Remove unused variable "i", which was triggering a compiler warning.

Fixes: 29750f71 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-By: Mina Almasry <almasrymina@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200517001245.361762-2-jhubbard@nvidia.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add mremap_dontunmap to .gitignore.

Fixes: 0c28759e ("selftests: add MREMAP_DONTUNMAP selftest")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Brian Geffon <bgeffon@google.com>
Link: http://lkml.kernel.org/r/20200517002509.362401-2-jhubbard@nvidia.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In the case of get_user_pages_fast() returning fewer pages than
requested, rio_dma_transfer() does not quite do the right thing.  It
attempts to release all the pages that were requested, rather than just
the pages that were pinned.

Fix the error handling so that only the pages that were successfully
pinned are released.

Fixes: e8de3701 ("rapidio: add mport char device driver")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200517235620.205225-2-jhubbard@nvidia.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is easily reproducible via CC=clang + CONFIG_STAGING=y +
CONFIG_VT6656=m.

It turns out that if your config tickles __builtin_constant_p via
differences in choices to inline or not, these statements produce
invalid assembly:

    $ cat foo.c
    long a(long b, long c) {
      asm("orb	%1, %0" : "+q"(c): "r"(b));
      return c;
    }
    $ gcc foo.c
    foo.c: Assembler messages:
    foo.c:2: Error: `%rax' not allowed with `orb'

Use the `%b` "x86 Operand Modifier" to instead force register allocation
to select a lower-8-bit GPR operand.

The "q" constraint only has meaning on -m32 otherwise is treated as
"r".  Not all GPRs have low-8-bit aliases for -m32.

Fixes: 1651e700 ("x86: Fix bitops.h warning with a moved cast")
Reported-by: kernelci.org bot <bot@kernelci.org>
Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Suggested-by: Brian Gerst <brgerst@gmail.com>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>	[build, clang-11]
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-By: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Marco Elver <elver@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20200508183230.229464-1-ndesaulniers@google.com
Link: https://github.com/ClangBuiltLinux/linux/issues/961
Link: https://lore.kernel.org/lkml/20200504193524.GA221287@google.com/
Link: https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#x86OperandmodifiersSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Assume we have kmem configured and loaded:

  [root@localhost ~]# cat /proc/iomem
  ...
  140000000-33fffffff : Persistent Memory$
    140000000-1481fffff : namespace0.0
    150000000-33fffffff : dax0.0
      150000000-33fffffff : System RAM

Assume we try to unload kmem. This force-unloading will work, even if
memory cannot get removed from the system.

  [root@localhost ~]# rmmod kmem
  [   86.380228] removing memory fails, because memory [0x0000000150000000-0x0000000157ffffff] is onlined
  ...
  [   86.431225] kmem dax0.0: DAX region [mem 0x150000000-0x33fffffff] cannot be hotremoved until the next reboot

Now, we can reconfigure the namespace:

  [root@localhost ~]# ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax
  [  131.409351] nd_pmem namespace0.0: could not reserve region [mem 0x140000000-0x33fffffff]dax
  [  131.410147] nd_pmem: probe of namespace0.0 failed with error -16namespace0.0 --mode=devdax
  ...

This fails as expected due to the busy memory resource, and the memory
cannot be used.  However, the dax0.0 device is removed, and along its
name.

The name of the memory resource now points at freed memory (name of the
device):

  [root@localhost ~]# cat /proc/iomem
  ...
  140000000-33fffffff : Persistent Memory
    140000000-1481fffff : namespace0.0
    150000000-33fffffff : �_�^7_��/_��wR��WQ���^��� ...
    150000000-33fffffff : System RAM

We have to make sure to duplicate the string.  While at it, remove the
superfluous setting of the name and fixup a stale comment.

