When run on a single CPU, this test would frequently access already-freed
memory.  Due to timing, this bug never showed up on multi-CPU tests.
Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Several test runners register individual worker threads with the
RCU library, but neglect to register the main thread, which can lead
to objects being freed while the main thread is in what appears to be
an RCU critical section.
Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Commit 4bba4c4b added tools/include/linux/compiler_types.h which
includes linux/compiler-gcc.h.  Unfortunately, we had our own (empty)
compiler_types.h which overrode the one added by that commit, and
so we lost the definition of __must_be_array().  Removing our empty
compiler_types.h fixes the problem and reduces our divergence from the
rest of the tools.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

A 16-bit limit is a more common limit than I had realised.  Make it
generally available.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Splitting an order-4 entry into order-2 entries would leave the array
containing pointers to 000040008000c000 instead of 000044448888cccc.
This is a one-character fix, but enhance the test suite to check this
case.
Reported-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

I wrote the documentation backwards; the new order of the entry is stored
in the xas and the caller passes the old entry.
Reported-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Pull VFIO fixes from Alex Williamson:

 - Fix pfnmap batch carryover (Daniel Jordan)

 - Fix nvlink Kconfig dependency (Jason Gunthorpe)

* tag 'vfio-v5.12-rc6' of git://github.com/awilliam/linux-vfio:
  vfio/nvlink: Add missing SPAPR_TCE_IOMMU depends
  vfio/type1: Empty batch for pfnmap pages

There are code paths that rely on zero_pfn to be fully initialized
before core_initcall.  For example, wq_sysfs_init() is a core_initcall
function that eventually results in a call to kernel_execve, which
causes a page fault with a subsequent mmput.  If zero_pfn is not
initialized by then it may not get cleaned up properly and result in an
error:

  BUG: Bad rss-counter state mm:(ptrval) type:MM_ANONPAGES val:1

Here is an analysis of the race as seen on a MIPS device. On this
particular MT7621 device (Ubiquiti ER-X), zero_pfn is PFN 0 until
initialized, at which point it becomes PFN 5120:

  1. wq_sysfs_init calls into kobject_uevent_env at core_initcall:
       kobject_uevent_env+0x7e4/0x7ec
       kset_register+0x68/0x88
       bus_register+0xdc/0x34c
       subsys_virtual_register+0x34/0x78
       wq_sysfs_init+0x1c/0x4c
       do_one_initcall+0x50/0x1a8
       kernel_init_freeable+0x230/0x2c8
       kernel_init+0x10/0x100
       ret_from_kernel_thread+0x14/0x1c

  2. kobject_uevent_env() calls call_usermodehelper_exec() which executes
     kernel_execve asynchronously.

  3. Memory allocations in kernel_execve cause a page fault, bumping the
     MM reference counter:
       add_mm_counter_fast+0xb4/0xc0
       handle_mm_fault+0x6e4/0xea0
       __get_user_pages.part.78+0x190/0x37c
       __get_user_pages_remote+0x128/0x360
       get_arg_page+0x34/0xa0
       copy_string_kernel+0x194/0x2a4
       kernel_execve+0x11c/0x298
       call_usermodehelper_exec_async+0x114/0x194

  4. In case zero_pfn has not been initialized yet, zap_pte_range does
     not decrement the MM_ANONPAGES RSS counter and the BUG message is
     triggered shortly afterwards when __mmdrop checks the ref counters:
       __mmdrop+0x98/0x1d0
       free_bprm+0x44/0x118
       kernel_execve+0x160/0x1d8
       call_usermodehelper_exec_async+0x114/0x194
       ret_from_kernel_thread+0x14/0x1c

To avoid races such as described above, initialize init_zero_pfn at
early_initcall level.  Depending on the architecture, ZERO_PAGE is
either constant or gets initialized even earlier, at paging_init, so
there is no issue with initializing zero_pfn earlier.

Link: https://lkml.kernel.org/r/CALCv0x2YqOXEAy2Q=hafjhHCtTHVodChv1qpM=niAXOpqEbt7w@mail.gmail.comSigned-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: stable@vger.kernel.org
Tested-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull MIPS fix from Thomas Bogendoerfer:

 - Fix compile error with option MIPS_ELF_APPENDED_DTB

* tag 'mips-fixes_5.12_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: kernel: setup.c: fix compilation error

Pull xen fix from Juergen Gross:
 "One Xen related security fix (XSA-371)"

* tag 'for-linus-5.12b-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-blkback: don't leak persistent grants from xen_blkbk_map()

With ath79_defconfig enabling CONFIG_MIPS_ELF_APPENDED_DTB gives a
compilation error. This patch fixes it.

