Gen P7 adapters needs to share a toggle bits information received
in kernel driver with the user space. User space needs this
info during the request notify call back to arm the CQ.

User space application can get this page using the
UAPI routines. Library will mmap this page and get the
toggle bits to be used in the next ARM Doorbell.

Uses a hash list to map the CQ structure from the CQ ID.
CQ structure is retrieved from the hash list while the
library calls the UAPI routine to get the toggle page
mapping. Currently the full page is mapped per CQ. This
can be optimized to enable multiple CQs from the same
application share the same page and different offsets
in the page.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1702535484-26844-3-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Gen P7 adapters require to share a toggle value for CQ
and SRQ. This is received by the driver as part of
interrupt notifications and needs to be shared with the
user space. Add a new UAPI infrastructure to get the
shared page for CQ and SRQ.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1702535484-26844-2-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Releasing the `priv->lock` while iterating the `priv->multicast_list` in
`ipoib_mcast_join_task()` opens a window for `ipoib_mcast_dev_flush()` to
remove the items while in the middle of iteration. If the mcast is removed
while the lock was dropped, the for loop spins forever resulting in a hard
lockup (as was reported on RHEL 4.18.0-372.75.1.el8_6 kernel):

    Task A (kworker/u72:2 below)       | Task B (kworker/u72:0 below)
    -----------------------------------+-----------------------------------
    ipoib_mcast_join_task(work)        | ipoib_ib_dev_flush_light(work)
      spin_lock_irq(&priv->lock)       | __ipoib_ib_dev_flush(priv, ...)
      list_for_each_entry(mcast,       | ipoib_mcast_dev_flush(dev = priv->dev)
          &priv->multicast_list, list) |
        ipoib_mcast_join(dev, mcast)   |
          spin_unlock_irq(&priv->lock) |
                                       |   spin_lock_irqsave(&priv->lock, flags)
                                       |   list_for_each_entry_safe(mcast, tmcast,
                                       |                  &priv->multicast_list, list)
                                       |     list_del(&mcast->list);
                                       |     list_add_tail(&mcast->list, &remove_list)
                                       |   spin_unlock_irqrestore(&priv->lock, flags)
          spin_lock_irq(&priv->lock)   |
                                       |   ipoib_mcast_remove_list(&remove_list)
   (Here, `mcast` is no longer on the  |     list_for_each_entry_safe(mcast, tmcast,
    `priv->multicast_list` and we keep |                            remove_list, list)
    spinning on the `remove_list` of   |  >>>  wait_for_completion(&mcast->done)
    the other thread which is blocked  |
    and the list is still valid on     |
    it's stack.)

Fix this by keeping the lock held and changing to GFP_ATOMIC to prevent
eventual sleeps.
Unfortunately we could not reproduce the lockup and confirm this fix but
based on the code review I think this fix should address such lockups.

crash> bc 31
PID: 747      TASK: ff1c6a1a007e8000  CPU: 31   COMMAND: "kworker/u72:2"
--
    [exception RIP: ipoib_mcast_join_task+0x1b1]
    RIP: ffffffffc0944ac1  RSP: ff646f199a8c7e00  RFLAGS: 00000002
    RAX: 0000000000000000  RBX: ff1c6a1a04dc82f8  RCX: 0000000000000000
                                  work (&priv->mcast_task{,.work})
    RDX: ff1c6a192d60ac68  RSI: 0000000000000286  RDI: ff1c6a1a04dc8000
           &mcast->list
    RBP: ff646f199a8c7e90   R8: ff1c699980019420   R9: ff1c6a1920c9a000
    R10: ff646f199a8c7e00  R11: ff1c6a191a7d9800  R12: ff1c6a192d60ac00
                                                         mcast
    R13: ff1c6a1d82200000  R14: ff1c6a1a04dc8000  R15: ff1c6a1a04dc82d8
           dev                    priv (&priv->lock)     &priv->multicast_list (aka head)
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
--- <NMI exception stack> ---
 #5 [ff646f199a8c7e00] ipoib_mcast_join_task+0x1b1 at ffffffffc0944ac1 [ib_ipoib]
 #6 [ff646f199a8c7e98] process_one_work+0x1a7 at ffffffff9bf10967

crash> rx ff646f199a8c7e68
ff646f199a8c7e68:  ff1c6a1a04dc82f8 <<< work = &priv->mcast_task.work

crash> list -hO ipoib_dev_priv.multicast_list ff1c6a1a04dc8000
(empty)

crash> ipoib_dev_priv.mcast_task.work.func,mcast_mutex.owner.counter ff1c6a1a04dc8000
  mcast_task.work.func = 0xffffffffc0944910 <ipoib_mcast_join_task>,
  mcast_mutex.owner.counter = 0xff1c69998efec000

crash> b 8
PID: 8        TASK: ff1c69998efec000  CPU: 33   COMMAND: "kworker/u72:0"
--
 #3 [ff646f1980153d50] wait_for_completion+0x96 at ffffffff9c7d7646
 #4 [ff646f1980153d90] ipoib_mcast_remove_list+0x56 at ffffffffc0944dc6 [ib_ipoib]
 #5 [ff646f1980153de8] ipoib_mcast_dev_flush+0x1a7 at ffffffffc09455a7 [ib_ipoib]
 #6 [ff646f1980153e58] __ipoib_ib_dev_flush+0x1a4 at ffffffffc09431a4 [ib_ipoib]
 #7 [ff646f1980153e98] process_one_work+0x1a7 at ffffffff9bf10967

crash> rx ff646f1980153e68
ff646f1980153e68:  ff1c6a1a04dc83f0 <<< work = &priv->flush_light

crash> ipoib_dev_priv.flush_light.func,broadcast ff1c6a1a04dc8000
  flush_light.func = 0xffffffffc0943820 <ipoib_ib_dev_flush_light>,
  broadcast = 0x0,

