Once we've copied some data for an iocb that is marked with IOCB_WAITQ,
we should no longer attempt to async lock a new page. Instead make sure
we return the copied amount, and let the caller retry, instead of
returning -EIOCBQUEUED for a new page.

This should only be possible with read-ahead disabled on the below
device, and multiple threads racing on the same file. Haven't been able
to reproduce on anything else.

Cc: stable@vger.kernel.org # v5.9
Fixes: 1a0a7853 ("mm: support async buffered reads in generic_file_buffered_read()")
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

__io_queue_proc() is used by both, poll reqs and apoll. Don't use
req->poll.events to copy poll mask because for apoll it aliases with
private data of the request.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Make sure the async io-wq workers inherit the loginuid and sessionid from
the original task, and restore them to unset once we're done with the
async work item.

While at it, disable the ability for kernel threads to write to their own
loginuid.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Even though we place the req_issued and req_complete in separate
cachelines, there's considerable overhead in doing the atomics
particularly on the completion side.

Get rid of having the two counters, and just use a percpu_counter for
this. That's what it was made for, after all. This considerably
reduces the overhead in __io_free_req().
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This avoids doing a copy for each new async IO, if some parts of the
io_identity has changed. We avoid reference counting for the normal
fast path of nothing ever changing.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This is, by definition, a per-task structure. So store it in the
task context, instead of doing carrying it in each io_kiocb. We're being
a bit inefficient if members have changed, as that requires an alloc and
copy of a new io_identity struct. The next patch will fix that up.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

If the io_identity doesn't completely match the task, then create a
copy of it and use that. The existing copy remains valid until the last
user of it has gone away.

This also changes the personality lookup to be indexed by io_identity,
instead of creds directly.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io-wq contains a pointer to the identity, which we just hold in io_kiocb
for now. This is in preparation for putting this outside io_kiocb. The
only exception is struct files_struct, which we'll need different rules
for to avoid a circular dependency.

No functional changes in this patch.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We solely rely on work->work_flags now, so use that for proper checking
and clearing/dropping of various identity items.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We have a number of bits that decide what context to inherit. Set up
io-wq flags for these instead. This is in preparation for always having
the various members set, but not always needing them for all requests.

No intended functional changes in this patch.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There was an assumption that kthread_create_on_node() would properly set
NUMA affinities in terms of CPUs allowed, but it doesn't. Make sure we
do this when creating an io-wq context on NUMA.

Cc: stable@vger.kernel.org
Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

syzbot reports the following crash:

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 8927 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register+0x2fd2/0x3ee0 fs/io_uring.c:9553
Code: ec 03 49 c1 ee 03 49 01 ec 49 01 ee e8 57 61 9c ff 41 80 3c 24 00 0f 85 9b 09 00 00 4d 8b af b8 01 00 00 4c 89 e8 48 c1 e8 03 <80> 3c 28 00 0f 85 76 09 00 00 49 8b 55 00 89 d8 c1 f8 09 48 98 4c
RSP: 0018:ffffc90009137d68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000ef2a000
RDX: 0000000000040000 RSI: ffffffff81d81dd9 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed1012882a37
R13: 0000000000000000 R14: ffffed1012882a38 R15: ffff888094415000
FS:  00007f4266f3c700(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000118c000 CR3: 000000008e57d000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de59
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4266f3bc78 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 00000000000083c0 RCX: 000000000045de59
RDX: 0000000020000280 RSI: 0000000000000002 RDI: 0000000000000005
RBP: 000000000118bf68 R08: 0000000000000000 R09: 0000000000000000
R10: 40000000000000a1 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fff2fa4f12f R14: 00007f4266f3c9c0 R15: 000000000118bf2c
Modules linked in:
---[ end trace 2a40a195e2d5e6e6 ]---
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register+0x2fd2/0x3ee0 fs/io_uring.c:9553
Code: ec 03 49 c1 ee 03 49 01 ec 49 01 ee e8 57 61 9c ff 41 80 3c 24 00 0f 85 9b 09 00 00 4d 8b af b8 01 00 00 4c 89 e8 48 c1 e8 03 <80> 3c 28 00 0f 85 76 09 00 00 49 8b 55 00 89 d8 c1 f8 09 48 98 4c
RSP: 0018:ffffc90009137d68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000ef2a000
RDX: 0000000000040000 RSI: ffffffff81d81dd9 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed1012882a37
R13: 0000000000000000 R14: ffffed1012882a38 R15: ffff888094415000
FS:  00007f4266f3c700(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000074a918 CR3: 000000008e57d000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

which is a copy of fget failure condition jumping to cleanup, but the
cleanup requires ctx->file_data to be assigned. Assign it when setup,
and ensure that we clear it again for the error path exit.

