Smack: Fix IPv6 handling of 0 secmark (2019-04-03 14:28:38 -0700)

KMSAN will complain if valid address length passed to bind()/connect()/
sendmsg() is shorter than sizeof("struct sockaddr"->sa_family) bytes.

Also, since smk_ipv6_port_label()/smack_netlabel_send()/
smack_ipv6host_label()/smk_ipv6_check()/smk_ipv6_port_check() are not
checking valid address length and/or address family, make sure we check
both. The minimal valid length in smack_socket_connect() is changed from
sizeof(struct sockaddr_in6) bytes to SIN6_LEN_RFC2133 bytes, for it seems
that Smack is not using "struct sockaddr_in6"->sin6_scope_id field.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

From Casey: "There's one bug fix for
IPv6 handling and two memory use improvements."

This reverts commit d1a08460.

From Al Viro:

"Rather bad way to do it - generally, register_filesystem() should be
the last thing done by initialization.  Any modular code that
does unregister_filesystem() on failure exit is flat-out broken;
here it's not instantly FUBAR, but it's a bloody bad example.

What's more, why not let simple_fill_super() do it?  Just
static int fill_super(struct super_block *sb, void *data, int silent)
{
        static const struct tree_descr files[] = {
                {"lsm", &lsm_ops, 0444},
                {""}
        };

and to hell with that call of securityfs_create_file() and all its
failure handling..."
Signed-off-by: James Morris <james.morris@microsoft.com>

Sparse complains yama_task_prctl can be static. Fix it by making
it static.
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

securityfs_create_file  may fail. The fix checks its status and
returns the error code upstream if it fails.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: James Morris <james.morris@microsoft.com>

The current code can perform concurrent updates and reads on
user->session_keyring and user->uid_keyring. Add a comment to
struct user_struct to document the nontrivial locking semantics, and use
READ_ONCE() for unlocked readers and smp_store_release() for writers to
prevent memory ordering issues.

Fixes: 69664cf1 ("keys: don't generate user and user session keyrings unless they're accessed")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

sparse complains that a bunch of places in kernel/cred.c access
cred->session_keyring without the RCU helpers required by the __rcu
annotation.

cred->session_keyring is written in the following places:

 - prepare_kernel_cred() [in a new cred struct]
 - keyctl_session_to_parent() [in a new cred struct]
 - prepare_creds [in a new cred struct, via memcpy]
 - install_session_keyring_to_cred()
  - from install_session_keyring() on new creds
  - from join_session_keyring() on new creds [twice]
  - from umh_keys_init()
   - from call_usermodehelper_exec_async() on new creds

All of these writes are before the creds are committed; therefore,
cred->session_keyring doesn't need RCU protection.

Remove the __rcu annotation and fix up all existing users that use __rcu.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

sparse complains that Yama defines functions and a variable as non-static
even though they don't exist in any header. Fix it by making them static.
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

Handle the case where the skb for an IPv6 packet contains
a 0 in the secmark for a packet generated locally. This
can only happen for system packets, so allow the access.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

This patch allows for small memory optimization by creating the
kmem cache for "struct smack_rule" instead of using kzalloc.
For adding new smack rule, kzalloc is used to allocate the memory
for "struct smack_rule". kzalloc will always allocate 32 or 64 bytes
for 1 structure depending upon the kzalloc cache sizes available in
system. Although the size of structure is 20 bytes only, resulting
in memory wastage per object in the default pool.

For e.g., if there are 20000 rules, then it will save 240KB(20000*12)
which is crucial for small memory targets.
Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

In this patch, global rule list has been removed. Now all
smack rules will be read using "smack_known_list". This list contains
all the smack labels and internally each smack label structure
maintains the list of smack rules corresponding to that smack label.
So there is no need to maintain extra list.