Build log:
...
  CC      kernel/locking/percpu-rwsem.o
../arch/mips/kernel/setup.c:46:39: error: conflicting types for
'__appended_dtb'
 const char __section(".appended_dtb") __appended_dtb[0x100000];
                                       ^~~~~~~~~~~~~~
In file included from ../arch/mips/kernel/setup.c:34:
../arch/mips/include/asm/bootinfo.h:118:13: note: previous declaration
of '__appended_dtb' was here
 extern char __appended_dtb[];
             ^~~~~~~~~~~~~~
  CC      fs/attr.o
make[4]: *** [../scripts/Makefile.build:271: arch/mips/kernel/setup.o]
 Error 1
...

Root cause seems to be:
Fixes: b83ba0b9 ("MIPS: of: Introduce helper function to get DTB")
Signed-off-by: Mauri Sandberg <sandberg@mailfence.com>
Reviewed-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: trivial@kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Compiling the nvlink stuff relies on the SPAPR_TCE_IOMMU otherwise there
are compile errors:

 drivers/vfio/pci/vfio_pci_nvlink2.c:101:10: error: implicit declaration of function 'mm_iommu_put' [-Werror,-Wimplicit-function-declaration]
                            ret = mm_iommu_put(data->mm, data->mem);

As PPC only defines these functions when the config is set.

Previously this wasn't a problem by chance as SPAPR_TCE_IOMMU was the only
IOMMU that could have satisfied IOMMU_API on POWERNV.

Fixes: 179209fa ("vfio: IOMMU_API should be selected")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <0-v1-83dba9768fc3+419-vfio_nvlink2_kconfig_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Pull xtensa fixes from Max Filippov:

 - fix build with separate exception vectors when they are placed too
   far from the rest of the kernel

 - fix uaccess-related livelock in do_page_fault.

* tag 'xtensa-20210329' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: fix uaccess-related livelock in do_page_fault
  xtensa: move coprocessor_flush to the .text section

If a uaccess (e.g. get_user()) triggers a fault and there's a
fault signal pending, the handler will return to the uaccess without
having performed a uaccess fault fixup, and so the CPU will immediately
execute the uaccess instruction again, whereupon it will livelock
bouncing between that instruction and the fault handler.

https://lore.kernel.org/lkml/20210121123140.GD48431@C02TD0UTHF1T.local/

Cc: stable@vger.kernel.org
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Merge tag 'perf-tools-fixes-for-v5.12-2020-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tooling fixes from Arnaldo Carvalho de Melo:

 - Avoid write of uninitialized memory when generating PERF_RECORD_MMAP*
   records.

 - Fix 'perf top' BPF support related crash with perf_event_paranoid=3 +
   kptr_restrict.

 - Validate raw event with sysfs exported format bits.

 - Fix waipid on SIGCHLD delivery bugs in 'perf daemon'.

 - Change to use bash for daemon test on Debian, where the default is
   dash and thus fails for use of bashisms in this test.

 - Fix memory leak in vDSO found using ASAN.

 - Remove now useless (due to the fact that BPF now supports static
   vars) failing sub test "BPF relocation checker".

 - Fix auxtrace queue conflict.

 - Sync linux/kvm.h with the kernel sources.

* tag 'perf-tools-fixes-for-v5.12-2020-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf test: Change to use bash for daemon test
  perf record: Fix memory leak in vDSO found using ASAN
  perf test: Remove now useless failing sub test "BPF relocation checker"
  perf daemon: Return from kill functions
  perf daemon: Force waipid for all session on SIGCHLD delivery
  perf top: Fix BPF support related crash with perf_event_paranoid=3 + kptr_restrict
  perf pmu: Validate raw event with sysfs exported format bits
  perf synthetic events: Avoid write of uninitialized memory when generating PERF_RECORD_MMAP* records
  tools headers UAPI: Sync linux/kvm.h with the kernel sources
  perf synthetic-events: Fix uninitialized 'kernel_thread' variable
  perf auxtrace: Fix auxtrace queue conflict

Pull auxdisplay fix from Miguel Ojeda:
 "Remove in_interrupt() usage (Sebastian Andrzej Siewior)"

* tag 'auxdisplay-for-linus-v5.12-rc6' of git://github.com/ojeda/linux:
  auxdisplay: Remove in_interrupt() usage.

Pull x86 fixes from Ingo Molnar:
 "Two fixes:

   - Fix build failure on Ubuntu with new GCC packages that turn
     on -fcf-protection

   - Fix SME memory encryption PTE encoding bug - AFAICT the code
     worked on 4K page sizes (level 1) but had the wrong shift at
     higher page level orders (level 2 and higher)"

* tag 'x86-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Turn off -fcf-protection for realmode targets
  x86/mem_encrypt: Correct physical address calculation in __set_clr_pte_enc()

Pull locking fix from Ingo Molnar:
 "Fix the non-debug mutex_lock_io_nested() method to map to
  mutex_lock_io() instead of mutex_lock().

