Commit Graph

378 Commits

Author SHA1 Message Date
Linus Torvalds bf953917be Various hardening fixes and cleanups for 5.16-rc1
Hi Linus,
 
 Please, pull the following hardening fixes and cleanups that I've
 been collecting during the last development cycle. All of them have
 been baking in linux-next.
 
 Fix -Wcast-function-type error:
 
 - firewire: Remove function callback casts (Oscar Carter)
 
 Fix application of sizeof operator:
 
 - firmware/psci: fix application of sizeof to pointer (jing yangyang)
 
 Replace open coded instances with size_t saturating arithmetic helpers:
 
 - assoc_array: Avoid open coded arithmetic in allocator arguments (Len Baker)
 - writeback: prefer struct_size over open coded arithmetic (Len Baker)
 - aio: Prefer struct_size over open coded arithmetic (Len Baker)
 - dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic (Len Baker)
 
 Flexible array transformation:
 
 - KVM: PPC: Replace zero-length array with flexible array member (Len Baker)
 
 Use 2-factor argument multiplication form:
 
 - nouveau/svm: Use kvcalloc() instead of kvzalloc() (Gustavo A. R. Silva)
 - xfs: Use kvcalloc() instead of kvzalloc() (Gustavo A. R. Silva)
 
 Thanks
 --
 Gustavo
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Merge tag 'kspp-misc-fixes-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull hardening fixes and cleanups from Gustavo A. R. Silva:
 "Various hardening fixes and cleanups that I've been collecting during
  the last development cycle:

  Fix -Wcast-function-type error:

   - firewire: Remove function callback casts (Oscar Carter)

  Fix application of sizeof operator:

   - firmware/psci: fix application of sizeof to pointer (jing yangyang)

  Replace open coded instances with size_t saturating arithmetic
  helpers:

   - assoc_array: Avoid open coded arithmetic in allocator arguments
     (Len Baker)

   - writeback: prefer struct_size over open coded arithmetic (Len
     Baker)

   - aio: Prefer struct_size over open coded arithmetic (Len Baker)

   - dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
     (Len Baker)

  Flexible array transformation:

   - KVM: PPC: Replace zero-length array with flexible array member (Len
     Baker)

  Use 2-factor argument multiplication form:

   - nouveau/svm: Use kvcalloc() instead of kvzalloc() (Gustavo A. R.
     Silva)

   - xfs: Use kvcalloc() instead of kvzalloc() (Gustavo A. R. Silva)"

* tag 'kspp-misc-fixes-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  firewire: Remove function callback casts
  nouveau/svm: Use kvcalloc() instead of kvzalloc()
  firmware/psci: fix application of sizeof to pointer
  dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
  KVM: PPC: Replace zero-length array with flexible array member
  aio: Prefer struct_size over open coded arithmetic
  writeback: prefer struct_size over open coded arithmetic
  xfs: Use kvcalloc() instead of kvzalloc()
  assoc_array: Avoid open coded arithmetic in allocator arguments
2021-11-01 17:29:10 -07:00
Jens Axboe 6b19b766e8 fs: get rid of the res2 iocb->ki_complete argument
The second argument was only used by the USB gadget code, yet everyone
pays the overhead of passing a zero to be passed into aio, where it
ends up being part of the aio res2 value.

Now that everybody is passing in zero, kill off the extra argument.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-25 10:36:24 -06:00
Len Baker 6446c4fb12 aio: Prefer struct_size over open coded arithmetic
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.

So, use the struct_size() helper to do the arithmetic instead of the
argument "size + size * count" in the kzalloc() function.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments

Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2021-10-20 18:24:31 -05:00
Thomas Gleixner b542e383d8 eventfd: Make signal recursion protection a task bit
The recursion protection for eventfd_signal() is based on a per CPU
variable and relies on the !RT semantics of spin_lock_irqsave() for
protecting this per CPU variable. On RT kernels spin_lock_irqsave() neither
disables preemption nor interrupts which allows the spin lock held section
to be preempted. If the preempting task invokes eventfd_signal() as well,
then the recursion warning triggers.

Paolo suggested to protect the per CPU variable with a local lock, but
that's heavyweight and actually not necessary. The goal of this protection
is to prevent the task stack from overflowing, which can be achieved with a
per task recursion protection as well.

Replace the per CPU variable with a per task bit similar to other recursion
protection bits like task_struct::in_page_owner. This works on both !RT and
RT kernels and removes as a side effect the extra per CPU storage.

No functional change for !RT kernels.

Reported-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/87wnp9idso.ffs@tglx
2021-08-28 01:33:02 +02:00
Brian Geffon 14d071134c Revert "mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio"
This reverts commit cd544fd1dc.

As discussed in [1] this commit was a no-op because the mapping type was
checked in vma_to_resize before move_vma is ever called.  This meant that
vm_ops->mremap() would never be called on such mappings.  Furthermore,
we've since expanded support of MREMAP_DONTUNMAP to non-anonymous
mappings, and these special mappings are still protected by the existing
check of !VM_DONTEXPAND and !VM_PFNMAP which will result in a -EINVAL.

1. https://lkml.org/lkml/2020/12/28/2340

Link: https://lkml.kernel.org/r/20210323182520.2712101-2-bgeffon@google.com
Signed-off-by: Brian Geffon <bgeffon@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Alejandro Colomar <alx.manpages@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Michael S . Tsirkin" <mst@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:39 -07:00
Linus Torvalds ac73e3dc8a Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...
2020-12-15 12:53:37 -08:00
Dmitry Safonov cd544fd1dc mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio
As kernel expect to see only one of such mappings, any further operations
on the VMA-copy may be unexpected by the kernel.  Maybe it's being on the
safe side, but there doesn't seem to be any expected use-case for this, so
restrict it now.

Link: https://lkml.kernel.org/r/20201013013416.390574-4-dima@arista.com
Fixes: commit e346b38130 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:41 -08:00
Linus Torvalds edd7ab7684 The new preemtible kmap_local() implementation:
- Consolidate all kmap_atomic() internals into a generic implementation
     which builds the base for the kmap_local() API and make the
     kmap_atomic() interface wrappers which handle the disabling/enabling of
     preemption and pagefaults.
 
   - Switch the storage from per-CPU to per task and provide scheduler
     support for clearing mapping when scheduling out and restoring them
     when scheduling back in.
 