1) Small Memory Optimization
For eg. if there are 20000 rules, then it will save 625KB(20000*32),
which is critical for small embedded systems.
2) Reducing the time taken in writing rules on load/load2 interface
3) Since global rule list is just used to read the rules, so there
will be no performance impact on system
Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Casey Schaufler <cschaufler@localhost.localdomain>

Fix for name mismatch and omitted colons in the
security_list_options documentation.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The shm_* hooks were changed in the commit
"shm/security: Pass kern_ipc_perm not shmid_kernel into the
shm security hooks" (7191adff). The type of the argument
shp was changed from shmid_kernel to kern_ipc_perm. This patch
updates the documentation for the hooks accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The sem_* hooks were changed in the commit
"sem/security: Pass kern_ipc_perm not sem_array into the
sem security hooks" (aefad959). The type of the argument
sma was changed from sem_array to kern_ipc_perm. This patch
updates the documentation for the hooks accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The msg_queue_* hooks were changed in the commit
"msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue
security hooks" (d8c6e854). The type of the argument msq was changed
from msq_queue to kern_ipc_perm. This patch updates the documentation
for the hooks accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

This patch updates the documentation for the audit_* hooks
to use the same arguments names as in the hook's declarations.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The path_chmod hook was changed in the commit
"switch security_path_chmod() to struct path *" (cdcf116d).
The argument @mnt was removed from the hook, @dentry was changed
to @path. This patch updates the documentation accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The socket_getpeersec_dgram hook was changed in the commit
"[AF_UNIX]: Kernel memory leak fix for af_unix datagram
getpeersec patch" (dc49c1f9). The arguments @secdata
and @seclen were changed to @sock and @secid. This patch
updates the documentation accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The task_setscheduler hook was changed in the commit
"security: remove unused parameter from security_task_setscheduler()"
(b0ae1981). The arguments @policy, @lp were removed from the hook.
This patch updates the documentation accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

This patch slightly fixes the documentation for the
socket_post_create hook. The documentation states that
i_security field is accessible through inode field of socket
structure (i.e., 'sock->inode->i_security'). There is no inode
field in the socket structure. The i_security field is accessible
through SOCK_INODE macro. The patch updates the documentation
to reflect this.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The syslog hook was changed in the commit
"capabilities/syslog: open code cap_syslog logic to
fix build failure" (12b3052c). The argument @from_file
was removed from the hook. This patch updates the
documentation for the syslog hook accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

The @type argument of the sb_copy_data hook was removed
in the commit "LSM/SELinux: Interfaces to allow FS to control
mount options" (e0007529). This commit removes the description
of the @type argument from the LSM documentation.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

Merge to Linux 5.1-rc2 for subsystems to work with.

Pull ext4 fixes from Ted Ts'o:
 "Miscellaneous ext4 bug fixes for 5.1"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: prohibit fstrim in norecovery mode
  ext4: cleanup bh release code in ext4_ind_remove_space()
  ext4: brelse all indirect buffer in ext4_ind_remove_space()
  ext4: report real fs size after failed resize
  ext4: add missing brelse() in add_new_gdb_meta_bg()
  ext4: remove useless ext4_pin_inode()
  ext4: avoid panic during forced reboot
  ext4: fix data corruption caused by unaligned direct AIO
  ext4: fix NULL pointer dereference while journal is aborted

Pull scheduler updates from Thomas Gleixner:
 "Third more careful attempt for this set of fixes:

   - Prevent a 32bit math overflow in the cpufreq code

   - Fix a buffer overflow when scanning the cgroup2 cpu.max property

   - A set of fixes for the NOHZ scheduler logic to prevent waking up
     CPUs even if the capacity of the busy CPUs is sufficient along with
     other tweaks optimizing the behaviour for asymmetric systems
     (big/little)"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Skip LLC NOHZ logic for asymmetric systems
  sched/fair: Tune down misfit NOHZ kicks
  sched/fair: Comment some nohz_balancer_kick() kick conditions
  sched/core: Fix buffer overflow in cgroup2 property cpu.max
  sched/cpufreq: Fix 32-bit math overflow

Pull perf updates from Thomas Gleixner:
 "A larger set of perf updates.

