Add a mapping for my old work email for BelDisplayTech to the personal
email, and make sure the Collabora email has the correct spelling of the
first name.

Link: https://lkml.kernel.org/r/20210917091016.30232-1-andrew.shadura@collabora.co.ukSigned-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Decrease nr_thps counter in file's mapping to ensure that the page cache
won't be dropped excessively on file write access if page has been
already split.

I've tried a test scenario running a big binary, kernel remaps it with
THPs, then force a THP split with /sys/kernel/debug/split_huge_pages.
During any further open of that binary with O_RDWR or O_WRITEONLY kernel
drops page cache for it, because of non-zero thps counter.

Link: https://lkml.kernel.org/r/20211012120237.2600-1-m.szyprowski@samsung.comSigned-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 09d91cda ("mm,thp: avoid writes to file with THP in pagecache")
Fixes: 06d3eff6 ("mm/thp: fix node page state in split_huge_page_to_list()")
Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: <sfoon.kim@samsung.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Check for a NULL page->mapping before dereferencing the mapping in
page_is_secretmem(), as the page's mapping can be nullified while gup()
is running, e.g.  by reclaim or truncation.

  BUG: kernel NULL pointer dereference, address: 0000000000000068
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 6 PID: 4173897 Comm: CPU 3/KVM Tainted: G        W
  RIP: 0010:internal_get_user_pages_fast+0x621/0x9d0
  Code: <48> 81 7a 68 80 08 04 bc 0f 85 21 ff ff 8 89 c7 be
  RSP: 0018:ffffaa90087679b0 EFLAGS: 00010046
  RAX: ffffe3f37905b900 RBX: 00007f2dd561e000 RCX: ffffe3f37905b934
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffe3f37905b900
  ...
  CR2: 0000000000000068 CR3: 00000004c5898003 CR4: 00000000001726e0
  Call Trace:
   get_user_pages_fast_only+0x13/0x20
   hva_to_pfn+0xa9/0x3e0
   try_async_pf+0xa1/0x270
   direct_page_fault+0x113/0xad0
   kvm_mmu_page_fault+0x69/0x680
   vmx_handle_exit+0xe1/0x5d0
   kvm_arch_vcpu_ioctl_run+0xd81/0x1c70
   kvm_vcpu_ioctl+0x267/0x670
   __x64_sys_ioctl+0x83/0xa0
   do_syscall_64+0x56/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Link: https://lkml.kernel.org/r/20211007231502.3552715-1-seanjc@google.com
Fixes: 1507f512 ("mm: introduce memfd_secret system call to create "secret" memory areas")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reported-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: Stephen <stephenackerman16@gmail.com>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If we open a file without read access and then pass the fd to a syscall
whose implementation calls kernel_read_file_from_fd(), we get a warning
from __kernel_read():

        if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))

This currently affects both finit_module() and kexec_file_load(), but it
could affect other syscalls in the future.

Link: https://lkml.kernel.org/r/20211007220110.600005-1-willy@infradead.org
Fixes: b844f0ec ("vfs: define kernel_copy_file_from_fd()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Hao Sun <sunhao.th@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 6e7b64b9 ("elfcore: fix building with clang") introduces
special handling for two architectures, ia64 and User Mode Linux.
However, the wrong name, i.e., CONFIG_UM, for the intended Kconfig
symbol for User-Mode Linux was used.

Although the directory for User Mode Linux is ./arch/um; the Kconfig
symbol for this architecture is called CONFIG_UML.

Luckily, ./scripts/checkkconfigsymbols.py warns on non-existing configs:

  UM
  Referencing files: include/linux/elfcore.h
  Similar symbols: UML, NUMA

Correct the name of the config to the intended one.

[akpm@linux-foundation.org: fix um/x86_64, per Catalin]
  Link: https://lkml.kernel.org/r/20211006181119.2851441-1-catalin.marinas@arm.com
  Link: https://lkml.kernel.org/r/YV6pejGzLy5ppEpt@arm.com

Link: https://lkml.kernel.org/r/20211006082209.417-1-lukas.bulwahn@gmail.com
Fixes: 6e7b64b9 ("elfcore: fix building with clang")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Barret Rhoden <brho@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kmem_cache_free_bulk() will call memcg_slab_free_hook() for all objects
when doing bulk free.  So we shouldn't call memcg_slab_free_hook() again
for bulk free to avoid incorrect memcg slab count.