   - Merge the migrate_disable/enable() code, which is also part of the
     scheduler pull request. This was required to make the kmap_local()
     interface available which does not disable preemption when a mapping
     is established. It has to disable migration instead to guarantee that
     the virtual address of the mapped slot is the same accross preemption.
 
   - Provide better debug facilities: guard pages and enforced utilization
     of the mapping mechanics on 64bit systems when the architecture allows
     it.
 
   - Provide the new kmap_local() API which can now be used to cleanup the
     kmap_atomic() usage sites all over the place. Most of the usage sites
     do not require the implicit disabling of preemption and pagefaults so
     the penalty on 64bit and 32bit non-highmem systems is removed and quite
     some of the code can be simplified. A wholesale conversion is not
     possible because some usage depends on the implicit side effects and
     some need to be cleaned up because they work around these side effects.
 
     The migrate disable side effect is only effective on highmem systems
     and when enforced debugging is enabled. On 64bit and 32bit non-highmem
     systems the overhead is completely avoided.
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Merge tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull kmap updates from Thomas Gleixner:
 "The new preemtible kmap_local() implementation:

   - Consolidate all kmap_atomic() internals into a generic
     implementation which builds the base for the kmap_local() API and
     make the kmap_atomic() interface wrappers which handle the
     disabling/enabling of preemption and pagefaults.

   - Switch the storage from per-CPU to per task and provide scheduler
     support for clearing mapping when scheduling out and restoring them
     when scheduling back in.

   - Merge the migrate_disable/enable() code, which is also part of the
     scheduler pull request. This was required to make the kmap_local()
     interface available which does not disable preemption when a
     mapping is established. It has to disable migration instead to
     guarantee that the virtual address of the mapped slot is the same
     across preemption.

   - Provide better debug facilities: guard pages and enforced
     utilization of the mapping mechanics on 64bit systems when the
     architecture allows it.

   - Provide the new kmap_local() API which can now be used to cleanup
     the kmap_atomic() usage sites all over the place. Most of the usage
     sites do not require the implicit disabling of preemption and
     pagefaults so the penalty on 64bit and 32bit non-highmem systems is
     removed and quite some of the code can be simplified. A wholesale
     conversion is not possible because some usage depends on the
     implicit side effects and some need to be cleaned up because they
     work around these side effects.

     The migrate disable side effect is only effective on highmem
     systems and when enforced debugging is enabled. On 64bit and 32bit
     non-highmem systems the overhead is completely avoided"

* tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  ARM: highmem: Fix cache_is_vivt() reference
  x86/crashdump/32: Simplify copy_oldmem_page()
  io-mapping: Provide iomap_local variant
  mm/highmem: Provide kmap_local*
  sched: highmem: Store local kmaps in task struct
  x86: Support kmap_local() forced debugging
  mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
  mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL
  microblaze/mm/highmem: Add dropped #ifdef back
  xtensa/mm/highmem: Make generic kmap_atomic() work correctly
  mm/highmem: Take kmap_high_get() properly into account
  highmem: High implementation details and document API
  Documentation/io-mapping: Remove outdated blurb
  io-mapping: Cleanup atomic iomap
  mm/highmem: Remove the old kmap_atomic cruft
  highmem: Get rid of kmap_types.h
  xtensa/mm/highmem: Switch to generic kmap atomic
  sparc/mm/highmem: Switch to generic kmap atomic
  powerpc/mm/highmem: Switch to generic kmap atomic
  nds32/mm/highmem: Switch to generic kmap atomic
  ...
2020-12-14 18:35:53 -08:00
Darrick J. Wong 8a3c84b649 vfs: separate __sb_start_write into blocking and non-blocking helpers
Break this function into two helpers so that it's obvious that the
trylock versions return a value that must be checked, and the blocking
versions don't require that.  While we're at it, clean up the return
type mismatch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-11-10 16:53:07 -08:00
Thomas Gleixner e8f147dc3f fs: Remove asm/kmap_types.h includes
Historical leftovers from the time where kmap() had fixed slots.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20201103095856.870272797@linutronix.de
2020-11-06 23:14:53 +01:00
Linus Torvalds 85ed13e78d Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull compat iovec cleanups from Al Viro:
 "Christoph's series around import_iovec() and compat variant thereof"

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  security/keys: remove compat_keyctl_instantiate_key_iov
  mm: remove compat_process_vm_{readv,writev}
  fs: remove compat_sys_vmsplice
  fs: remove the compat readv/writev syscalls
  fs: remove various compat readv/writev helpers
  iov_iter: transparently handle compat iovecs in import_iovec
  iov_iter: refactor rw_copy_check_uvector and import_iovec
  iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c
  compat.h: fix a spelling error in <linux/compat.h>
2020-10-12 16:35:51 -07:00
Christoph Hellwig 89cd35c58b iov_iter: transparently handle compat iovecs in import_iovec
Use in compat_syscall to import either native or the compat iovecs, and
remove the now superflous compat_import_iovec.

This removes the need for special compat logic in most callers, and
the remaining ones can still be simplified by using __import_iovec
with a bool compat parameter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-03 00:02:13 -04:00
Gustavo A. R. Silva df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Peter Collingbourne 45e55300f1 mm: remove unnecessary wrapper function do_mmap_pgoff()
The current split between do_mmap() and do_mmap_pgoff() was introduced in
commit 1fcfd8db7f ("mm, mpx: add "vm_flags_t vm_flags" arg to
do_mmap_pgoff()") to support MPX.

The wrapper function do_mmap_pgoff() always passed 0 as the value of the
vm_flags argument to do_mmap().  However, MPX support has subsequently
been removed from the kernel and there were no more direct callers of
do_mmap(); all calls were going via do_mmap_pgoff().

Simplify the code by removing do_mmap_pgoff() and changing all callers to
directly call do_mmap(), which now no longer takes a vm_flags argument.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200727194109.1371462-1-pcc@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:27 -07:00
Gustavo A. R. Silva 241cb28e38 aio: Replace zero-length array with flexible-array
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-06-15 23:08:25 -05:00
Christoph Hellwig 9bf5b9eb23 kernel: move use_mm/unuse_mm to kthread.c
Patch series "improve use_mm / unuse_mm", v2.

This series improves the use_mm / unuse_mm interface by better documenting
the assumptions, and my taking the set_fs manipulations spread over the
callers into the core API.

This patch (of 3):

Use the proper API instead.

Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de

These helpers are only for use with kernel threads, and I will tie them
more into the kthread infrastructure going forward.  Also move the
prototypes to kthread.h - mmu_context.h was a little weird to start with
as it otherwise contains very low-level MM bits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200416053158.586887-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200404094101.672954-5-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-10 19:14:18 -07:00
Michel Lespinasse d8ed45c5dc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Miklos Szeredi 530f32fc37 aio: fix async fsync creds
Avi Kivity reports that on fuse filesystems running in a user namespace
asyncronous fsync fails with EOVERFLOW.

The reason is that f_ops->fsync() is called with the creds of the kthread
performing aio work instead of the creds of the process originally
submitting IOCB_CMD_FSYNC.

Fuse sends the creds of the caller in the request header and it needs to
translate the uid and gid into the server's user namespace.  Since the
kthread is running in init_user_ns, the translation will fail and the
operation returns an error.

It can be argued that fsync doesn't actually need any creds, but just
zeroing out those fields in the header (as with requests that currently
don't take creds) is a backward compatibility risk.

Instead of working around this issue in fuse, solve the core of the problem
by calling the filesystem with the proper creds.

Reported-by: Avi Kivity <avi@scylladb.com>
Tested-by: Giuseppe Scrivano <gscrivan@redhat.com>
Fixes: c9582eb0ff ("fuse: Fail all requests with invalid uids or gids")
Cc: stable@vger.kernel.org  # 4.18+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14 16:44:24 +02:00
Jens Axboe 01d7a35687 aio: prevent potential eventfd recursion on poll
If we have nested or circular eventfd wakeups, then we can deadlock if
we run them inline from our poll waitqueue wakeup handler. It's also
possible to have very long chains of notifications, to the extent where
we could risk blowing the stack.

Check the eventfd recursion count before calling eventfd_signal(). If
it's non-zero, then punt the signaling to async context. This is always
safe, as it takes us out-of-line in terms of stack and locking context.

Cc: stable@vger.kernel.org # 4.19+
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-02-03 17:27:47 -07:00
Linus Torvalds ceb3074745 y2038: syscall implementation cleanups
This is a series of cleanups for the y2038 work, mostly intended
 for namespace cleaning: the kernel defines the traditional
 time_t, timeval and timespec types that often lead to y2038-unsafe
 code. Even though the unsafe usage is mostly gone from the kernel,
 having the types and associated functions around means that we
 can still grow new users, and that we may be missing conversions
 to safe types that actually matter.
 
 There are still a number of driver specific patches needed to
 get the last users of these types removed, those have been
 submitted to the respective maintainers.
 
 Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull y2038 cleanups from Arnd Bergmann:
 "y2038 syscall implementation cleanups

  This is a series of cleanups for the y2038 work, mostly intended for
  namespace cleaning: the kernel defines the traditional time_t, timeval
  and timespec types that often lead to y2038-unsafe code. Even though
  the unsafe usage is mostly gone from the kernel, having the types and
  associated functions around means that we can still grow new users,
  and that we may be missing conversions to safe types that actually
  matter.

  There are still a number of driver specific patches needed to get the
  last users of these types removed, those have been submitted to the
  respective maintainers"

Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/

* tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (26 commits)
  y2038: alarm: fix half-second cut-off
  y2038: ipc: fix x32 ABI breakage
  y2038: fix typo in powerpc vdso "LOPART"
  y2038: allow disabling time32 system calls
  y2038: itimer: change implementation to timespec64
  y2038: move itimer reset into itimer.c
  y2038: use compat_{get,set}_itimer on alpha
  y2038: itimer: compat handling to itimer.c
  y2038: time: avoid timespec usage in settimeofday()
  y2038: timerfd: Use timespec64 internally
  y2038: elfcore: Use __kernel_old_timeval for process times
  y2038: make ns_to_compat_timeval use __kernel_old_timeval
  y2038: socket: use __kernel_old_timespec instead of timespec
  y2038: socket: remove timespec reference in timestamping
  y2038: syscalls: change remaining timeval to __kernel_old_timeval
  y2038: rusage: use __kernel_old_timeval
  y2038: uapi: change __kernel_time_t to __kernel_old_time_t
  y2038: stat: avoid 'time_t' in 'struct stat'
  y2038: ipc: remove __kernel_time_t reference from headers
  y2038: vdso: powerpc: avoid timespec references
  ...
2019-12-01 14:00:59 -08:00
Arnd Bergmann 3ca47e958a y2038: remove CONFIG_64BIT_TIME
The CONFIG_64BIT_TIME option is defined on all architectures, and can
be removed for simplicity now.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15 14:38:27 +01:00
Guillem Jover 97eba80fcc aio: Fix io_pgetevents() struct __compat_aio_sigset layout
This type is used to pass the sigset_t from userland to the kernel,
but it was using the kernel native pointer type for the member
representing the compat userland pointer to the userland sigset_t.

This messes up the layout, and makes the kernel eat up both the
userland pointer and the size members into the kernel pointer, and
then reads garbage into the kernel sigsetsize. Which makes the sigset_t
size consistency check fail, and consequently the syscall always
returns -EINVAL.

This breaks both libaio and strace on 32-bit userland running on 64-bit
kernels. And there are apparently no users in the wild of the current
broken layout (at least according to codesearch.debian.org and a brief
check over github.com search). So it looks safe to fix this directly
in the kernel, instead of either letting userland deal with this
permanently with the additional overhead or trying to make the syscall
infer what layout userland used, even though this is also being worked
around in libaio to temporarily cope with kernels that have not yet
been fixed.

We use a proper compat_uptr_t instead of a compat_sigset_t pointer.

Fixes: 7a074e96de ("aio: implement io_pgetevents")
Signed-off-by: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-21 19:12:19 -04:00
Linus Torvalds 933a90bf4f Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...
2019-07-19 10:42:02 -07:00
Keith Busch 371096949f mm: migrate: remove unused mode argument
migrate_page_move_mapping() doesn't use the mode argument.  Remove it
and update callers accordingly.

Link: http://lkml.kernel.org/r/20190508210301.8472-1-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
Oleg Nesterov b772434be0 signal: simplify set_user_sigmask/restore_user_sigmask
task->saved_sigmask and ->restore_sigmask are only used in the ret-from-
syscall paths.  This means that set_user_sigmask() can save ->blocked in
->saved_sigmask and do set_restore_sigmask() to indicate that ->blocked
was modified.

