e2>] ? cpuidle_enter_state+0x52/0xc0
[ 1877.236990] [<ffffffff81483615>] cpuidle_idle_call+0xc5/0x200
[ 1877.243676] [<ffffffff8101bc7e>] arch_cpu_idle+0xe/0x30
[ 1877.249831] [<ffffffff810b4725>] cpu_startup_entry+0xf5/0x290
[ 1877.256513] [<ffffffff815cfee1>] start_secondary+0x265/0x27b
[ 1877.263111] Code: Bad RIP value.
[ 1877.267296] RIP [< (null)>] (null)
[ 1877.273264] RSP <ffff88046fd63df8>
[ 1877.277531] CR2: 0000000000000000

Fixes: 19098df2 ("IB/mlx5: Refactor mlx5_ib_qp to accommodate other QP types")
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

Commit 44c58487 ("IB/core: Define 'ib' and 'roce' rdma_ah_attr types")
introduced the concept of type in ah_attr:
 * During ib_register_device, each port is checked for its type which
   is stored in ib_device's port_immutable array.
 * During uverbs' modify_qp, the type is inferred using the port number
   in ib_uverbs_qp_dest struct (address vector) by accessing the
   relevant port_immutable array and the type is passed on to
   providers.

IB spec (version 1.3) enforces a valid port value only in Reset to
Init. During Init to RTR, the address vector must be valid but port
number is not mentioned as a field in the address vector, so its
value is not validated, which leads to accesses to a non-allocated
memory when inferring the port type.

Save the real port number in ib_qp during modify to Init (when the
comp_mask indicates that the port number is valid) and use this value
to infer the port type.

Avoid copying the address vector fields if the matching bit is not set
in the attr_mask. Address vector can't be modified before the port, so
no valid flow is affected.

Fixes: 44c58487 ('IB/core: Define 'ib' and 'roce' rdma_ah_attr types')
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

This fixes several instances of blk_status_t and bare errno ints being
mixed up, some of which are real bugs.

In the normal case, 0 matches BLK_STS_OK, so we don't observe any
effects of the missing conversion, but in case of errors or passes
through the repair/retry paths, the errors get mixed up.

The changes were identified using 'sparse', we don't have reports of the
buggy behaviour.

Fixes: 4e4cbee9 ("block: switch bios to blk_status_t")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Performing the following task with kmemleak enabled:

 # cd /sys/kernel/tracing/events/irq/irq_handler_entry/
 # echo 'enable_event:kmem:kmalloc:3 if irq >' > trigger
 # echo 'enable_event:kmem:kmalloc:3 if irq > 31' > trigger
 # echo scan > /sys/kernel/debug/kmemleak
 # cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff8800b9290308 (size 32):
  comm "bash", pid 1114, jiffies 4294848451 (age 141.139s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81cef5aa>] kmemleak_alloc+0x4a/0xa0
    [<ffffffff81357938>] kmem_cache_alloc_trace+0x158/0x290
    [<ffffffff81261c09>] create_filter_start.constprop.28+0x99/0x940
    [<ffffffff812639c9>] create_filter+0xa9/0x160
    [<ffffffff81263bdc>] create_event_filter+0xc/0x10
    [<ffffffff812655e5>] set_trigger_filter+0xe5/0x210
    [<ffffffff812660c4>] event_enable_trigger_func+0x324/0x490
    [<ffffffff812652e2>] event_trigger_write+0x1a2/0x260
    [<ffffffff8138cf87>] __vfs_write+0xd7/0x380
    [<ffffffff8138f421>] vfs_write+0x101/0x260
    [<ffffffff8139187b>] SyS_write+0xab/0x130
    [<ffffffff81cfd501>] entry_SYSCALL_64_fastpath+0x1f/0xbe
    [<ffffffffffffffff>] 0xffffffffffffffff

The function create_filter() is passed a 'filterp' pointer that gets
allocated, and if "set_str" is true, it is up to the caller to free it, even
on error. The problem is that the pointer is not freed by create_filter()
when set_str is false. This is a bug, and it is not up to the caller to free
the filter on error if it doesn't care about the string.