Fixes: 5398ae69 ("io_uring: clean file_data access in files_register")
Reported-by: syzbot+f4ebcc98223dafd8991e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 738277ad.

This change didn't make a lot of sense, and as Linus reports, it actually
fails on clang:

   /tmp/io_uring-dd40c4.s:26476: Warning: ignoring changed section
   attributes for .data..read_mostly

The arrays are already marked const so, by definition, they are not
just read-mostly, they are read-only.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

REQ_F_COMP_LOCKED is used and implemented in a buggy way. The problem is
that the flag is set before io_put_req() but not cleared after, and if
that wasn't the final reference, the request will be freed with the flag
set from some other context, which may not hold a spinlock. That means
possible races with removing linked timeouts and unsynchronised
completion (e.g. access to CQ).

Instead of fixing REQ_F_COMP_LOCKED, kill the flag and use
task_work_add() to move such requests to a fresh context to free from
it, as was done with __io_free_req_finish().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_req_clean_work() checks REQ_F_COMP_LOCK to pass this two layers up.
Move the check up into __io_free_req(), so at least it doesn't looks so
ugly and would facilitate further changes.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Move io_put_req() in io_poll_task_handler() from under spinlock. This
eliminates the need to use REQ_F_COMP_LOCKED, at the expense of
potentially having to grab the lock again. That's still a better trade
off than relying on the locked flag.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

If a request had REQ_F_LINK_TIMEOUT it would've been cleared in
__io_kill_linked_timeout() by the time of __io_fail_links(), so no need
to care about it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

__io_kill_linked_timeout() sets REQ_F_COMP_LOCKED for a linked timeout
even if it can't cancel it, e.g. it's already running. It not only races
with io_link_timeout_fn() for ->flags field, but also leaves the flag
set and so io_link_timeout_fn() may find it and decide that it holds the
lock. Hopefully, the second problem is potential.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

An incorrect sizeof() is being used, sizeof(file_data->table) is not
correct, it should be sizeof(*file_data->table).

Fixes: 5398ae69 ("io_uring: clean file_data access in files_register")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Sizeof not portable (SIZEOF_MISMATCH)")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull overlayfs updates from Miklos Szeredi:

 - Improve performance for certain container setups by introducing a
   "volatile" mode

 - ioctl improvements

 - continue preparation for unprivileged overlay mounts

* tag 'ovl-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: use generic vfs_ioc_setflags_prepare() helper
  ovl: support [S|G]ETFLAGS and FS[S|G]ETXATTR ioctls for directories
  ovl: rearrange ovl_can_list()
  ovl: enumerate private xattrs
  ovl: pass ovl_fs down to functions accessing private xattrs
  ovl: drop flags argument from ovl_do_setxattr()
  ovl: adhere to the vfs_ vs. ovl_do_ conventions for xattrs
  ovl: use ovl_do_getxattr() for private xattr
  ovl: fold ovl_getxattr() into ovl_get_redirect_xattr()
  ovl: clean up ovl_getxattr() in copy_up.c
  duplicate ovl_getxattr()
  ovl: provide a mount option "volatile"
  ovl: check for incompatible features in work dir

Pull afs updates from David Howells:
 "A collection of fixes to fix afs_cell struct refcounting, thereby
  fixing a slew of related syzbot bugs:

   - Fix the cell tree in the netns to use an rwsem rather than RCU.

     There seem to be some problems deriving from the use of RCU and a
     seqlock to walk the rbtree, but it's not entirely clear what since
     there are several different failures being seen.

     Changing things to use an rwsem instead makes it more robust. The
     extra performance derived from using RCU isn't necessary in this
     case since the only time we're looking up a cell is during mount or
     when cells are being manually added.