  Not all of them are strictly fixes, but that's solely the tip
  maintainers fault as they let the timely -rc1 pull request fall
  through the cracks for various reasons including travel. So I'm
  sending this nevertheless because rebasing and distangling fixes and
  updates would be a mess and risky as well. As of tomorrow, a strict
  fixes separation is happening again. Sorry for the slip-up.

  Kernel:

   - Handle RECORD_MMAP vs. RECORD_MMAP2 correctly so different
     consumers of the mmap event get what they requested.

  Tools:

   - A larger set of updates to perf record/report/scripts vs. time
     stamp handling

   - More Python3 fixups

   - A pile of memory leak plumbing

   - perf BPF improvements and fixes

   - Finalize the perf.data directory storage"

[ Note: the kernel part is strictly a fix, the updates are purely to
  tooling       - Linus ]

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits)
  perf bpf: Show more BPF program info in print_bpf_prog_info()
  perf bpf: Extract logic to create program names from perf_event__synthesize_one_bpf_prog()
  perf tools: Save bpf_prog_info and BTF of new BPF programs
  perf evlist: Introduce side band thread
  perf annotate: Enable annotation of BPF programs
  perf build: Check what binutils's 'disassembler()' signature to use
  perf bpf: Process PERF_BPF_EVENT_PROG_LOAD for annotation
  perf symbols: Introduce DSO_BINARY_TYPE__BPF_PROG_INFO
  perf feature detection: Add -lopcodes to feature-libbfd
  perf top: Add option --no-bpf-event
  perf bpf: Save BTF information as headers to perf.data
  perf bpf: Save BTF in a rbtree in perf_env
  perf bpf: Save bpf_prog_info information as headers to perf.data
  perf bpf: Save bpf_prog_info in a rbtree in perf_env
  perf bpf: Make synthesize_bpf_events() receive perf_session pointer instead of perf_tool
  perf bpf: Synthesize bpf events with bpf_program__get_prog_info_linear()
  bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump()
  tools lib bpf: Introduce bpf_program__get_prog_info_linear()
  perf record: Replace option --bpf-event with --no-bpf-event
  perf tests: Fix a memory leak in test__perf_evsel__tp_sched_test()
  ...

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes:

   - Prevent potential NULL pointer dereferences in the HPET and HyperV
     code

   - Exclude the GART aperture from /proc/kcore to prevent kernel
     crashes on access

   - Use the correct macros for Cyrix I/O on Geode processors

   - Remove yet another kernel address printk leak

   - Announce microcode reload completion as requested by quite some
     people. Microcode loading has become popular recently.

   - Some 'Make Clang' happy fixlets

   - A few cleanups for recently added code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/gart: Exclude GART aperture from kcore
  x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error
  x86/mm/pti: Make local symbols static
  x86/cpu/cyrix: Remove {get,set}Cx86_old macros used for Cyrix processors
  x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors
  x86/microcode: Announce reload operation's completion
  x86/hyperv: Prevent potential NULL pointer dereference
  x86/hpet: Prevent potential NULL pointer dereference
  x86/lib: Fix indentation issue, remove extra tab
  x86/boot: Restrict header scope to make Clang happy
  x86/mm: Don't leak kernel addresses
  x86/cpufeature: Fix various quality problems in the <asm/cpu_device_hd.h> header

Pull timer fixes from Thomas Gleixner:
 "A set of small fixes plus the removal of stale board support code:

   - Remove the board support code from the clpx711x clocksource driver.
     This change had fallen through the cracks and I'm sending it now
     rather than dealing with people who want to improve that stale code
     for 3 month.