The mcast(s) on the `remove_list` (the remaining part of the ex `priv->multicast_list`):

crash> list -s ipoib_mcast.done.done ipoib_mcast.list -H ff646f1980153e10 | paste - -
ff1c6a192bd0c200          done.done = 0x0,
ff1c6a192d60ac00          done.done = 0x0,
Reported-by: Yuya Fujita-bishamonten <fj-lsoft-rh-driver@dl.jp.fujitsu.com>
Signed-off-by: Daniel Vacek <neelx@redhat.com>
Link: https://lore.kernel.org/all/20231212080746.1528802-1-neelx@redhat.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

These two series from Mark and Shun extend RDMA mlx5 API.

Mark's series provides c0 register used to match egress
traffic sent by local device.

Shun's series adds new type for ICM area.

Link: https://lore.kernel.org/all/cover.1701871118.git.leon@kernel.orgSigned-off-by: Leon Romanovsky <leon@kernel.org>

This patch introduces improvements for matching egress traffic sent by the
local device. When applicable, all egress traffic from the local vport is
now tagged with the provided value. This enhancement is particularly useful
for FDB steering purposes.

The primary focus of this update is facilitating the transmission of
traffic from the hypervisor to a VF. To achieve this, one must initiate an
SQ on the hypervisor and subsequently create a rule in the FDB that matches
on the eswitch manager vport and the SQN of the aforementioned SQ.

Obtaining the SQN can be had from SQ opened, and the eswitch manager vport
match can be substituted with the register c0 value exposed by this patch.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Link: https://lore.kernel.org/r/aa4120a91c98ff1c44f1213388c744d4cb0324d6.1701871118.git.leon@kernel.orgSigned-off-by: Leon Romanovsky <leon@kernel.org>

Expose the ability the query the eswitch manager vport number.
Next patch will utilize this capability to reveal the correct
register C0 value to the users.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Link: https://lore.kernel.org/r/614fb0e216250e2ce3340471ec141b83ec45c7f4.1701871118.git.leon@kernel.orgSigned-off-by: Leon Romanovsky <leon@kernel.org>

Support allocate/deallocate the new SW encap ICM type memory.
The new ICM type is used for encap context allocation managed by SW,
instead FW. It can increase encap context maximum number and allocation
speed
Signed-off-by: Shun Hao <shunh@nvidia.com>
Link: https://lore.kernel.org/r/bed5121255918eb132a1334141c76a0594df8143.1701871118.git.leon@kernel.orgSigned-off-by: Leon Romanovsky <leon@kernel.org>

New type for this ICM area, now the user can allocate/deallocate
the new type of SW encap ICM memory, to store the encap header data
which are managed by SW.
Signed-off-by: Shun Hao <shunh@nvidia.com>
Link: https://lore.kernel.org/r/546fe43fc700240709e30acf7713ec6834d652bd.1701871118.git.leon@kernel.orgSigned-off-by: Leon Romanovsky <leon@kernel.org>

Add new fields for device memory capabilities, in order to support
creation of new ICM memory type of SW encap.
Signed-off-by: Shun Hao <shunh@nvidia.com>
Link: https://lore.kernel.org/r/107cca7dd6a932a1704abf6ebd1b801105546a8e.1701871118.git.leon@kernel.orgSigned-off-by: Leon Romanovsky <leon@kernel.org>

GenP7 HW expects an MSN table instead of PSN table. Check
for the HW retransmission capability and populate the MSN
table if HW retansmission is supported.
Signed-off-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1701946060-13931-7-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Update the Doorbell routines to support the latest HW
definitions. Use common routine to prepare the Doorbell
key.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1701946060-13931-6-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Get the toggle bits from CQ completions. For older adapters
these values are 0.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1701946060-13931-5-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Adds HW interface definitions to support the new
chip revision.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1701946060-13931-4-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Update the BAR offsets for handling GenP7 adapters.
Use the values populated by L2 driver for getting the
Doorbell offsets.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1701946060-13931-3-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Add basic support for 5760X P7 devices. Add new chip
revisions. The first version support is similar to
the existing P5 adapters. Extend the current support
for P5 adapters to P7 also.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1701946060-13931-2-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

Pull scheduler fix from Borislav Petkov:

 - Make sure tasks are thawed exactly and only once to avoid their state
   getting corrupted

* tag 'sched_urgent_for_v6.7_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  freezer,sched: Do not restore saved_state of a thawed task

Pull perf event fix from Borislav Petkov:

 - Make sure perf event size validation is done on every event in the
   group

* tag 'perf_urgent_for_v6.7_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix perf_event_validate_size()

Pull x86 fixes from Borislav Petkov:

 - Add a forgotten CPU vendor check in the AMD microcode post-loading
   callback so that the callback runs only on AMD

 - Make sure SEV-ES protocol negotiation happens only once and on the
   BSP

* tag 'x86_urgent_for_v6.7_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: Check vendor in the AMD microcode callback
  x86/sev: Fix kernel crash due to late update to read-only ghcb_version

Pull kvm fixes from Paolo Bonzini:
 "Generic:

   - Set .owner for various KVM file_operations so that files refcount
     the KVM module until KVM is done executing _all_ code, including
     the last few instructions of kvm_put_kvm(). And then revert the
     misguided attempt to rely on "struct kvm" refcounts to pin
     KVM-the-module.