Fixes: 9f960da7 ("device-dax: "Hotremove" persistent memory that is used like normal RAM")
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>	[5.3]
Link: http://lkml.kernel.org/r/20200508084217.9160-2-david@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull io_uring fixes from Jens Axboe:
 "A small collection of small fixes that should go into this release:

   - Two fixes for async request preparation (Pavel)

   - Busy clear fix for SQPOLL (Xiaoguang)

   - Don't use kiocb->private for O_DIRECT buf index, some file systems
     use it (Bijan)

   - Kill dead check in io_splice()

   - Ensure sqo_wait is initialized early

   - Cancel task_work if we fail adding to original process

   - Only add (IO)pollable requests to iopoll list, fixing a regression
     in this merge window"

* tag 'io_uring-5.7-2020-05-22' of git://git.kernel.dk/linux-block:
  io_uring: reset -EBUSY error when io sq thread is waken up
  io_uring: don't add non-IO requests to iopoll pending list
  io_uring: don't use kiocb.private to store buf_index
  io_uring: cancel work if task_work_add() fails
  io_uring: remove dead check in io_splice()
  io_uring: fix FORCE_ASYNC req preparation
  io_uring: don't prepare DRAIN reqs twice
  io_uring: initialize ctx->sqo_wait earlier

Pull block fixes from Jens Axboe:
 "Two fixes for null_blk zone mode"

* tag 'block-5.7-2020-05-22' of git://git.kernel.dk/linux-block:
  null_blk: don't allow discard for zoned mode
  null_blk: return error for invalid zone size

Pull RISC-V fixes from Palmer Dabbelt:
 "Two fixes:

   - Another !MMU build fix that was a straggler from last week

   - A fix to use the "register" keyword for the GP global register
     variable"

* tag 'riscv-for-linus-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: gp_in_global needs register keyword
  riscv: Fix print_vm_layout build error if NOMMU

Pull arm64 fixes from Catalin Marinas:

 - Bring the PTRACE_SYSEMU semantics in line with the man page.

 - Annotate variable assignment in get_user() with the type to avoid
   sparse warnings.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Add get_user() type annotation on the !access_ok() path
  arm64: Fix PTRACE_SYSEMU semantics

Pull sound fixes from Takashi Iwai:
 "Just a few small fixes: the only significant one is a slight
  improvement for PCM running position update with no-period-elapsed
  case while the rest are HD-audio fixups and ice1712 model quirk"

* tag 'sound-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Add more fixup entries for Clevo machines
  ALSA: iec1712: Initialize STDSP24 properly when using the model=staudio option
  ALSA: hda/realtek - Fix silent output on Gigabyte X570 Aorus Xtreme
  ALSA: pcm: fix incorrect hw_base increase

Sparse reports "Using plain integer as NULL pointer" when the arm64
__get_user_error() assigns 0 to a pointer type. Use proper type
annotation.
Signed-of-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: kbuild test robot <lkp@intel.com>
Link: http://lkml.kernel.org/r/20200522142321.GP23230@ZenIV.linux.org.ukSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pull powerpc fixes from Michael Ellerman:

 - a revert of a recent change to the PTE bits for 32-bit BookS, which
   broke swap.

 - a "fix" to disable STRICT_KERNEL_RWX for 64-bit in Kconfig, as it's
   causing crashes for some people.

Thanks to Christophe Leroy and Rui Salvaterra.

* tag 'powerpc-5.7-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Disable STRICT_KERNEL_RWX
  Revert "powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits."

Merge tag 'apparmor-pr-2020-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor bug fixes from John Johansen:

 - Fix use-after-free in aa_audit_rule_init

 - Fix refcnt leak in policy_update

 - Fix potential label refcnt leak in aa_change_profile

* tag 'apparmor-pr-2020-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: Fix use-after-free in aa_audit_rule_init
  apparmor: Fix aa_label refcnt leak in policy_update
  apparmor: fix potential label refcnt leak in aa_change_profile

As Ubuntu and Fedora release new version used kernel version equal to or
higher than v5.4, They started to support kernel exfat filesystem.

Linus reported a mount error with new version of exfat on Fedora:

        exfat: Unknown parameter 'namecase'

This is because there is a difference in mount option between old
staging/exfat and new exfat.  And utf8, debug, and codepage options as
well as namecase have been removed from new exfat.