Link: https://lkml.kernel.org/r/20210916123920.48704-6-linmiaohe@huawei.com
Fixes: d1b2cf6c ("mm: memcg/slab: uncharge during kmem_cache_free_bulk()")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When sysfs_slab_add failed, we shouldn't call debugfs_slab_add() for s
because s will be freed soon.  And slab_debugfs_fops will use s later
leading to a use-after-free.

Link: https://lkml.kernel.org/r/20210916123920.48704-5-linmiaohe@huawei.com
Fixes: 64dd6849 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In error path, the random_seq of slub cache might be leaked.  Fix this
by using __kmem_cache_release() to release all the relevant resources.

Link: https://lkml.kernel.org/r/20210916123920.48704-4-linmiaohe@huawei.com
Fixes: 210e7a43 ("mm: SLUB freelist randomization")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If object's reuse is delayed, it will be excluded from the reconstructed
freelist.  But we forgot to adjust the cnt accordingly.  So there will
be a mismatch between reconstructed freelist depth and cnt.  This will
lead to free_debug_processing() complaining about freelist count or a
incorrect slub inuse count.

Link: https://lkml.kernel.org/r/20210916123920.48704-3-linmiaohe@huawei.com
Fixes: c3895391 ("kasan, slub: fix handling of kasan_slab_free hook")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "Fixups for slub".

This series contains various bug fixes for slub.  We fix memoryleak,
use-afer-free, NULL pointer dereferencing and so on in slub.  More
details can be found in the respective changelogs.

This patch (of 5):

It's possible that __seq_open_private() will return NULL.  So we should
check it before using lest dereferencing NULL pointer.  And in error
paths, we forgot to release private buffer via seq_release_private().
Memory will leak in these paths.

Link: https://lkml.kernel.org/r/20210916123920.48704-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210916123920.48704-2-linmiaohe@huawei.com
Fixes: 64dd6849 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

syzbot reported access to unitialized memory in mbind() [1]

Issue came with commit bda420b9 ("numa balancing: migrate on fault
among multiple bound nodes")

This commit added a new bit in MPOL_MODE_FLAGS, but only checked valid
combination (MPOL_F_NUMA_BALANCING can only be used with MPOL_BIND) in
do_set_mempolicy()

This patch moves the check in sanitize_mpol_flags() so that it is also
used by mbind()

  [1]
  BUG: KMSAN: uninit-value in __mpol_equal+0x567/0x590 mm/mempolicy.c:2260
   __mpol_equal+0x567/0x590 mm/mempolicy.c:2260
   mpol_equal include/linux/mempolicy.h:105 [inline]
   vma_merge+0x4a1/0x1e60 mm/mmap.c:1190
   mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811
   do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333
   kernel_mbind mm/mempolicy.c:1483 [inline]
   __do_sys_mbind mm/mempolicy.c:1490 [inline]
   __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486
   __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486
   do_syscall_x64 arch/x86/entry/common.c:51 [inline]
   do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
   entry_SYSCALL_64_after_hwframe+0x44/0xae