  ARM:

   - Do not redo the mapping of vLPIs, if they have already been mapped

  s390:

   - Do not leave bits behind in PTEs

   - Properly catch page invalidations that affect the prefix of a
     nested guest

  x86:

   - When checking if a _running_ vCPU is "in-kernel", i.e. running at
     CPL0, get the CPL directly instead of relying on
     preempted_in_kernel (which is valid if and only if the vCPU was
     preempted, i.e. NOT running).

   - Fix a benign "return void" that was recently introduced.

  Selftests:

   - Makefile tweak for dependency generation

   - '-Wformat' fix"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: SVM: Update EFER software model on CR0 trap for SEV-ES
  KVM: selftests: add -MP to CFLAGS
  KVM: selftests: Actually print out magic token in NX hugepages skip message
  KVM: x86: Remove 'return void' expression for 'void function'
  Revert "KVM: Prevent module exit until all VMs are freed"
  KVM: Set file_operations.owner appropriately for all such structures
  KVM: x86: Get CPL directly when checking if loaded vCPU is in kernel mode
  KVM: arm64: GICv4: Do not perform a map to a mapped vLPI
  KVM: s390/mm: Properly reset no-dat
  KVM: s390: vsie: fix wrong VIR 37 when MSO is used

Pull powerpc fix from Michael Ellerman:

 - Fix stack teardown in ftrace_no_trace, seen as crashes doing CPU
   hotplug while ftrace is active.

   Thanks to Naveen N Rao.

* tag 'powerpc-6.7-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/ftrace: Fix stack teardown in ftrace_no_trace

Pull gpio fix from Bartosz Golaszewski:

 - fix an error path after a failed export in sysfs code

* tag 'gpio-fixes-for-v6.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpiolib: sysfs: Fix error handling on failed export

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 6.7-rc5 to resolve some reported
  issues. Included in here are:

   - usb gadget f_hid, and uevent fix

   - xhci driver revert to resolve a much-reported issue

   - typec driver fix

  All of these have been in linux-next with no reported issues"

* tag 'usb-6.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: gadget: f_hid: fix report descriptor allocation
  Revert "xhci: Loosen RPM as default policy to cover for AMD xHC 1.1"
  usb: typec: class: fix typec_altmode_put_partner to put plugs
  USB: gadget: core: adjust uevent timing on gadget unbind

Pull serial driver fixes from Greg KH:
 "Here are some small serial driver fixes for 6.7-rc4 to resolve some
  reported issues. Included in here are:

   - pl011 dma support fix

   - sc16is7xx driver fix

   - ma35d1 console index fix

   - 8250 driver fixes for small issues

  All of these have been in linux-next with no reported issues"

* tag 'tty-6.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_dw: Add ACPI ID for Granite Rapids-D UART
  serial: ma35d1: Validate console index before assignment
  ARM: PL011: Fix DMA support
  serial: sc16is7xx: address RX timeout interrupt errata
  serial: 8250: 8250_omap: Clear UART_HAS_RHR_IT_DIS bit
  serial: 8250_omap: Add earlycon support for the AM654 UART controller
  serial: 8250: 8250_omap: Do not start RX DMA on THRI interrupt

Pull char / misc driver fixes from Greg KH:
 "Here are some small fixes for 6.7-rc5 for a variety of small driver
  subsystems. Included in here are:

   - debugfs revert for reported issue

   - greybus revert for reported issue

   - greybus fixup for endian build warning

   - coresight driver fixes

   - nvmem driver fixes

   - devcoredump fix

   - parport new device id

   - ndtest build fix

  All of these have ben in linux-next with no reported issues"

* tag 'char-misc-6.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  nvmem: Do not expect fixed layouts to grab a layout driver
  parport: Add support for Brainboxes IX/UC/PX parallel cards
  Revert "greybus: gb-beagleplay: Ensure le for values in transport"
  greybus: gb-beagleplay: Ensure le for values in transport
  greybus: BeaglePlay driver needs CRC_CCITT
  Revert "debugfs: annotate debugfs handlers vs. removal with lockdep"
  devcoredump: Send uevent once devcd is ready
  ndtest: fix typo class_regster -> class_register
  misc: mei: client.c: fix problem of return '-EOVERFLOW' in mei_cl_write
  misc: mei: client.c: return negative error code in mei_cl_write
  mei: pxp: fix mei_pxp_send_message return value
  coresight: ultrasoc-smb: Fix uninitialized before use buf_hw_base
  coresight: ultrasoc-smb: Config SMB buffer before register sink
  coresight: ultrasoc-smb: Fix sleep while close preempt in enable_smb
  Documentation: coresight: fix `make refcheckdocs` warning
  hwtracing: hisi_ptt: Don't try to attach a task
  hwtracing: hisi_ptt: Handle the interrupt in hardirq context
  hwtracing: hisi_ptt: Add dummy callback pmu::read()
  coresight: Fix crash when Perf and sysfs modes are used concurrently
  coresight: etm4x: Remove bogous __exit annotation for some functions