This patch add the dummy mount options as deprecated option to be
backward compatible with old one.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In the implementation of aa_audit_rule_init(), when aa_label_parse()
fails the allocated memory for rule is released using
aa_audit_rule_free(). But after this release, the return statement
tries to access the label field of the rule which results in
use-after-free. Before releasing the rule, copy errNo and return it
after release.

Fixes: 52e8c380 ("apparmor: Fix memory leak of rule on error exit path")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

policy_update() invokes begin_current_label_crit_section(), which
returns a reference of the updated aa_label object to "label" with
increased refcount.

When policy_update() returns, "label" becomes invalid, so the refcount
should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
policy_update(). When aa_may_manage_policy() returns not NULL, the
refcnt increased by begin_current_label_crit_section() is not decreased,
causing a refcnt leak.

Fix this issue by jumping to "end_section" label when
aa_may_manage_policy() returns not NULL.

Fixes: 5ac8c355 ("apparmor: allow introspecting the loaded policy pre internal transform")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

aa_change_profile() invokes aa_get_current_label(), which returns
a reference of the current task's label.

According to the comment of aa_get_current_label(), the returned
reference must be put with aa_put_label().
However, when the original object pointed by "label" becomes
unreachable because aa_change_profile() returns or a new object
is assigned to "label", reference count increased by
aa_get_current_label() is not decreased, causing a refcnt leak.

Fix this by calling aa_put_label() before aa_change_profile() return
and dropping unnecessary aa_get_current_label().

Fixes: 9fcf78cc ("apparmor: update domain transitions that are subsets of confinement at nnp")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

The Intel kernel build robot recently pointed out that I missed the
register keyword on this one when I refactored the code to remove local
register variables (which aren't supported by LLVM).  GCC's manual
indicates that global register variables must have the register keyword,
As far as I can tell lacking the register keyword causes GCC to ignore
the __asm__ and treat this as a regular variable, but I'm not sure how
that didn't show up as some sort of failure.

Fixes: 52e7c52d ("RISC-V: Stop relying on GCC's register allocator's hueristics")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Pull virtio fixes from Michael Tsirkin:
 "Fix a couple of build warnings"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: missing __user tags
  vdpasim: remove unused variable 'ret'

Pull dmaengine fixes from Vinod Koul:
 "Some driver fixes:

   - dmatest restoration of defaults

   - tegra210-adma probe handling fix

   - k3-udma flags fixed for slave_sg and memcpy

   - list fix for zynqmp_dma

   - idxd interrupt completion fix

   - lock fix for owl"

* tag 'dmaengine-fix-5.7-rc7' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: tegra210-adma: Fix an error handling path in 'tegra_adma_probe()'
  dmaengine: ti: k3-udma: Fix TR mode flags for slave_sg and memcpy
  dmaengine: zynqmp_dma: Move list_del inside zynqmp_dma_free_descriptor.
  dmaengine: dmatest: Restore default for channel
  dmaengine: idxd: fix interrupt completion after unmasking
  dmaengine: owl: Use correct lock in owl_dma_get_pchan()

Pull ext4 fixes from Ted Ts'o:
 "Fix regression in ext4's FIEMAP handling introduced in v5.7-rc1"

* tag 'fiemap-regression-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix fiemap size checks for bitmap files
  ext4: fix EXT4_MAX_LOGICAL_BLOCK macro

Zoned block device specification do not define the behavior of
discard/trim command as this command is generally replaced by the reset
write pointer (zone reset) command. Emulate this in null_blk by making
zoned and discard options mutually exclusive.
Suggested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In null_init_zone_dev() check if the zone size is larger than device
capacity, return error if needed.

