Right now, pages inflated as part of a balloon driver will be dumped by
dump tools like makedumpfile.  While XEN is able to check in the crash
kernel whether a certain pfn is actuall backed by memory in the
hypervisor (see xen_oldmem_pfn_is_ram) and optimize this case, dumps of
other balloon inflated memory will essentially result in zero pages
getting allocated by the hypervisor and the dump getting filled with
this data.

The allocation and reading of zero pages can directly be avoided if a
dumping tool could know which pages only contain stale information not
to be dumped.

We now have PG_offline which can be (and already is by virtio-balloon)
used for marking pages as logically offline.  Follow up patches will
make use of this flag also in other balloon implementations.

Let's export PG_offline via PAGE_OFFLINE_MAPCOUNT_VALUE, so makedumpfile
can directly skip pages that are logically offline and the content
therefore stale.

Please note that this is also helpful for a problem we were seeing under
Hyper-V: Dumping logically offline memory (pages kept fake offline while
onlining a section via online_page_callback) would under some condicions
result in a kernel panic when dumping them.

Link: http://lkml.kernel.org/r/20181119101616.8901-4-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NDave Young <dyoung@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Hansen <chansen3@cisco.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juergen Gross <jgross@suse.com>
Cc: Julien Freche <jfreche@vmware.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Pankaj gupta <pagupta@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PG_balloon was introduced to implement page migration/compaction for
pages inflated in virtio-balloon.  Nowadays, it is only a marker that a
page is part of virtio-balloon and therefore logically offline.

We also want to make use of this flag in other balloon drivers - for
inflated pages or when onlining a section but keeping some pages offline
(e.g.  used right now by XEN and Hyper-V via set_online_page_callback()).

We are going to expose this flag to dump tools like makedumpfile.  But
instead of exposing PG_balloon, let's generalize the concept of marking
pages as logically offline, so it can be reused for other purposes later
on.

Rename PG_balloon to PG_offline.  This is an indicator that the page is
logically offline, the content stale and that it should not be touched
(e.g.  a hypervisor would have to allocate backing storage in order for
the guest to dump an unused page).  We can then e.g.  exclude such pages
from dumps.

We replace and reuse KPF_BALLOON (23), as this shouldn't really harm
(and for now the semantics stay the same).  In following patches, we
will make use of this bit also in other balloon drivers.  While at it,
document PGTABLE.

[akpm@linux-foundation.org: fix comment text, per David]
Link: http://lkml.kernel.org/r/20181119101616.8901-3-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NPankaj gupta <pagupta@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Christian Hansen <chansen3@cisco.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Julien Freche <jfreche@vmware.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/kdump: allow to exclude pages that are logically
offline"

Right now, pages inflated as part of a balloon driver will be dumped by
dump tools like makedumpfile.  While XEN is able to check in the crash
kernel whether a certain pfn is actuall backed by memory in the
hypervisor (see xen_oldmem_pfn_is_ram) and optimize this case, dumps of
virtio-balloon, hv-balloon and VMWare balloon inflated memory will
essentially result in zero pages getting allocated by the hypervisor and
the dump getting filled with this data.

The allocation and reading of zero pages can directly be avoided if a
dumping tool could know which pages only contain stale information not
to be dumped.

Also for XEN, calling into the kernel and asking the hypervisor if a pfn
is backed can be avoided if the duming tool would skip such pages right
from the beginning.

Dumping tools have no idea whether a given page is part of a balloon
driver and shall not be dumped.  Esp.  PG_reserved cannot be used for
that purpose as all memory allocated during early boot is also
PG_reserved, see discussion at [1].  So some other way of indication is
required and a new page flag is frowned upon.

We have PG_balloon (MAPCOUNT value), which is essentially unused now.  I
suggest renaming it to something more generic (PG_offline) to mark pages
as logically offline.  This flag can than e.g.  also be used by
virtio-mem in the future to mark subsections as offline.  Or by other
code that wants to put pages logically offline (e.g.  later maybe
poisoned pages that shall no longer be used).

This series converts PG_balloon to PG_offline, allows dumping tools to
query the value to detect such pages and marks pages in the hv-balloon
and XEN balloon properly as PG_offline.  Note that virtio-balloon
already set pages to PG_balloon (and now PG_offline).

Please note that this is also helpful for a problem we were seeing under
Hyper-V: Dumping logically offline memory (pages kept fake offline while
onlining a section via online_page_callback) would under some condicions
result in a kernel panic when dumping them.

As I don't have access to neither XEN nor Hyper-V nor VMWare
installations, this was only tested with the virtio-balloon and pages
were properly skipped when dumping.  I'll also attach the makedumpfile
patch to this series.

[1] https://lkml.org/lkml/2018/7/20/566

This patch (of 8):

Commit b1123ea6 ("mm: balloon: use general non-lru movable page
feature") reworked balloon handling to make use of the general non-lru
movable page feature.  The big comment block in balloon_compaction.h
contains quite some outdated information.  Let's fix this.

Link: http://lkml.kernel.org/r/20181119101616.8901-2-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Hansen <chansen3@cisco.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juergen Gross <jgross@suse.com>
Cc: Julien Freche <jfreche@vmware.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Pankaj gupta <pagupta@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When freeing pages are done with higher order, time spent on coalescing
pages by buddy allocator can be reduced.  With section size of 256MB,
hot add latency of a single section shows improvement from 50-60 ms to
less than 1 ms, hence improving the hot add latency by 60 times.  Modify
external providers of online callback to align with the change.

[arunks@codeaurora.org: v11]
  Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org
[akpm@linux-foundation.org: remove unused local, per Arun]
[akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar]
[akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch]
[arunks@codeaurora.org: v8]
  Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org
[arunks@codeaurora.org: v9]
  Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org
Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.orgSigned-off-by: NArun KS <arunks@codeaurora.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NAlexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"addr" function argument is not used in alloc_consistency_checks() at
all, so remove it.

Link: http://lkml.kernel.org/r/20190211123214.35592-1-cai@lca.pw
Fixes: becfda68 ("slub: convert SLAB_DEBUG_FREE to SLAB_CONSISTENCY_CHECKS")
Signed-off-by: NQian Cai <cai@lca.pw>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Capitialize comment string, use C89 comment style, correct
grammar/punctuation in comments.

Link: http://lkml.kernel.org/r/20190204005713.9463-2-tobin@kernel.org
Link: http://lkml.kernel.org/r/20190204005713.9463-3-tobin@kernel.org
Link: http://lkml.kernel.org/r/20190204005713.9463-4-tobin@kernel.orgSigned-off-by: NTobin C. Harding <tobin@kernel.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Kmemleak throws endless warnings during boot due to in
__alloc_alien_cache(),

    alc = kmalloc_node(memsize, gfp, node);
    init_arraycache(&alc->ac, entries, batch);
    kmemleak_no_scan(ac);

Kmemleak does not track the array cache (alc->ac) but the alien cache
(alc) instead, so let it track the latter by lifting kmemleak_no_scan()
out of init_arraycache().