Merge tag 'loongarch-fixes-6.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Preserve syscall nr across execve(), slightly clean up drdtime(), fix
  the Clang built zboot kernel, fix a stack unwinder bug and several bpf
  jit bugs"

* tag 'loongarch-fixes-6.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: BPF: Fix unconditional bswap instructions
  LoongArch: BPF: Fix sign-extension mov instructions
  LoongArch: BPF: Don't sign extend function return value
  LoongArch: BPF: Don't sign extend memory load operand
  LoongArch: Preserve syscall nr across execve()
  LoongArch: Set unwind stack type to unknown rather than set error flag
  LoongArch: Slightly clean up drdtime()
  LoongArch: Apply dynamic relocations for LLD

Pull MIPS fixes from Thomas Bogendoerfer:

 - Fixes for broken Loongson firmware

 - Fix lockdep splat

 - Fix FPU states when creating kernel threads

* tag 'mips-fixes_6.7_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: kernel: Clear FPU states when setting up kernel threads
  MIPS: Loongson64: Handle more memory types passed from firmware
  MIPS: Loongson64: Enable DMA noncoherent support
  MIPS: Loongson64: Reserve vgabios memory on boot
  mips/smp: Call rcutree_report_cpu_starting() earlier

Merge tag 'perf-tools-fixes-for-v6.7-2-2023-12-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools fixes from Namhyung Kim:
 "A random set of small bug fixes including:

   - Fix segfault on AmpereOne due to missing default metricgroup name

   - Fix segfault on `perf list --json` due to NULL pointer"

* tag 'perf-tools-fixes-for-v6.7-2-2023-12-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf list: Fix JSON segfault by setting the used skip_duplicate_pmus callback
  perf vendor events arm64: AmpereOne: Add missing DefaultMetricgroupName fields
  perf metrics: Avoid segv if default metricgroup isn't set

Pull smb client fixes from Steve French:
 "Six smb3 client fixes:

   - Fixes for copy_file_range and clone (cache invalidation and file
     size), also addresses an xfstest failure

   - Fix to return proper error if REMAP_FILE_DEDUP set (also fixes
     xfstest generic/304)

   - Fix potential null pointer reference with DFS

   - Multichannel fix addressing (reverting an earlier patch) some of
     the problems with enabling/disabling channels dynamically

  Still working on a followon multichannel fix to address another issue
  found in reconnect testing that will send next week"

* tag '6.7-rc4-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: reconnect worker should take reference on server struct unconditionally
  Revert "cifs: reconnect work should have reference on server struct"
  cifs: Fix non-availability of dedup breaking generic/304
  smb: client: fix potential NULL deref in parse_dfs_referrals()
  cifs: Fix flushing, invalidation and file size with FICLONE
  cifs: Fix flushing, invalidation and file size with copy_file_range()

We can see that "bswap32: Takes an unsigned 32-bit number in either big-
or little-endian format and returns the equivalent number with the same
bit width but opposite endianness" in BPF Instruction Set Specification,
so it should clear the upper 32 bits in "case 32:" for both BPF_ALU and
BPF_ALU64.

[root@linux fedora]# echo 1 > /proc/sys/net/core/bpf_jit_enable
[root@linux fedora]# modprobe test_bpf

Before:
test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 ret 1460850314 != -271733879 (0x5712ce8a != 0xefcdab89)FAIL (1 times)
test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 ret -1460850316 != 271733878 (0xa8ed3174 != 0x10325476)FAIL (1 times)

After:
test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 4 PASS
test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 4 PASS

Fixes: 4ebf9216 ("LoongArch: BPF: Support unconditional bswap instructions")
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

We can see that "Short form of movsx, dst_reg = (s8,s16,s32)src_reg" in
include/linux/filter.h, additionally, for BPF_ALU64 the value of the
destination register is unchanged whereas for BPF_ALU the upper 32 bits
of the destination register are zeroed, so it should clear the upper 32
bits for BPF_ALU.

[root@linux fedora]# echo 1 > /proc/sys/net/core/bpf_jit_enable
[root@linux fedora]# modprobe test_bpf

Before:
test_bpf: #81 ALU_MOVSX | BPF_B jited:1 ret 2 != 1 (0x2 != 0x1)FAIL (1 times)
test_bpf: #82 ALU_MOVSX | BPF_H jited:1 ret 2 != 1 (0x2 != 0x1)FAIL (1 times)

After:
test_bpf: #81 ALU_MOVSX | BPF_B jited:1 6 PASS
test_bpf: #82 ALU_MOVSX | BPF_H jited:1 6 PASS

By the way, the bpf selftest case "./test_progs -t verifier_movsx" can
also be fixed with this patch.