Link: http://lkml.kernel.org/r/1502705898-27571-2-git-send-email-chuhu@redhat.com

Cc: stable@vger.kernel.org
Fixes: 38b78eb8 ("tracing: Factorize filter creation")
Reported-by: Chunyu Hu <chuhu@redhat.com>
Tested-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kmemleak reported the below leak when I was doing clear of the hist
trigger. With this patch, the kmeamleak is gone.

unreferenced object 0xffff94322b63d760 (size 32):
  comm "bash", pid 1522, jiffies 4403687962 (age 2442.311s)
  hex dump (first 32 bytes):
    00 01 00 00 04 00 00 00 08 00 00 00 ff 00 00 00  ................
    10 00 00 00 00 00 00 00 80 a8 7a f2 31 94 ff ff  ..........z.1...
  backtrace:
    [<ffffffff9e96c27a>] kmemleak_alloc+0x4a/0xa0
    [<ffffffff9e424cba>] kmem_cache_alloc_trace+0xca/0x1d0
    [<ffffffff9e377736>] tracing_map_array_alloc+0x26/0x140
    [<ffffffff9e261be0>] kretprobe_trampoline+0x0/0x50
    [<ffffffff9e38b935>] create_hist_data+0x535/0x750
    [<ffffffff9e38bd47>] event_hist_trigger_func+0x1f7/0x420
    [<ffffffff9e38893d>] event_trigger_write+0xfd/0x1a0
    [<ffffffff9e44dfc7>] __vfs_write+0x37/0x170
    [<ffffffff9e44f552>] vfs_write+0xb2/0x1b0
    [<ffffffff9e450b85>] SyS_write+0x55/0xc0
    [<ffffffff9e203857>] do_syscall_64+0x67/0x150
    [<ffffffff9e977ce7>] return_from_SYSCALL_64+0x0/0x6a
    [<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff9431f27aa880 (size 128):
  comm "bash", pid 1522, jiffies 4403687962 (age 2442.311s)
  hex dump (first 32 bytes):
    00 00 8c 2a 32 94 ff ff 00 f0 8b 2a 32 94 ff ff  ...*2......*2...
    00 e0 8b 2a 32 94 ff ff 00 d0 8b 2a 32 94 ff ff  ...*2......*2...
  backtrace:
    [<ffffffff9e96c27a>] kmemleak_alloc+0x4a/0xa0
    [<ffffffff9e425348>] __kmalloc+0xe8/0x220
    [<ffffffff9e3777c1>] tracing_map_array_alloc+0xb1/0x140
    [<ffffffff9e261be0>] kretprobe_trampoline+0x0/0x50
    [<ffffffff9e38b935>] create_hist_data+0x535/0x750
    [<ffffffff9e38bd47>] event_hist_trigger_func+0x1f7/0x420
    [<ffffffff9e38893d>] event_trigger_write+0xfd/0x1a0
    [<ffffffff9e44dfc7>] __vfs_write+0x37/0x170
    [<ffffffff9e44f552>] vfs_write+0xb2/0x1b0
    [<ffffffff9e450b85>] SyS_write+0x55/0xc0
    [<ffffffff9e203857>] do_syscall_64+0x67/0x150
    [<ffffffff9e977ce7>] return_from_SYSCALL_64+0x0/0x6a
    [<ffffffffffffffff>] 0xffffffffffffffff

Link: http://lkml.kernel.org/r/1502705898-27571-1-git-send-email-chuhu@redhat.com

Cc: stable@vger.kernel.org
Fixes: 08d43a5f ("tracing: Add lock-free tracing_map")
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

There's a small race when function graph shutsdown and the calling of the
registered function graph entry callback. The callback must not reference
the task's ret_stack without first checking that it is not NULL. Note, when
a ret_stack is allocated for a task, it stays allocated until the task exits.
The problem here, is that function_graph is shutdown, and a new task was
created, which doesn't have its ret_stack allocated. But since some of the
functions are still being traced, the callbacks can still be called.

The normal function_graph code handles this, but starting with commit
8861dd30 ("ftrace: Access ret_stack->subtime only in the function
profiler") the profiler code references the ret_stack on function entry, but
doesn't check if it is NULL first.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196611

Cc: stable@vger.kernel.org
Fixes: 8861dd30 ("ftrace: Access ret_stack->subtime only in the function profiler")
Reported-by: lilydjwg@gmail.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

This reverts commit c8c03f18.