There is another place that calls init_arraycache(), but
alloc_kmem_cache_cpus() uses the percpu allocation where will never be
considered as a leak.

  kmemleak: Found object by alias at 0xffff8007b9aa7e38
  CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2
  Call trace:
   dump_backtrace+0x0/0x168
   show_stack+0x24/0x30
   dump_stack+0x88/0xb0
   lookup_object+0x84/0xac
   find_and_get_object+0x84/0xe4
   kmemleak_no_scan+0x74/0xf4
   setup_kmem_cache_node+0x2b4/0x35c
   __do_tune_cpucache+0x250/0x2d4
   do_tune_cpucache+0x4c/0xe4
   enable_cpucache+0xc8/0x110
   setup_cpu_cache+0x40/0x1b8
   __kmem_cache_create+0x240/0x358
   create_cache+0xc0/0x198
   kmem_cache_create_usercopy+0x158/0x20c
   kmem_cache_create+0x50/0x64
   fsnotify_init+0x58/0x6c
   do_one_initcall+0x194/0x388
   kernel_init_freeable+0x668/0x688
   kernel_init+0x18/0x124
   ret_from_fork+0x10/0x18
  kmemleak: Object 0xffff8007b9aa7e00 (size 256):
  kmemleak:   comm "swapper/0", pid 1, jiffies 4294697137
  kmemleak:   min_count = 1
  kmemleak:   count = 0
  kmemleak:   flags = 0x1
  kmemleak:   checksum = 0
  kmemleak:   backtrace:
       kmemleak_alloc+0x84/0xb8
       kmem_cache_alloc_node_trace+0x31c/0x3a0
       __kmalloc_node+0x58/0x78
       setup_kmem_cache_node+0x26c/0x35c
       __do_tune_cpucache+0x250/0x2d4
       do_tune_cpucache+0x4c/0xe4
       enable_cpucache+0xc8/0x110
       setup_cpu_cache+0x40/0x1b8
       __kmem_cache_create+0x240/0x358
       create_cache+0xc0/0x198
       kmem_cache_create_usercopy+0x158/0x20c
       kmem_cache_create+0x50/0x64
       fsnotify_init+0x58/0x6c
       do_one_initcall+0x194/0x388
       kernel_init_freeable+0x668/0x688
       kernel_init+0x18/0x124
  kmemleak: Not scanning unknown object at 0xffff8007b9aa7e38
  CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2
  Call trace:
   dump_backtrace+0x0/0x168
   show_stack+0x24/0x30
   dump_stack+0x88/0xb0
   kmemleak_no_scan+0x90/0xf4
   setup_kmem_cache_node+0x2b4/0x35c
   __do_tune_cpucache+0x250/0x2d4
   do_tune_cpucache+0x4c/0xe4
   enable_cpucache+0xc8/0x110
   setup_cpu_cache+0x40/0x1b8
   __kmem_cache_create+0x240/0x358
   create_cache+0xc0/0x198
   kmem_cache_create_usercopy+0x158/0x20c
   kmem_cache_create+0x50/0x64
   fsnotify_init+0x58/0x6c
   do_one_initcall+0x194/0x388
   kernel_init_freeable+0x668/0x688
   kernel_init+0x18/0x124
   ret_from_fork+0x10/0x18

Link: http://lkml.kernel.org/r/20190129184518.39808-1-cai@lca.pw
Fixes: 1fe00d50 ("slab: factor out initialization of array cache")
Signed-off-by: NQian Cai <cai@lca.pw>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

new_slab_objects() will return immediately if freelist is not NULL.

         if (freelist)
                 return freelist;

One more assignment operation could be avoided.

Link: http://lkml.kernel.org/r/20181229062512.30469-1-rocking@whu.edu.cnSigned-off-by: NPeng Wang <rocking@whu.edu.cn>
Reviewed-by: NPekka Enberg <penberg@kernel.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

(Taken from https://bugzilla.kernel.org/show_bug.cgi?id=200647)

'get_unused_fd_flags' in kthread cause kernel crash.  It works fine on
4.1, but causes crash after get 64 fds.  It also cause crash on
ubuntu1404/1604/1804, centos7.5, and the crash messages are almost the
same.

The crash message on centos7.5 shows below:

  start fd 61
  start fd 62
  start fd 63
  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: __wake_up_common+0x2e/0x90
  PGD 0
  Oops: 0000 [#1] SMP
  Modules linked in: test(OE) xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter devlink sunrpc kvm_intel kvm irqbypass crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd sg ppdev pcspkr virtio_balloon parport_pc parport i2c_piix4 joydev ip_tables xfs libcrc32c sr_mod cdrom sd_mod crc_t10dif crct10dif_generic ata_generic pata_acpi virtio_scsi virtio_console virtio_net cirrus drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm crct10dif_pclmul crct10dif_common crc32c_intel drm ata_piix serio_raw libata virtio_pci virtio_ring i2c_core
   virtio floppy dm_mirror dm_region_hash dm_log dm_mod
  CPU: 2 PID: 1820 Comm: test_fd Kdump: loaded Tainted: G           OE  ------------   3.10.0-862.3.3.el7.x86_64 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
  task: ffff8e92b9431fa0 ti: ffff8e94247a0000 task.ti: ffff8e94247a0000
  RIP: 0010:__wake_up_common+0x2e/0x90
  RSP: 0018:ffff8e94247a2d18  EFLAGS: 00010086
  RAX: 0000000000000000 RBX: ffffffff9d09daa0 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffffffff9d09daa0
  RBP: ffff8e94247a2d50 R08: 0000000000000000 R09: ffff8e92b95dfda8
  R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9d09daa8
  R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000003
  FS:  0000000000000000(0000) GS:ffff8e9434e80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000017c686000 CR4: 00000000000207e0
  Call Trace:
    __wake_up+0x39/0x50
    expand_files+0x131/0x250
    __alloc_fd+0x47/0x170
    get_unused_fd_flags+0x30/0x40
    test_fd+0x12a/0x1c0 [test]
    kthread+0xd1/0xe0
    ret_from_fork_nospec_begin+0x21/0x21
  Code: 66 90 55 48 89 e5 41 57 41 89 f7 41 56 41 89 ce 41 55 41 54 49 89 fc 49 83 c4 08 53 48 83 ec 10 48 8b 47 08 89 55 cc 4c 89 45 d0 <48> 8b 08 49 39 c4 48 8d 78 e8 4c 8d 69 e8 75 08 eb 3b 4c 89 ef
  RIP   __wake_up_common+0x2e/0x90
   RSP <ffff8e94247a2d18>
  CR2: 0000000000000000

This issue exists since CentOS 7.5 3.10.0-862 and CentOS 7.4
(3.10.0-693.21.1 ) is ok.  Root cause: the item 'resize_wait' is not
initialized before being used.
Reported-by: NRichard Zhang <zhang.zijian@h3c.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It seems that commits 5f16f322 and 00a1a053, both with same
commitlog ("ext4: atomically set inode->i_flags in ext4_set_inode_flags()")
introduced the set_mask_bits API, but somehow missed not using it in ext4
in the end.

