Currently, the KUNIT_EXPECT_STREQ() and related macros assign both
string arguments to variables of their own type (via typeof()). This
seems to be to prevent the macro argument from being evaluated multiple
times.

However, this doesn't work if one of these is a fixed-length character
array, rather than a character pointer, as (for example) char[16] will
always allocate a new string.

By always using 'const char*' (the type strcmp expects), we're always
just taking a pointer to the string, which works even with character
arrays.
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The use of typecheck() in KUNIT_EXPECT_EQ() and friends is causing more
problems than I think it's worth. Things like enums need to have their
values explicitly cast, and literals all need to be very precisely
typed, else a large warning will be printed.

While typechecking does have its uses, the additional overhead of having
lots of needless casts -- combined with the awkward error messages which
don't mention which types are involved -- makes tests less readable and
more difficult to write.

By removing the typecheck() call, the two arguments still need to be of
compatible types, but don't need to be of exactly the same time, which
seems a less confusing and more useful compromise.
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

We'll be replacing :doc:`foo` references to
Documentation/foo.rst. Yet, here it happens inside a table.
Doing a search-and-replace would break it.

Yet, as there's no good reason to use a table there,
let's just convert it into a list.
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Add basic support to run QEMU via kunit_tool. Add support for i386,
x86_64, arm, arm64, and a bunch more.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Document QEMU support, what it does, and how to use it in kunit_tool.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Add a new kernel command-line option, 'kunit_shutdown', which allows the
user to specify that the kernel poweroff, halt, or reboot after
completing all KUnit tests; this is very handy for running KUnit tests
on UML or a VM so that the UML/VM process exits cleanly immediately
after running all tests without needing a special initramfs.
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Tested-By: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

When one parameter of a parameterised test failed, its failure would be
propagated to the overall test, but not to the suite result (unless it
was the last parameter).

This is because test_case->success was being reset to the test->success
result after each parameter was used, so a failing test's result would
be overwritten by a non-failing result. The overall test result was
handled in a third variable, test_result, but this was discarded after
the status line was printed.

Instead, just propagate the result after each parameter run.
Signed-off-by: David Gow <davidgow@google.com>
Fixes: fadb08e7 ("kunit: Support for Parameterized Testing")
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The kunit_tool documentation page was pretty minimal, and a bit
outdated. Update it and flesh it out a bit.

In particular,
- Mention that .kunitconfig is now in the build directory
- Describe the use of --kunitconfig to specify a different config
  framgent
- Mention the split functionality (i.e., commands other than 'run')
- Describe --raw_output and kunit.py parse
- Mention the globbing support
- Provide a quick overview of other options, including --build_dir and
  --alltests

Note that this does overlap a little with the new running_tips page. I
don't think it's a problem having both: this page is supposed to be a
bit more of a reference, rather than a list of useful tips, so the fact
that they both describe the same features isn't a problem.
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

This is long overdue.

There are several things that aren't nailed down (in-tree
.kunitconfig's), or partially broken (GCOV on UML), but having them
documented, warts and all, is better than having nothing.

This covers a bunch of the more recent features
* kunit_filter_glob
* kunit.py run --kunitconfig
* slightly more detail on building tests as modules
* CONFIG_KUNIT_DEBUGFS

By my count, the only headline features now not mentioned are the KASAN
integration and KernelCI json output support (kunit.py run --json).

And then it also discusses how to get code coverage reports under UML
and non-UML since this is a question people have repeatedly asked.

Non-UML coverage collection is no different from normal, but we should
probably explicitly call this out.

As for UML, I was able to get it working again with two small hacks.*
E.g. with CONFIG_KUNIT=y && CONFIG_KUNIT_ALL_TESTS=y
  Overall coverage rate:
    lines......: 15.1% (18294 of 120776 lines)
    functions..: 16.8% (1860 of 11050 functions)

Note: this doesn't document --alltests since this is not stable yet.
Hopefully being run more frequently as part of KernelCI will help...

*Using gcc/gcov-6 and not using uml_abort() in os_dump_core().
I've documented these hacks in "Notes" but left TODOs for
brendanhiggins@google.com who tracked down the runtime issue in GCC.
To be clear: these are not issues specific to KUnit, but rather to UML.
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Merge tag 'driver-core-5.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are two driver fixes for driver core changes that happened in
  5.13-rc1.