Fixes: f48012f1 ("LoongArch: BPF: Support sign-extension mov instructions")
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

The `cls_redirect` test triggers a kernel panic like:

  # ./test_progs -t cls_redirect
  Can't find bpf_testmod.ko kernel module: -2
  WARNING! Selftests relying on bpf_testmod.ko will be skipped.
  [   30.938489] CPU 3 Unable to handle kernel paging request at virtual address fffffffffd814de0, era == ffff800002009fb8, ra == ffff800002009f9c
  [   30.939331] Oops[#1]:
  [   30.939513] CPU: 3 PID: 1260 Comm: test_progs Not tainted 6.7.0-rc2-loong-devel-g2f56bb0d2327 #35 a896aca3f4164f09cc346f89f2e09832e07be5f6
  [   30.939732] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [   30.939901] pc ffff800002009fb8 ra ffff800002009f9c tp 9000000104da4000 sp 9000000104da7ab0
  [   30.940038] a0 fffffffffd814de0 a1 9000000104da7a68 a2 0000000000000000 a3 9000000104da7c10
  [   30.940183] a4 9000000104da7c14 a5 0000000000000002 a6 0000000000000021 a7 00005555904d7f90
  [   30.940321] t0 0000000000000110 t1 0000000000000000 t2 fffffffffd814de0 t3 0004c4b400000000
  [   30.940456] t4 ffffffffffffffff t5 00000000c3f63600 t6 0000000000000000 t7 0000000000000000
  [   30.940590] t8 000000000006d803 u0 0000000000000020 s9 9000000104da7b10 s0 900000010504c200
  [   30.940727] s1 fffffffffd814de0 s2 900000010504c200 s3 9000000104da7c10 s4 9000000104da7ad0
  [   30.940866] s5 0000000000000000 s6 90000000030e65bc s7 9000000104da7b44 s8 90000000044f6fc0
  [   30.941015]    ra: ffff800002009f9c bpf_prog_846803e5ae81417f_cls_redirect+0xa0/0x590
  [   30.941535]   ERA: ffff800002009fb8 bpf_prog_846803e5ae81417f_cls_redirect+0xbc/0x590
  [   30.941696]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [   30.942224]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [   30.942330]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [   30.942453]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [   30.942612] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [   30.942764]  BADV: fffffffffd814de0
  [   30.942854]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [   30.942974] Modules linked in:
  [   30.943078] Process test_progs (pid: 1260, threadinfo=00000000ce303226, task=000000007d10bb76)
  [   30.943306] Stack : 900000010a064000 90000000044f6fc0 9000000104da7b48 0000000000000000
  [   30.943495]         0000000000000000 9000000104da7c14 9000000104da7c10 900000010504c200
  [   30.943626]         0000000000000001 ffff80001b88c000 9000000104da7b70 90000000030e6668
  [   30.943785]         0000000000000000 9000000104da7b58 ffff80001b88c048 9000000003d05000
  [   30.943936]         900000000303ac88 0000000000000000 0000000000000000 9000000104da7b70
  [   30.944091]         0000000000000000 0000000000000001 0000000731eeab00 0000000000000000
  [   30.944245]         ffff80001b88c000 0000000000000000 0000000000000000 54b99959429f83b8
  [   30.944402]         ffff80001b88c000 90000000044f6fc0 9000000101d70000 ffff80001b88c000
  [   30.944538]         000000000000005a 900000010504c200 900000010a064000 900000010a067000
  [   30.944697]         9000000104da7d88 0000000000000000 9000000003d05000 90000000030e794c
  [   30.944852]         ...
  [   30.944924] Call Trace:
  [   30.945120] [<ffff800002009fb8>] bpf_prog_846803e5ae81417f_cls_redirect+0xbc/0x590
  [   30.945650] [<90000000030e6668>] bpf_test_run+0x1ec/0x2f8
  [   30.945958] [<90000000030e794c>] bpf_prog_test_run_skb+0x31c/0x684
  [   30.946065] [<90000000026d4f68>] __sys_bpf+0x678/0x2724
  [   30.946159] [<90000000026d7288>] sys_bpf+0x20/0x2c
  [   30.946253] [<90000000032dd224>] do_syscall+0x7c/0x94
  [   30.946343] [<9000000002541c5c>] handle_syscall+0xbc/0x158
  [   30.946492]
  [   30.946549] Code: 0015030e  5c0009c0  5001d000 <28c00304> 02c00484  29c00304  00150009  2a42d2e4  0280200d
  [   30.946793]
  [   30.946971] ---[ end trace 0000000000000000 ]---
  [   32.093225] Kernel panic - not syncing: Fatal exception in interrupt
  [   32.093526] Kernel relocated by 0x2320000
  [   32.093630]  .text @ 0x9000000002520000
  [   32.093725]  .data @ 0x9000000003400000
  [   32.093792]  .bss  @ 0x9000000004413200
  [   34.971998] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

This is because we signed-extend function return values. When subprog
mode is enabled, we have:

  cls_redirect()
    -> get_global_metrics() returns pcpu ptr 0xfffffefffc00b480

The pointer returned is later signed-extended to 0xfffffffffc00b480 at
`BPF_JMP | BPF_EXIT`. During BPF prog run, this triggers unhandled page
fault and a kernel panic.

Drop the unnecessary signed-extension on return values like other
architectures do.