Also, set_mask_bits() is used in fs quite a bit and we can possibly come
up with a generic llsc based implementation (w/o the cmpxchg loop)

Link: http://lkml.kernel.org/r/1548275584-18096-3-git-send-email-vgupta@synopsys.comSigned-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NAnthony Yznaga <anthony.yznaga@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the code to use a zero-sized array instead of a pointer in
structure ocfs2_slot_info and use struct_size() in kzalloc().

Notice that one of the more common cases of allocation size calculations
is finding the size of a structure that has a zero-sized array at the
end, along with memory for some number of elements for that array.  For
example:

  struct foo {
      int stuff;
      void *entry[];
  };

  instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

  instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Link: http://lkml.kernel.org/r/20190108191903.GA22056@embeddedorSigned-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The user reported this problem, the upper application IO was timeout
when fstrim was running on this ocfs2 partition.  the application
monitoring resource agent considered that this application did not work,
then this node was fenced by the cluster brain (e.g.  pacemaker).

The root cause is that fstrim thread always holds main_bm meta-file
related locks until all the cluster groups are trimmed.  This patch will
make fstrim thread release main_bm meta-file related locks when each
cluster group is trimmed, this will let the current application IO has a
chance to claim the clusters from main_bm meta-file.

Link: http://lkml.kernel.org/r/20190111090014.31645-1-ghe@suse.comSigned-off-by: NGang He <ghe@suse.com>
Reviewed-by: NChangwei Ge <ge.changwei@h3c.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the process of creating a node, it will cause NULL pointer
dereference in kernel if o2cb_ctl failed in the interval (mkdir,
o2cb_set_node_attribute(node_num)] in function o2cb_add_node.

The node num is initialized to 0 in function o2nm_node_group_make_item,
o2nm_node_group_drop_item will mistake the node number 0 for a valid
node number when we delete the node before the node number is set
correctly.  If the local node number of the current host happens to be
0, cluster->cl_local_node will be set to O2NM_INVALID_NODE_NUM while
o2hb_thread still running.  The panic stack is generated as follows:

  o2hb_thread
      \-o2hb_do_disk_heartbeat
          \-o2hb_check_own_slot
              |-slot = &reg->hr_slots[o2nm_this_node()];
              //o2nm_this_node() return O2NM_INVALID_NODE_NUM

We need to check whether the node number is set when we delete the node.

Link: http://lkml.kernel.org/r/133d8045-72cc-863e-8eae-5013f9f6bc51@huawei.comSigned-off-by: NJia Guo <guojia12@huawei.com>
Reviewed-by: NJoseph Qi <jiangqi903@gmail.com>
Acked-by: NJun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The __SYSCALL macro's arguments are system call number, system call
entry name and number of arguments for the system call.

Argument- nargs in __SYSCALL(nr, entry, nargs) is neither calculated nor
used anywhere.  So it would be better to keep the implementation as
__SYSCALL(nr, entry).  This unifies the implementation with some other
architectures too.

Link: http://lkml.kernel.org/r/1546443445-21075-2-git-send-email-firoz.khan@linaro.orgSigned-off-by: NFiroz Khan <firoz.khan@linaro.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

decode line:

  RIP: 0010:khugepaged+0x2a2/0x2280

into

  RIP: 0010:khugepaged (mm/khugepaged.c:1885)

Link: http://lkml.kernel.org/r/154660071227.52726.15645307951282727605.stgit@buzzSigned-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kasan_p4d_table(), kasan_pmd_table() and kasan_pud_table() are declared
as returning bool, but return 0 instead of false, which produces a
coccinelle warning.  Fix it.

Link: http://lkml.kernel.org/r/1fa6fadf644859e8a6a8ecce258444b49be8c7ee.1551716733.git.andreyknvl@google.com
Fixes: 0207df4f ("kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN")
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reported-by: Nkbuild test robot <lkp@intel.com>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Building little-endian allmodconfig kernels on arm64 started failing
with the generated atomic.h implementation, since we now try to call
kasan helpers from the EFI stub:

  aarch64-linux-gnu-ld: drivers/firmware/efi/libstub/arm-stub.stub.o: in function `atomic_set':
  include/generated/atomic-instrumented.h:44: undefined reference to `__efistub_kasan_check_write'

I suspect that we get similar problems in other files that explicitly
disable KASAN for some reason but call atomic_t based helper functions.

We can fix this by checking the predefined __SANITIZE_ADDRESS__ macro
that the compiler sets instead of checking CONFIG_KASAN, but this in
turn requires a small hack in mm/kasan/common.c so we do see the extern
declaration there instead of the inline function.

Link: http://lkml.kernel.org/r/20181211133453.2835077-1-arnd@arndb.de
Fixes: b1864b828644 ("locking/atomics: build atomic headers as required")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reported-by: NAnders Roxell <anders.roxell@linaro.org>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

KASAN does not play well with the page poisoning (CONFIG_PAGE_POISONING).
It triggers false positives in the allocation path:

  BUG: KASAN: use-after-free in memchr_inv+0x2ea/0x330
  Read of size 8 at addr ffff88881f800000 by task swapper/0
  CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc1+ #54
  Call Trace:
   dump_stack+0xe0/0x19a
   print_address_description.cold.2+0x9/0x28b
   kasan_report.cold.3+0x7a/0xb5
   __asan_report_load8_noabort+0x19/0x20
   memchr_inv+0x2ea/0x330
   kernel_poison_pages+0x103/0x3d5
   get_page_from_freelist+0x15e7/0x4d90

because KASAN has not yet unpoisoned the shadow page for allocation
before it checks memchr_inv() but only found a stale poison pattern.

Also, false positives in free path,

  BUG: KASAN: slab-out-of-bounds in kernel_poison_pages+0x29e/0x3d5
  Write of size 4096 at addr ffff8888112cc000 by task swapper/0/1
  CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1+ #55
  Call Trace:
   dump_stack+0xe0/0x19a
   print_address_description.cold.2+0x9/0x28b
   kasan_report.cold.3+0x7a/0xb5
   check_memory_region+0x22d/0x250
   memset+0x28/0x40
   kernel_poison_pages+0x29e/0x3d5
   __free_pages_ok+0x75f/0x13e0

due to KASAN adds poisoned redzones around slab objects, but the page
poisoning needs to poison the whole page.