This also fixes the following oops :-

null_blk: changed the number of conventional zones to 4294967295
BUG: kernel NULL pointer dereference, address: 0000000000000010
PGD 7d76c5067 P4D 7d76c5067 PUD 7d240c067 PMD 0
Oops: 0002 [#1] SMP NOPTI
CPU: 4 PID: 5508 Comm: nullbtests.sh Tainted: G OE 5.7.0-rc4lblk-fnext0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e4
RIP: 0010:null_init_zoned_dev+0x17a/0x27f [null_blk]
RSP: 0018:ffffc90007007e00 EFLAGS: 00010246
RAX: 0000000000000020 RBX: ffff8887fb3f3c00 RCX: 0000000000000007
RDX: 0000000000000000 RSI: ffff8887ca09d688 RDI: ffff888810fea510
RBP: 0000000000000010 R08: ffff8887ca09d688 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8887c26e8000
R13: ffffffffa05e9390 R14: 0000000000000000 R15: 0000000000000001
FS:  00007fcb5256f740(0000) GS:ffff888810e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000081e8fe000 CR4: 00000000003406e0
Call Trace:
 null_add_dev+0x534/0x71b [null_blk]
 nullb_device_power_store.cold.41+0x8/0x2e [null_blk]
 configfs_write_file+0xe6/0x150
 vfs_write+0xba/0x1e0
 ksys_write+0x5f/0xe0
 do_syscall_64+0x60/0x250
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7fcb51c71840
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Several strange crashes have been eventually traced back to
STRICT_KERNEL_RWX and its interaction with code patching.

Various paths in our ftrace, kprobes and other patching code need to
be hardened against patching failures, otherwise we can end up running
with partially/incorrectly patched ftrace paths, kprobes or jump
labels, which can then cause strange crashes.

Although fixes for those are in development, they're not -rc material.

There also seem to be problems with the underlying strict RWX logic,
which needs further debugging.

So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from
enabling the option and tripping over the bugs.

Fixes: 1e0fc9d1 ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au

arch/riscv/mm/init.c: In function ‘print_vm_layout’:
arch/riscv/mm/init.c:68:37: error: ‘FIXADDR_START’ undeclared (first use in this function);
arch/riscv/mm/init.c:69:20: error: ‘FIXADDR_TOP’ undeclared
arch/riscv/mm/init.c:70:37: error: ‘PCI_IO_START’ undeclared
arch/riscv/mm/init.c:71:20: error: ‘PCI_IO_END’ undeclared
arch/riscv/mm/init.c:72:38: error: ‘VMEMMAP_START’ undeclared
arch/riscv/mm/init.c:73:20: error: ‘VMEMMAP_END’ undeclared (first use in this function);
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Pull MTD fixes from Richard Weinberger:

 - Fix a PM regression in brcmnand driver

 - Propagate ECC information correctly on SPI-NAND

 - Make sure no MTD name is used multiple time in nvmem

* tag 'fixes-for-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd:rawnand: brcmnand: Fix PM resume crash
  mtd: Fix mtd not registered due to nvmem name collision
  mtd: spinand: Propagate ECC information to the MTD structure

Pull UBI and UBIFS fixes from Richard Weinberger:

 - Correctly set next cursor for detailed_erase_block_info debugfs file

 - Don't use crypto_shash_descsize() for digest size in UBIFS

 - Remove broken lazytime support from UBIFS

* tag 'for-linus-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubi: Fix seq_file usage in detailed_erase_block_info debugfs file
  ubifs: fix wrong use of crypto_shash_descsize()
  ubifs: remove broken lazytime support

Pull UML fixes from Richard Weinberger:

 - Two missing includes which caused build issues on recent systems

 - Correctly set TRANS_GRE_LEN in our vector network driver

* tag 'for-linus-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Fix typo in vector driver transport option definition
  um: syscall.c: include <asm/unistd.h>
  um: Fix xor.h include

Pull power management fix from Rafael Wysocki:
 "This makes a recently introduced suspend-to-idle wakeup issue on Dell
  XPS13 9360 go away"

* tag 'pm-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: EC: PM: Avoid flushing EC work when EC GPE is inactive

Pull overlayfs fixes from Miklos Szeredi:
 "Fix two bugs introduced in this cycle and one introduced in v5.5"

* tag 'ovl-fixes-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: potential crash in ovl_fid_to_fh()
  ovl: clear ATTR_OPEN from attr->ia_valid
  ovl: clear ATTR_FILE from attr->ia_valid

syzbot is reporting that splice()ing from non-empty read side to
already-full write side causes unkillable task, for opipe_prep() is by
error not inverting pipe_full() test.