With this change, we have:

  # ./test_progs -t cls_redirect
  Can't find bpf_testmod.ko kernel module: -2
  WARNING! Selftests relying on bpf_testmod.ko will be skipped.
  #51/1    cls_redirect/cls_redirect_inlined:OK
  #51/2    cls_redirect/IPv4 TCP accept unknown (no hops, flags: SYN):OK
  #51/3    cls_redirect/IPv6 TCP accept unknown (no hops, flags: SYN):OK
  #51/4    cls_redirect/IPv4 TCP accept unknown (no hops, flags: ACK):OK
  #51/5    cls_redirect/IPv6 TCP accept unknown (no hops, flags: ACK):OK
  #51/6    cls_redirect/IPv4 TCP forward unknown (one hop, flags: ACK):OK
  #51/7    cls_redirect/IPv6 TCP forward unknown (one hop, flags: ACK):OK
  #51/8    cls_redirect/IPv4 TCP accept known (one hop, flags: ACK):OK
  #51/9    cls_redirect/IPv6 TCP accept known (one hop, flags: ACK):OK
  #51/10   cls_redirect/IPv4 UDP accept unknown (no hops, flags: none):OK
  #51/11   cls_redirect/IPv6 UDP accept unknown (no hops, flags: none):OK
  #51/12   cls_redirect/IPv4 UDP forward unknown (one hop, flags: none):OK
  #51/13   cls_redirect/IPv6 UDP forward unknown (one hop, flags: none):OK
  #51/14   cls_redirect/IPv4 UDP accept known (one hop, flags: none):OK
  #51/15   cls_redirect/IPv6 UDP accept known (one hop, flags: none):OK
  #51/16   cls_redirect/cls_redirect_subprogs:OK
  #51/17   cls_redirect/IPv4 TCP accept unknown (no hops, flags: SYN):OK
  #51/18   cls_redirect/IPv6 TCP accept unknown (no hops, flags: SYN):OK
  #51/19   cls_redirect/IPv4 TCP accept unknown (no hops, flags: ACK):OK
  #51/20   cls_redirect/IPv6 TCP accept unknown (no hops, flags: ACK):OK
  #51/21   cls_redirect/IPv4 TCP forward unknown (one hop, flags: ACK):OK
  #51/22   cls_redirect/IPv6 TCP forward unknown (one hop, flags: ACK):OK
  #51/23   cls_redirect/IPv4 TCP accept known (one hop, flags: ACK):OK
  #51/24   cls_redirect/IPv6 TCP accept known (one hop, flags: ACK):OK
  #51/25   cls_redirect/IPv4 UDP accept unknown (no hops, flags: none):OK
  #51/26   cls_redirect/IPv6 UDP accept unknown (no hops, flags: none):OK
  #51/27   cls_redirect/IPv4 UDP forward unknown (one hop, flags: none):OK
  #51/28   cls_redirect/IPv6 UDP forward unknown (one hop, flags: none):OK
  #51/29   cls_redirect/IPv4 UDP accept known (one hop, flags: none):OK
  #51/30   cls_redirect/IPv6 UDP accept known (one hop, flags: none):OK
  #51/31   cls_redirect/cls_redirect_dynptr:OK
  #51/32   cls_redirect/IPv4 TCP accept unknown (no hops, flags: SYN):OK
  #51/33   cls_redirect/IPv6 TCP accept unknown (no hops, flags: SYN):OK
  #51/34   cls_redirect/IPv4 TCP accept unknown (no hops, flags: ACK):OK
  #51/35   cls_redirect/IPv6 TCP accept unknown (no hops, flags: ACK):OK
  #51/36   cls_redirect/IPv4 TCP forward unknown (one hop, flags: ACK):OK
  #51/37   cls_redirect/IPv6 TCP forward unknown (one hop, flags: ACK):OK
  #51/38   cls_redirect/IPv4 TCP accept known (one hop, flags: ACK):OK
  #51/39   cls_redirect/IPv6 TCP accept known (one hop, flags: ACK):OK
  #51/40   cls_redirect/IPv4 UDP accept unknown (no hops, flags: none):OK
  #51/41   cls_redirect/IPv6 UDP accept unknown (no hops, flags: none):OK
  #51/42   cls_redirect/IPv4 UDP forward unknown (one hop, flags: none):OK
  #51/43   cls_redirect/IPv6 UDP forward unknown (one hop, flags: none):OK
  #51/44   cls_redirect/IPv4 UDP accept known (one hop, flags: none):OK
  #51/45   cls_redirect/IPv6 UDP accept known (one hop, flags: none):OK
  #51      cls_redirect:OK
  Summary: 1/45 PASSED, 0 SKIPPED, 0 FAILED

Fixes: 5dc61552 ("LoongArch: Add BPF JIT support")
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

The `cgrp_local_storage` test triggers a kernel panic like:

  # ./test_progs -t cgrp_local_storage
  Can't find bpf_testmod.ko kernel module: -2
  WARNING! Selftests relying on bpf_testmod.ko will be skipped.
  [  550.930632] CPU 1 Unable to handle kernel paging request at virtual address 0000000000000080, era == ffff80000200be34, ra == ffff80000200be00
  [  550.931781] Oops[#1]:
  [  550.931966] CPU: 1 PID: 1303 Comm: test_progs Not tainted 6.7.0-rc2-loong-devel-g2f56bb0d2327 #35 a896aca3f4164f09cc346f89f2e09832e07be5f6
  [  550.932215] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  550.932403] pc ffff80000200be34 ra ffff80000200be00 tp 9000000108350000 sp 9000000108353dc0
  [  550.932545] a0 0000000000000000 a1 0000000000000517 a2 0000000000000118 a3 00007ffffbb15558
  [  550.932682] a4 00007ffffbb15620 a5 90000001004e7700 a6 0000000000000021 a7 0000000000000118
  [  550.932824] t0 ffff80000200bdc0 t1 0000000000000517 t2 0000000000000517 t3 00007ffff1c06ee0
  [  550.932961] t4 0000555578ae04d0 t5 fffffffffffffff8 t6 0000000000000004 t7 0000000000000020
  [  550.933097] t8 0000000000000040 u0 00000000000007b8 s9 9000000108353e00 s0 90000001004e7700
  [  550.933241] s1 9000000004005000 s2 0000000000000001 s3 0000000000000000 s4 0000555555eb2ec8
  [  550.933379] s5 00007ffffbb15bb8 s6 00007ffff1dafd60 s7 000055555663f610 s8 00007ffff1db0050
  [  550.933520]    ra: ffff80000200be00 bpf_prog_98f1b9e767be2a84_on_enter+0x40/0x200
  [  550.933911]   ERA: ffff80000200be34 bpf_prog_98f1b9e767be2a84_on_enter+0x74/0x200
  [  550.934105]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  550.934596]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  550.934712]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  550.934836]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  550.934976] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  550.935097]  BADV: 0000000000000080
  [  550.935181]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  550.935291] Modules linked in:
  [  550.935391] Process test_progs (pid: 1303, threadinfo=000000006c3b1c41, task=0000000061f84a55)
  [  550.935643] Stack : 00007ffffbb15bb8 0000555555eb2ec8 0000000000000000 0000000000000001
  [  550.935844]         9000000004005000 ffff80001b864000 00007ffffbb15450 90000000029aa034
  [  550.935990]         0000000000000000 9000000108353ec0 0000000000000118 d07d9dfb09721a09
  [  550.936175]         0000000000000001 0000000000000000 9000000108353ec0 0000000000000118
  [  550.936314]         9000000101d46ad0 900000000290abf0 000055555663f610 0000000000000000
  [  550.936479]         0000000000000003 9000000108353ec0 00007ffffbb15450 90000000029d7288
  [  550.936635]         00007ffff1dafd60 000055555663f610 0000000000000000 0000000000000003
  [  550.936779]         9000000108353ec0 90000000035dd1f0 00007ffff1dafd58 9000000002841c5c
  [  550.936939]         0000000000000119 0000555555eea5a8 00007ffff1d78780 00007ffffbb153e0
  [  550.937083]         ffffffffffffffda 00007ffffbb15518 0000000000000040 00007ffffbb15558
  [  550.937224]         ...
  [  550.937299] Call Trace:
  [  550.937521] [<ffff80000200be34>] bpf_prog_98f1b9e767be2a84_on_enter+0x74/0x200
  [  550.937910] [<90000000029aa034>] bpf_trace_run2+0x90/0x154
  [  550.938105] [<900000000290abf0>] syscall_trace_enter.isra.0+0x1cc/0x200
  [  550.938224] [<90000000035dd1f0>] do_syscall+0x48/0x94
  [  550.938319] [<9000000002841c5c>] handle_syscall+0xbc/0x158
  [  550.938477]
  [  550.938607] Code: 580009ae  50016000  262402e4 <28c20085> 14092084  03a00084  16000024  03240084  00150006
  [  550.938851]
  [  550.939021] ---[ end trace 0000000000000000 ]---

Further investigation shows that this panic is triggered by memory
load operations:

  ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
                             BPF_LOCAL_STORAGE_GET_F_CREATE);

The expression `task->cgroups->dfl_cgrp` involves two memory load.
Since the field offset fits in imm12 or imm14, we use ldd or ldptrd
instructions. But both instructions have the side effect that it will
signed-extended the imm operand. Finally, we got the wrong addresses
and panics is inevitable.

Use a generic ldxd instruction to avoid this kind of issues.

With this change, we have:

  # ./test_progs -t cgrp_local_storage
  Can't find bpf_testmod.ko kernel module: -2
  WARNING! Selftests relying on bpf_testmod.ko will be skipped.
  test_cgrp_local_storage:PASS:join_cgroup /cgrp_local_storage 0 nsec
  #48/1    cgrp_local_storage/tp_btf:OK
  test_attach_cgroup:PASS:skel_open 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  libbpf: prog 'update_cookie_tracing': failed to attach: ERROR: strerror_r(-524)=22
  test_attach_cgroup:FAIL:prog_attach unexpected error: -524
  #48/2    cgrp_local_storage/attach_cgroup:FAIL
  test_recursion:PASS:skel_open_and_load 0 nsec
  libbpf: prog 'on_lookup': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'on_lookup': failed to auto-attach: -524
  test_recursion:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/3    cgrp_local_storage/recursion:FAIL
  #48/4    cgrp_local_storage/negative:OK
  #48/5    cgrp_local_storage/cgroup_iter_sleepable:OK
  test_yes_rcu_lock:PASS:skel_open 0 nsec
  test_yes_rcu_lock:PASS:skel_load 0 nsec
  libbpf: prog 'yes_rcu_lock': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'yes_rcu_lock': failed to auto-attach: -524
  test_yes_rcu_lock:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/6    cgrp_local_storage/yes_rcu_lock:FAIL
  #48/7    cgrp_local_storage/no_rcu_lock:OK
  #48      cgrp_local_storage:FAIL

  All error logs:
  test_cgrp_local_storage:PASS:join_cgroup /cgrp_local_storage 0 nsec
  test_attach_cgroup:PASS:skel_open 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  libbpf: prog 'update_cookie_tracing': failed to attach: ERROR: strerror_r(-524)=22
  test_attach_cgroup:FAIL:prog_attach unexpected error: -524
  #48/2    cgrp_local_storage/attach_cgroup:FAIL
  test_recursion:PASS:skel_open_and_load 0 nsec
  libbpf: prog 'on_lookup': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'on_lookup': failed to auto-attach: -524
  test_recursion:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/3    cgrp_local_storage/recursion:FAIL
  test_yes_rcu_lock:PASS:skel_open 0 nsec
  test_yes_rcu_lock:PASS:skel_load 0 nsec
  libbpf: prog 'yes_rcu_lock': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'yes_rcu_lock': failed to auto-attach: -524
  test_yes_rcu_lock:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/6    cgrp_local_storage/yes_rcu_lock:FAIL
  #48      cgrp_local_storage:FAIL
  Summary: 0/4 PASSED, 0 SKIPPED, 1 FAILED

No panics any more (The test still failed because lack of BPF trampoline
which I am actively working on).