Link: http://lkml.kernel.org/r/20190114233405.67843-1-cai@lca.pwSigned-off-by: NQian Cai <cai@lca.pw>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use after scope bugs detector seems to be almost entirely useless for
the linux kernel.  It exists over two years, but I've seen only one
valid bug so far [1].  And the bug was fixed before it has been
reported.  There were some other use-after-scope reports, but they were
false-positives due to different reasons like incompatibility with
structleak plugin.

This feature significantly increases stack usage, especially with GCC <
9 version, and causes a 32K stack overflow.  It probably adds
performance penalty too.

Given all that, let's remove use-after-scope detector entirely.

While preparing this patch I've noticed that we mistakenly enable
use-after-scope detection for clang compiler regardless of
CONFIG_KASAN_EXTRA setting.  This is also fixed now.

[1] http://lkml.kernel.org/r/<20171129052106.rhgbjhhis53hkgfn@wfg-t540p.sh.intel.com>

Link: http://lkml.kernel.org/r/20190111185842.13978-1-aryabinin@virtuozzo.comSigned-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Will Deacon <will.deacon@arm.com>		[arm64]
Cc: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When soft_offline_in_use_page() runs on a thp tail page after pmd is
split, we trigger the following VM_BUG_ON_PAGE():

  Memory failure: 0x3755ff: non anonymous thp
  __get_any_page: 0x3755ff: unknown zero refcount page type 2fffff80000000
  Soft offlining pfn 0x34d805 at process virtual address 0x20fff000
  page:ffffea000d360140 count:0 mapcount:0 mapping:0000000000000000 index:0x1
  flags: 0x2fffff80000000()
  raw: 002fffff80000000 ffffea000d360108 ffffea000d360188 0000000000000000
  raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
  page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
  ------------[ cut here ]------------
  kernel BUG at ./include/linux/mm.h:519!

soft_offline_in_use_page() passed refcount and page lock from tail page
to head page, which is not needed because we can pass any subpage to
split_huge_page().

Naoya had fixed a similar issue in c3901e72 ("mm: hwpoison: fix thp
split handling in memory_failure()").  But he missed fixing soft
offline.

Link: http://lkml.kernel.org/r/1551452476-24000-1-git-send-email-zhongjiang@huawei.com
Fixes: 61f5d698 ("mm: re-enable THP")
Signed-off-by: Nzhongjiang <zhongjiang@huawei.com>
Acked-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>	[4.5+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull MIPS updates from Paul Burton:

 - Support for the MIPSr6 MemoryMapID register & Global INValidate TLB
   (GINVT) instructions, allowing for more efficient TLB maintenance
   when running on a CPU such as the I6500 that supports these.

 - Enable huge page support for MIPS64r6.

 - Optimize post-DMA cache sync by removing that code entirely for
   kernel configurations in which we know it won't be needed.

 - The number of pages allocated for interrupt stacks is now calculated
   correctly, where before we would wastefully allocate too much memory
   in some configurations.

 - The ath79 platform migrates to devicetree.

 - The bcm47xx platform sees fixes for the Buffalo WHR-G54S board.

 - The ingenic/jz4740 platform gains support for appended devicetrees.

 - The cavium_octeon, lantiq, loongson32 & sgi-ip27 platforms all see
   cleanups as do various pieces of core architecture code.

* tag 'mips_5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (66 commits)
  MIPS: lantiq: Remove separate GPHY Firmware loader
  MIPS: ingenic: Add support for appended devicetree
  MIPS: SGI-IP27: rework HUB interrupts
  MIPS: SGI-IP27: do boot CPU init later
  MIPS: SGI-IP27: do xtalk scanning later
  MIPS: SGI-IP27: use pr_info/pr_emerg and pr_cont to fix output
  MIPS: SGI-IP27: clean up bridge access and header files
  MIPS: SGI-IP27: get rid of volatile and hubreg_t
  MIPS: irq: Allocate accurate order pages for irq stack
  MIPS: dma-noncoherent: Remove bogus condition in dma_sync_phys()
  MIPS: eBPF: Remove REG_32BIT_ZERO_EX
  MIPS: eBPF: Always return sign extended 32b values
  MIPS: CM: Fix indentation
  MIPS: BCM47XX: Fix/improve Buffalo WHR-G54S support
  MIPS: OCTEON: program rx/tx-delay always from DT
  MIPS: OCTEON: delete board-specific link status
  MIPS: OCTEON: don't lie about interface type of CN3005 board
  MIPS: OCTEON: warn if deprecated link status is being used
  MIPS: OCTEON: add fixed-link nodes to in-kernel device tree
  MIPS: Delete unused flush_cache_sigtramp()
  ...

Pull parisc updates from Helge Deller:
 "The most important changes in this patch set are:

   - DMA-related cleanups for parisc with the aim to move anything not
     required by drivers out of <asm/dma-mapping.h>, by Christoph
     Hellwig

   - Switch to memblock_alloc(), by Mike Rapoport

   - Makefile cleanups by Masahiro Yamada

   - Switch to bust_spinlocks(), by Sergey Senozhatsky

   - Improved initial SMP affinity selection for IRQs

   - Added IPI- and rescheduling interrupts in /proc/interrupts output"

* 'parisc-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (21 commits)
  parisc: use memblock_alloc() instead of custom get_memblock()
  parisc: Add constants for various PDC firmware calls
  parisc: Add constant for PDC_PAT_COMPLEX firmware call
  parisc: Show machine product number during boot
  parisc: Add constants for PDC_RELOCATE PDC call
  parisc: Add PDC_CRASH_PREP PDC function number
  parisc: Use F_EXTEND() macro in iosapic code
  parisc: remove the HBA_DATA macro
  parisc/lba_pci: use container_of in LBA_DEV
  parisc/dino: use container_of in DINO_DEV
  parisc: properly type the return value of parisc_walk_tree
  parisc: properly type the iommu field in struct pci_hba_data
  parisc: turn GET_IOC into an inline function
  parisc: move internal implementation details out of <asm/dma-mapping.h>
  parisc: don't include <asm/cacheflush.h> in <asm/dma-mapping.h>
  parisc: remove meaningless ccflags-y in arch/parisc/boot/Makefile
  parisc: replace oops_in_progress manipulation with bust_spinlocks()
  parisc: Improve initial IRQ to CPU assignment
  parisc: Count IPI function call interrupts
  parisc: Show rescheduling interrupts on SMP machines only
  ...

