Add explicit KCSAN checks for bitops.
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This switches atomic-instrumented.h to use the generic instrumentation
wrappers provided by instrumented.h.

No functional change intended.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This adds instrumented.h, which provides generic wrappers for memory
access instrumentation that the compiler cannot emit for various
sanitizers. Currently this unifies KASAN and KCSAN instrumentation. In
future this will also include KMSAN instrumentation.

Note that, copy_{to,from}_user should use special instrumentation, since
we should be able to instrument both source and destination memory
accesses if both are kernel memory.

The current patch only instruments the memory access where the address
is always in kernel space, however, both may in fact be kernel addresses
when a compat syscall passes an argument allocated in the kernel to a
real syscall. In a future change, both KASAN and KCSAN should check both
addresses in such cases, as well as KMSAN will make use of both
addresses. [It made more sense to provide the completed function
signature, rather than updating it and changing all locations again at a
later time.]
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Even with KCSAN_REPORT_VALUE_CHANGE_ONLY, KCSAN still reports data
races between reads and watchpointed writes, even if the writes wrote
values already present.  This commit causes KCSAN to unconditionally
skip reporting in this case.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

We must avoid any recursion into lockdep if KCSAN is enabled on utilities
used by lockdep. One manifestation of this is corruption of lockdep's
IRQ trace state (if TRACE_IRQFLAGS), resulting in spurious warnings
(see below).  This commit fixes this by:

1. Using raw_local_irq{save,restore} in kcsan_setup_watchpoint().
2. Disabling lockdep in kcsan_report().

Tested with:

  CONFIG_LOCKDEP=y
  CONFIG_DEBUG_LOCKDEP=y
  CONFIG_TRACE_IRQFLAGS=y

This fix eliminates spurious warnings such as the following one:

    WARNING: CPU: 0 PID: 2 at kernel/locking/lockdep.c:4406 check_flags.part.0+0x101/0x220
    Modules linked in:
    CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.5.0-rc1+ #11
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
    RIP: 0010:check_flags.part.0+0x101/0x220
    <snip>
    Call Trace:
     lock_is_held_type+0x69/0x150
     freezer_fork+0x20b/0x370
     cgroup_post_fork+0x2c9/0x5c0
     copy_process+0x2675/0x3b40
     _do_fork+0xbe/0xa30
     ? _raw_spin_unlock_irqrestore+0x40/0x50
     ? match_held_lock+0x56/0x250
     ? kthread_park+0xf0/0xf0
     kernel_thread+0xa6/0xd0
     ? kthread_park+0xf0/0xf0
     kthreadd+0x321/0x3d0
     ? kthread_create_on_cpu+0x130/0x130
     ret_from_fork+0x3a/0x50
    irq event stamp: 64
    hardirqs last  enabled at (63): [<ffffffff9a7995d0>] _raw_spin_unlock_irqrestore+0x40/0x50
    hardirqs last disabled at (64): [<ffffffff992a96d2>] kcsan_setup_watchpoint+0x92/0x460
    softirqs last  enabled at (32): [<ffffffff990489b8>] fpu__copy+0xe8/0x470
    softirqs last disabled at (30): [<ffffffff99048939>] fpu__copy+0x69/0x470
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

KCSAN data-race reports can occur quite frequently, so much so as
to render the system useless.  This commit therefore adds support for
time-based rate-limiting KCSAN reports, with the time interval specified
by a new KCSAN_REPORT_ONCE_IN_MS Kconfig option.  The default is 3000
milliseconds, also known as three seconds.

Because KCSAN must detect data races in allocators and in other contexts
where use of allocation is ill-advised, a fixed-size array is used to
buffer reports during each reporting interval.  To reduce the number of
reports lost due to array overflow, this commit stores only one instance
of duplicate reports, which has the benefit of further reducing KCSAN's
console output rate.
Reported-by: Qian Cai <cai@lca.pw>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This commit adds access-type information to KCSAN's reports as follows:
"read", "read (marked)", "write", and "write (marked)".
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Prefer __always_inline for fast-path functions that are called outside
of user_access_save, to avoid generating UACCESS warnings when
optimizing for size (CC_OPTIMIZE_FOR_SIZE). It will also avoid future
surprises with compiler versions that change the inlining heuristic even
when optimizing for performance.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/58708908-84a0-0a81-a836-ad97e33dbb62@infradead.org