  The clk driver fix resolves a many-reported issue with booting some
  devices, and the USB typec fix resolves the reported problem of USB
  systems on some embedded boards.

  Both of these have been in linux-next this week with no reported
  issues"

* tag 'driver-core-5.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  clk: Skip clk provider registration when np is NULL
  usb: typec: tcpm: Don't block probing of consumers of "connector" nodes

Pull staging and IIO driver fixes from Greg KH:
 "Here are some small IIO driver fixes and one Staging driver fix for
  5.13-rc2.

  Nothing major, just some resolutions for reported problems:

   - gcc-11 bogus warning fix for rtl8723bs

   - iio driver tiny fixes

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

* tag 'staging-5.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: tsl2583: Fix division by a zero lux_val
  iio: core: return ENODEV if ioctl is unknown
  iio: core: fix ioctl handlers removal
  iio: gyro: mpu3050: Fix reported temperature value
  iio: hid-sensors: select IIO_TRIGGERED_BUFFER under HID_SENSOR_IIO_TRIGGER
  iio: proximity: pulsedlight: Fix rumtime PM imbalance on error
  iio: light: gp2ap002: Fix rumtime PM imbalance on error
  staging: rtl8723bs: avoid bogus gcc warning

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 5.13-rc2. They consist of a number
  of resolutions for reported issues:

   - typec fixes for found problems

   - xhci fixes and quirk additions

   - dwc3 driver fixes

   - minor fixes found by Coverity

   - cdc-wdm fixes for reported problems

  All of these have been in linux-next for a few days with no reported
  issues"

* tag 'usb-5.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (28 commits)
  usb: core: hub: fix race condition about TRSMRCY of resume
  usb: typec: tcpm: Fix SINK_DISCOVERY current limit for Rp-default
  xhci: Add reset resume quirk for AMD xhci controller.
  usb: xhci: Increase timeout for HC halt
  xhci: Do not use GFP_KERNEL in (potentially) atomic context
  xhci: Fix giving back cancelled URBs even if halted endpoint can't reset
  xhci-pci: Allow host runtime PM as default for Intel Alder Lake xHCI
  usb: musb: Fix an error message
  usb: typec: tcpm: Fix wrong handling for Not_Supported in VDM AMS
  usb: typec: tcpm: Send DISCOVER_IDENTITY from dedicated work
  usb: typec: ucsi: Retrieve all the PDOs instead of just the first 4
  usb: fotg210-hcd: Fix an error message
  docs: usb: function: Modify path name
  usb: dwc3: omap: improve extcon initialization
  usb: typec: ucsi: Put fwnode in any case during ->probe()
  usb: typec: tcpm: Fix wrong handling in GET_SINK_CAP
  usb: dwc2: Remove obsolete MODULE_ constants from platform.c
  usb: dwc3: imx8mp: fix error return code in dwc3_imx8mp_probe()
  usb: dwc3: imx8mp: detect dwc3 core node via compatible string
  usb: dwc3: gadget: Return success always for kick transfer in ep queue
  ...

Pull timer fixes from Thomas Gleixner:
 "Two fixes for timers:

   - Use the ALARM feature check in the alarmtimer core code insted of
     the old method of checking for the set_alarm() callback.

     Drivers can have that callback set but the feature bit cleared. If
     such a RTC device is selected then alarms wont work.

   - Use a proper define to let the preprocessor check whether Hyper-V
     VDSO clocksource should be active.

     The code used a constant in an enum with #ifdef, which evaluates to
     always false and disabled the clocksource for VDSO"

* tag 'timers-urgent-2021-05-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/hyper-v: Re-enable VDSO_CLOCKMODE_HVCLOCK on X86
  alarmtimer: Check RTC features instead of ops

Pull xen fixes from Juergen Gross:

 - two patches for error path fixes

 - a small series for fixing a regression with swiotlb with Xen on Arm

* tag 'for-linus-5.13b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/swiotlb: check if the swiotlb has already been initialized
  arm64: do not set SWIOTLB_NO_FORCE when swiotlb is required
  xen/arm: move xen_swiotlb_detect to arm/swiotlb-xen.h
  xen/unpopulated-alloc: fix error return code in fill_list()
  xen/gntdev: fix gntdev_mmap() error exit path

Pull x86 fixes from Borislav Petkov:
 "The three SEV commits are not really urgent material. But we figured
  since getting them in now will avoid a huge amount of conflicts
  between future SEV changes touching tip, the kvm and probably other
  trees, sending them to you now would be best.