Pull s390 updates from Martin Schwidefsky:

 - A copy of Arnds compat wrapper generation series

 - Pass information about the KVM guest to the host in form the control
   program code and the control program version code

 - Map IOV resources to support PCI physical functions on s390

 - Add vector load and store alignment hints to improve performance

 - Use the "jdd" constraint with gcc 9 to make jump labels working again

 - Remove amode workaround for old z/VM releases from the DCSS code

 - Add support for in-kernel performance measurements using the CPU
   measurement counter facility

 - Introduce a new PMU device cpum_cf_diag to capture counters and store
   thenn as event raw data.

 - Bug fixes and cleanups

* tag 's390-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
  Revert "s390/cpum_cf: Add kernel message exaplanations"
  s390/dasd: fix read device characteristic with CONFIG_VMAP_STACK=y
  s390/suspend: fix prefix register reset in swsusp_arch_resume
  s390: warn about clearing als implied facilities
  s390: allow overriding facilities via command line
  s390: clean up redundant facilities list setup
  s390/als: remove duplicated in-place implementation of stfle
  s390/cio: Use cpa range elsewhere within vfio-ccw
  s390/cio: Fix vfio-ccw handling of recursive TICs
  s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
  s390/cpum_cf: Handle EBUSY return code from CPU counter facility reservation
  s390/cpum_cf: Add kernel message exaplanations
  s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace
  s390/cpum_cf: add ctr_stcctm() function
  s390/cpum_cf: move common functions into a separate file
  s390/cpum_cf: introduce kernel_cpumcf_avail() function
  s390/cpu_mf: replace stcctm5() with the stcctm() function
  s390/cpu_mf: add store cpu counter multiple instruction support
  s390/cpum_cf: Add minimal in-kernel interface for counter measurements
  s390/cpum_cf: introduce kernel_cpumcf_alert() to obtain measurement alerts
  ...

Pull m68k updates from Geert Uytterhoeven:

 - VLA removal

 - gcc-8.x build fixes

 - small improvements and cleanups

 - defconfig updates

* tag 'm68k-for-v5.1-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Add -ffreestanding to CFLAGS
  m68k/apollo: Fix comment in Makefile
  dio: Fix buffer overflow in case of unknown board
  m68k/defconfig: Update defconfigs for v5.0-rc1
  m68k/atari: Avoid VLA use in atari_switches_setup()
  m68k: Avoid VLA use in mangle_kernel_stack()
  m68k/mac: Use '030 reset method on SE/30
  m68k/mac: Remove obsolete comment
  m68k/mac: Skip VIA port setup unless RTC is connected
  m68k/mac: Clean up unused timer definitions
  m68k/defconfig: Drop NET_VENDOR_<FOO>=n

Linux supports ELF binaries for ~25 years now.  a.out coredumping has
bitrotten quite significantly and would need some fixing to get it into
shape again but considering how even the toolchains cannot create a.out
executables in its default configuration, let's deprecate a.out support
and remove it a couple of releases later, instead.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NRichard Weinberger <richard@nod.at>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jann Horn <jannh@google.com>
Cc: <linux-api@vger.kernel.org>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: lkml <linux-kernel@vger.kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <x86@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We're (finally) phasing out a.out support for good.  As Borislav Petkov
points out, we've supported ELF binaries for about 25 years by now, and
coredumping in particular has bitrotted over the years.

None of the tool chains even support generating a.out binaries any more,
and the plan is to deprecate a.out support entirely for the kernel.  But
I want to start with just removing the core dumping code, because I can
still imagine that somebody actually might want to support a.out as a
simpler biinary format.

Particularly if you generate some random binaries on the fly, ELF is a
much more complicated format (admittedly ELF also does have a lot of
toolchain support, mitigating that complexity a lot and you really
should have moved over in the last 25 years).

So it's at least somewhat possible that somebody out there has some
workflow that still involves generating and running a.out executables.

In contrast, it's very unlikely that anybody depends on debugging any
legacy a.out core files.  But regardless, I want this phase-out to be
done in two steps, so that we can resurrect a.out support (if needed)
without having to resurrect the core file dumping that is almost
certainly not needed.

Jann Horn pointed to the <asm/a.out-core.h> file that my first trivial
cut at this had missed.

And Alan Cox points out that the a.out binary loader _could_ be done in
user space if somebody wants to, but we might keep just the loader in
the kernel if somebody really wants it, since the loader isn't that big
and has no really odd special cases like the core dumping does.
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Jann Horn <jannh@google.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull crypto update from Herbert Xu:
 "API:
   - Add helper for simple skcipher modes.
   - Add helper to register multiple templates.
   - Set CRYPTO_TFM_NEED_KEY when setkey fails.
   - Require neither or both of export/import in shash.
   - AEAD decryption test vectors are now generated from encryption
     ones.
   - New option CONFIG_CRYPTO_MANAGER_EXTRA_TESTS that includes random
     fuzzing.

  Algorithms:
   - Conversions to skcipher and helper for many templates.
   - Add more test vectors for nhpoly1305 and adiantum.

  Drivers:
   - Add crypto4xx prng support.
   - Add xcbc/cmac/ecb support in caam.
   - Add AES support for Exynos5433 in s5p.
   - Remove sha384/sha512 from artpec7 as hardware cannot do partial
     hash"

[ There is a merge of the Freescale SoC tree in order to pull in changes
  required by patches to the caam/qi2 driver. ]

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (174 commits)
  crypto: s5p - add AES support for Exynos5433
  dt-bindings: crypto: document Exynos5433 SlimSSS
  crypto: crypto4xx - add missing of_node_put after of_device_is_available
  crypto: cavium/zip - fix collision with generic cra_driver_name
  crypto: af_alg - use struct_size() in sock_kfree_s()
  crypto: caam - remove redundant likely/unlikely annotation
  crypto: s5p - update iv after AES-CBC op end
  crypto: x86/poly1305 - Clear key material from stack in SSE2 variant
  crypto: caam - generate hash keys in-place
  crypto: caam - fix DMA mapping xcbc key twice
  crypto: caam - fix hash context DMA unmap size
  hwrng: bcm2835 - fix probe as platform device
  crypto: s5p-sss - Use AES_BLOCK_SIZE define instead of number
  crypto: stm32 - drop pointless static qualifier in stm32_hash_remove()
  crypto: chelsio - Fixed Traffic Stall
  crypto: marvell - Remove set but not used variable 'ivsize'
  crypto: ccp - Update driver messages to remove some confusion
  crypto: adiantum - add 1536 and 4096-byte test vectors
  crypto: nhpoly1305 - add a test vector with len % 16 != 0
  crypto: arm/aes-ce - update IV after partial final CTR block
  ...

Pull networking updates from David Miller:
 "Here we go, another merge window full of networking and #ebpf changes:

   1) Snoop DHCPACKS in batman-adv to learn MAC/IP pairs in the DHCP
      range without dealing with floods of ARP traffic, from Linus
      Lüssing.