   - Fix the refcounting by splitting the usage counter into a memory
     refcount and an active users counter. The usage counter was doing
     double duty, keeping track of whether a cell is still in use and
     keeping track of when it needs to be destroyed - but this makes the
     clean up tricky. Separating these out simplifies the logic.

   - Fix purging a cell that has an alias. A cell alias pins the cell
     it's an alias of, but the alias is always later in the list. Trying
     to purge in a single pass causes rmmod to hang in such a case.

   - Fix cell removal. If a cell's manager is requeued whilst it's
     removing itself, the manager will run again and re-remove itself,
     causing problems in various places. Follow Hillf Danton's
     suggestion to insert a more terminal state that causes the manager
     to do nothing post-removal.

  In additional to the above, two other changes:

   - Add a tracepoint for the cell refcount and active users count. This
     helped with debugging the above and may be useful again in future.

   - Downgrade an assertion to a print when a still-active server is
     seen during purging. This was happening as a consequence of
     incomplete cell removal before the servers were cleaned up"

* tag 'afs-fixes-20201016' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Don't assert on unpurgeable server records
  afs: Add tracing for cell refcount and active user count
  afs: Fix cell removal
  afs: Fix cell purging with aliases
  afs: Fix cell refcounting by splitting the usage counter
  afs: Fix rapid cell addition/removal by not using RCU on cells tree

Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've added new features such as zone capacity for ZNS
  and a new GC policy, ATGC, along with in-memory segment management. In
  addition, we could improve the decompression speed significantly by
  changing virtual mapping method. Even though we've fixed lots of small
  bugs in compression support, I feel that it becomes more stable so
  that I could give it a try in production.

  Enhancements:
   - suport zone capacity in NVMe Zoned Namespace devices
   - introduce in-memory current segment management
   - add standart casefolding support
   - support age threshold based garbage collection
   - improve decompression speed by changing virtual mapping method

  Bug fixes:
   - fix condition checks in some ioctl() such as compression, move_range, etc
   - fix 32/64bits support in data structures
   - fix memory allocation in zstd decompress
   - add some boundary checks to avoid kernel panic on corrupted image
   - fix disallowing compression for non-empty file
   - fix slab leakage of compressed block writes

  In addition, it includes code refactoring for better readability and
  minor bug fixes for compression and zoned device support"

* tag 'f2fs-for-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits)
  f2fs: code cleanup by removing unnecessary check
  f2fs: wait for sysfs kobject removal before freeing f2fs_sb_info
  f2fs: fix writecount false positive in releasing compress blocks
  f2fs: introduce check_swap_activate_fast()
  f2fs: don't issue flush in f2fs_flush_device_cache() for nobarrier case
  f2fs: handle errors of f2fs_get_meta_page_nofail
  f2fs: fix to set SBI_NEED_FSCK flag for inconsistent inode
  f2fs: reject CASEFOLD inode flag without casefold feature
  f2fs: fix memory alignment to support 32bit
  f2fs: fix slab leak of rpages pointer
  f2fs: compress: fix to disallow enabling compress on non-empty file
  f2fs: compress: introduce cic/dic slab cache
  f2fs: compress: introduce page array slab cache
  f2fs: fix to do sanity check on segment/section count
  f2fs: fix to check segment boundary during SIT page readahead
  f2fs: fix uninit-value in f2fs_lookup
  f2fs: remove unneeded parameter in find_in_block()
  f2fs: fix wrong total_sections check and fsmeta check
  f2fs: remove duplicated code in sanity_check_area_boundary
  f2fs: remove unused check on version_bitmap
  ...

Pull documentation updates from Mauro Carvalho Chehab:
 "A series of patches addressing warnings produced by make htmldocs.
  This includes:

   - kernel-doc markup fixes

   - ReST fixes

   - Updates at the build system in order to support newer versions of
     the docs build toolchain (Sphinx)

  After this series, the number of html build warnings should reduce
  significantly, and building with Sphinx 3.1 or later should now be
  supported (although it is still recommended to use Sphinx 2.4.4).

  As agreed with Jon, I should be sending you a late pull request by the
  end of the merge window addressing remaining issues with docs build,
  as there are a number of warning fixes that depends on pull requests
  that should be happening along the merge window.