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Conflicts:
	arch/x86/purgatory/Makefile
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull arm64 fixes from Will Deacon:

 - Fix panic() when it occurs during secondary CPU startup

 - Fix "kpti=off" when KASLR is enabled

 - Fix howler in compat syscall table for vDSO clock_getres() fallback

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: compat: Fix syscall number of compat_clock_getres
  arm64: kpti: Fix "kpti=off" when KASLR is enabled
  arm64: smp: fix crash_smp_send_stop() behaviour
  arm64: smp: fix smp_send_stop() behaviour

Pull char/misc driver fixes from Greg KH:
 "Here are some small different driver fixes for 5.6-rc7:

   - binderfs fix, yet again

   - slimbus new device id added

   - hwtracing bugfixes for reported issues and a new device id

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

* tag 'char-misc-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  intel_th: pci: Add Elkhart Lake CPU support
  intel_th: Fix user-visible error codes
  intel_th: msu: Fix the unexpected state warning
  stm class: sys-t: Fix the use of time_after()
  slimbus: ngd: add v2.1.0 compatible
  binderfs: use refcount for binder control devices too

Pull staging/IIO fixes from Greg KH:
 "Here are a number of small staging and IIO driver fixes for 5.6-rc7

  Nothing major here, just resolutions for some reported problems:
   - iio bugfixes for a number of different drivers
   - greybus loopback_test fixes
   - wfx driver fixes

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

* tag 'staging-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: rtl8188eu: Add device id for MERCUSYS MW150US v2
  staging: greybus: loopback_test: fix potential path truncations
  staging: greybus: loopback_test: fix potential path truncation
  staging: greybus: loopback_test: fix poll-mask build breakage
  staging: wfx: fix RCU usage between hif_join() and ieee80211_bss_get_ie()
  staging: wfx: fix RCU usage in wfx_join_finalize()
  staging: wfx: make warning about pending frame less scary
  staging: wfx: fix lines ending with a comma instead of a semicolon
  staging: wfx: fix warning about freeing in-use mutex during device unregister
  staging/speakup: fix get_word non-space look-ahead
  iio: ping: set pa_laser_ping_cfg in of_ping_match
  iio: chemical: sps30: fix missing triggered buffer dependency
  iio: st_sensors: remap SMO8840 to LIS2DH12
  iio: light: vcnl4000: update sampling periods for vcnl4040
  iio: light: vcnl4000: update sampling periods for vcnl4200
  iio: accel: adxl372: Set iio_chan BE
  iio: magnetometer: ak8974: Fix negative raw values in sysfs
  iio: trigger: stm32-timer: disable master mode when stopping
  iio: adc: stm32-dfsdm: fix sleep in atomic context
  iio: adc: at91-sama5d2_adc: fix differential channels in triggered mode

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 5.6-rc7. And there's a thunderbolt
  driver fix thrown in for good measure as well.

  These fixes are:
   - new device ids for usb-serial drivers
   - thunderbolt error code fix
   - xhci driver fixes
   - typec fixes
   - cdc-acm driver fixes
   - chipidea driver fix
   - more USB quirks added for devices that need them.

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

* tag 'usb-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: cdc-acm: fix rounding error in TIOCSSERIAL
  USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL
  usb: quirks: add NO_LPM quirk for RTL8153 based ethernet adapters
  usb: chipidea: udc: fix sleeping function called from invalid context
  USB: serial: pl2303: add device-id for HP LD381
  USB: serial: option: add ME910G1 ECM composition 0x110b
  usb: host: xhci-plat: add a shutdown
  usb: typec: ucsi: displayport: Fix a potential race during registration
  usb: typec: ucsi: displayport: Fix NULL pointer dereference
  USB: Disable LPM on WD19's Realtek Hub
  usb: xhci: apply XHCI_SUSPEND_DELAY to AMD XHCI controller 1022:145c
  xhci: Do not open code __print_symbolic() in xhci trace events
  thunderbolt: Fix error code in tb_port_is_width_supported()

Pull tty fixes from Greg KH:
 "Here are three small tty_io bugfixes for reported issues that Eric has
  resolved for 5.6-rc7

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

* tag 'tty-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix compat TIOCGSERIAL checking wrong function ptr
  tty: fix compat TIOCGSERIAL leaking uninitialized memory
  tty: drop outdated comments about release_tty() locking

Pull sound fixes from Takashi Iwai:
 "A few fixes covering the issues reported by syzkaller, a couple of
  fixes for the MIDI decoding bug, and a few usual HD-audio quirks.