  Uninit was created at:
   slab_alloc_node mm/slub.c:3221 [inline]
   slab_alloc mm/slub.c:3230 [inline]
   kmem_cache_alloc+0x751/0xff0 mm/slub.c:3235
   mpol_new mm/mempolicy.c:293 [inline]
   do_mbind+0x912/0x15f0 mm/mempolicy.c:1289
   kernel_mbind mm/mempolicy.c:1483 [inline]
   __do_sys_mbind mm/mempolicy.c:1490 [inline]
   __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486
   __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486
   do_syscall_x64 arch/x86/entry/common.c:51 [inline]
   do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  =====================================================
  Kernel panic - not syncing: panic_on_kmsan set ...
  CPU: 0 PID: 15049 Comm: syz-executor.0 Tainted: G    B             5.15.0-rc2-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Call Trace:
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x1ff/0x28e lib/dump_stack.c:106
   dump_stack+0x25/0x28 lib/dump_stack.c:113
   panic+0x44f/0xdeb kernel/panic.c:232
   kmsan_report+0x2ee/0x300 mm/kmsan/report.c:186
   __msan_warning+0xd7/0x150 mm/kmsan/instrumentation.c:208
   __mpol_equal+0x567/0x590 mm/mempolicy.c:2260
   mpol_equal include/linux/mempolicy.h:105 [inline]
   vma_merge+0x4a1/0x1e60 mm/mmap.c:1190
   mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811
   do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333
   kernel_mbind mm/mempolicy.c:1483 [inline]
   __do_sys_mbind mm/mempolicy.c:1490 [inline]
   __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486
   __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486
   do_syscall_x64 arch/x86/entry/common.c:51 [inline]
   do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Link: https://lkml.kernel.org/r/20211001215630.810592-1-eric.dumazet@gmail.com
Fixes: bda420b9 ("numa balancing: migrate on fault among multiple bound nodes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mem=[X][G|M] is broken on ARM64 platform, there are cases that even
type.cnt is 1, but total_size is not 0 because regions are merged into
1.  So only check 'cnt' is not enough, total_size should be used,
othersize bootargs 'mem=[X][G|B]' not work anymore.

Link: https://lkml.kernel.org/r/20210930024437.32598-1-peng.fan@oss.nxp.com
Fixes: e888fa7b ("memblock: Check memory add/cap ordering")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Starting with kernel 5.11 built with CONFIG_FORTIFY_SOURCE mouting an
ocfs2 filesystem with either o2cb or pcmk cluster stack fails with the
trace below.  Problem seems to be that strings for cluster stack and
cluster name are not guaranteed to be null terminated in the disk
representation, while strlcpy assumes that the source string is always
null terminated.  This causes a read outside of the source string
triggering the buffer overflow detection.

  detected buffer overflow in strlen
  ------------[ cut here ]------------
  kernel BUG at lib/string.c:1149!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 1 PID: 910 Comm: mount.ocfs2 Not tainted 5.14.0-1-amd64 #1
    Debian 5.14.6-2
  RIP: 0010:fortify_panic+0xf/0x11
  ...
  Call Trace:
   ocfs2_initialize_super.isra.0.cold+0xc/0x18 [ocfs2]
   ocfs2_fill_super+0x359/0x19b0 [ocfs2]
   mount_bdev+0x185/0x1b0
   legacy_get_tree+0x27/0x40
   vfs_get_tree+0x25/0xb0
   path_mount+0x454/0xa20
   __x64_sys_mount+0x103/0x140
   do_syscall_64+0x3b/0xc0
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Link: https://lkml.kernel.org/r/20210929180654.32460-1-vvidic@valentin-vidic.from.hrSigned-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 6dbf7bb5 ("fs: Don't invalidate page buffers in
block_write_full_page()") uncovered a latent bug in ocfs2 conversion
from inline inode format to a normal inode format.

The code in ocfs2_convert_inline_data_to_extents() attempts to zero out
the whole cluster allocated for file data by grabbing, zeroing, and
dirtying all pages covering this cluster.  However these pages are
beyond i_size, thus writeback code generally ignores these dirty pages
and no blocks were ever actually zeroed on the disk.

This oversight was fixed by commit 693c241a ("ocfs2: No need to zero
pages past i_size.") for standard ocfs2 write path, inline conversion
path was apparently forgotten; the commit log also has a reasoning why
the zeroing actually is not needed.

After commit 6dbf7bb5, things became worse as writeback code stopped
invalidating buffers on pages beyond i_size and thus these pages end up
with clean PageDirty bit but with buffers attached to these pages being
still dirty.  So when a file is converted from inline format, then
writeback triggers, and then the file is grown so that these pages
become valid, the invalid dirtiness state is preserved,
mark_buffer_dirty() does nothing on these pages (buffers are already
dirty) but page is never written back because it is clean.  So data
written to these pages is lost once pages are reclaimed.

Simple reproducer for the problem is:

  xfs_io -f -c "pwrite 0 2000" -c "pwrite 2000 2000" -c "fsync" \
    -c "pwrite 4000 2000" ocfs2_file

After unmounting and mounting the fs again, you can observe that end of
'ocfs2_file' has lost its contents.

Fix the problem by not doing the pointless zeroing during conversion
from inline format similarly as in the standard write path.