   - Use the proper clocksource mask on RICSV

   - Make local scope functions and variables static"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/clps711x: Remove board support
  clocksource/drivers/riscv: Fix clocksource mask
  clocksource/drivers/mips-gic-timer: Make gic_compare_irqaction static
  clocksource/drivers/timer-ti-dm: Make omap_dm_timer_set_load_start() static
  clocksource/drivers/tcb_clksrc: Make tc_clksrc_suspend/resume() static
  clocksource/drivers/clps711x: Make clps711x_clksrc_init() static
  time/jiffies: Make refined_jiffies static

Pull locking fixes from Thomas Gleixner:
 "Two small fixes:

   - Cure a recently introduces error path hickup which tries to
     unregister a not registered lockdep key in te workqueue code

   - Prevent unaligned cmpxchg() crashes in the robust list handling
     code by sanity checking the user space supplied futex pointer"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Ensure that futex address is aligned in handle_futex_death()
  workqueue: Only unregister a registered lockdep key

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for the interrupt subsystem:

   - Remove secondary GIC support on systems w/o device-tree support

   - A set of small fixlets in various irqchip drivers

   - static and fall-through annotations

   - Kernel doc and typo fixes"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Mark expected switch case fall-through
  genirq/devres: Remove excess parameter from kernel doc
  irqchip/irq-mvebu-sei: Make mvebu_sei_ap806_caps static
  irqchip/mbigen: Don't clear eventid when freeing an MSI
  irqchip/stm32: Don't set rising configuration registers at init
  irqchip/stm32: Don't clear rising/falling config registers at init
  dt-bindings: irqchip: renesas-irqc: Document r8a774c0 support
  irqchip/mmp: Make mmp_irq_domain_ops static
  irqchip/brcmstb-l2: Make two init functions static
  genirq: Fix typo in comment of IRQD_MOVE_PCNTXT
  irqchip/gic-v3-its: Fix comparison logic in lpi_range_cmp
  irqchip/gic: Drop support for secondary GIC in non-DT systems
  irqchip/imx-irqsteer: Fix of_property_read_u32() error handling

Pull core fixes from Thomas Gleixner:
 "Two small fixes:

   - Move the large objtool_file struct off the stack so objtool works
     in setups with a tight stack limit.

   - Make a few variables static in the watchdog core code"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  watchdog/core: Make variables static
  objtool: Move objtool_file struct off the stack

Pull thermal management fixes from Zhang Rui:

 - Fix a wrong __percpu structure declaration in intel_powerclamp driver
   (Luc Van Oostenryck)

 - Fix truncated name of the idle injection kthreads created by
   intel_powerclamp driver (Zhang Rui)

 - Fix the missing UUID supports in int3400 thermal driver (Matthew
   Garrett)

 - Fix a crash when accessing the debugfs of bcm2835 SoC thermal driver
   (Phil Elwell)

 - A couple of trivial fixes/cleanups in some SoC thermal drivers

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal/intel_powerclamp: fix truncated kthread name
  thermal: mtk: Allocate enough space for mtk_thermal.
  thermal/int340x_thermal: fix mode setting
  thermal/int340x_thermal: Add additional UUIDs
  thermal: cpu_cooling: Remove unused cur_freq variable
  thermal: bcm2835: Fix crash in bcm2835_thermal_debugfs
  thermal: samsung: Fix incorrect check after code merge
  thermal/intel_powerclamp: fix __percpu declaration of worker_data

Pull smb3 fixes from Steve French:

 - two fixes for stable for guest mount problems with smb3.1.1

 - two fixes for crediting (SMB3 flow control) on resent requests

 - a byte range lock leak fix

 - two fixes for incorrect rc mappings

* tag '5.1-rc1-cifs-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number
  SMB3: Fix SMB3.1.1 guest mounts to Samba
  cifs: Fix slab-out-of-bounds when tracing SMB tcon
  cifs: allow guest mounts to work for smb3.11
  fix incorrect error code mapping for OBJECTID_NOT_FOUND
  cifs: fix that return -EINVAL when do dedupe operation
  CIFS: Fix an issue with re-sending rdata when transport returning -EAGAIN
  CIFS: Fix an issue with re-sending wdata when transport returning -EAGAIN