  Some of them are about ALSA core stuff, but they are small fixes just
  for corner cases, and nothing thrilling"

* tag 'sound-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Enable the headset of Acer N50-600 with ALC662
  ALSA: hda/realtek - Enable headset mic of Acer X2660G with ALC662
  ALSA: seq: oss: Fix running status after receiving sysex
  ALSA: seq: virmidi: Fix running status after receiving sysex
  ALSA: pcm: oss: Remove WARNING from snd_pcm_plug_alloc() checks
  ALSA: hda/realtek: Fix pop noise on ALC225
  ALSA: line6: Fix endless MIDI read loop
  ALSA: pcm: oss: Avoid plugin buffer overflow

Pull drm fixes from Dave Airlie:
 "Hope you are well hiding out above the garage. A few amdgpu changes
  but nothing too major. I've had a wisdom tooth out this week so
  haven't been to on top of things, but all seems good.

  core:
   - fix lease warning

  i915:
   - Track active elements during dequeue
   - Fix failure to handle all MCR ranges
   - Revert unnecessary workaround

  amdgpu:
   - Pageflip fix
   - VCN clockgating fixes
   - GPR debugfs fix for umr
   - GPU reset fix
   - eDP fix for MBP
   - DCN2.x fix

  dw-hdmi:
   - fix AVI frame colorimetry

  komeda:
   - fix compiler warning

  bochs:
   - downgrade a binding failure to a warning"

* tag 'drm-fixes-2020-03-20' of git://anongit.freedesktop.org/drm/drm:
  drm/amd/display: Fix pageflip event race condition for DCN.
  drm/amdgpu: fix typo for vcn2.5/jpeg2.5 idle check
  drm/amdgpu: fix typo for vcn2/jpeg2 idle check
  drm/amdgpu: fix typo for vcn1 idle check
  drm/lease: fix WARNING in idr_destroy
  drm/i915: Handle all MCR ranges
  Revert "drm/i915/tgl: Add extra hdc flush workaround"
  drm/i915/execlists: Track active elements during dequeue
  drm/bochs: downgrade pci_request_region failure from error to warning
  drm/amd/display: Add link_rate quirk for Apple 15" MBP 2017
  drm/amdgpu: add fbdev suspend/resume on gpu reset
  drm/amd/amdgpu: Fix GPR read from debugfs (v2)
  drm/amd/display: fix typos for dcn20_funcs and dcn21_funcs struct
  drm/komeda: mark PM functions as __maybe_unused
  drm/bridge: dw-hdmi: fix AVI frame colorimetry

Merge tag 'drm-intel-fixes-2020-03-19' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

drm/i915 fixes for v5.6-rc7:
- Track active elements during dequeue
- Fix failure to handle all MCR ranges
- Revert unnecessary workaround
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/877dzgepvu.fsf@intel.com

Merge tag 'amd-drm-fixes-5.6-2020-03-19' of git://people.freedesktop.org/~agd5f/linux into drm-fixes

amd-drm-fixes-5.6-2020-03-19:

amdgpu:
- Pageflip fix
- VCN clockgating fixes
- GPR debugfs fix for umr
- GPU reset fix
- eDP fix for MBP
- DCN2.x fix
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexdeucher@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200319204054.1036478-1-alexander.deucher@amd.com

Commit '16f17eda ("drm/amd/display: Send vblank and user
events at vsartup for DCN")' introduces a new way of pageflip
completion handling for DCN, and some trouble.

The current implementation introduces a race condition, which
can cause pageflip completion events to be sent out one vblank
too early, thereby confusing userspace and causing flicker:

prepare_flip_isr():

1. Pageflip programming takes the ddev->event_lock.
2. Sets acrtc->pflip_status == AMDGPU_FLIP_SUBMITTED
3. Releases ddev->event_lock.

--> Deadline for surface address regs double-buffering passes on
    target pipe.

4. dc_commit_updates_for_stream() MMIO programs the new pageflip
   into hw, but too late for current vblank.