[akpm@linux-foundation.org: fix whitespace, per Joseph]

Link: https://lkml.kernel.org/r/20210930095405.21433-1-jack@suse.cz
Fixes: 6dbf7bb5 ("fs: Don't invalidate page buffers in block_write_full_page()")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Gang He <ghe@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: "Markov, Andrey" <Markov.Andrey@Dell.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The node demotion order needs to be updated during CPU hotplug.  Because
whether a NUMA node has CPU may influence the demotion order.  The
update function should be called during CPU online/offline after the
node_states[N_CPU] has been updated.  That is done in
CPUHP_AP_ONLINE_DYN during CPU online and in CPUHP_MM_VMSTAT_DEAD during
CPU offline.  But in commit 884a6e5d ("mm/migrate: update node
demotion order on hotplug events"), the function to update node demotion
order is called in CPUHP_AP_ONLINE_DYN during CPU online/offline.  This
doesn't satisfy the order requirement.

For example, there are 4 CPUs (P0, P1, P2, P3) in 2 sockets (P0, P1 in S0
and P2, P3 in S1), the demotion order is

 - S0 -> NUMA_NO_NODE
 - S1 -> NUMA_NO_NODE

After P2 and P3 is offlined, because S1 has no CPU now, the demotion
order should have been changed to

 - S0 -> S1
 - S1 -> NO_NODE

but it isn't changed, because the order updating callback for CPU
hotplug doesn't see the new nodemask.  After that, if P1 is offlined,
the demotion order is changed to the expected order as above.

So in this patch, we added CPUHP_AP_MM_DEMOTION_ONLINE and
CPUHP_MM_DEMOTION_DEAD to be called after CPUHP_AP_ONLINE_DYN and
CPUHP_MM_VMSTAT_DEAD during CPU online and offline, and register the
update function on them.

Link: https://lkml.kernel.org/r/20210929060351.7293-1-ying.huang@intel.com
Fixes: 884a6e5d ("mm/migrate: update node demotion order on hotplug events")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Once upon a time, the node demotion updates were driven solely by memory
hotplug events.  But now, there are handlers for both CPU and memory
hotplug.

However, the #ifdef around the code checks only memory hotplug.  A
system that has HOTPLUG_CPU=y but MEMORY_HOTPLUG=n would miss CPU
hotplug events.

Update the #ifdef around the common code.  Add memory and CPU-specific
#ifdefs for their handlers.  These memory/CPU #ifdefs avoid unused
function warnings when their Kconfig option is off.

[arnd@arndb.de: rework hotplug_memory_notifier() stub]
  Link: https://lkml.kernel.org/r/20211013144029.2154629-1-arnd@kernel.org

Link: https://lkml.kernel.org/r/20210924161255.E5FE8F7E@davehans-spike.ostc.intel.com
Fixes: 884a6e5d ("mm/migrate: update node demotion order on hotplug events")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/migrate: 5.15 fixes for automatic demotion", v2.

This contains two fixes for the "automatic demotion" code which was
merged into 5.15:

 * Fix memory hotplug performance regression by watching
   suppressing any real action on irrelevant hotplug events.

 * Ensure CPU hotplug handler is registered when memory hotplug
   is disabled.

This patch (of 2):

== tl;dr ==

Automatic demotion opted for a simple, lazy approach to handling hotplug
events.  This noticeably slows down memory hotplug[1].  Optimize away
updates to the demotion order when memory hotplug events should have no
effect.

This has no effect on CPU hotplug.  There is no known problem on the CPU
side and any work there will be in a separate series.

== Background ==

Automatic demotion is a memory migration strategy to ensure that new
allocations have room in faster memory tiers on tiered memory systems.
The kernel maintains an array (node_demotion[]) to drive these
migrations.

The node_demotion[] path is calculated by starting at nodes with CPUs
and then "walking" to nodes with memory.  Only hotplug events which
online or offline a node with memory (N_ONLINE) or CPUs (N_CPU) will
actually affect the migration order.

== Problem ==

However, the current code is lazy.  It completely regenerates the
migration order on *any* CPU or memory hotplug event.  The logic was
that these events are extremely rare and that the overhead from
indiscriminate order regeneration is minimal.