  The idea is that the tip, kvm etc branches for 5.14 will all base
  ontop of -rc2 and thus everything will be peachy. What is more, those
  changes are purely mechanical and defines movement so they should be
  fine to go now (famous last words).

  Summary:

   - Enable -Wundef for the compressed kernel build stage

   - Reorganize SEV code to streamline and simplify future development"

* tag 'x86_urgent_for_v5.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/compressed: Enable -Wundef
  x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFG
  x86/sev: Move GHCB MSR protocol and NAE definitions in a common header
  x86/sev-es: Rename sev-es.{ch} to sev.{ch}

Pull powerpc fixes from Michael Ellerman:

 - Fix a regression in the conversion of the 64-bit BookE interrupt
   entry to C.

 - Fix KVM hosts running with the hash MMU since the recent KVM gfn
   changes.

 - Fix a deadlock in our paravirt spinlocks when hcall tracing is
   enabled.

 - Several fixes for oopses in our runtime code patching for security
   mitigations.

 - A couple of minor fixes for the recent conversion of 32-bit interrupt
   entry/exit to C.

 - Fix __get_user() causing spurious crashes in sigreturn due to a bad
   inline asm constraint, spotted with GCC 11.

 - A fix for the way we track IRQ masking state vs NMI interrupts when
   using the new scv system call entry path.

 - A couple more minor fixes.

Thanks to Cédric Le Goater, Christian Zigotzky, Christophe Leroy,
Naveen N. Rao, Nicholas Piggin Paul Menzel, and Sean Christopherson.

* tag 'powerpc-5.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64e/interrupt: Fix nvgprs being clobbered
  powerpc/64s: Make NMI record implicitly soft-masked code as irqs disabled
  powerpc/64s: Fix stf mitigation patching w/strict RWX & hash
  powerpc/64s: Fix entry flush patching w/strict RWX & hash
  powerpc/64s: Fix crashes when toggling entry flush barrier
  powerpc/64s: Fix crashes when toggling stf barrier
  KVM: PPC: Book3S HV: Fix kvm_unmap_gfn_range_hv() for Hash MMU
  powerpc/legacy_serial: Fix UBSAN: array-index-out-of-bounds
  powerpc/signal: Fix possible build failure with unsafe_copy_fpr_{to/from}_user
  powerpc/uaccess: Fix __get_user() with CONFIG_CC_HAS_ASM_GOTO_OUTPUT
  powerpc/pseries: warn if recursing into the hcall tracing code
  powerpc/pseries: use notrace hcall variant for H_CEDE idle
  powerpc/pseries: Don't trace hcall tracing wrapper
  powerpc/pseries: Fix hcall tracing recursion in pv queued spinlocks
  powerpc/syscall: Calling kuap_save_and_lock() is wrong
  powerpc/interrupts: Fix kuep_unlock() call

Pull scheduler fixes from Ingo Molnar:
 "Fix an idle CPU selection bug, and an AMD Ryzen maximum frequency
  enumeration bug"

* tag 'sched-urgent-2021-05-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations
  sched/fair: Fix clearing of has_idle_cores flag in select_idle_cpu()

Pull objtool fixes from Ingo Molnar:
 "Fix a couple of endianness bugs that crept in"

* tag 'objtool-urgent-2021-05-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool/x86: Fix elf_add_alternative() endianness
  objtool: Fix elf_create_undef_symbol() endianness

Pull irq fix from Ingo Molnar:
 "Fix build warning on SH"

* tag 'irq-urgent-2021-05-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sh: Remove unused variable

Pull x86 stack randomization fix from Ingo Molnar:
 "Fix an assembly constraint that affected LLVM up to version 12"

* tag 'core-urgent-2021-05-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stack: Replace "o" output with "r" input constraint

Merge misc fixes from Andrew Morton:
 "13 patches.