Pull auxdisplay updates from Miguel Ojeda:
 "A few fixes and improvements for auxdisplay:

   - Series to fix a memory leak in hd44780 while introducing
     charlcd_free(). From Andy Shevchenko

   - Series to clean up the Kconfig menus and a couple of improvements
     for charlcd. From Mans Rullgard"

* tag 'auxdisplay-for-linus-v5.1-rc2' of git://github.com/ojeda/linux:
  auxdisplay: charlcd: make backlight initial state configurable
  auxdisplay: charlcd: simplify init message display
  auxdisplay: deconfuse configuration
  auxdisplay: hd44780: Convert to use charlcd_free()
  auxdisplay: panel: Convert to use charlcd_free()
  auxdisplay: charlcd: Introduce charlcd_free() helper
  auxdisplay: charlcd: Move to_priv() to charlcd namespace
  auxdisplay: hd44780: Fix memory leak on ->remove()

Pull SCSI fixes from James Bottomley:
 "Six fixes to four drivers and two core fixes.

  One core fix simply corrects a missed destroy_rcu_head() but the other
  is hopefully the end of an ongoing effort to make suspend/resume play
  nicely with scsi quiesce"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ibmvscsi: Fix empty event pool access during host removal
  scsi: ibmvscsi: Protect ibmvscsi_head from concurrent modificaiton
  scsi: hisi_sas: Add softreset in hisi_sas_I_T_nexus_reset()
  scsi: qla2xxx: Fix NULL pointer crash due to stale CPUID
  scsi: qla2xxx: Fix FC-AL connection target discovery
  scsi: core: Avoid that a kernel warning appears during system resume
  scsi: core: Also call destroy_rcu_head() for passthrough requests
  scsi: iscsi: flush running unbind operations when removing a session

Since board support for the CLPS711X platform was removed,
remove the board support from the clps711x-timer driver.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lkml.kernel.org/r/20181220111626.17140-1-shc_work@mail.ru

Pull io_uring fixes and improvements from Jens Axboe:
 "The first five in this series are heavily inspired by the work Al did
  on the aio side to fix the races there.

  The last two re-introduce a feature that was in io_uring before it got
  merged, but which I pulled since we didn't have a good way to have
  BVEC iters that already have a stable reference. These aren't
  necessarily related to block, it's just how io_uring pins fixed
  buffers"

* tag 'io_uring-20190323' of git://git.kernel.dk/linux-block:
  block: add BIO_NO_PAGE_REF flag
  iov_iter: add ITER_BVEC_FLAG_NO_REF flag
  io_uring: mark me as the maintainer
  io_uring: retry bulk slab allocs as single allocs
  io_uring: fix poll races
  io_uring: fix fget/fput handling
  io_uring: add prepped flag
  io_uring: make io_read/write return an integer
  io_uring: use regular request ref counts

Pull block fixes from Jens Axboe:
 "A set of fixes/changes that should go into this series. This contains:

   - Kernel doc / comment updates (Bart, Shenghui)

   - Un-export of core-only used function (Bart)

   - Fix race on loop file access (Dongli)

   - pf/pcd queue cleanup fixes (me)

   - Use appropriate helper for RESTART bit set (Yufen)

   - Use named identifier for classic poll (Yufen)"

* tag 'for-linus-20190323' of git://git.kernel.dk/linux-block:
  sbitmap: trivial - update comment for sbitmap_deferred_clear_bit
  blkcg: Fix kernel-doc warnings
  blk-iolatency: #include "blk.h"
  block: Unexport blk_mq_add_to_requeue_list()
  block: add BLK_MQ_POLL_CLASSIC for hybrid poll and return EINVAL for unexpected value
  blk-mq: remove unused 'nr_expired' from blk_mq_hw_ctx
  loop: access lo_backing_file only when the loop device is Lo_bound
  blk-mq: use blk_mq_sched_mark_restart_hctx to set RESTART
  paride/pcd: cleanup queues when detection fails
  paride/pf: cleanup queues when detection fails