This way the callers do not need 2 sigset_t's passed to set/restore and
restore_user_sigmask() renamed to restore_saved_sigmask_unless() turns
into the trivial helper which just calls restore_saved_sigmask().

Link: http://lkml.kernel.org/r/20190606113206.GA9464@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Wong <e@80x24.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: David Laight <David.Laight@aculab.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16 19:23:24 -07:00
Linus Torvalds a2d79c7174 for-5.3/io_uring-20190711
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Merge tag 'for-5.3/io_uring-20190711' of git://git.kernel.dk/linux-block

Pull io_uring updates from Jens Axboe:
 "This contains:

   - Support for recvmsg/sendmsg as first class opcodes.

     I don't envision going much further down this path, as there are
     plans in progress to support potentially any system call in an
     async fashion through io_uring. But I think it does make sense to
     have certain core ops available directly, especially those that can
     support a "try this non-blocking" flag/mode. (me)

   - Handle generic short reads automatically.

     This can happen fairly easily if parts of the buffered read is
     cached. Since the application needs to issue another request for
     the remainder, just do this internally and save kernel/user
     roundtrip while providing a nicer more robust API. (me)

   - Support for linked SQEs.

     This allows SQEs to depend on each other, enabling an application
     to eg queue a read-from-this-file,write-to-that-file pair. (me)

   - Fix race in stopping SQ thread (Jackie)"

* tag 'for-5.3/io_uring-20190711' of git://git.kernel.dk/linux-block:
  io_uring: fix io_sq_thread_stop running in front of io_sq_thread
  io_uring: add support for recvmsg()
  io_uring: add support for sendmsg()
  io_uring: add support for sqe links
  io_uring: punt short reads to async context
  uio: make import_iovec()/compat_import_iovec() return bytes on success
2019-07-13 10:36:53 -07:00
Oleg Nesterov 97abc889ee signal: remove the wrong signal_pending() check in restore_user_sigmask()
This is the minimal fix for stable, I'll send cleanups later.

Commit 854a6ed568 ("signal: Add restore_user_sigmask()") introduced
the visible change which breaks user-space: a signal temporary unblocked
by set_user_sigmask() can be delivered even if the caller returns
success or timeout.

Change restore_user_sigmask() to accept the additional "interrupted"
argument which should be used instead of signal_pending() check, and
update the callers.

Eric said:

: For clarity.  I don't think this is required by posix, or fundamentally to
: remove the races in select.  It is what linux has always done and we have
: applications who care so I agree this fix is needed.
:
: Further in any case where the semantic change that this patch rolls back
: (aka where allowing a signal to be delivered and the select like call to
: complete) would be advantage we can do as well if not better by using
: signalfd.
:
: Michael is there any chance we can get this guarantee of the linux
: implementation of pselect and friends clearly documented.  The guarantee
: that if the system call completes successfully we are guaranteed that no
: signal that is unblocked by using sigmask will be delivered?

Link: http://lkml.kernel.org/r/20190604134117.GA29963@redhat.com
Fixes: 854a6ed568 ("signal: Add restore_user_sigmask()")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Eric Wong <e@80x24.org>
Tested-by: Eric Wong <e@80x24.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: <stable@vger.kernel.org>	[5.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-29 16:43:45 +08:00
Jens Axboe 87e5e6dab6 uio: make import_iovec()/compat_import_iovec() return bytes on success
Currently these functions return < 0 on error, and 0 for success.
Change that so that we return < 0 on error, but number of bytes
for success.

Some callers already treat the return value that way, others need a
slight tweak.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-31 15:30:03 -06:00
David Howells 52db59df17 vfs: Convert aio to use the new mount API
Convert the aio filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Benjamin LaHaise <bcrl@kvack.org>
cc: linux-aio@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-25 18:00:04 -04:00
Al Viro 1f58bb18f6 mount_pseudo(): drop 'name' argument, switch to d_make_root()
Once upon a time we used to set ->d_name of e.g. pipefs root
so that d_path() on pipes would work.  These days it's
completely pointless - dentries of pipes are not even connected
to pipefs root.  However, mount_pseudo() had set the root
dentry name (passed as the second argument) and callers
kept inventing names to pass to it.  Including those that
didn't *have* any non-root dentries to start with...

All of that had been pointless for about 8 years now; it's
time to get rid of that cargo-culting...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-25 17:59:24 -04:00
Wei Yongjun 6af1c849df aio: use kmem_cache_free() instead of kfree()
memory allocated by kmem_cache_alloc() should be freed using
kmem_cache_free(), not kfree().

Fixes: fa0ca2aee3 ("deal with get_reqs_available() in aio_get_req() itself")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-04 20:13:59 -04:00
Dan Carpenter 18bfb9c6a8 aio: Fix an error code in __io_submit_one()
This accidentally returns the wrong variable.  The "req->ki_eventfd"
pointer is NULL so this return success.

Fixes: 7316b49c2a ("aio: move sanity checks and request allocation to io_submit_one()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-03 12:47:36 -04:00
Al Viro 7316b49c2a aio: move sanity checks and request allocation to io_submit_one()
makes for somewhat cleaner control flow in __io_submit_one()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:32 -04:00
Al Viro fa0ca2aee3 deal with get_reqs_available() in aio_get_req() itself
simplifies the caller

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:31 -04:00
Al Viro 7425970347 aio: move dropping ->ki_eventfd into iocb_destroy()
no reason to duplicate that...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:30 -04:00
Al Viro 958c13ce14 make aio_read()/aio_write() return int
that ssize_t is a rudiment of earlier calling conventions; it's been
used only to pass 0 and -E... since last autumn.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:29 -04:00
Al Viro af5c72b1fc Fix aio_poll() races
aio_poll() has to cope with several unpleasant problems:
	* requests that might stay around indefinitely need to
be made visible for io_cancel(2); that must not be done to
a request already completed, though.
	* in cases when ->poll() has placed us on a waitqueue,
wakeup might have happened (and request completed) before ->poll()
returns.
	* worse, in some early wakeup cases request might end
up re-added into the queue later - we can't treat "woken up and
currently not in the queue" as "it's not going to stick around
indefinitely"
	* ... moreover, ->poll() might have decided not to
put it on any queues to start with, and that needs to be distinguished
from the previous case
	* ->poll() might have tried to put us on more than one queue.
Only the first will succeed for aio poll, so we might end up missing
wakeups.  OTOH, we might very well notice that only after the
wakeup hits and request gets completed (all before ->poll() gets
around to the second poll_wait()).  In that case it's too late to
decide that we have an error.

req->woken was an attempt to deal with that.  Unfortunately, it was
broken.  What we need to keep track of is not that wakeup has happened -
the thing might come back after that.  It's that async reference is
already gone and won't come back, so we can't (and needn't) put the
request on the list of cancellables.