   2) Throttle buffered multicast packet transmission in mt76, from
      Felix Fietkau.

   3) Support adaptive interrupt moderation in ice, from Brett Creeley.

   4) A lot of struct_size conversions, from Gustavo A. R. Silva.

   5) Add peek/push/pop commands to bpftool, as well as bash completion,
      from Stanislav Fomichev.

   6) Optimize sk_msg_clone(), from Vakul Garg.

   7) Add SO_BINDTOIFINDEX, from David Herrmann.

   8) Be more conservative with local resends due to local congestion,
      from Yuchung Cheng.

   9) Allow vetoing of unsupported VXLAN FDBs, from Petr Machata.

  10) Add health buffer support to devlink, from Eran Ben Elisha.

  11) Add TXQ scheduling API to mac80211, from Toke Høiland-Jørgensen.

  12) Add statistics to basic packet scheduler filter, from Cong Wang.

  13) Add GRE tunnel support for mlxsw Spectrum-2, from Nir Dotan.

  14) Lots of new IP tunneling forwarding tests, also from Nir Dotan.

  15) Add 3ad stats to bonding, from Nikolay Aleksandrov.

  16) Lots of probing improvements for bpftool, from Quentin Monnet.

  17) Various nfp drive #ebpf JIT improvements from Jakub Kicinski.

  18) Allow #ebpf programs to access gso_segs from skb shared info, from
      Eric Dumazet.

  19) Add sock_diag support for AF_XDP sockets, from Björn Töpel.

  20) Support 22260 iwlwifi devices, from Luca Coelho.

  21) Use rbtree for ipv6 defragmentation, from Peter Oskolkov.

  22) Add JMP32 instruction class support to #ebpf, from Jiong Wang.

  23) Add spinlock support to #ebpf, from Alexei Starovoitov.

  24) Support 256-bit keys and TLS 1.3 in ktls, from Dave Watson.

  25) Add device infomation API to devlink, from Jakub Kicinski.

  26) Add new timestamping socket options which are y2038 safe, from
      Deepa Dinamani.

  27) Add RX checksum offloading for various sh_eth chips, from Sergei
      Shtylyov.

  28) Flow offload infrastructure, from Pablo Neira Ayuso.

  29) Numerous cleanups, improvements, and bug fixes to the PHY layer
      and many drivers from Heiner Kallweit.

  30) Lots of changes to try and make packet scheduler classifiers run
      lockless as much as possible, from Vlad Buslov.

  31) Support BCM957504 chip in bnxt_en driver, from Erik Burrows.

  32) Add concurrency tests to tc-tests infrastructure, from Vlad
      Buslov.

  33) Add hwmon support to aquantia, from Heiner Kallweit.

  34) Allow 64-bit values for SO_MAX_PACING_RATE, from Eric Dumazet.

  And I would be remiss if I didn't thank the various major networking
  subsystem maintainers for integrating much of this work before I even
  saw it. Alexei Starovoitov, Daniel Borkmann, Pablo Neira Ayuso,
  Johannes Berg, Kalle Valo, and many others. Thank you!"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2207 commits)
  net/sched: avoid unused-label warning
  net: ignore sysctl_devconf_inherit_init_net without SYSCTL
  phy: mdio-mux: fix Kconfig dependencies
  net: phy: use phy_modify_mmd_changed in genphy_c45_an_config_aneg
  net: dsa: mv88e6xxx: add call to mv88e6xxx_ports_cmode_init to probe for new DSA framework
  selftest/net: Remove duplicate header
  sky2: Disable MSI on Dell Inspiron 1545 and Gateway P-79
  net/mlx5e: Update tx reporter status in case channels were successfully opened
  devlink: Add support for direct reporter health state update
  devlink: Update reporter state to error even if recover aborted
  sctp: call iov_iter_revert() after sending ABORT
  team: Free BPF filter when unregistering netdev
  ip6mr: Do not call __IP6_INC_STATS() from preemptible context
  isdn: mISDN: Fix potential NULL pointer dereference of kzalloc
  net: dsa: mv88e6xxx: support in-band signalling on SGMII ports with external PHYs
  cxgb4/chtls: Prefix adapter flags with CXGB4
  net-sysfs: Switch to bitmap_zalloc()
  mellanox: Switch to bitmap_zalloc()
  bpf: add test cases for non-pointer sanitiation logic
  mlxsw: i2c: Extend initialization by querying resources data
  ...

This reverts commit fb3a0b61.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Merge tag 'leds-for-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED updates from Jacek Anaszewski:

 - finalize previously announced support for initialization of pattern
   triggers from Device Tree

 - fix for null deref on firmware load failure in leds-lp55xx-common.c

* tag 'leds-for-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: lp55xx: fix null deref on firmware load failure
  leds: trigger: timer: Add initialization from Device Tree
  leds: trigger: oneshot: Add initialization from Device Tree
  leds: trigger: pattern: Add pattern initialization from Device Tree
  leds: Add helper for getting default pattern from Device Tree
  dt-bindings: leds: Add pattern initialization from Device Tree

Pull hwmon updates from Guenter Roeck:

 - Add support for LM96000, DPS-650AB to existing drivers

 - Use permission specific SENSOR[_DEVICE]_ATTR variants in several
   drivers

 - Replace S_<PERMS> with octal values in several drivers

 - Update some license headers

 - Various minor fixes and improvements in several drivers

* tag 'hwmon-for-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: (89 commits)
  dt-bindings: hwmon: Add missing documentation for lm75
  hwmon: (ad7418) Add device tree probing
  hwmon: (ad741x) Add DT bindings for Analog Devices AD741x
  hwmon: (ntc_thermistor) Convert to new hwmon API
  hwmon: (pwm-fan) Add optional regulator support
  dt-bindings: hwmon: Add optional regulator support to pwm-fan
  hwmon: (f71882fg) Mark expected switch fall-through
  hwmon: (ad7418) Catch I2C errors
  hwmon: (lm85) add support for LM96000 high frequencies
  hwmon: (lm85) support the LM96000
  dt-bindings: Add LM96000 as a trivial device
  hwmon: (lm85) remove freq_map size hardcodes
  hwmon: (occ) Fix license headers
  hwmon: (via-cputemp) Use permission specific SENSOR[_DEVICE]_ATTR variants
  hwmon: (vexpress-hwmon) Use permission specific SENSOR[_DEVICE]_ATTR variants
  hwmon: (tmp421) Replace S_<PERMS> with octal values
  hwmon: (tmp103) Use permission specific SENSOR[_DEVICE]_ATTR variants
  hwmon: (tmp102) Replace S_<PERMS> with octal values
  hwmon: (tc74) Use permission specific SENSOR[_DEVICE]_ATTR variants
  hwmon: (tc654) Use permission specific SENSOR[_DEVICE]_ATTR variants
  ...