Part of the update logic involves a synchronize_rcu(), which is a pretty
big hammer.  Its overhead was large enough to be detected by some 0day
tests that watch memory hotplug performance[1].

== Solution ==

Add a new helper (node_demotion_topo_changed()) which can differentiate
between superfluous and impactful hotplug events.  Skip the expensive
update operation for superfluous events.

== Aside: Locking ==

It took me a few moments to declare the locking to be safe enough for
node_demotion_topo_changed() to work.  It all hinges on the memory
hotplug lock:

During memory hotplug events, 'mem_hotplug_lock' is held for write.
This ensures that two memory hotplug events can not be called
simultaneously.

CPU hotplug has a similar lock (cpuhp_state_mutex) which also provides
mutual exclusion between CPU hotplug events.  In addition, the demotion
code acquire and hold the mem_hotplug_lock for read during its CPU
hotplug handlers.  This provides mutual exclusion between the demotion
memory hotplug callbacks and the CPU hotplug callbacks.

This effectively allows treating the migration target generation code to
act as if it is single-threaded.

1. https://lore.kernel.org/all/20210905135932.GE15026@xsang-OptiPlex-9020/

Link: https://lkml.kernel.org/r/20210924161251.093CCD06@davehans-spike.ostc.intel.com
Link: https://lkml.kernel.org/r/20210924161253.D7673E31@davehans-spike.ostc.intel.com
Fixes: 884a6e5d ("mm/migrate: update node demotion order on hotplug events")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A race is possible when a process exits, its VMAs are removed by
exit_mmap() and at the same time userfaultfd_writeprotect() is called.

The race was detected by KASAN on a development kernel, but it appears
to be possible on vanilla kernels as well.

Use mmget_not_zero() to prevent the race as done in other userfaultfd
operations.

Link: https://lkml.kernel.org/r/20210921200247.25749-1-namit@vmware.com
Fixes: 63b2d417 ("userfaultfd: wp: add the writeprotect API to userfaultfd ioctl")
Signed-off-by: Nadav Amit <namit@vmware.com>
Tested-by: Li  Wang <liwang@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In RHEL's gating selftests we've encountered memory corruption in the
uffd event test even with upstream kernel:

        # ./userfaultfd anon 128 4
        nr_pages: 32768, nr_pages_per_cpu: 32768
        bounces: 3, mode: rnd racing read, userfaults: 6240 missing (6240) 14729 wp (14729)
        bounces: 2, mode: racing read, userfaults: 1444 missing (1444) 28877 wp (28877)
        bounces: 1, mode: rnd read, userfaults: 6055 missing (6055) 14699 wp (14699)
        bounces: 0, mode: read, userfaults: 82 missing (82) 25196 wp (25196)
        testing uffd-wp with pagemap (pgsize=4096): done
        testing uffd-wp with pagemap (pgsize=2097152): done
        testing events (fork, remap, remove): ERROR: nr 32427 memory corruption 0 1 (errno=0, line=963)
        ERROR: faulting process failed (errno=0, line=1117)

It can be easily reproduced when global thp enabled, which is the
default for RHEL.

It's also known as a side effect of commit 0db282ba ("selftest: use
mmap instead of posix_memalign to allocate memory", 2021-07-23), which
is imho right itself on using mmap() to make sure the addresses will be
untagged even on arm.

The problem is, for each test we allocate buffers using two
allocate_area() calls.  We assumed these two buffers won't affect each
other, however they could, because mmap() could have found that the two
buffers are near each other and having the same VMA flags, so they got
merged into one VMA.

It won't be a big problem if thp is not enabled, but when thp is
agressively enabled it means when initializing the src buffer it could
accidentally setup part of the dest buffer too when there's a shared THP
that overlaps the two regions.  Then some of the dest buffer won't be
able to be trapped by userfaultfd missing mode, then it'll cause memory
corruption as described.

To fix it, do release_pages() after initializing the src buffer.

Since the previous two release_pages() calls are after
uffd_test_ctx_clear() which will unmap all the buffers anyway (which is
stronger than release pages; as unmap() also tear town pgtables), drop
them as they shouldn't really be anything useful.