The easiest case is "request hadn't been put on any waitqueues"; we
can tell by seeing NULL apt.head, and in that case there won't be
anything async.  We should either complete the request ourselves
(if vfs_poll() reports anything of interest) or return an error.

In all other cases we get exclusion with wakeups by grabbing the
queue lock.

If request is currently on queue and we have something interesting
from vfs_poll(), we can steal it and complete the request ourselves.

If it's on queue and vfs_poll() has not reported anything interesting,
we either put it on the cancellable list, or, if we know that it
hadn't been put on all queues ->poll() wanted it on, we steal it and
return an error.

If it's _not_ on queue, it's either been already dealt with (in which
case we do nothing), or there's aio_poll_complete_work() about to be
executed.  In that case we either put it on the cancellable list,
or, if we know it hadn't been put on all queues ->poll() wanted it on,
simulate what cancel would've done.

It's a lot more convoluted than I'd like it to be.  Single-consumer APIs
suck, and unfortunately aio is not an exception...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:28 -04:00
Al Viro 2bb874c0d8 aio: store event at final iocb_put()
Instead of having aio_complete() set ->ki_res.{res,res2}, do that
explicitly in its callers, drop the reference (as aio_complete()
used to do) and delay the rest until the final iocb_put().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:27 -04:00
Al Viro a9339b7855 aio: keep io_event in aio_kiocb
We want to separate forming the resulting io_event from putting it
into the ring buffer.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:26 -04:00
Al Viro 833f4154ed aio: fold lookup_kiocb() into its sole caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:25 -04:00
Linus Torvalds b53119f13a pin iocb through aio.
aio_poll() is not the only case that needs file pinned; worse, while
aio_read()/aio_write() can live without pinning iocb itself, the
proof is rather brittle and can easily break on later changes.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-17 20:52:24 -04:00
Linus Torvalds b1b988a6a0 Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull year 2038 updates from Thomas Gleixner:
 "Another round of changes to make the kernel ready for 2038. After lots
  of preparatory work this is the first set of syscalls which are 2038
  safe:

    403 clock_gettime64
    404 clock_settime64
    405 clock_adjtime64
    406 clock_getres_time64
    407 clock_nanosleep_time64
    408 timer_gettime64
    409 timer_settime64
    410 timerfd_gettime64
    411 timerfd_settime64
    412 utimensat_time64
    413 pselect6_time64
    414 ppoll_time64
    416 io_pgetevents_time64
    417 recvmmsg_time64
    418 mq_timedsend_time64
    419 mq_timedreceiv_time64
    420 semtimedop_time64
    421 rt_sigtimedwait_time64
    422 futex_time64
    423 sched_rr_get_interval_time64

  The syscall numbers are identical all over the architectures"

* 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  riscv: Use latest system call ABI
  checksyscalls: fix up mq_timedreceive and stat exceptions
  unicore32: Fix __ARCH_WANT_STAT64 definition
  asm-generic: Make time32 syscall numbers optional
  asm-generic: Drop getrlimit and setrlimit syscalls from default list
  32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option
  compat ABI: use non-compat openat and open_by_handle_at variants
  y2038: add 64-bit time_t syscalls to all 32-bit architectures
  y2038: rename old time and utime syscalls
  y2038: remove struct definition redirects
  y2038: use time32 syscall names on 32-bit
  syscalls: remove obsolete __IGNORE_ macros
  y2038: syscalls: rename y2038 compat syscalls
  x86/x32: use time64 versions of sigtimedwait and recvmmsg
  timex: change syscalls to use struct __kernel_timex
  timex: use __kernel_timex internally
  sparc64: add custom adjtimex/clock_adjtime functions
  time: fix sys_timer_settime prototype
  time: Add struct __kernel_timex
  time: make adjtime compat handling available for 32 bit
  ...
2019-03-05 14:08:26 -08:00
Linus Torvalds 4f9020ffde Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Assorted fixes that sat in -next for a while, all over the place"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: Fix locking in aio_poll()
  exec: Fix mem leak in kernel_read_file
  copy_mount_string: Limit string length to PATH_MAX
  cgroup: saner refcounting for cgroup_root
  fix cgroup_do_mount() handling of failure exits
2019-03-04 13:24:27 -08:00
Linus Torvalds 84c4e1f89f aio: simplify - and fix - fget/fput for io_submit()
Al Viro root-caused a race where the IOCB_CMD_POLL handling of
fget/fput() could cause us to access the file pointer after it had
already been freed:

 "In more details - normally IOCB_CMD_POLL handling looks so:

   1) io_submit(2) allocates aio_kiocb instance and passes it to
      aio_poll()

   2) aio_poll() resolves the descriptor to struct file by req->file =
      fget(iocb->aio_fildes)

   3) aio_poll() sets ->woken to false and raises ->ki_refcnt of that
      aio_kiocb to 2 (bumps by 1, that is).

   4) aio_poll() calls vfs_poll(). After sanity checks (basically,
      "poll_wait() had been called and only once") it locks the queue.
      That's what the extra reference to iocb had been for - we know we
      can safely access it.

   5) With queue locked, we check if ->woken has already been set to
      true (by aio_poll_wake()) and, if it had been, we unlock the
      queue, drop a reference to aio_kiocb and bugger off - at that
      point it's a responsibility to aio_poll_wake() and the stuff
      called/scheduled by it. That code will drop the reference to file
      in req->file, along with the other reference to our aio_kiocb.

   6) otherwise, we see whether we need to wait. If we do, we unlock the
      queue, drop one reference to aio_kiocb and go away - eventual
      wakeup (or cancel) will deal with the reference to file and with
      the other reference to aio_kiocb

   7) otherwise we remove ourselves from waitqueue (still under the
      queue lock), so that wakeup won't get us. No async activity will
      be happening, so we can safely drop req->file and iocb ourselves.