  CPU: 0 PID: 9460 Comm: syz-executor.5 Not tainted 5.6.0-rc3-next-20200228-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:rol32 include/linux/bitops.h:105 [inline]
  RIP: 0010:iterate_chain_key kernel/locking/lockdep.c:369 [inline]
  RIP: 0010:__lock_acquire+0x6a3/0x5270 kernel/locking/lockdep.c:4178
  Call Trace:
     lock_acquire+0x197/0x420 kernel/locking/lockdep.c:4720
     __mutex_lock_common kernel/locking/mutex.c:956 [inline]
     __mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
     pipe_lock_nested fs/pipe.c:66 [inline]
     pipe_double_lock+0x1a0/0x1e0 fs/pipe.c:104
     splice_pipe_to_pipe fs/splice.c:1562 [inline]
     do_splice+0x35f/0x1520 fs/splice.c:1141
     __do_sys_splice fs/splice.c:1447 [inline]
     __se_sys_splice fs/splice.c:1427 [inline]
     __x64_sys_splice+0x2b5/0x320 fs/splice.c:1427
     do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:295
     entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: syzbot+b48daca8639150bc5e73@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=9386d051e11e09973d5a4cf79af5e8cedf79386d
Fixes: 8cefc107 ("pipe: Use head and tail pointers for the ring, not cursor and length")
Cc: stable@vger.kernel.org # 5.5+
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In io_sq_thread(), currently if we get an -EBUSY error and go to sleep,
we will won't clear it again, which will result in io_sq_thread() will
never have a chance to submit sqes again. Below test program test.c
can reveal this bug:

int main(int argc, char *argv[])
{
        struct io_uring ring;
        int i, fd, ret;
        struct io_uring_sqe *sqe;
        struct io_uring_cqe *cqe;
        struct iovec *iovecs;
        void *buf;
        struct io_uring_params p;

        if (argc < 2) {
                printf("%s: file\n", argv[0]);
                return 1;
        }

        memset(&p, 0, sizeof(p));
        p.flags = IORING_SETUP_SQPOLL;
        ret = io_uring_queue_init_params(4, &ring, &p);
        if (ret < 0) {
                fprintf(stderr, "queue_init: %s\n", strerror(-ret));
                return 1;
        }

        fd = open(argv[1], O_RDONLY | O_DIRECT);
        if (fd < 0) {
                perror("open");
                return 1;
        }

        iovecs = calloc(10, sizeof(struct iovec));
        for (i = 0; i < 10; i++) {
                if (posix_memalign(&buf, 4096, 4096))
                        return 1;
                iovecs[i].iov_base = buf;
                iovecs[i].iov_len = 4096;
        }

        ret = io_uring_register_files(&ring, &fd, 1);
        if (ret < 0) {
                fprintf(stderr, "%s: register %d\n", __FUNCTION__, ret);
                return ret;
        }

        for (i = 0; i < 10; i++) {
                sqe = io_uring_get_sqe(&ring);
                if (!sqe)
                        break;

                io_uring_prep_readv(sqe, 0, &iovecs[i], 1, 0);
                sqe->flags |= IOSQE_FIXED_FILE;

                ret = io_uring_submit(&ring);
                sleep(1);
                printf("submit %d\n", i);
        }

        for (i = 0; i < 10; i++) {
                io_uring_wait_cqe(&ring, &cqe);
                printf("receive: %d\n", i);
                if (cqe->res != 4096) {
                        fprintf(stderr, "ret=%d, wanted 4096\n", cqe->res);
                        ret = 1;
                }
                io_uring_cqe_seen(&ring, cqe);
        }

        close(fd);
        io_uring_queue_exit(&ring);
        return 0;
}
sudo ./test testfile
above command will hang on the tenth request, to fix this bug, when io
sq_thread is waken up, we reset the variable 'ret' to be zero.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 697ece78.