  Right now nothing uses this API explicitly, but this is an
  accident waiting to happen"

* tag 'locking-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/mutex: Fix non debug version of mutex_lock_io_nested()

Pull cifs fixes from Steve French:
 "Five cifs/smb3 fixes, two for stable.

  Includes an important fix for encryption and an ACL fix, as well as a
  fix for possible reflink data corruption"

* tag '5.12-rc4-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: fix cached file size problems in duplicate extents (reflink)
  cifs: Silently ignore unknown oplock break handle
  cifs: revalidate mapping when we open files for SMB1 POSIX
  cifs: Fix chmod with modefromsid when an older ACE already exists.
  cifs: Adjust key sizes and key generation routines for AES256 encryption

Pull io_uring fixes from Jens Axboe:

 - Use thread info versions of flag testing, as discussed last week.

 - The series enabling PF_IO_WORKER to just take signals, instead of
   needing to special case that they do not in a bunch of places. Ends
   up being pretty trivial to do, and then we can revert all the special
   casing we're currently doing.

 - Kill dead pointer assignment

 - Fix hashed part of async work queue trace

 - Fix sign extension issue for IORING_OP_PROVIDE_BUFFERS

 - Fix a link completion ordering regression in this merge window

 - Cancellation fixes

* tag 'io_uring-5.12-2021-03-27' of git://git.kernel.dk/linux-block:
  io_uring: remove unsued assignment to pointer io
  io_uring: don't cancel extra on files match
  io_uring: don't cancel-track common timeouts
  io_uring: do post-completion chore on t-out cancel
  io_uring: fix timeout cancel return code
  Revert "signal: don't allow STOP on PF_IO_WORKER threads"
  Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing"
  Revert "kernel: treat PF_IO_WORKER like PF_KTHREAD for ptrace/signals"
  Revert "signal: don't allow sending any signals to PF_IO_WORKER threads"
  kernel: stop masking signals in create_io_thread()
  io_uring: handle signals for IO threads like a normal thread
  kernel: don't call do_exit() for PF_IO_WORKER threads
  io_uring: maintain CQE order of a failed link
  io-wq: fix race around pending work on teardown
  io_uring: do ctx sqd ejection in a clear context
  io_uring: fix provide_buffers sign extension
  io_uring: don't skip file_end_write() on reissue
  io_uring: correct io_queue_async_work() traces
  io_uring: don't use {test,clear}_tsk_thread_flag() for current

Pull block fixes from Jens Axboe:

 - Fix regression from this merge window with the xarray partition
   change, which allowed partition counts that overflow the u8 that
   holds the partition number (Ming)

 - Fix zone append warning (Johannes)

 - Segmentation count fix for multipage bvecs (David)

 - Partition scan fix (Chris)

* tag 'block-5.12-2021-03-27' of git://git.kernel.dk/linux-block:
  block: don't create too many partitions
  block: support zone append bvecs
  block: recalculate segment count for multi-segment discards correctly
  block: clear GD_NEED_PART_SCAN later in bdev_disk_changed

Pull SCSI fixes from James Bottomley:
 "Seven fixes, all in drivers (qla2xxx, mkt3sas, qedi, target,
  ibmvscsi).

  The most serious are the target pscsi oom and the qla2xxx revert which
  can otherwise cause a use after free"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: target: pscsi: Clean up after failure in pscsi_map_sg()
  scsi: target: pscsi: Avoid OOM in pscsi_map_sg()
  scsi: mpt3sas: Fix error return code of mpt3sas_base_attach()
  scsi: qedi: Fix error return code of qedi_alloc_global_queues()
  scsi: Revert "qla2xxx: Make sure that aborted commands are freed"
  scsi: ibmvfc: Make ibmvfc_wait_for_ops() MQ aware
  scsi: ibmvfc: Fix potential race in ibmvfc_wait_for_ops()

There is an assignment to io that is never read after the assignment,
the assignment is redundant and can be removed.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

As tasks always wait and kill their io-wq on exec/exit, files are of no
more concern to us, so we don't need to specifically cancel them by hand
in those cases. Moreover we should not, because io_match_task() looks at
req->task->files now, which is always true and so leads to extra
cancellations, that wasn't a case before per-task io-wq.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0566c1de9b9dd417f5de345c817ca953580e0e2e.1616696997.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Don't account usual timeouts (i.e. not linked) as REQ_F_INFLIGHT but
keep behaviour prior to dd59a3d5 ("io_uring: reliably cancel linked
timeouts").
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/104441ef5d97e3932113d44501fda0df88656b83.1616696997.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Don't forget about io_commit_cqring() + io_cqring_ev_posted() after
exit/exec cancelling timeouts. Both functions declared only after
io_kill_timeouts(), so to avoid tons of forward declarations move
it down.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/72ace588772c0f14834a6a4185d56c445a366fb4.1616696997.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

When we cancel a timeout we should emit a sensible return code, like
-ECANCELED but not 0, otherwise it may trick users.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7b0ad1065e3bd1994722702bd0ba9e7bc9b0683b.1616696997.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 4db4b1a0.