  Subsystems affected by this patch series: resource, squashfs, hfsplus,
  modprobe, and mm (hugetlb, slub, userfaultfd, ksm, pagealloc, kasan,
  pagemap, and ioremap)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm/ioremap: fix iomap_max_page_shift
  docs: admin-guide: update description for kernel.modprobe sysctl
  hfsplus: prevent corruption in shrinking truncate
  mm/filemap: fix readahead return types
  kasan: fix unit tests with CONFIG_UBSAN_LOCAL_BOUNDS enabled
  mm: fix struct page layout on 32-bit systems
  ksm: revert "use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree()"
  userfaultfd: release page in error path to avoid BUG_ON
  squashfs: fix divide error in calculate_skip()
  kernel/resource: fix return code check in __request_free_mem_region
  mm, slub: move slub_debug static key enabling outside slab_mutex
  mm/hugetlb: fix cow where page writtable in child
  mm/hugetlb: fix F_SEAL_FUTURE_WRITE

Pull ARC fixes from Vineet Gupta:

 - PAE fixes

 - syscall num check off-by-one bug

 - misc fixes

* tag 'arc-5.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: mm: Use max_high_pfn as a HIGHMEM zone border
  ARC: mm: PAE: use 40-bit physical page mask
  ARC: entry: fix off-by-one error in syscall number validation
  ARC: kgdb: add 'fallthrough' to prevent a warning
  arc: Fix typos/spellos

Pull block fixes from Jens Axboe:

 - Fix for shared tag set exit (Bart)

 - Correct ioctl range for zoned ioctls (Damien)

 - Removed dead/unused function (Lin)

 - Fix perf regression for shared tags (Ming)

 - Fix out-of-bounds issue with kyber and preemption (Omar)

 - BFQ merge fix (Paolo)

 - Two error handling fixes for nbd (Sun)

 - Fix weight update in blk-iocost (Tejun)

 - NVMe pull request (Christoph):
      - correct the check for using the inline bio in nvmet (Chaitanya
        Kulkarni)
      - demote unsupported command warnings (Chaitanya Kulkarni)
      - fix corruption due to double initializing ANA state (me, Hou Pu)
      - reset ns->file when open fails (Daniel Wagner)
      - fix a NULL deref when SEND is completed with error in nvmet-rdma
        (Michal Kalderon)

 - Fix kernel-doc warning (Bart)

* tag 'block-5.13-2021-05-14' of git://git.kernel.dk/linux-block:
  block/partitions/efi.c: Fix the efi_partition() kernel-doc header
  blk-mq: Swap two calls in blk_mq_exit_queue()
  blk-mq: plug request for shared sbitmap
  nvmet: use new ana_log_size instead the old one
  nvmet: seset ns->file when open fails
  nbd: share nbd_put and return by goto put_nbd
  nbd: Fix NULL pointer in flush_workqueue
  blkdev.h: remove unused codes blk_account_rq
  block, bfq: avoid circular stable merges
  blk-iocost: fix weight updates of inner active iocgs
  nvmet: demote fabrics cmd parse err msg to debug
  nvmet: use helper to remove the duplicate code
  nvmet: demote discovery cmd parse err msg to debug
  nvmet-rdma: Fix NULL deref when SEND is completed with error
  nvmet: fix inline bio check for passthru
  nvmet: fix inline bio check for bdev-ns
  nvme-multipath: fix double initialization of ANA state
  kyber: fix out of bounds access when preempted
  block: uapi: fix comment about block device ioctl

Pull io_uring fixes from Jens Axboe:
 "Just a few minor fixes/changes:

   - Fix issue with double free race for linked timeout completions

   - Fix reference issue with timeouts

   - Remove last few places that make SQPOLL special, since it's just an
     io thread now.

   - Bump maximum allowed registered buffers, as we don't allocate as
     much anymore"

* tag 'io_uring-5.13-2021-05-14' of git://git.kernel.dk/linux-block:
  io_uring: increase max number of reg buffers
  io_uring: further remove sqpoll limits on opcodes
  io_uring: fix ltout double free on completion race
  io_uring: fix link timeout refs

Pull erofs fixes from Gao Xiang:
 "This mainly fixes 1 lcluster-sized pclusters for the big pcluster
  feature, which can be forcely generated by mkfs as a specific on-disk
  case for per-(sub)file compression strategies but missed to handle in
  runtime properly.