Pull spi updates from Mark Brown:
 "A fairly quiet release for SPI, the biggest thing is the conversion to
  use GPIO descriptors which is now 90% done but still needs some
  stragglers converting.

  Summary:

   - Support for inter-word delays

   - Conversion of the core and most drivers to use GPIO descriptors for
     GPIO controlled chip selects

   - New drivers for NXP FlexSPI and QuadSPI, SiFive and Spreadtrum"

* tag 'spi-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (104 commits)
  spi: sh-msiof: Restrict bits per word to 8/16/24/32 on R-Car Gen2/3
  spi: sifive: Remove redundant dev_err call in sifive_spi_probe()
  spi: sifive: Remove spi_master_put in sifive_spi_remove()
  spi: spi-gpio: fix SPI_CS_HIGH capability
  spi: pxa2xx: Setup maximum supported DMA transfer length
  spi: sifive: Add driver for the SiFive SPI controller
  spi: sifive: Add DT documentation for SiFive SPI controller
  spi: sprd: Add a prefix for SPI DMA channel macros
  spi: sprd: spi: sprd: Add DMA mode support
  dt-bindings: spi: Add the DMA properties for the SPI dma mode
  spi: sprd: Add the SPI irq function for the SPI DMA mode
  dt-bindings: spi: imx: Add an entry for the i.MX8QM compatible
  spi: use gpio[d]_set_value_cansleep for setting chipselect GPIO
  spi: gpio: Advertise support for SPI_CS_HIGH
  spi: sh-msiof: Replace spi_master by spi_controller
  spi: sh-hspi: Replace spi_master by spi_controller
  spi: rspi: Replace spi_master by spi_controller
  spi: atmel-quadspi: add support for sam9x60 qspi controller
  dt-bindings: spi: atmel-quadspi: QuadSPI driver for Microchip SAM9X60
  spi: atmel-quadspi: add support for named peripheral clock
  ...

Pull regulator updates from Mark Brown:
 "The bulk of the standout changes in this release are cleanups, with
  the core work being a combination of factoring out common code into
  helpers and the completion of the conversion of the core to use GPIO
  descriptors.

  Summary:

   - Addition of helper functions for current limits and conversion of
     drivers to use them by Axel Lin.

   - Lots and lots of cleanups from Axel Lin.

   - Conversion of the core to use GPIO descriptors rather than numbers
     by Linus Walleij.

   - New drivers for Maxim MAX77650 and ROHM BD70528"

* tag 'regulator-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (131 commits)
  regulator: mc13xxx: Constify regulator_ops variables
  regulator: palmas: Constify palmas_smps_ramp_delay array
  regulator: wm831x-dcdc: Convert to use regulator_set/get_current_limit_regmap
  regulator: pv88090: Convert to use regulator_set/get_current_limit_regmap
  regulator: pv88080: Convert to use regulator_set/get_current_limit_regmap
  regulator: pv88060: Convert to use regulator_set/get_current_limit_regmap
  regulator: max77650: Convert to use regulator_set/get_current_limit_regmap
  regulator: lp873x: Convert to use regulator_set/get_current_limit_regmap
  regulator: lp872x: Convert to use regulator_set/get_current_limit_regmap
  regulator: da9210: Convert to use regulator_set/get_current_limit_regmap
  regulator: da9055: Convert to use regulator_set/get_current_limit_regmap
  regulator: core: Add set/get_current_limit helpers for regmap users
  regulator: Fix comment for csel_reg and csel_mask
  regulator: stm32-vrefbuf: add power management support
  regulator: 88pm8607: Remove unused fields from struct pm8607_regulator_info
  regulator: 88pm8607: Simplify pm8607_list_voltage implementation
  regulator: cpcap: Constify omap4_regulators and xoom_regulators
  regulator: cpcap: Remove unused vsel_shift from struct cpcap_regulator
  dt-bindings: regulator: tps65218: rectify units of LS3
  dt-bindings: regulator: add LS2 load switch documentation
  ...

Pull regmap updates from Mark Brown:
 "There are only two changes here:

   - fix for conflicting attributes on the rbtree node structure

   - implementation of main status register support in the interrupt
     code which supports chips that have a register to cut down on the
     number of per-interrupt status registers that need to be checked
     when handling interrupts"

* tag 'regmap-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Remove attribute packed from struct 'regcache_rbtree_node'
  regmap: regmap-irq: Add main status register support

Pull MMC updates from Ulf Hansson:
 "MMC core:
   - Fixup max_discard/trim calculations
   - Announce SD specs greater than 4.0
   - Add discard support for SD cards
   - Don't do retries for CMD6 (SWITCH command)
   - Various cleanups and re-structuring

  MMC host:
   - cqhci:
      * Add maintainers for eMMC CQHCI driver
   - sdhci:
      * Consolidate WP GPIO code
      * Add ADMA3 DMA support for V4 enabled host
      * Fixup card detect support in pci-o2micro driver
      * Add support for CMDQ and SDMMC pads auto-calibration in tegra
        driver
      * Add DCMD support and CMDQ support, support for i.MX6ULL variant,
        fixup HS400 timing issue and add HS400_ES support for i.MX8QXP
        to esdhc-imx driver
      * Avoid CRC errors by adjusting settings to speed mode and fixup
        card initialization for high speed mode in renesas_sdhi
      * Fixup timeout settings for omap
      * Enable 8 bits bus-width support in atmel-mci
      * Convert some legacy code in jz4740 driver to use modern APIs
      * Send a CMD12 to clear DPSM at errors for STM32 sdmmc mmci
        driver"

* tag 'mmc-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (69 commits)
  mmc:fix a bug when max_discard is 0
  mmc: core: Add a debug print when the card may have been replaced
  mmc: core: Add sd discard timeout
  mmc: core: Add discard support to sd
  mmc: sdhci-esdhc-imx: clear the HALT bit when enable CQE
  mmc: core: do not retry CMD6 in __mmc_switch()
  mmc: core: Convert mmc_align_data_size() into an SDIO specific function
  mmc: core: Move mmc_of_parse_voltage() to host.c
  mmc: core: Convert mmc_regulator_get_ocrmask() to static
  mmc: core: Move regulator helpers to separate file
  mmc: of_mmc_spi: Convert to mmc_of_parse_voltage()
  mmc: core: Drop retries as in-parameter to mmc_wait_for_app_cmd()
  mmc: core: Convert mmc_wait_for_app_cmd() to static
  mmc: renesas_sdhi: Change HW adjustment register according to speed mode
  mmc: mmci: Send a CMD12 to clear the DPSM at errors
  mmc: sdhci-xenon: Fixup already marked switch fall-through
  mmc: sdhci-tegra: drop ->get_ro() implementation
  mmc: sdhci-omap: drop ->get_ro() implementation
  mmc: sdhci: use WP GPIO in sdhci_check_ro()
  mmc: wmt-sdmmc: Drop unused include
  ...