=> pflip_status == AMDGPU_FLIP_SUBMITTED, but flip won't complete
   in current vblank due to missing the double-buffering deadline
   by a tiny bit.

5. VSTARTUP trigger point in vblank is reached, VSTARTUP irq fires,
   dm_dcn_crtc_high_irq() gets called.

6. Detects pflip_status == AMDGPU_FLIP_SUBMITTED and assumes the
   pageflip has been completed/will complete in this vblank and
   sends out pageflip completion event to userspace and resets
   pflip_status = AMDGPU_FLIP_NONE.

=> Flip completion event sent out one vblank too early.

This behaviour has been observed during my testing with measurement
hardware a couple of time.

The commit message says that the extra flip event code was added to
dm_dcn_crtc_high_irq() to prevent missing to send out pageflip events
in case the pflip irq doesn't fire, because the "DCH HUBP" component
is clock gated and doesn't fire pflip irqs in that state. Also that
this clock gating may happen if no planes are active. This suggests
that the problem addressed by that commit can't happen if planes
are active.

The proposed solution is therefore to only execute the extra pflip
completion code iff the count of active planes is zero and otherwise
leave pflip completion handling to the pflip irq handler, for a
more race-free experience.

Note that i don't know if this fixes the problem the original commit
tried to address, as i don't know what the test scenario was. It
does fix the observed too early pageflip events though and points
out the problem introduced.

Fixes: 16f17eda ("drm/amd/display: Send vblank and user events at vsartup for DCN")
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Pull MMC fixes from Ulf Hansson:

 - rtsx_pci: Fix support for some various speed modes

 - sdhci-of-at91: Fix support for GPIO card detect on SAMA5D2

 - sdhci-cadence: Fix support for DDR52 speed mode for eMMC on UniPhier

 - sdhci-acpi: Fix broken WP support on Acer Aspire Switch 10

 - sdhci-acpi: Workaround FW bug for suspend on Lenovo Miix 320

* tag 'mmc-v5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: rtsx_pci: Fix support for speed-modes that relies on tuning
  mmc: sdhci-of-at91: fix cd-gpios for SAMA5D2
  mmc: sdhci-cadence: set SDHCI_QUIRK2_PRESET_VALUE_BROKEN for UniPhier
  mmc: sdhci-acpi: Disable write protect detection on Acer Aspire Switch 10 (SW5-012)
  mmc: sdhci-acpi: Switch signal voltage back to 3.3V on suspend on external microSD on Lenovo Miix 320

The syscall number of compat_clock_getres was erroneously set to 247
(__NR_io_cancel!) instead of 264. This causes the vDSO fallback of
clock_getres() to land on the wrong syscall for compat tasks.

Fix the numbering.

Cc: <stable@vger.kernel.org>
Fixes: 53c489e1 ("arm64: compat: Add missing syscall numbers")
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

Pull cifs fixes from Steve French:
 "Three small smb3 fixes, two for stable"

* tag '5.6-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: fiemap: do not return EINVAL if get nothing
  CIFS: Increment num_remote_opens stats counter even in case of smb2_query_dir_first
  cifs: potential unintitliazed error code in cifs_getattr()

Merge tag 'kbuild-fixes-v5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - fix __uint128_t capability test in Kconfig when GCC that defaults to
   32-bit is used to build the 64-bit kernel

 - suppress new noisy Clang warnings -Wpointer-to-enum-cast

 - move the namespace field in Module.symvers for the backward
   compatibility reason for the depmod tool

 - use available compression for initramdisk when INTRAMFS_SOURCE is
   defined, which was the original behavior

 - fix modpost to handle correct large section numbers when it refers to
   modversion CRCs and module namespaces

 - fix comments and documents

* tag 'kbuild-fixes-v5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  scripts/kallsyms: fix wrong kallsyms_relative_base
  modpost: Get proper section index by get_secindex() instead of st_shndx
  initramfs: restore default compression behavior
  modpost: move the namespace field in Module.symvers last
  kbuild: Disable -Wpointer-to-enum-cast
  kbuild: doc: fix references to other documents
  int128: fix __uint128_t compiler test in Kconfig
  kconfig: introduce m32-flag and m64-flag
  kbuild: Fix inconsistent comment