The IO threads allow and handle SIGSTOP now, so don't special case them
anymore in task_set_jobctl_pending().
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 15b2219f.

Before IO threads accepted signals, the freezer using take signals to wake
up an IO thread would cause them to loop without any way to clear the
pending signal. That is no longer the case, so stop special casing
PF_IO_WORKER in the freezer.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 6fb8f43c.

The IO threads do allow signals now, including SIGSTOP, and we can allow
ptrace attach. Attaching won't reveal anything interesting for the IO
threads, but it will allow eg gdb to attach to a task with io_urings
and IO threads without complaining. And once attached, it will allow
the usual introspection into regular threads.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 5be28c8f.

IO threads now take signals just fine, so there's no reason to limit them
specifically. Revert the change that prevented that from happening.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This is racy - move the blocking into when the task is created and
we're marking it as PF_IO_WORKER anyway. The IO threads are now
prepared to handle signals like SIGSTOP as well, so clear that from
the mask to allow proper stopping of IO threads.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We go through various hoops to disallow signals for the IO threads, but
there's really no reason why we cannot just allow them. The IO threads
never return to userspace like a normal thread, and hence don't go through
normal signal processing. Instead, just check for a pending signal as part
of the work loop, and call get_signal() to handle it for us if anything
is pending.

With that, we can support receiving signals, including special ones like
SIGSTOP.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit a33df75c ("block: use an xarray for disk->part_tbl") drops the
check on max supported number of partitionsr, and allows partition with
bigger partition numbers to be added. However, ->bd_partno is defined as
u8, so partition index of xarray table may not match with ->bd_partno.
Then delete_partition() may delete one unmatched partition, and caused
use-after-free.
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reported-by: syzbot+8fede7e30c7cee0de139@syzkaller.appspotmail.com
Fixes: a33df75c ("block: use an xarray for disk->part_tbl")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There were two problems (one of which could cause data corruption)
that were noticed with duplicate extents (ie reflink)
when debugging why various xfstests were being incorrectly skipped
(e.g. generic/138, generic/140, generic/142). First, we were not
updating the file size locally in the cache when extending a
file due to reflink (it would refresh after actimeo expires)
but xfstest was checking the size immediately which was still
0 so caused the test to be skipped.  Second, we were setting
the target file size (which could shrink the file) in all cases
to the end of the reflinked range rather than only setting the
target file size when reflink would extend the file.

CC: <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Make SMB2 not print out an error when an oplock break is received for an
unknown handle, similar to SMB1.  The debug message which is printed for
these unknown handles may also be misleading, so fix that too.

The SMB2 lease break path is not affected by this patch.

Without this, a program which writes to a file from one thread, and
opens, reads, and writes the same file from another thread triggers the
below errors several times a minute when run against a Samba server
configured with "smb2 leases = no".

 CIFS: VFS: \\192.168.0.1 No task to wake, unknown frame received! NumMids 2
 00000000: 424d53fe 00000040 00000000 00000012  .SMB@...........
 00000010: 00000001 00000000 ffffffff ffffffff  ................
 00000020: 00000000 00000000 00000000 00000000  ................
 00000030: 00000000 00000000 00000000 00000000  ................
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

RHBZ: 1933527

Under SMB1 + POSIX, if an inode is reused on a server after we have read and
cached a part of a file, when we then open the new file with the
re-cycled inode there is a chance that we may serve the old data out of cache
to the application.
This only happens for SMB1 (deprecated) and when posix are used.
The simplest solution to avoid this race is to force a revalidate
on smb1-posix open.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

My recent fixes to cifsacl to maintain inherited ACEs had
regressed modefromsid when an older ACL already exists.

Found testing xfstest 495 with modefromsid mount option

Fixes: f5065508 ("cifs: Retain old ACEs when converting between mode bits and ACL")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

Right now we're never calling get_signal() from PF_IO_WORKER threads, but
in preparation for doing so, don't handle a fatal signal for them. The
workers have state they need to cleanup when exiting, so just return
instead of calling do_exit() on their behalf. The threads themselves will
detect a fatal signal and do proper shutdown.
Signed-off-by: Jens Axboe <axboe@kernel.dk>