It turns out that while fixing the ptmx file descriptor to have the
correct 'struct path' to the associated slave pty is a really good
thing, it breaks some user space tools for a very annoying reason.

The problem is that /dev/ptmx and its associated slave pty (/dev/pts/X)
are on different mounts.  That was what caused us to have the wrong path
in the first place (we would mix up the vfsmount of the 'ptmx' node,
with the dentry of the pty slave node), but it also means that now while
we use the right vfsmount, having the pty master open also keeps the pts
mount busy.

And it turn sout that that makes 'pbuilder' very unhappy, as noted by
Stefan Lippers-Hollmann:

 "This patch introduces a regression for me when using pbuilder
  0.228.7[2] (a helper to build Debian packages in a chroot and to
  create and update its chroots) when trying to umount /dev/ptmx (inside
  the chroot) on Debian/ unstable (full log and pbuilder configuration
  file[3] attached).

  [...]
  Setting up build-essential (12.3) ...
  Processing triggers for libc-bin (2.24-15) ...
  I: unmounting dev/ptmx filesystem
  W: Could not unmount dev/ptmx: umount: /var/cache/pbuilder/build/1340/dev/ptmx: target is busy
          (In some cases useful info about processes that
           use the device is found by lsof(8) or fuser(1).)"

apparently pbuilder tries to unmount the /dev/pts filesystem while still
holding at least one master node open, which is arguably not very nice,
but we don't break user space even when fixing other bugs.

So this commit has to be reverted.

I'll try to figure out a way to avoid caching the path to the slave pty
in the master pty.  The only thing that actually wants that slave pty
path is the "TIOCGPTPEER" ioctl, and I think we could just recreate the
path at that time.
Reported-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Cc: Eric W Biederman <ebiederm@xmission.com>
Cc: Christian Brauner <christian.brauner@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

CEC support was added for Exynos5 in 4.13, but for the Odroids we need to set
'needs-hpd' as well since CEC is disabled when there is no HDMI hotplug signal,
just as for the exynos4 Odroid-U3.

This is due to the level-shifter that is disabled when there is no HPD, thus
blocking the CEC signal as well. Same close-but-no-cigar board design as the
Odroid-U3.

Tested with my Odroid XU4.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Pull arm64 fixes from Will Deacon:
 "Late arm64 fixes.

  They fix very early boot failures with KASLR where the early mapping
  of the kernel is incorrect, so the failure mode looks like a hang with
  no output. There's also a signal-handling fix when a uaccess routine
  faults with a fatal signal pending, which could be used to create
  unkillable user tasks using userfaultfd and finally a state leak fix
  for the floating pointer registers across a call to exec().

  We're still seeing some random issues crop up (inode memory corruption
  and spinlock recursion) but we've not managed to reproduce things
  reliably enough to debug or bisect them yet.

  Summary:

   - Fix very early boot failures with KASLR enabled

   - Fix fatal signal handling on userspace access from kernel

   - Fix leakage of floating point register state across exec()"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kaslr: Adjust the offset to avoid Image across alignment boundary
  arm64: kaslr: ignore modulo offset when validating virtual displacement
  arm64: mm: abort uaccess retries upon fatal signal
  arm64: fpsimd: Prevent registers leaking across exec

Pull GPIO fixes from Linus Walleij:
 "Here are the (hopefully) last GPIO fixes for v4.13:

   - an important core fix to reject invalid GPIOs *before* trying to
     obtain a GPIO descriptor for it.

   - a driver fix for the mvebu driver IRQ handling"

* tag 'gpio-v4.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mvebu: Fix cause computation in irq handler
  gpio: reject invalid gpio before getting gpio_desc

Pull SCSI fixes from James Bottomley:
 "Six minor and error leg fixes, plus one major change: the reversion of
  scsi-mq as the default.