We can mark the Fixes tag upon 0db282ba as it's reported to only
happen there, however the real "Fixes" IMHO should be 8ba6e864, as
before that commit we'll always do explicit release_pages() before
registration of uffd, and 8ba6e864 changed that logic by adding
extra unmap/map and we didn't release the pages at the right place.
Meanwhile I don't have a solid glue anyway on whether posix_memalign()
could always avoid triggering this bug, hence it's safer to attach this
fix to commit 8ba6e864.

Link: https://lkml.kernel.org/r/20210923232512.210092-1-peterx@redhat.com
Fixes: 8ba6e864 ("userfaultfd/selftests: reinitialize test context in each test")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1994931Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Li Wang <liwan@redhat.com>
Tested-by: Li Wang <liwang@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.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 libata fixes from Damien Le Moal:
 "Two fixes for this cycle:

   - Fix a null pointer dereference in ahci-platform driver (from Hai)

   - Fix uninitialized variables in pata_legacy driver (from Dan)"

* tag 'libata-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: ahci_platform: fix null-ptr-deref in ahci_platform_enable_regulators()
  pata_legacy: fix a couple uninitialized variable bugs

Pull block fixes from Jens Axboe:
 "Bigger than usual for this point in time, the majority is fixing some
  issues around BDI lifetimes with the move from the request_queue to
  the disk in this release. In detail:

   - Series on draining fs IO for del_gendisk() (Christoph)

   - NVMe pull request via Christoph:
        - fix the abort command id (Keith Busch)
        - nvme: fix per-namespace chardev deletion (Adam Manzanares)

   - brd locking scope fix (Tetsuo)

   - BFQ fix (Paolo)"

* tag 'block-5.15-2021-10-17' of git://git.kernel.dk/linux-block:
  block, bfq: reset last_bfqq_created on group change
  block: warn when putting the final reference on a registered disk
  brd: reduce the brd_devices_mutex scope
  kyber: avoid q->disk dereferences in trace points
  block: keep q_usage_counter in atomic mode after del_gendisk
  block: drain file system I/O on del_gendisk
  block: split bio_queue_enter from blk_queue_enter
  block: factor out a blk_try_enter_queue helper
  block: call submit_bio_checks under q_usage_counter
  nvme: fix per-namespace chardev deletion
  block/rnbd-clt-sysfs: fix a couple uninitialized variable bugs
  nvme-pci: Fix abort command id

Pull io_uring fix from Jens Axboe:
 "Just a single fix for a wrong condition for grabbing a lock, a
  regression in this merge window"

* tag 'io_uring-5.15-2021-10-17' of git://git.kernel.dk/linux-block:
  io_uring: fix wrong condition to grab uring lock

Pull virtio fixes from Michael Tsirkin:
 "Fixes up some issues in rc5"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost-vdpa: Fix the wrong input in config_cb
  VDUSE: fix documentation underline warning
  Revert "virtio-blk: Add validation for block size in config space"
  vhost_vdpa: unset vq irq before freeing irq
  virtio: write back F_VERSION_1 before validate

Pull powerpc fixes from Michael Ellerman:

 - Fix a bug where guests on P9 with interrupts passed through could get
   stuck in synchronize_irq().

 - Fix a bug in KVM on P8 where secondary threads entering a guest would
   write outside their allocated stack.

 - Fix a bug in KVM on P8 where secondary threads could confuse the host
   offline code and cause the guest or host to crash.

Thanks to Cédric Le Goater.

* tag 'powerpc-5.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  KVM: PPC: Book3S HV: Make idle_kvm_start_guest() return 0 if it went to guest
  KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
  powerpc/xive: Discard disabled interrupts in get_irqchip_state()

Pull objtool fixes from Borislav Petkov:

 - Update section headers before the respective relocations to not
   trigger a safety check in elftoolchain's implementation of libelf

 - Do not add garbage data to the .rela.orc_unwind_ip section

* tag 'objtool_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Update section header before relocations
  objtool: Check for gelf_update_rel[a] failures

Pull EDAC fix from Borislav Petkov:

 - Log the "correct" uncorrectable error count in the armada_xp driver

* tag 'edac_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/armada-xp: Fix output of uncorrectable error counter

Pull perf fix from Borislav Petkov:

 - Add Sapphire Rapids to the list of CPUs supporting the SMI count MSR

* tag 'perf_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/msr: Add Sapphire Rapids CPU support

Pull EFI fixes from Borislav Petkov:
 "Forwarded from Ard Biesheuvel through the tip tree. Ard will send
  stuff directly in the near future.