  The end goal is to have a clean htmldocs build on Kernel 5.10.

  PS. It should be noticed that Sphinx 3.0 is not currently supported,
  as it lacks support for C domain namespaces. Such feature, needed in
  order to document uAPI system calls with Sphinx 3.x, was added only on
  Sphinx 3.1"

* tag 'docs/v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (75 commits)
  PM / devfreq: remove a duplicated kernel-doc markup
  mm/doc: fix a literal block markup
  workqueue: fix a kernel-doc warning
  docs: virt: user_mode_linux_howto_v2.rst: fix a literal block markup
  Input: sparse-keymap: add a description for @sw
  rcu/tree: docs: document bkvcache new members at struct kfree_rcu_cpu
  nl80211: docs: add a description for s1g_cap parameter
  usb: docs: document altmode register/unregister functions
  kunit: test.h: fix a bad kernel-doc markup
  drivers: core: fix kernel-doc markup for dev_err_probe()
  docs: bio: fix a kerneldoc markup
  kunit: test.h: solve kernel-doc warnings
  block: bio: fix a warning at the kernel-doc markups
  docs: powerpc: syscall64-abi.rst: fix a malformed table
  drivers: net: hamradio: fix document location
  net: appletalk: Kconfig: Fix docs location
  dt-bindings: fix references to files converted to yaml
  memblock: get rid of a :c:type leftover
  math64.h: kernel-docs: Convert some markups into normal comments
  media: uAPI: buffer.rst: remove a left-over documentation
  ...

Pull tracing fix from Steven Rostedt:
 "Fix mismatch section of adding early trace events.

  Fixes the issue of a mismatch section that was missed due to gcc
  inlining the offending function, while clang did not (and reported the
  issue)"

* tag 'trace-v5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Remove __init from __trace_early_add_new_event()

Pull printk fix from Petr Mladek:
 "Prevent overflow in the new lockless ringbuffer"

* tag 'printk-for-5.10-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: ringbuffer: Wrong data pointer when appending small string

Pull kgdb updates from Daniel Thompson:
 "A fairly modest set of changes for this cycle.

  Of particular note are an earlycon fix from Doug Anderson and my own
  changes to get kgdb/kdb to honour the kprobe blocklist. The later
  creates a safety rail that strongly encourages developers not to place
  breakpoints in, for example, arch specific trap handling code.

  Also included are a couple of small fixes and tweaks: an API update,
  eliminate a coverity dead code warning, improved handling of search
  during multi-line printk and a couple of typo corrections"

* tag 'kgdb-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  kdb: Fix pager search for multi-line strings
  kernel: debug: Centralize dbg_[de]activate_sw_breakpoints
  kgdb: Add NOKPROBE labels on the trap handler functions
  kgdb: Honour the kprobe blocklist when setting breakpoints
  kernel/debug: Fix spelling mistake in debug_core.c
  kdb: Use newer api for tasklist scanning
  kgdb: Make "kgdbcon" work properly with "kgdb_earlycon"
  kdb: remove unnecessary null check of dbg_io_ops

Pull MIPS updates from Thomas Bogendoerfer:

 - removed support for PNX833x alias NXT_STB22x

 - included Ingenic SoC support into generic MIPS kernels

 - added support for new Ingenic SoCs

 - converted workaround selection to use Kconfig

 - replaced old boot mem functions by memblock_*

 - enabled COP2 usage in kernel for Loongson64 to make use
   of 16byte load/stores possible