  We're doing the latter temporarily (with a backport to stable) to give
  us time to fix all the issues that turned up with this default before
  trying again"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: cxgb4i: call neigh_event_send() to update MAC address
  Revert "scsi: default to scsi-mq"
  scsi: sd_zbc: Write unlock zone from sd_uninit_cmnd()
  scsi: aacraid: Fix out of bounds in aac_get_name_resp
  scsi: csiostor: fail probe if fw does not support FCoE
  scsi: megaraid_sas: fix error handle in megasas_probe_one

My previous patch fixed a link error for all at91 platforms when
CONFIG_ARM_CPU_SUSPEND was not set, however this caused another
problem on a configuration that enabled CONFIG_ARCH_AT91 but none
of the individual SoCs, and that also enabled CPU_ARM720 as
the only CPU:

warning: (ARCH_AT91 && SOC_IMX23 && SOC_IMX28 && ARCH_PXA && MACH_MVEBU_V7 && SOC_IMX6 && ARCH_OMAP3 && ARCH_OMAP4 && SOC_OMAP5 && SOC_AM33XX && SOC_DRA7XX && ARCH_EXYNOS3 && ARCH_EXYNOS4 && EXYNOS5420_MCPM && EXYNOS_CPU_SUSPEND && ARCH_VEXPRESS_TC2_PM && ARM_BIG_LITTLE_CPUIDLE && ARM_HIGHBANK_CPUIDLE && QCOM_PM) selects ARM_CPU_SUSPEND which has unmet direct dependencies (ARCH_SUSPEND_POSSIBLE)
arch/arm/kernel/sleep.o: In function `cpu_resume':
(.text+0xf0): undefined reference to `cpu_arm720_suspend_size'
arch/arm/kernel/suspend.o: In function `__cpu_suspend_save':
suspend.c:(.text+0x134): undefined reference to `cpu_arm720_do_suspend'

This improves the hack some more by only selecting ARM_CPU_SUSPEND
for the part that requires it, and changing pm.c to drop the
contents of unused init functions so we no longer refer to
cpu_resume on at91 platforms that don't need it.

Fixes: cc7a938f ("ARM: at91: select CONFIG_ARM_CPU_SUSPEND")
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Pull ext4 fixes from Ted Ts'o:
 "Fix a clang build regression and an potential xattr corruption bug"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: add missing xattr hash update
  ext4: fix clang build regression

acpi_graph_get_child_prop_value() is intended to find a child node with a
certain property value pair. The check

	if (!fwnode_property_read_u32(fwnode, prop_name, &nr))
		continue;

is faulty: fwnode_property_read_u32() returns zero on success, not on
failure, leading to comparing values only if the searched property was not
found.

Moreover, the check is made against the parent device node instead of
the child one as it should be.

Fixes: 79389a83 (ACPI / property: Add support for remote endpoints)
Reported-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: 4.12+ <stable@vger.kernel.org> # 4.12+
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 2d2a9543 (ACPICA: Update two error messages to emit
control method name) causes acpi_evaluate_object_typed() to fail
if its pathname argument is NULL, but some callers of that function
in the kernel, particularly acpi_nondev_subnode_data_ok(), pass
NULL as pathname to it and expect it to work.

For this reason, make acpi_evaluate_object_typed() check if its
pathname argument is NULL and fall back to using the pathname of
its handle argument if that is the case.
Reported-by: Sakari Ailus <sakari.ailus@intel.com>
Tested-by: Yang, Hyungwoo <hyungwoo.yang@intel.com>
Fixes: 2d2a9543 (ACPICA: Update two error messages to emit control method name)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Initializing cq_context with ev_queue in create_cq(), leads to NULL pointer
dereference in ib_uverbs_comp_handler(), if application doesnot use completion
channel. This patch fixes the cq_context initialization.

Fixes: 1e7710f3 ("IB/core: Change completion channel to use the reworked")
Cc: stable@vger.kernel.org # 4.12
Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
(cherry picked from commit 699a2d5b)

Pull MFD fix from Lee Jones:
 "Revert duplicate commit in da9062-core"

* tag 'mfd-fixes-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
  Revert "mfd: da9061: Fix to remove BBAT_CONT register from chip model"

With 16KB pages and a kernel Image larger than 16MB, the current
kaslr_early_init() logic for avoiding mappings across swapper table
boundaries fails since increasing the offset by kimg_sz just moves the
problem to the next boundary.

This patch rounds the offset down to (1 << SWAPPER_TABLE_SHIFT) if the
Image crosses a PMD_SIZE boundary.

Fixes: afd0e5a8 ("arm64: kaslr: Fix up the kernel image alignment")
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

In the KASLR setup routine, we ensure that the early virtual mapping
of the kernel image does not cover more than a single table entry at
the level above the swapper block level, so that the assembler routines
involved in setting up this mapping can remain simple.