  If wakeup happens while we are in vfs_poll(), we are fine - aio_kiocb
  won't get freed under us, so we can do all the checks and locking
  safely. And we don't touch ->file if we detect that case.

  However, vfs_poll() most certainly *does* touch the file it had been
  given. So wakeup coming while we are still in ->poll() might end up
  doing fput() on that file. That case is not too rare, and usually we
  are saved by the still present reference from descriptor table - that
  fput() is not the final one.

  But if another thread closes that descriptor right after our fget()
  and wakeup does happen before ->poll() returns, we are in trouble -
  final fput() done while we are in the middle of a method:

Al also wrote a patch to take an extra reference to the file descriptor
to fix this, but I instead suggested we just streamline the whole file
pointer handling by submit_io() so that the generic aio submission code
simply keeps the file pointer around until the aio has completed.

Fixes: bfe4037e72 ("aio: implement IOCB_CMD_POLL")
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: syzbot+503d4cc169fcec1cb18c@syzkaller.appspotmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-04 10:32:48 -08:00
Bart Van Assche d3d6a18d7d aio: Fix locking in aio_poll()
wake_up_locked() may but does not have to be called with interrupts
disabled. Since the fuse filesystem calls wake_up_locked() without
disabling interrupts aio_poll_wake() may be called with interrupts
enabled. Since the kioctx.ctx_lock may be acquired from IRQ context,
all code that acquires that lock from thread context must disable
interrupts. Hence change the spin_trylock() call in aio_poll_wake()
into a spin_trylock_irqsave() call. This patch fixes the following
lockdep complaint:

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.0.0-rc4-next-20190131 #23 Not tainted
-----------------------------------------------------
syz-executor2/13779 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
0000000098ac1230 (&fiq->waitq){+.+.}, at: spin_lock include/linux/spinlock.h:329 [inline]
0000000098ac1230 (&fiq->waitq){+.+.}, at: aio_poll fs/aio.c:1772 [inline]
0000000098ac1230 (&fiq->waitq){+.+.}, at: __io_submit_one fs/aio.c:1875 [inline]
0000000098ac1230 (&fiq->waitq){+.+.}, at: io_submit_one+0xedf/0x1cf0 fs/aio.c:1908

and this task is already holding:
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline]
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1771 [inline]
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1875 [inline]
000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb6/0x1cf0 fs/aio.c:1908
which would create a new lock dependency:
 (&(&ctx->ctx_lock)->rlock){..-.} -> (&fiq->waitq){+.+.}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&(&ctx->ctx_lock)->rlock){..-.}

... which became SOFTIRQ-irq-safe at:
  lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
  __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
  _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
  spin_lock_irq include/linux/spinlock.h:354 [inline]
  free_ioctx_users+0x2d/0x4a0 fs/aio.c:610
  percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline]
  percpu_ref_put include/linux/percpu-refcount.h:301 [inline]
  percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline]
  percpu_ref_switch_to_atomic_rcu+0x3e7/0x520 lib/percpu-refcount.c:158
  __rcu_reclaim kernel/rcu/rcu.h:240 [inline]
  rcu_do_batch kernel/rcu/tree.c:2486 [inline]
  invoke_rcu_callbacks kernel/rcu/tree.c:2799 [inline]
  rcu_core+0x928/0x1390 kernel/rcu/tree.c:2780
  __do_softirq+0x266/0x95a kernel/softirq.c:292
  run_ksoftirqd kernel/softirq.c:654 [inline]
  run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646
  smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164
  kthread+0x357/0x430 kernel/kthread.c:247
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

to a SOFTIRQ-irq-unsafe lock:
 (&fiq->waitq){+.+.}

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
  __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
  _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
  spin_lock include/linux/spinlock.h:329 [inline]
  flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
  fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
  fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
  fuse_send_init fs/fuse/inode.c:989 [inline]
  fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
  mount_nodev+0x68/0x110 fs/super.c:1392
  fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
  legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
  vfs_get_tree+0x123/0x450 fs/super.c:1481
  do_new_mount fs/namespace.c:2610 [inline]
  do_mount+0x1436/0x2c40 fs/namespace.c:2932
  ksys_mount+0xdb/0x150 fs/namespace.c:3148
  __do_sys_mount fs/namespace.c:3162 [inline]
  __se_sys_mount fs/namespace.c:3159 [inline]
  __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
  do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&fiq->waitq);
                               local_irq_disable();
                               lock(&(&ctx->ctx_lock)->rlock);
                               lock(&fiq->waitq);
  <Interrupt>
    lock(&(&ctx->ctx_lock)->rlock);

 *** DEADLOCK ***

1 lock held by syz-executor2/13779:
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline]
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll fs/aio.c:1771 [inline]
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: __io_submit_one fs/aio.c:1875 [inline]
 #0: 000000003c46111c (&(&ctx->ctx_lock)->rlock){..-.}, at: io_submit_one+0xeb6/0x1cf0 fs/aio.c:1908