 - cleanups and fixes

* tag 'mips_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (92 commits)
  MIPS: DEC: Restore bootmem reservation for firmware working memory area
  MIPS: dec: fix section mismatch
  bcm963xx_tag.h: fix duplicated word
  mips: ralink: enable zboot support
  MIPS: ingenic: Remove CPU_SUPPORTS_HUGEPAGES
  MIPS: cpu-probe: remove MIPS_CPU_BP_GHIST option bit
  MIPS: cpu-probe: introduce exclusive R3k CPU probe
  MIPS: cpu-probe: move fpu probing/handling into its own file
  MIPS: replace add_memory_region with memblock
  MIPS: Loongson64: Clean up numa.c
  MIPS: Loongson64: Select SMP in Kconfig to avoid build error
  mips: octeon: Add Ubiquiti E200 and E220 boards
  MIPS: SGI-IP28: disable use of ll/sc in kernel
  MIPS: tx49xx: move tx4939_add_memory_regions into only user
  MIPS: pgtable: Remove used PAGE_USERIO define
  MIPS: alchemy: Share prom_init implementation
  MIPS: alchemy: Fix build breakage, if TOUCHSCREEN_WM97XX is disabled
  MIPS: process: include exec.h header in process.c
  MIPS: process: Add prototype for function arch_dup_task_struct
  MIPS: idle: Add prototype for function check_wait
  ...

Pull s390 updates from Vasily Gorbik:

 - Remove address space overrides using set_fs()

 - Convert to generic vDSO

 - Convert to generic page table dumper

 - Add ARCH_HAS_DEBUG_WX support

 - Add leap seconds handling support

 - Add NVMe firmware-assisted kernel dump support

 - Extend NVMe boot support with memory clearing control and addition of
   kernel parameters

 - AP bus and zcrypt api code rework. Add adapter configure/deconfigure
   interface. Extend debug features. Add failure injection support

 - Add ECC secure private keys support

 - Add KASan support for running protected virtualization host with
   4-level paging

 - Utilize destroy page ultravisor call to speed up secure guests
   shutdown

 - Implement ioremap_wc() and ioremap_prot() with MIO in PCI code

 - Various checksum improvements

 - Other small various fixes and improvements all over the code

* tag 's390-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (85 commits)
  s390/uaccess: fix indentation
  s390/uaccess: add default cases for __put_user_fn()/__get_user_fn()
  s390/zcrypt: fix wrong format specifications
  s390/kprobes: move insn_page to text segment
  s390/sie: fix typo in SIGP code description
  s390/lib: fix kernel doc for memcmp()
  s390/zcrypt: Introduce Failure Injection feature
  s390/zcrypt: move ap_msg param one level up the call chain
  s390/ap/zcrypt: revisit ap and zcrypt error handling
  s390/ap: Support AP card SCLP config and deconfig operations
  s390/sclp: Add support for SCLP AP adapter config/deconfig
  s390/ap: add card/queue deconfig state
  s390/ap: add error response code field for ap queue devices
  s390/ap: split ap queue state machine state from device state
  s390/zcrypt: New config switch CONFIG_ZCRYPT_DEBUG
  s390/zcrypt: introduce msg tracking in zcrypt functions
  s390/startup: correct early pgm check info formatting
  s390: remove orphaned extern variables declarations
  s390/kasan: make sure int handler always run with DAT on
  s390/ipl: add support to control memory clearing for nvme re-IPL
  ...

Pull powerpc updates from Michael Ellerman:

 - A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM & selecting
   it for powerpc, as well as a related fix for sparc.

 - Remove support for PowerPC 601.

 - Some fixes for watchpoints & addition of a new ptrace flag for
   detecting ISA v3.1 (Power10) watchpoint features.

 - A fix for kernels using 4K pages and the hash MMU on bare metal
   Power9 systems with > 16TB of RAM, or RAM on the 2nd node.

 - A basic idle driver for shallow stop states on Power10.

 - Tweaks to our sched domains code to better inform the scheduler about
   the hardware topology on Power9/10, where two SMT4 cores can be
   presented by firmware as an SMT8 core.

 - A series doing further reworks & cleanups of our EEH code.

 - Addition of a filter for RTAS (firmware) calls done via sys_rtas(),
   to prevent root from overwriting kernel memory.

 - Other smaller features, fixes & cleanups.

Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Athira Rajeev, Biwen Li, Cameron Berkenpas, Cédric Le Goater, Christophe
Leroy, Christoph Hellwig, Colin Ian King, Daniel Axtens, David Dai, Finn
Thain, Frederic Barrat, Gautham R. Shenoy, Greg Kurz, Gustavo Romero,
Ira Weiny, Jason Yan, Joel Stanley, Jordan Niethe, Kajol Jain, Konrad
Rzeszutek Wilk, Laurent Dufour, Leonardo Bras, Liu Shixin, Luca
Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar, Nathan Lynch, Nicholas
Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Pedro
Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai, Qinglang
Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott Cheloha,
Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt,
Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain,
Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang
Yingliang, zhengbin.

* tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (228 commits)
  Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed"
  selftests/powerpc: Fix eeh-basic.sh exit codes
  cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier
  powerpc/time: Make get_tb() common to PPC32 and PPC64
  powerpc/time: Make get_tbl() common to PPC32 and PPC64
  powerpc/time: Remove get_tbu()
  powerpc/time: Avoid using get_tbl() and get_tbu() internally
  powerpc/time: Make mftb() common to PPC32 and PPC64
  powerpc/time: Rename mftbl() to mftb()
  powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S
  powerpc/32s: Rename head_32.S to head_book3s_32.S
  powerpc/32s: Setup the early hash table at all time.
  powerpc/time: Remove ifdef in get_dec() and set_dec()
  powerpc: Remove get_tb_or_rtc()
  powerpc: Remove __USE_RTC()
  powerpc: Tidy up a bit after removal of PowerPC 601.
  powerpc: Remove support for PowerPC 601
  powerpc: Remove PowerPC 601
  powerpc: Drop SYNC_601() ISYNC_601() and SYNC()
  powerpc: Remove CONFIG_PPC601_SYNC_FIX
  ...

Merge more updates from Andrew Morton:
 "155 patches.

  Subsystems affected by this patch series: mm (dax, debug, thp,
  readahead, page-poison, util, memory-hotplug, zram, cleanups), misc,
  core-kernel, get_maintainer, MAINTAINERS, lib, bitops, checkpatch,
  binfmt, ramfs, autofs, nilfs, rapidio, panic, relay, kgdb, ubsan,
  romfs, and fault-injection"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (155 commits)
  lib, uaccess: add failure injection to usercopy functions
  lib, include/linux: add usercopy failure capability
  ROMFS: support inode blocks calculation
  ubsan: introduce CONFIG_UBSAN_LOCAL_BOUNDS for Clang
  sched.h: drop in_ubsan field when UBSAN is in trap mode
  scripts/gdb/tasks: add headers and improve spacing format
  scripts/gdb/proc: add struct mount & struct super_block addr in lx-mounts command
  kernel/relay.c: drop unneeded initialization
  panic: dump registers on panic_on_warn
  rapidio: fix the missed put_device() for rio_mport_add_riodev
  rapidio: fix error handling path
  nilfs2: fix some kernel-doc warnings for nilfs2
  autofs: harden ioctl table
  ramfs: fix nommu mmap with gaps in the page cache
  mm: remove the now-unnecessary mmget_still_valid() hack
  mm/gup: take mmap_lock in get_dump_page()
  binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot
  coredump: rework elf/elf_fdpic vma_dump_size() into common helper
  coredump: refactor page range dumping into common helper
  coredump: let dump_emit() bail out on short writes
  ...

To test fault-tolerance of user memory access functions, introduce fault
injection to usercopy functions.

If a failure is expected return either -EFAULT or the total amount of
bytes that were not copied.
Signed-off-by: Albert van der Linde <alinde@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20200831171733.955393-3-alinde@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "add fault injection to user memory access", v3.

The goal of this series is to improve testing of fault-tolerance in usages
of user memory access functions, by adding support for fault injection.

syzkaller/syzbot are using the existing fault injection modes and will use
this particular feature also.

The first patch adds failure injection capability for usercopy functions.
The second changes usercopy functions to use this new failure capability
(copy_from_user, ...).  The third patch adds get/put/clear_user failures
to x86.

This patch (of 3):

Add a failure injection capability to improve testing of fault-tolerance
in usages of user memory access functions.

Add CONFIG_FAULT_INJECTION_USERCOPY to enable faults in usercopy
functions.  The should_fail_usercopy function is to be called by these
functions (copy_from_user, get_user, ...) in order to fail or not.
Signed-off-by: Albert van der Linde <alinde@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20200831171733.955393-1-alinde@google.com
Link: http://lkml.kernel.org/r/20200831171733.955393-2-alinde@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When use 'stat' tool to display file status, the 'Blocks' field always in
'0', this is not good for tool 'du'(e.g.: busybox 'du'), it always output
'0' size for the files under ROMFS since such tool calculates number of
512B Blocks.