Pull i3c updates from Boris Brezillon:

 - Add a /* fall-through */ comment in the dw-i3c-master driver

 - Update the I3C entries in MAINTAINERS to add an IRC chan

* tag 'i3c/for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
  i3c: master: dw-i3c-master: mark expected switch fall-through
  MAINTAINERS: Add an IRC channel for the I3C subsystem

Pull MTD updates from Boris Brezillon:
 "Core MTD changes:
   - Use struct_size() where appropriate
   - mtd_{read,write}() as wrappers around mtd_{read,write}_oob()
   - Fix misuse of PTR_ERR() in docg3
   - Coding style improvements in mtdcore.c

  SPI NOR changes:
    Core changes:
     - Add support of octal mode I/O transfer
     - Add a bunch of SPI NOR entries to the flash_info table

    SPI NOR controller driver changes:
     - cadence-quadspi:
        * Add support for Octal SPI controller
        * write upto 8-bytes data in STIG mode
     - mtk-quadspi:
        * rename config to a common one
        * add SNOR_HWCAPS_READ to spi_nor_hwcaps mask
     - Add Tudor as SPI-NOR co-maintainer

  NAND changes:
    NAND core changes:
     - Fourth batch of fixes/cleanup to the raw NAND core impacting
       various controller drivers (Sunxi, Marvell, MTK, TMIO, OMAP2).
     - Check the return code of nand_reset() and nand_readid_op().
     - Remove ->legacy.erase and single_erase().
     - Simplify the locking.
     - Several implicit fall through annotations.

    Raw NAND controllers drivers changes:
     - Fix various possible object reference leaks (MTK, JZ4780, Atmel)
     - ST:
        * Add support for STM32 FMC2 NAND flash controller
     - Meson:
        * Add support for Amlogic NAND flash controller
     - Denali:
        * Several cleanup patches
     - Sunxi:
        * Several cleanup patches
     - FSMC:
        * Disable NAND on remove()
        * Reset NAND timings on resume()

    SPI-NAND drivers changes:
     - Toshiba:
        * Add support for all Toshiba products.
     - Macronix:
        * Fix ECC status read.
     - Gigadevice:
        * Add support for GD5F1GQ4UExxG"

* tag 'mtd/for-5.1' of git://git.infradead.org/linux-mtd: (64 commits)
  mtd: spi-nor: Fix wrong abbreviation HWCPAS
  mtd: spi-nor: cadence-quadspi: fix spelling mistake: "Couldnt't" -> "Couldn't"
  mtd: spi-nor: Add support for en25qh64
  mtd: spi-nor: Add support for MX25V8035F
  mtd: spi-nor: Add support for EN25Q80A
  mtd: spi-nor: cadence-quadspi: Add support for Octal SPI controller
  dt-bindings: cadence-quadspi: Add new compatible for AM654 SoC
  mtd: spi-nor: split s25fl128s into s25fl128s0 and s25fl128s1
  mtd: spi-nor: cadence-quadspi: write upto 8-bytes data in STIG mode
  mtd: spi-nor: Add support for mx25u3235f
  mtd: rawnand: denali_dt: remove single anonymous clock support
  mtd: rawnand: mtk: fix possible object reference leak
  mtd: rawnand: jz4780: fix possible object reference leak
  mtd: rawnand: atmel: fix possible object reference leak
  mtd: rawnand: fsmc: Disable NAND on remove()
  mtd: rawnand: fsmc: Reset NAND timings on resume()
  mtd: spinand: Add support for GigaDevice GD5F1GQ4UExxG
  mtd: rawnand: denali: remove unused dma_addr field from denali_nand_info
  mtd: rawnand: denali: remove unused function argument 'raw'
  mtd: rawnand: denali: remove unneeded denali_reset_irq() call
  ...

Pull VFIO updates from Alex Williamson:

 - Switch mdev to generic UUID API (Andy Shevchenko)

 - Fixup platform reset include paths (Masahiro Yamada)

 - Fix usage of MINORMASK (Chengguang Xu)

 - Remove noise from duplicate spapr table unsets (Alexey Kardashevskiy)

 - Restore device state after PM reset (Alex Williamson)

 - Ensure memory translation enabled for PCI ROM access (Eric Auger)

* tag 'vfio-v5.1-rc1' of git://github.com/awilliam/linux-vfio:
  vfio_pci: Enable memory accesses before calling pci_map_rom
  vfio/pci: Restore device state on PM transition
  vfio/spapr_tce: Skip unsetting already unset table
  samples/vfio-mdev/mtty: expand minor range when registering chrdev region
  samples/vfio-mdev/mdpy: expand minor range when registering chrdev region
  samples/vfio-mdev/mbochs: expand minor range when registering chrdev region
  vfio: expand minor range when registering chrdev region
  vfio: platform: reset: fix up include directives to remove ccflags-y
  vfio-mdev: Switch to use new generic UUID API

The current implementation of splice() and tee() ignores O_NONBLOCK set
on pipe file descriptors and checks only the SPLICE_F_NONBLOCK flag for
blocking on pipe arguments.  This is inconsistent since splice()-ing
from/to non-pipe file descriptors does take O_NONBLOCK into
consideration.

Fix this by promoting O_NONBLOCK, when set on a pipe, to
SPLICE_F_NONBLOCK.

Some context for how the current implementation of splice() leads to
inconsistent behavior.  In the ongoing work[1] to add VM tracing
capability to trace-cmd we stream tracing data over named FIFOs or
vsockets from guests back to the host.

When we receive SIGINT from user to stop tracing, we set O_NONBLOCK on
the input file descriptor and set SPLICE_F_NONBLOCK for the next call to
splice().  If splice() was blocked waiting on data from the input FIFO,
after SIGINT splice() restarts with the same arguments (no
SPLICE_F_NONBLOCK) and blocks again instead of returning -EAGAIN when no
data is available.

This differs from the splice() behavior when reading from a vsocket or
when we're doing a traditional read()/write() loop (trace-cmd's
--nosplice argument).

With this patch applied we get the same behavior in all situations after
setting O_NONBLOCK which also matches the behavior of doing a
read()/write() loop instead of splice().

This change does have potential of breaking users who don't expect
EAGAIN from splice() when SPLICE_F_NONBLOCK is not set.  OTOH programs
that set O_NONBLOCK and don't anticipate EAGAIN are arguably buggy[2].

 [1] https://github.com/skaslev/trace-cmd/tree/vsock
 [2] https://github.com/torvalds/linux/blob/d47e3da1759230e394096fd742aad423c291ba48/fs/read_write.c#L1425Signed-off-by: NSlavomir Kaslev <kaslevs@vmware.com>
Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>