The implementation of SWAP on powerpc requires page protection
bits to not be one of the least significant PTE bits.

Until the SWAP implementation is changed and this requirement voids,
we have to keep at least _PAGE_RW outside of the 3 last bits.

For now, revert to previous PTE bits order. A further rework
may come later.

Fixes: 697ece78 ("powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits.")
Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b34706f8de87f84d135abb5f3ede6b6f16fb1f41.1589969799.git.christophe.leroy@csgroup.eu

Quoth the man page:
```
       If the tracee was restarted by PTRACE_SYSCALL or PTRACE_SYSEMU, the
       tracee enters syscall-enter-stop just prior to entering any system
       call (which will not be executed if the restart was using
       PTRACE_SYSEMU, regardless of any change made to registers at this
       point or how the tracee is restarted after this stop).
```

The parenthetical comment is currently true on x86 and powerpc,
but not currently true on arm64. arm64 re-checks the _TIF_SYSCALL_EMU
flag after the syscall entry ptrace stop. However, at this point,
it reflects which method was used to re-start the syscall
at the entry stop, rather than the method that was used to reach it.
Fix that by recording the original flag before performing the ptrace
stop, bringing the behavior in line with documentation and x86/powerpc.

Fixes: f086f674 ("arm64: ptrace: add support for syscall emulation")
Cc: <stable@vger.kernel.org> # 5.3.x-
Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Bin Lu <Bin.Lu@arm.com>
[catalin.marinas@arm.com: moved 'flags' bit masking]
[catalin.marinas@arm.com: changed 'flags' type to unsigned long]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

We normally disable any commands that aren't specifically poll commands
for a ring that is setup for polling, but we do allow buffer provide and
remove commands to support buffer selection for polled IO. Once a
request is issued, we add it to the poll list to poll for completion. But
we should not do that for non-IO commands, as those request complete
inline immediately and aren't pollable. If we do, we can leave requests
on the iopoll list after they are freed.

Fixes: ddf0322d ("io_uring: add IORING_OP_PROVIDE_BUFFERS")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull vfs fix from Al Viro:
 "Stable fodder fix: copy_fdtable() would get screwed on 64bit boxen
  with sysctl_nr_open raised to 512M or higher, which became possible
  since 2.6.25.

  Nobody sane would set the things up that way, but..."

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix multiplication overflow in copy_fdtable()

Pull ARC fixes from Vineet Gupta:

 - fix recent DSP code regression on ARC700 platforms

 - fix thinkos in ICCM/DCCM size checks

 - USB regression fix

 - other small fixes here and there

* tag 'arc-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: show_regs: avoid extra line of output
  ARC: guard dsp early init against non ARCv2
  ARC: [plat-eznps]: Restrict to CONFIG_ISA_ARCOMPACT
  ARC: entry: comment
  arc: remove #ifndef CONFIG_AS_CFI_SIGNAL_FRAME
  arc: ptrace: hard-code "arc" instead of UTS_MACHINE
  ARC: [plat-hsdk]: fix USB regression
  ARC: Fix ICCM & DCCM runtime size checks

cpy and set really should be size_t; we won't get an overflow on that,
since sysctl_nr_open can't be set above ~(size_t)0 / sizeof(void *),
so nr that would've managed to overflow size_t on that multiplication
won't get anywhere near copy_fdtable() - we'll fail with EMFILE
before that.

Cc: stable@kernel.org # v2.6.25+
Fixes: 9cfe015a (get rid of NR_OPEN and introduce a sysctl_nr_open)
Reported-by: Thiago Macieira <thiago.macieira@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kiocb.private is used in iomap_dio_rw() so store buf_index separately.
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>

Move 'buf_index' to a hole in io_kiocb.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add an extra validation of the len parameter, as for ext4 some files
might have smaller file size limits than others.  This also means the
redundant size check in ext4_ioctl_get_es_cache can go away, as all
size checking is done in the shared fiemap handler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200505154324.3226743-3-hch@lst.deSigned-off-by: Theodore Ts'o <tytso@mit.edu>