I have hit the following build error:

  armv7a-hardfloat-linux-gnueabi-ld: drivers/rtc/rtc-max8907.o: in function `max8907_rtc_probe':
  rtc-max8907.c:(.text+0x400): undefined reference to `regmap_irq_get_virq'

max8907 should select REGMAP_IRQ

Fixes: 94c01ab6 ("rtc: add MAX8907 RTC driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is the code in the read_symbol function in 'scripts/kallsyms.c':

	if (is_ignored_symbol(name, type))
		return NULL;

	/* Ignore most absolute/undefined (?) symbols. */
	if (strcmp(name, "_text") == 0)
		_text = addr;

But the is_ignored_symbol function returns true for name="_text" and
type='A'. So the next condition is not executed and the _text variable
is always zero.

It makes the wrong kallsyms_relative_base symbol as a result of the code
(CONFIG_KALLSYMS_BASE_RELATIVE is defined):

	if (base_relative) {
		output_label("kallsyms_relative_base");
		output_address(relative_base);
		printf("\n");
	}

Because the output_address function uses the _text variable.

So the kallsyms_lookup function and all related functions in the kernel
do not work properly. For example, the stack trace in oops:

 Call Trace:
 [aa095e58] [809feab8] kobj_ns_ops_tbl+0x7ff09ac8/0x7ff1c1c4 (unreliable)
 [aa095e98] [80002b64] kobj_ns_ops_tbl+0x7f50db74/0x80000010
 [aa095ef8] [809c3d24] kobj_ns_ops_tbl+0x7feced34/0x7ff1c1c4
 [aa095f28] [80002ed0] kobj_ns_ops_tbl+0x7f50dee0/0x80000010
 [aa095f38] [8000f238] kobj_ns_ops_tbl+0x7f51a248/0x80000010

The right stack trace:

 Call Trace:
 [aa095e58] [809feab8] module_vdu_video_init+0x2fc/0x3bc (unreliable)
 [aa095e98] [80002b64] do_one_initcall+0x40/0x1f0
 [aa095ef8] [809c3d24] kernel_init_freeable+0x164/0x1d8
 [aa095f28] [80002ed0] kernel_init+0x14/0x124
 [aa095f38] [8000f238] ret_from_kernel_thread+0x14/0x1c

[masahiroy@kernel.org:

This issue happens on binutils <= 2.22
The following commit fixed it:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d2667025dd30611514810c28bee9709e4623012a

The symbol type of _text is 'T' on binutils >= 2.23
The minimal supported binutils version for the kernel build is 2.21
]
Signed-off-by: Mikhail Petrov <Mikhail.Petrov@mir.dev>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Enabling KASLR forces the use of non-global page-table entries for kernel
mappings, as this is a decision that we have to make very early on before
mapping the kernel proper. When used in conjunction with the "kpti=off"
command-line option, it is possible to use non-global kernel mappings but
with the kpti trampoline disabled.

Since commit 09e3c22a ("arm64: Use a variable to store non-global
mappings decision"), arm64_kernel_unmapped_at_el0() reflects only the use of
non-global mappings and does not take into account whether the kpti
trampoline is enabled. This breaks context switching of the TPIDRRO_EL0
register for 64-bit tasks, where the clearing of the register is deferred to
the ret-to-user code, but it also breaks the ARM SPE PMU driver which
helpfully recommends passing "kpti=off" on the command line!

Report whether or not KPTI is actually enabled in
arm64_kernel_unmapped_at_el0() and check the 'arm64_use_ng_mappings' global
variable directly when determining the protection flags for kernel mappings.

Cc: Mark Brown <broonie@kernel.org>
Reported-by: Hongbo Yao <yaohongbo@huawei.com>
Tested-by: Hongbo Yao <yaohongbo@huawei.com>
Fixes: 09e3c22a ("arm64: Use a variable to store non-global mappings decision")
Signed-off-by: Will Deacon <will@kernel.org>

Merge tag 'drm-misc-fixes-2020-03-18-1' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

- drm/lease: fix WARNING in idr_destroy
- Fix AVI frame colorimetry in the dw-hdmi bridge.
- Fix compiler warning in komeda by annotating functions as __maybe_unused.
- Downgrade bochs pci_request_region failure from error to warning to
  workaround firmware fb.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7654ac39-deb8-c9ca-9fd5-ef77b2636380@linux.intel.com

fix typo for vcn2.5/jpeg2.5 idle check
Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

fix typo for vcn2/jpeg2 idle check
Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

fix typo for vcn1 idle check
Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

There is measurable performance impact in some synthetic tests due to
commit 6d390e4b (locks: fix a potential use-after-free problem when
wakeup a waiter). Fix the race condition instead by clearing the
fl_blocker pointer after the wake_up, using explicit acquire/release
semantics.