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&(&ctx->ctx_lock)->rlock){..-.} {
   IN-SOFTIRQ-W at:
                    lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                    __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
                    _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
                    spin_lock_irq include/linux/spinlock.h:354 [inline]
                    free_ioctx_users+0x2d/0x4a0 fs/aio.c:610
                    percpu_ref_put_many include/linux/percpu-refcount.h:285 [inline]
                    percpu_ref_put include/linux/percpu-refcount.h:301 [inline]
                    percpu_ref_call_confirm_rcu lib/percpu-refcount.c:123 [inline]
                    percpu_ref_switch_to_atomic_rcu+0x3e7/0x520 lib/percpu-refcount.c:158
                    __rcu_reclaim kernel/rcu/rcu.h:240 [inline]
                    rcu_do_batch kernel/rcu/tree.c:2486 [inline]
                    invoke_rcu_callbacks kernel/rcu/tree.c:2799 [inline]
                    rcu_core+0x928/0x1390 kernel/rcu/tree.c:2780
                    __do_softirq+0x266/0x95a kernel/softirq.c:292
                    run_ksoftirqd kernel/softirq.c:654 [inline]
                    run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646
                    smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164
                    kthread+0x357/0x430 kernel/kthread.c:247
                    ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
   INITIAL USE at:
                   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                   __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
                   _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:160
                   spin_lock_irq include/linux/spinlock.h:354 [inline]
                   __do_sys_io_cancel fs/aio.c:2052 [inline]
                   __se_sys_io_cancel fs/aio.c:2035 [inline]
                   __x64_sys_io_cancel+0xd5/0x5a0 fs/aio.c:2035
                   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                   entry_SYSCALL_64_after_hwframe+0x49/0xbe
 }
 ... key      at: [<ffffffff8a574140>] __key.52370+0x0/0x40
 ... acquired at:
   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
   _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
   spin_lock include/linux/spinlock.h:329 [inline]
   aio_poll fs/aio.c:1772 [inline]
   __io_submit_one fs/aio.c:1875 [inline]
   io_submit_one+0xedf/0x1cf0 fs/aio.c:1908
   __do_sys_io_submit fs/aio.c:1953 [inline]
   __se_sys_io_submit fs/aio.c:1923 [inline]
   __x64_sys_io_submit+0x1bd/0x580 fs/aio.c:1923
   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
-> (&fiq->waitq){+.+.} {
   HARDIRQ-ON-W at:
                    lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
                    spin_lock include/linux/spinlock.h:329 [inline]
                    flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
                    fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
                    fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
                    fuse_send_init fs/fuse/inode.c:989 [inline]
                    fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
                    mount_nodev+0x68/0x110 fs/super.c:1392
                    fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
                    legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
                    vfs_get_tree+0x123/0x450 fs/super.c:1481
                    do_new_mount fs/namespace.c:2610 [inline]
                    do_mount+0x1436/0x2c40 fs/namespace.c:2932
                    ksys_mount+0xdb/0x150 fs/namespace.c:3148
                    __do_sys_mount fs/namespace.c:3162 [inline]
                    __se_sys_mount fs/namespace.c:3159 [inline]
                    __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
                    do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                    entry_SYSCALL_64_after_hwframe+0x49/0xbe
   SOFTIRQ-ON-W at:
                    lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
                    spin_lock include/linux/spinlock.h:329 [inline]
                    flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
                    fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
                    fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
                    fuse_send_init fs/fuse/inode.c:989 [inline]
                    fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
                    mount_nodev+0x68/0x110 fs/super.c:1392
                    fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
                    legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
                    vfs_get_tree+0x123/0x450 fs/super.c:1481
                    do_new_mount fs/namespace.c:2610 [inline]
                    do_mount+0x1436/0x2c40 fs/namespace.c:2932
                    ksys_mount+0xdb/0x150 fs/namespace.c:3148
                    __do_sys_mount fs/namespace.c:3162 [inline]
                    __se_sys_mount fs/namespace.c:3159 [inline]
                    __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
                    do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                    entry_SYSCALL_64_after_hwframe+0x49/0xbe
   INITIAL USE at:
                   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
                   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                   _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
                   spin_lock include/linux/spinlock.h:329 [inline]
                   flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415
                   fuse_request_queue_background+0x2d1/0x580 fs/fuse/dev.c:676
                   fuse_request_send_background+0x58/0x120 fs/fuse/dev.c:687
                   fuse_send_init fs/fuse/inode.c:989 [inline]
                   fuse_fill_super+0x13bb/0x1730 fs/fuse/inode.c:1214
                   mount_nodev+0x68/0x110 fs/super.c:1392
                   fuse_mount+0x2d/0x40 fs/fuse/inode.c:1239
                   legacy_get_tree+0xf2/0x200 fs/fs_context.c:590
                   vfs_get_tree+0x123/0x450 fs/super.c:1481
                   do_new_mount fs/namespace.c:2610 [inline]
                   do_mount+0x1436/0x2c40 fs/namespace.c:2932
                   ksys_mount+0xdb/0x150 fs/namespace.c:3148
                   __do_sys_mount fs/namespace.c:3162 [inline]
                   __se_sys_mount fs/namespace.c:3159 [inline]
                   __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159
                   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
                   entry_SYSCALL_64_after_hwframe+0x49/0xbe
 }
 ... key      at: [<ffffffff8a60dec0>] __key.43450+0x0/0x40
 ... acquired at:
   lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
   _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
   spin_lock include/linux/spinlock.h:329 [inline]
   aio_poll fs/aio.c:1772 [inline]
   __io_submit_one fs/aio.c:1875 [inline]
   io_submit_one+0xedf/0x1cf0 fs/aio.c:1908
   __do_sys_io_submit fs/aio.c:1953 [inline]
   __se_sys_io_submit fs/aio.c:1923 [inline]
   __x64_sys_io_submit+0x1bd/0x580 fs/aio.c:1923
   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

stack backtrace:
CPU: 0 PID: 13779 Comm: syz-executor2 Not tainted 5.0.0-rc4-next-20190131 #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_bad_irq_dependency kernel/locking/lockdep.c:1573 [inline]
 check_usage.cold+0x60f/0x940 kernel/locking/lockdep.c:1605
 check_irq_usage kernel/locking/lockdep.c:1650 [inline]
 check_prev_add_irq kernel/locking/lockdep_states.h:8 [inline]
 check_prev_add kernel/locking/lockdep.c:1860 [inline]
 check_prevs_add kernel/locking/lockdep.c:1968 [inline]
 validate_chain kernel/locking/lockdep.c:2339 [inline]
 __lock_acquire+0x1f12/0x4790 kernel/locking/lockdep.c:3320
 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3826
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:329 [inline]
 aio_poll fs/aio.c:1772 [inline]
 __io_submit_one fs/aio.c:1875 [inline]
 io_submit_one+0xedf/0x1cf0 fs/aio.c:1908
 __do_sys_io_submit fs/aio.c:1953 [inline]
 __se_sys_io_submit fs/aio.c:1923 [inline]
 __x64_sys_io_submit+0x1bd/0x580 fs/aio.c:1923
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>
Fixes: e8693bcfa0 ("aio: allow direct aio poll comletions for keyed wakeups") # v4.19
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
[ bvanassche: added a comment ]
Reluctantly-Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-21 22:16:47 -05:00
Arnd Bergmann 8dabe7245b y2038: syscalls: rename y2038 compat syscalls
A lot of system calls that pass a time_t somewhere have an implementation
using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have
been reworked so that this implementation can now be used on 32-bit
architectures as well.

The missing step is to redefine them using the regular SYSCALL_DEFINEx()
to get them out of the compat namespace and make it possible to build them
on 32-bit architectures.

Any system call that ends in 'time' gets a '32' suffix on its name for
that version, while the others get a '_time32' suffix, to distinguish
them from the normal version, which takes a 64-bit time argument in the
future.