  Also, documentation updates are included to fix the broken
  illustration due to the ReST conversion by accident and complete the
  big pcluster introduction.

  Summary:

   - update documentation to fix the broken illustration due to ReST
     conversion by accident at that time and complete the big pcluster
     introduction

   - fix 1 lcluster-sized pclusters for the big pcluster feature"

* tag 'erofs-for-5.13-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix 1 lcluster-sized pcluster for big pcluster
  erofs: update documentation about data compression
  erofs: fix broken illustration in documentation

Pull libnvdimm fixes from Dan Williams:
 "A regression fix for a bootup crash condition introduced in this merge
  window and some other minor fixups:

   - Fix regression in ACPI NFIT table handling leading to crashes and
     driver load failures.

   - Move the nvdimm mailing list

   - Miscellaneous minor fixups"

* tag 'libnvdimm-fixes-5.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  ACPI: NFIT: Fix support for variable 'SPA' structure size
  MAINTAINERS: Move nvdimm mailing list
  tools/testing/nvdimm: Make symbol '__nfit_test_ioremap' static
  libnvdimm: Remove duplicate struct declaration

Pull dax fixes from Dan Williams:
 "A fix for a hang condition due to missed wakeups in the filesystem-dax
  core when exercised by virtiofs.

  This bug has been there from the beginning, but the condition has
  not triggered on other filesystems since they hold a lock over
  invalidation events"

* tag 'dax-fixes-5.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Wake up all waiters after invalidating dax entry
  dax: Add a wakeup mode parameter to put_unlocked_entry()
  dax: Add an enum for specifying dax wakup mode

Pull more drm fixes from Dave Airlie:
 "Looks like I wasn't the only one not fully switched on this week. The
  msm pull has a missing tag so I missed it, and i915 team were a bit
  late. In my defence I did have a day with the roof of my home office
  removed, so was sitting at my kids desk.

  msm:
   - dsi regression fix
   - dma-buf pinning fix
   - displayport fixes
   - llc fix

  i915:
   - Fix active callback alignment annotations and subsequent crashes
   - Retract link training strategy to slow and wide, again
   - Avoid division by zero on gen2
   - Use correct width reads for C0DRB3/C1DRB3 registers
   - Fix double free in pdp allocation failure path
   - Fix HDMI 2.1 PCON downstream caps check"

* tag 'drm-fixes-2021-05-15' of git://anongit.freedesktop.org/drm/drm:
  drm/i915: Use correct downstream caps for check Src-Ctl mode for PCON
  drm/i915/overlay: Fix active retire callback alignment
  drm/i915: Fix crash in auto_retire
  drm/i915/gt: Fix a double free in gen8_preallocate_top_level_pdp
  drm/i915: Read C0DRB3/C1DRB3 as 16 bits again
  drm/i915: Avoid div-by-zero on gen2
  drm/i915/dp: Use slow and wide link training for everything
  drm/msm/dp: initialize audio_comp when audio starts
  drm/msm/dp: check sink_count before update is_connected status
  drm/msm: fix minor version to indicate MSM_PARAM_SUSPENDS support
  drm/msm/dsi: fix msm_dsi_phy_get_clk_provider return code
  drm/msm/dsi: dsi_phy_28nm_8960: fix uninitialized variable access
  drm/msm: fix LLC not being enabled for mmu500 targets
  drm/msm: Do not unpin/evict exported dma-buf's

syzbot is reporting OOB write at vga16fb_imageblit() [1], for
resize_screen() from ioctl(VT_RESIZE) returns 0 without checking whether
requested rows/columns fit the amount of memory reserved for the graphical
screen if current mode is KD_GRAPHICS.

----------
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <sys/ioctl.h>
  #include <linux/kd.h>
  #include <linux/vt.h>

  int main(int argc, char *argv[])
  {
        const int fd = open("/dev/char/4:1", O_RDWR);
        struct vt_sizes vt = { 0x4100, 2 };

        ioctl(fd, KDSETMODE, KD_GRAPHICS);
        ioctl(fd, VT_RESIZE, &vt);
        ioctl(fd, KDSETMODE, KD_TEXT);
        return 0;
  }
----------

Allow framebuffer drivers to return -EINVAL, by moving vc->vc_mode !=
KD_GRAPHICS check from resize_screen() to fbcon_resize().

Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1]
Reported-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iomap_max_page_shift is expected to contain a page shift, so it can't be a
'bool', has to be an 'unsigned int'

And fix the default values: P4D_SHIFT is when huge iomap is allowed.

However, on some architectures (eg: powerpc book3s/64), P4D_SHIFT is not a
constant so it can't be used to initialise a static variable.  So,
initialise iomap_max_page_shift with a maximum shift supported by the
architecture, it is gated by P4D_SHIFT in vmap_try_huge_p4d() anyway.

Link: https://lkml.kernel.org/r/ad2d366015794a9f21320dcbdd0a8eb98979e9df.1620898113.git.christophe.leroy@csgroup.eu
Fixes: bbc180a5 ("mm: HUGE_VMAP arch support cleanup")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When I added CONFIG_MODPROBE_PATH, I neglected to update Documentation/.
It's still true that this defaults to /sbin/modprobe, but now via a level
of indirection.  So document that the kernel might have been built with
something other than /sbin/modprobe as the initial value.

Link: https://lkml.kernel.org/r/20210420125324.1246826-1-linux@rasmusvillemoes.dk
Fixes: 17652f42 ("modules: add CONFIG_MODPROBE_PATH")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I believe there are some issues introduced by commit 31651c60
("hfsplus: avoid deadlock on file truncation")

HFS+ has extent records which always contains 8 extents.  In case the
first extent record in catalog file gets full, new ones are allocated from
extents overflow file.

In case shrinking truncate happens to middle of an extent record which
locates in extents overflow file, the logic in hfsplus_file_truncate() was
changed so that call to hfs_brec_remove() is not guarded any more.

Right action would be just freeing the extents that exceed the new size
inside extent record by calling hfsplus_free_extents(), and then check if
the whole extent record should be removed.  However since the guard
(blk_cnt > start) is now after the call to hfs_brec_remove(), this has
unfortunate effect that the last matching extent record is removed
unconditionally.

To reproduce this issue, create a file which has at least 10 extents, and
then perform shrinking truncate into middle of the last extent record, so
that the number of remaining extents is not under or divisible by 8.  This
causes the last extent record (8 extents) to be removed totally instead of
truncating into middle of it.  Thus this causes corruption, and lost data.

Fix for this is simply checking if the new truncated end is below the
start of this extent record, making it safe to remove the full extent
record.  However call to hfs_brec_remove() can't be moved to it's previous
place since we're dropping ->tree_lock and it can cause a race condition
and the cached info being invalidated possibly corrupting the node data.

Another issue is related to this one.  When entering into the block
(blk_cnt > start) we are not holding the ->tree_lock.  We break out from
the loop not holding the lock, but hfs_find_exit() does unlock it.  Not
sure if it's possible for someone else to take the lock under our feet,
but it can cause hard to debug errors and premature unlocking.  Even if
there's no real risk of it, the locking should still always be kept in
balance.  Thus taking the lock now just before the check.

Link: https://lkml.kernel.org/r/20210429165139.3082828-1-jouni.roivas@tuxera.com
Fixes: 31651c60 ("hfsplus: avoid deadlock on file truncation")
Signed-off-by: Jouni Roivas <jouni.roivas@tuxera.com>
Reviewed-by: Anton Altaparmakov <anton@tuxera.com>
Cc: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A readahead request will not allocate more memory than can be represented
by a size_t, even on systems that have HIGHMEM available.  Change the
length functions from returning an loff_t to a size_t.

Link: https://lkml.kernel.org/r/20210510201201.1558972-1-willy@infradead.org
Fixes: 32c0a6bc ("btrfs: add and use readahead_batch_length")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

These tests deliberately access these arrays out of bounds, which will
cause the dynamic local bounds checks inserted by
CONFIG_UBSAN_LOCAL_BOUNDS to fail and panic the kernel.  To avoid this
problem, access the arrays via volatile pointers, which will prevent the
compiler from being able to determine the array bounds.

These accesses use volatile pointers to char (char *volatile) rather than
the more conventional pointers to volatile char (volatile char *) because
we want to prevent the compiler from making inferences about the pointer
itself (i.e.  its array bounds), not the data that it refers to.