This patch calculates approx.  number of 512B blocks based on inode size.
Signed-off-by: Libing Zhou <libing.zhou@nokia-sbell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: http://lkml.kernel.org/r/20200811052606.4243-1-libing.zhou@nokia-sbell.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When the kernel is compiled with Clang, -fsanitize=bounds expands to
-fsanitize=array-bounds and -fsanitize=local-bounds.

Enabling -fsanitize=local-bounds with Clang has the unfortunate
side-effect of inserting traps; this goes back to its original intent,
which was as a hardening and not a debugging feature [1].  The same
feature made its way into -fsanitize=bounds, but the traps remained.  For
that reason, -fsanitize=bounds was split into 'array-bounds' and
'local-bounds' [2].

Since 'local-bounds' doesn't behave like a normal sanitizer, enable it
with Clang only if trapping behaviour was requested by
CONFIG_UBSAN_TRAP=y.

Add the UBSAN_BOUNDS_LOCAL config to Kconfig.ubsan to enable the
'local-bounds' option by default when UBSAN_TRAP is enabled.

[1] http://lists.llvm.org/pipermail/llvm-dev/2012-May/049972.html
[2] http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20131021/091536.htmlSuggested-by: Marco Elver <elver@google.com>
Signed-off-by: George Popescu <georgepope@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Brazdil <dbrazdil@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lkml.kernel.org/r/20200922074330.2549523-1-georgepope@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

in_ubsan field of task_struct is only used in lib/ubsan.c, which in its
turn is used only `ifneq ($(CONFIG_UBSAN_TRAP),y)`.

Removing unnecessary field from a task_struct will help preserve the ABI
between vanilla and CONFIG_UBSAN_TRAP'ed kernels.  In particular, this
will help enabling bounds sanitizer transparently for Android's GKI.
Signed-off-by: Elena Petrova <lenaptr@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>
Link: https://lkml.kernel.org/r/20200910134802.3160311-1-lenaptr@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With the patch.
<e.g. o/p>
      TASK          PID    COMM
0xffffffff82c2b8c0   0   swapper/0
0xffff888a0ba20040   1   systemd
0xffff888a0ba24040   2   kthreadd
0xffff888a0ba28040   3   rcu_gp

w/o
0xffffffff82c2b8c0 <init_task> 0 swapper/0
0xffff888a0ba20040 1 systemd
0xffff888a0ba24040 2 kthreadd
0xffff888a0ba28040 3 rcu_gp
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Link: http://lkml.kernel.org/r/54c868c79b5fc364a8be7799891934a6fe6d1464.1597742951.git.riteshh@linux.ibm.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is many times found useful while debugging some FS related
issue.

<e.g. output>
      mount          super_block     devname pathname fstype options
0xffff888a0bfa4b40 0xffff888a0bfc1000 none / rootfs rw 0 0
0xffff888a033f75c0 0xffff8889fcf65000 /dev/root / ext4 rw,relatime 0 0
0xffff8889fc8ce040 0xffff888a0bb51000 devtmpfs /dev devtmpfs rw,relatime 0 0
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Link: http://lkml.kernel.org/r/a3c4177e1597b3e06d66d55e07d72c0c46a03571.1597742951.git.riteshh@linux.ibm.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The variable 'consumed' is initialized with the consumed count but
immediately after that the consumed count is updated and assigned to
'consumed' again thus overwriting the previous value.  So, drop the
unneeded initialization.
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20201005205727.1147-1-sudipm.mukherjee@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently we print stack and registers for ordinary warnings but we do not
for panic_on_warn which looks as oversight - panic() will reboot the
machine but won't print registers.

This moves printing of registers and modules earlier.

This does not move the stack dumping as panic() dumps it.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Link: https://lkml.kernel.org/r/20200804095054.68724-1-aik@ozlabs.ruSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rio_mport_add_riodev() misses to call put_device() when the device already
exists.  Add the missed function call to fix it.

Fixes: e8de3701 ("rapidio: add mport char device driver")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Link: https://lkml.kernel.org/r/20200922072525.42330-1-jingxiangfeng@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>