In this step, only 64-bit architectures are changed, doing this rename
first lets us avoid touching the 32-bit architectures twice.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-07 00:13:27 +01:00
Mike Marshall ec51f8ee1e aio: initialize kiocb private in case any filesystems expect it.
A recent optimization had left private uninitialized.

Fixes: 2bc4ca9bb6 ("aio: don't zero entire aio_kiocb aio_get_req()")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-06 08:04:22 -07:00
Linus Torvalds f346b0becb Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - large KASAN update to use arm's "software tag-based mode"

 - a few misc things

 - sh updates

 - ocfs2 updates

 - just about all of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (167 commits)
  kernel/fork.c: mark 'stack_vm_area' with __maybe_unused
  memcg, oom: notify on oom killer invocation from the charge path
  mm, swap: fix swapoff with KSM pages
  include/linux/gfp.h: fix typo
  mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
  hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race
  hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization
  memory_hotplug: add missing newlines to debugging output
  mm: remove __hugepage_set_anon_rmap()
  include/linux/vmstat.h: remove unused page state adjustment macro
  mm/page_alloc.c: allow error injection
  mm: migrate: drop unused argument of migrate_page_move_mapping()
  blkdev: avoid migration stalls for blkdev pages
  mm: migrate: provide buffer_migrate_page_norefs()
  mm: migrate: move migrate_page_lock_buffers()
  mm: migrate: lock buffers before migrate_page_move_mapping()
  mm: migration: factor out code to compute expected number of page references
  mm, page_alloc: enable pcpu_drain with zone capability
  kmemleak: add config to select auto scan
  mm/page_alloc.c: don't call kasan_free_pages() at deferred mem init
  ...
2018-12-28 16:55:46 -08:00
Linus Torvalds 956eb6cb36 for-4.21/aio-20181221
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Merge tag 'for-4.21/aio-20181221' of git://git.kernel.dk/linux-block

Pull aio updates from Jens Axboe:
 "Flushing out pre-patches for the buffered/polled aio series. Some
  fixes in here, but also optimizations"

* tag 'for-4.21/aio-20181221' of git://git.kernel.dk/linux-block:
  aio: abstract out io_event filler helper
  aio: split out iocb copy from io_submit_one()
  aio: use iocb_put() instead of open coding it
  aio: only use blk plugs for > 2 depth submissions
  aio: don't zero entire aio_kiocb aio_get_req()
  aio: separate out ring reservation from req allocation
  aio: use assigned completion handler
2018-12-28 13:57:59 -08:00
Linus Torvalds 0e9da3fbf7 for-4.21/block-20181221
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Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "This is the main pull request for block/storage for 4.21.

  Larger than usual, it was a busy round with lots of goodies queued up.
  Most notable is the removal of the old IO stack, which has been a long
  time coming. No new features for a while, everything coming in this
  week has all been fixes for things that were previously merged.

  This contains:

   - Use atomic counters instead of semaphores for mtip32xx (Arnd)

   - Cleanup of the mtip32xx request setup (Christoph)

   - Fix for circular locking dependency in loop (Jan, Tetsuo)

   - bcache (Coly, Guoju, Shenghui)
      * Optimizations for writeback caching
      * Various fixes and improvements

   - nvme (Chaitanya, Christoph, Sagi, Jay, me, Keith)
      * host and target support for NVMe over TCP
      * Error log page support
      * Support for separate read/write/poll queues
      * Much improved polling
      * discard OOM fallback
      * Tracepoint improvements

   - lightnvm (Hans, Hua, Igor, Matias, Javier)
      * Igor added packed metadata to pblk. Now drives without metadata
        per LBA can be used as well.
      * Fix from Geert on uninitialized value on chunk metadata reads.
      * Fixes from Hans and Javier to pblk recovery and write path.
      * Fix from Hua Su to fix a race condition in the pblk recovery
        code.
      * Scan optimization added to pblk recovery from Zhoujie.
      * Small geometry cleanup from me.

   - Conversion of the last few drivers that used the legacy path to
     blk-mq (me)

   - Removal of legacy IO path in SCSI (me, Christoph)

   - Removal of legacy IO stack and schedulers (me)

   - Support for much better polling, now without interrupts at all.
     blk-mq adds support for multiple queue maps, which enables us to
     have a map per type. This in turn enables nvme to have separate
     completion queues for polling, which can then be interrupt-less.
     Also means we're ready for async polled IO, which is hopefully
     coming in the next release.

   - Killing of (now) unused block exports (Christoph)

   - Unification of the blk-rq-qos and blk-wbt wait handling (Josef)

   - Support for zoned testing with null_blk (Masato)

   - sx8 conversion to per-host tag sets (Christoph)

   - IO priority improvements (Damien)

   - mq-deadline zoned fix (Damien)

   - Ref count blkcg series (Dennis)

   - Lots of blk-mq improvements and speedups (me)

   - sbitmap scalability improvements (me)

   - Make core inflight IO accounting per-cpu (Mikulas)

   - Export timeout setting in sysfs (Weiping)

   - Cleanup the direct issue path (Jianchao)

   - Export blk-wbt internals in block debugfs for easier debugging
     (Ming)

   - Lots of other fixes and improvements"

* tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block: (364 commits)
  kyber: use sbitmap add_wait_queue/list_del wait helpers
  sbitmap: add helpers for add/del wait queue handling
  block: save irq state in blkg_lookup_create()
  dm: don't reuse bio for flushes
  nvme-pci: trace SQ status on completions
  nvme-rdma: implement polling queue map
  nvme-fabrics: allow user to pass in nr_poll_queues
  nvme-fabrics: allow nvmf_connect_io_queue to poll
  nvme-core: optionally poll sync commands
  block: make request_to_qc_t public
  nvme-tcp: fix spelling mistake "attepmpt" -> "attempt"
  nvme-tcp: fix endianess annotations
  nvmet-tcp: fix endianess annotations
  nvme-pci: refactor nvme_poll_irqdisable to make sparse happy
  nvme-pci: only set nr_maps to 2 if poll queues are supported
  nvmet: use a macro for default error location
  nvmet: fix comparison of a u16 with -1
  blk-mq: enable IO poll if .nr_queues of type poll > 0
  blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()
  blk-mq: skip zero-queue maps in blk_mq_map_swqueue
  ...
2018-12-28 13:19:59 -08:00