Link: https://lkml.kernel.org/r/20210507025915.1464056-1-pcc@google.com
Link: https://linux-review.googlesource.com/id/I90b1713fbfa1bf68ff895aef099ea77b98a7c3b9Signed-off-by: Peter Collingbourne <pcc@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

32-bit architectures which expect 8-byte alignment for 8-byte integers and
need 64-bit DMA addresses (arm, mips, ppc) had their struct page
inadvertently expanded in 2019.  When the dma_addr_t was added, it forced
the alignment of the union to 8 bytes, which inserted a 4 byte gap between
'flags' and the union.

Fix this by storing the dma_addr_t in one or two adjacent unsigned longs.
This restores the alignment to that of an unsigned long.  We always
store the low bits in the first word to prevent the PageTail bit from
being inadvertently set on a big endian platform.  If that happened,
get_user_pages_fast() racing against a page which was freed and
reallocated to the page_pool could dereference a bogus compound_head(),
which would be hard to trace back to this cause.

Link: https://lkml.kernel.org/r/20210510153211.1504886-1-willy@infradead.org
Fixes: c25fff71 ("mm: add dma_addr_t to struct page")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Matteo Croce <mcroce@linux.microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 3e96b6a2.  General
Protection Fault in rmap_walk_ksm() under memory pressure:
remove_rmap_item_from_tree() needs to take page lock, of course.

Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2105092253500.1127@eggly.anvilsSigned-off-by: Hugh Dickins <hughd@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Consider the following sequence of events:

1. Userspace issues a UFFD ioctl, which ends up calling into
   shmem_mfill_atomic_pte(). We successfully account the blocks, we
   shmem_alloc_page(), but then the copy_from_user() fails. We return
   -ENOENT. We don't release the page we allocated.
2. Our caller detects this error code, tries the copy_from_user() after
   dropping the mmap_lock, and retries, calling back into
   shmem_mfill_atomic_pte().
3. Meanwhile, let's say another process filled up the tmpfs being used.
4. So shmem_mfill_atomic_pte() fails to account blocks this time, and
   immediately returns - without releasing the page.

This triggers a BUG_ON in our caller, which asserts that the page
should always be consumed, unless -ENOENT is returned.

To fix this, detect if we have such a "dangling" page when accounting
fails, and if so, release it before returning.

Link: https://lkml.kernel.org/r/20210428230858.348400-1-axelrasmussen@google.com
Fixes: cb658a45 ("userfaultfd: shmem: avoid leaking blocks and used blocks in UFFDIO_COPY")
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Reported-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Sysbot has reported a "divide error" which has been identified as being
caused by a corrupted file_size value within the file inode.  This value
has been corrupted to a much larger value than expected.

Calculate_skip() is passed i_size_read(inode) >> msblk->block_log.  Due to
the file_size value corruption this overflows the int argument/variable in
that function, leading to the divide error.

This patch changes the function to use u64.  This will accommodate any
unexpectedly large values due to corruption.

The value returned from calculate_skip() is clamped to be never more than
SQUASHFS_CACHED_BLKS - 1, or 7.  So file_size corruption does not lead to
an unexpectedly large return result here.

Link: https://lkml.kernel.org/r/20210507152618.9447-1-phillip@squashfs.org.ukSigned-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: <syzbot+e8f781243ce16ac2f962@syzkaller.appspotmail.com>
Reported-by: <syzbot+7b98870d4fec9447b951@syzkaller.appspotmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Splitting an earlier version of a patch that allowed calling
__request_region() while holding the resource lock into a series of
patches required changing the return code for the newly introduced
__request_region_locked().

Unfortunately this change was not carried through to a subsequent commit
56fd9491 ("kernel/resource: fix locking in request_free_mem_region")
in the series.  This resulted in a use-after-free due to freeing the
struct resource without properly releasing it.  Fix this by correcting the
return code check so that the struct is not freed if the request to add it
was successful.

Link: https://lkml.kernel.org/r/20210512073528.22334-1-apopple@nvidia.com
Fixes: 56fd9491 ("kernel/resource: fix locking in request_free_mem_region")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Muchun Song <smuchun@gmail.com>
Cc: Oliver Sang <oliver.sang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>