In this calculation we add the proposed KASLR offset to the values of
the _text and _end markers, and reject it if they would end up falling
in different swapper table sized windows.

However, when taking the addresses of _text and _end, the modulo offset
(the physical displacement modulo 2 MB) is already accounted for, and
so adding it again results in incorrect results. So disregard the modulo
offset from the calculation.

Fixes: 08cdac61 ("arm64: relocatable: deal with physically misaligned ...")
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

When there's a fatal signal pending, arm64's do_page_fault()
implementation returns 0. The intent is that we'll return to the
faulting userspace instruction, delivering the signal on the way.

However, if we take a fatal signal during fixing up a uaccess, this
results in a return to the faulting kernel instruction, which will be
instantly retried, resulting in the same fault being taken forever. As
the task never reaches userspace, the signal is not delivered, and the
task is left unkillable. While the task is stuck in this state, it can
inhibit the forward progress of the system.

To avoid this, we must ensure that when a fatal signal is pending, we
apply any necessary fixup for a faulting kernel instruction. Thus we
will return to an error path, and it is up to that code to make forward
progress towards delivering the fatal signal.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

There are some tricky dependencies between the different stages of
flushing the FPSIMD register state during exec, and these can race
with context switch in ways that can cause the old task's regs to
leak across.  In particular, a context switch during the memset() can
cause some of the task's old FPSIMD registers to reappear.

Disabling preemption for this small window would be no big deal for
performance: preemption is already disabled for similar scenarios
like updating the FPSIMD registers in sigreturn.

So, instead of rearranging things in ways that might swap existing
subtle bugs for new ones, this patch just disables preemption
around the FPSIMD state flushing so that races of this type can't
occur here.  This brings fpsimd_flush_thread() into line with other
code paths.

Cc: stable@vger.kernel.org
Fixes: 674c242c ("arm64: flush FP/SIMD state correctly after execve()")
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Merge tag 'at91-ab-4.13-drivers-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux into fixes

Pull "Driver fixes for 4.13" from Alexandre Belloni:

 - Multiple EBI/SMC timing setting/calculation fixes

* tag 'at91-ab-4.13-drivers-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  memory: atmel-ebi: Fix smc cycle xlate converter
  memory: atmel-ebi: Allow t_DF timings of zero ns
  memory: atmel-ebi: Fix smc timing return value evaluation

This patch was applied to the MFD twice, causing unwanted behavour.

This reverts commit b77eb79a.

Fixes: b77eb79a ("mfd: da9061: Fix to remove BBAT_CONT register from chip model")
Reported-by: Steve Twiss <stwiss.opensource@diasemi.com>
Reviewed-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Pull sparc fixes from David Miller:
 "Just a couple small fixes, two of which have to do with gcc-7:

   1) Don't clobber kernel fixed registers in __multi4 libgcc helper.

   2) Fix a new uninitialized variable warning on sparc32 with gcc-7,
      from Thomas Petazzoni.

   3) Adjust pmd_t initializer on sparc32 to make gcc happy.

   4) If ATU isn't available, don't bark in the logs. From Tushar Dave"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: kernel/pcic: silence gcc 7.x warning in pcibios_fixup_bus()
  sparc64: remove unnecessary log message
  sparc64: Don't clibber fixed registers in __multi4.
  mm: add pmd_t initializer __pmd() to work around a GCC bug.

When building the kernel for Sparc using gcc 7.x, the build fails
with:

arch/sparc/kernel/pcic.c: In function ‘pcibios_fixup_bus’:
arch/sparc/kernel/pcic.c:647:8: error: ‘cmd’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
    cmd |= PCI_COMMAND_IO;
        ^~

The simplified code looks like this:

unsigned int cmd;
[...]
pcic_read_config(dev->bus, dev->devfn, PCI_COMMAND, 2, &cmd);
[...]
cmd |= PCI_COMMAND_IO;

I.e, the code assumes that pcic_read_config() will always initialize
cmd. But it's not the case. Looking at pcic_read_config(), if
bus->number is != 0 or if the size is not one of 1, 2 or 4, *val will
not be initialized.

As a simple fix, we initialize cmd to zero at the beginning of
pcibios_fixup_bus.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>