This does mean that we can no longer use the clearing of fl_blocker as
the wait condition, so switch the waiters over to checking whether the
fl_blocked_member list_head is empty.
Reviewed-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Fixes: 6d390e4b (locks: fix a potential use-after-free problem when wakeup a waiter)
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(uint16_t) st_shndx is limited to 65535(i.e. SHN_XINDEX) so sym_get_data() gets
wrong section index by st_shndx if requested symbol contains extended section
index that is more than 65535.  In this case, we need to get proper section index
by .symtab_shndx section.

Module.symvers generated by building kernel with "-ffunction-sections -fdata-sections"
shows the issue.

Fixes: 56067812 ("kbuild: modversions: add infrastructure for emitting relative CRCs")
Fixes: e84f9fbb ("modpost: refactor namespace_from_kstrtabns() to not hard-code section name")
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This is just a cleanup addition to Jann's fix to properly update the
transaction ID for the slub slowpath in commit fd4d9c7d ("mm: slub:
add missing TID bump..").

The transaction ID is what protects us against any concurrent accesses,
but we should really also make sure to make the 'freelist' comparison
itself always use the same freelist value that we then used as the new
next free pointer.

Jann points out that if we do all of this carefully, we could skip the
transaction ID update for all the paths that only remove entries from
the lists, and only update the TID when adding entries (to avoid the ABA
issue with cmpxchg and list handling re-adding a previously seen value).

But this patch just does the "make sure to cmpxchg the same value we
used" rather than then try to be clever.
Acked-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When kmem_cache_alloc_bulk() attempts to allocate N objects from a percpu
freelist of length M, and N > M > 0, it will first remove the M elements
from the percpu freelist, then call ___slab_alloc() to allocate the next
element and repopulate the percpu freelist. ___slab_alloc() can re-enable
IRQs via allocate_slab(), so the TID must be bumped before ___slab_alloc()
to properly commit the freelist head change.

Fix it by unconditionally bumping c->tid when entering the slowpath.

Cc: stable@vger.kernel.org
Fixes: ebe909e0 ("slub: improve bulk alloc strategy")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm_lease_create takes ownership of leases. And leases will be released
by drm_master_put.

drm_master_put
    ->drm_master_destroy
            ->idr_destroy

So we needn't call idr_destroy again.

Reported-and-tested-by: syzbot+05835159fe322770fe3d@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1584518030-4173-1-git-send-email-hqjagain@gmail.com

Commit 77654350 ("take compat TIOC[SG]SERIAL treatment into
tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
checking for the presence of the ->set_serial function pointer rather
than ->get_serial.  This appears to be a copy-and-paste error, since
->get_serial is the function pointer that is called as well as the
pointer that is checked by the non-compat version of TIOCGSERIAL.

Fix this by checking the correct function pointer.

Fixes: 77654350 ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200224182044.234553-3-ebiggers@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 77654350 ("take compat TIOC[SG]SERIAL treatment into
tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
copying a whole 'serial_struct32' to userspace rather than individual
fields, but failed to initialize all padding and fields -- namely the
hole after the 'iomem_reg_shift' field, and the 'reserved' field.

Fix this by initializing the struct to zero.

[v2: use sizeof, and convert the adjacent line for consistency.]

Reported-by: syzbot+8da9175e28eadcb203ce@syzkaller.appspotmail.com
Fixes: 77654350 ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200224182044.234553-2-ebiggers@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The current version of the TTY code unlocks the tty_struct(s) before
release_tty() rather than after.  Moreover, tty_unlock_pair() no longer
exists.  Thus, remove the outdated comments regarding tty_unlock_pair().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200224073359.292795-1-ebiggers@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The TX/RX register should not be treated the same way to allow for better
support of tuning. Fix this by using a default initial value for TX.
Signed-off-by: Ricky Wu <ricky_wu@realtek.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200316025232.1167-1-ricky_wu@realtek.com
[Ulf: Updated changelog]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>