  Low priority fixes but fixes nonetheless:

   - update stub diagnostic print that is no longer accurate

   - avoid statically allocated buffer for CPER error record decoding

   - avoid sleeping on the efi_runtime semaphore when calling the
     ResetSystem EFI runtime service"

* tag 'efi-urgent-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Change down_interruptible() in virt_efi_reset_system() to down_trylock()
  efi/cper: use stack buffer for error record decoding
  efi/libstub: Simplify "Exiting bootservices" message

Pull x86 fixes from Borislav Petkov:

 - Do not enable AMD memory encryption in Kconfig by default due to
   shortcomings of some platforms, leading to boot failures.

 - Mask out invalid bits in the MXCSR for 32-bit kernels again because
   Thomas and I don't know how to mask out bits properly. Third time's
   the charm.

* tag 'x86_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Mask out the invalid MXCSR bits properly
  x86/Kconfig: Do not enable AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT automatically

Merge tag 'driver-core-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are some small driver core fixes for 5.15-rc6, all of which have
  been in linux-next for a while with no reported issues.

  They include:

   - kernfs negative dentry bugfix

   - simple pm bus fixes to resolve reported issues"

* tag 'driver-core-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  drivers: bus: Delete CONFIG_SIMPLE_PM_BUS
  drivers: bus: simple-pm-bus: Add support for probing simple bus only devices
  driver core: Reject pointless SYNC_STATE_ONLY device links
  kernfs: don't create a negative dentry if inactive node exists

Pull char/misc driver fixes from Greg KH:
 "Here are some small char/misc driver fixes for 5.15-rc6 for reported
  issues that include:

   - habanalabs driver fixes

   - mei driver fixes and new ids

   - fpga new device ids

   - MAINTAINER file updates for fpga subsystem

   - spi module id table additions and fixes

   - fastrpc locking fixes

   - nvmem driver fix

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  eeprom: 93xx46: fix MODULE_DEVICE_TABLE
  nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells
  mei: hbm: drop hbm responses on early shutdown
  mei: me: add Ice Lake-N device id.
  eeprom: 93xx46: Add SPI device ID table
  eeprom: at25: Add SPI ID table
  misc: HI6421V600_IRQ should depend on HAS_IOMEM
  misc: fastrpc: Add missing lock before accessing find_vma()
  cb710: avoid NULL pointer subtraction
  misc: gehc: Add SPI ID table
  MAINTAINERS: Drop outdated FPGA Manager website
  MAINTAINERS: Add Hao and Yilun as maintainers
  habanalabs: fix resetting args in wait for CS IOCTL
  fpga: ice40-spi: Add SPI device ID table

Pull staging and IIO driver fixes from Greg KH:
 "Here are a number of small IIO and staging driver fixes for 5.15-rc6.

  They include:

   - vc04_services bugfix for reported problem

   - r8188eu array underflow fix

   - iio driver fixes for a lot of tiny reported issues.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: r8188eu: prevent array underflow in rtw_hal_update_ra_mask()
  staging: vc04_services: shut up out-of-range warning
  iio: light: opt3001: Fixed timeout error when 0 lux
  iio: adis16480: fix devices that do not support sleep mode
  iio: mtk-auxadc: fix case IIO_CHAN_INFO_PROCESSED
  iio: adis16475: fix deadlock on frequency set
  iio: ssp_sensors: add more range checking in ssp_parse_dataframe()
  iio: ssp_sensors: fix error code in ssp_print_mcu_debug()
  iio: adc: ad7793: Fix IRQ flag
  iio: adc: ad7780: Fix IRQ flag
  iio: adc: ad7192: Add IRQ flag
  iio: adc: aspeed: set driver data when adc probe.
  iio: adc: rzg2l_adc: add missing clk_disable_unprepare() in rzg2l_adc_pm_runtime_resume()
  iio: adc: max1027: Fix the number of max1X31 channels
  iio: adc: max1027: Fix wrong shift with 12-bit devices
  iio: adc128s052: Fix the error handling path of 'adc128_probe()'
  iio: adc: rzg2l_adc: Fix -EBUSY timeout error return
  iio: accel: fxls8962af: return IRQ_HANDLED when fifo is flushed
  iio: dac: ti-dac5571: fix an error code in probe()