Fixes: 5dc61552 ("LoongArch: Add BPF JIT support")
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Currently, we store syscall nr in pt_regs::regs[11] and syscall execve()
accidentally overrides it during its execution:

    sys_execve()
      -> do_execve()
        -> do_execveat_common()
          -> bprm_execve()
            -> exec_binprm()
              -> search_binary_handler()
                -> load_elf_binary()
                  -> ELF_PLAT_INIT()

ELF_PLAT_INIT() reset regs[11] to 0, so in syscall_exit_to_user_mode()
we later get a wrong syscall nr. This breaks tools like execsnoop since
it relies on execve() tracepoints.

Skip pt_regs::regs[11] reset in ELF_PLAT_INIT() to fix the issue.
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

During unwinding, unwind_done() is used as an end condition. Normally it
unwind to the user stack and then set the stack type to unknown, which
is a normal exit. When something unexpected happens in unwind process
and we cannot unwind anymore, we should set the error flag, and also set
the stack type to unknown to indicate that the unwind process can not
continue. The error flag emphasizes that the unwind process produce an
unexpected error. There is no unexpected things when we unwind the PT_REGS
in the top of IRQ stack and find out that is an user mode PT_REGS. Thus,
we should not set error flag and just set stack type to unknown.
Reported-by: Hengqi Chen <hengqi.chen@gmail.com>
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

As we are just discarding the stable clock ID, simply write it into
$zero instead of allocating a temporary register.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

For the following assembly code:

     .text
     .global func
 func:
     nop

     .data
 var:
     .dword func

When linked with `-pie`, GNU LD populates the `var` variable with the
pre-relocated value of `func`. However, LLVM LLD does not exhibit the
same behavior. This issue also arises with the `kernel_entry` in arch/
loongarch/kernel/head.S:

 _head:
     .word   MZ_MAGIC                /* "MZ", MS-DOS header */
     .org    0x8
     .dword  kernel_entry            /* Kernel entry point */

The correct kernel entry from the MS-DOS header is crucial for jumping
to vmlinux from zboot. This necessity is why the compressed relocatable
kernel compiled by Clang encounters difficulties in booting.

To address this problem, it is proposed to apply dynamic relocations to
place with `--apply-dynamic-relocs`.

Link: https://github.com/ClangBuiltLinux/linux/issues/1962Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Pull SCSI fix from James Bottomley:
 "One tiny fix to the be2iscsi driver fixing a memory leak in an error
  leg"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: be2iscsi: Fix a memleak in beiscsi_init_wrb_handle()

Pull block fixes from Jens Axboe:
 "Nothing major in here, just miscellanous fixes for MD and NVMe:

   - NVMe pull request via Keith:
      - Proper nvme ctrl state setting (Keith)
      - Passthrough command optimization (Keith)
      - Spectre fix (Nitesh)
      - Kconfig clarifications (Shin'ichiro)
      - Frozen state deadlock fix (Bitao)
      - Power setting quirk (Georg)

   - MD pull requests via Song:
      - 6.7 regresisons with recovery/sync (Yu)
      - Reshape fix (David)"

* tag 'block-6.7-2023-12-08' of git://git.kernel.dk/linux:
  md: split MD_RECOVERY_NEEDED out of mddev_resume
  nvme-pci: Add sleep quirk for Kingston drives
  md: fix stopping sync thread
  md: don't leave 'MD_RECOVERY_FROZEN' in error path of md_set_readonly()
  md: fix missing flush of sync_work
  nvme: fix deadlock between reset and scan
  nvme: prevent potential spectre v1 gadget
  nvme: improve NVME_HOST_AUTH and NVME_TARGET_AUTH config descriptions
  nvme-ioctl: move capable() admin check to the end
  nvme: ensure reset state check ordering
  nvme: introduce helper function to get ctrl state
  md/raid6: use valid sector values to determine if an I/O should wait on the reshape

Pull io_uring fixes from Jens Axboe:
 "Two minor fixes for issues introduced in this release cycle, and two
  fixes for issues or potential issues that are heading to stable.

  One of these ends up disabling passing io_uring file descriptors via
  SCM_RIGHTS. There really shouldn't be an overlap between that kind of
  historic use case and modern usage of io_uring, which is why this was
  deemed appropriate"

* tag 'io_uring-6.7-2023-12-08' of git://git.kernel.dk/linux:
  io_uring/af_unix: disable sending io_uring over sockets
  io_uring/kbuf: check for buffer list readiness after NULL check
  io_uring/kbuf: Fix an NULL vs IS_ERR() bug in io_alloc_pbuf_ring()
  io_uring: fix mutex_unlock with unreferenced ctx