Pull serial driver fix from Greg KH:
 "Here is a single 8250 Kconfig fix for 5.15-rc6 that resolves a
  regression that showed up in 5.15-rc1. It has been in linux-next for a
  while with no reported issues"

* tag 'tty-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250: allow disabling of Freescale 16550 compile test

Pull USB fixes from Greg KH:
 "Here are some small USB fixes that resolve a number of tiny issues.
  They include:

   - new USB serial driver ids

   - xhci driver fixes for a bunch of issues

   - musb error path fixes.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'usb-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: musb: dsps: Fix the probe error path
  xhci: Enable trust tx length quirk for Fresco FL11 USB controller
  xhci: Fix command ring pointer corruption while aborting a command
  USB: xhci: dbc: fix tty registration race
  xhci: add quirk for host controllers that don't update endpoint DCS
  xhci: guard accesses to ep_state in xhci_endpoint_reset()
  USB: serial: qcserial: add EM9191 QDL support
  USB: serial: option: add Quectel EC200S-CN module support
  USB: serial: option: add prod. id for Quectel EG91
  USB: serial: option: add Telit LE910Cx composition 0x1204

Pull input fixes from Dmitry Torokhov:

 - a new product ID for the xpad joystick driver

 - fixes to resistive-adc-touch and snvs_pwrkey drivers

 - a change to touchscreen helpers to make clang happier

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: touchscreen - avoid bitwise vs logical OR warning
  Input: xpad - add support for another USB ID of Nacon GC-100
  Input: resistive-adc-touch - fix division by zero error on z1 == 0
  Input: snvs_pwrkey - add clk handling

Since commit 430a67f9 ("block, bfq: merge bursts of newly-created
queues"), BFQ maintains a per-group pointer to the last bfq_queue
created. If such a queue, say bfqq, happens to move to a different
group, then bfqq is no more a valid last bfq_queue created for its
previous group. That pointer must then be cleared. Not resetting such
a pointer may also cause UAF, if bfqq happens to also be freed after
being moved to a different group. This commit performs this missing
reset. As such it fixes commit 430a67f9 ("block, bfq: merge bursts
of newly-created queues").

Such a missing reset is most likely the cause of the crash reported in [1].
With some analysis, we found that this crash was due to the
above UAF. And such UAF did go away with this commit applied [1].

Anyway, before this commit, that crash happened to be triggered in
conjunction with commit 2d52c58b ("block, bfq: honor already-setup
queue merges"). The latter was then reverted by commit ebc69e89
("Revert "block, bfq: honor already-setup queue merges""). Yet commit
2d52c58b ("block, bfq: honor already-setup queue merges") contains
no error related with the above UAF, and can then be restored.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=214503

Fixes: 430a67f9 ("block, bfq: merge bursts of newly-created queues")
Tested-by: Grzegorz Kowal <custos.mentis@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20211015144336.45894-2-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Warn when the last reference on a live disk is put without calling
del_gendisk first.  There are some BDI related bug reports that look
like a case of this, so make sure we have the proper instrumentation
to catch it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211014130231.1468538-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

As with commit 8b52d8be ("loop: reorder loop_exit"),
unregister_blkdev() needs to be called first in order to avoid calling
brd_alloc() from brd_probe() after brd_del_one() from brd_exit(). Then,
we can avoid holding global mutex during add_disk()/del_gendisk() as with
commit 1c500ad7 ("loop: reduce the loop_ctl_mutex scope").
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/e205f13d-18ff-a49c-0988-7de6ea5ff823@i-love.sakura.ne.jpSigned-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'perf-tools-fixes-for-v5.15-2021-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix 'perf test evsel' build error on !x86 architectures

 - Fix libperf's test_stat_cpu mixup of CPU numbers and CPU indexes

 - Output offsets for decompressed records, not just useless zeros

* tag 'perf-tools-fixes-for-v5.15-2021-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  libperf tests: Fix test_stat_cpu
  libperf test evsel: Fix build error on !x86 architectures
  perf report: Output non-zero offset for decompressed records