Vijendar Mukunda [Mon, 18 Oct 2021 11:20:37 +0000 (16:50 +0530)]
ASoC: amd: add acp6x irq handler
Add ACP6x irq handler for handling irq events for ACP IP.
Add pdm irq events handling.
Whenever audio data equal to the PDM watermark level are consumed,
interrupt is generated. Acknowledge the interrupt.
Vijendar Mukunda [Mon, 18 Oct 2021 11:20:36 +0000 (16:50 +0530)]
ASoC: amd: add acp6x pdm platform driver
PDM platform driver binds to the platform device created by
ACP6x PCI device. PDM driver registers ALSA DMA and CPU DAI
components with ASoC framework.
Vijendar Mukunda [Mon, 18 Oct 2021 11:20:35 +0000 (16:50 +0530)]
ASoC: amd: add platform devices for acp6x pdm driver and dmic driver
ACP6.x IP has PDM decoder block.
Create a platform device for it, so that the PDM platform driver
can be bound to this device.
Pass PCI resources like MMIO to this platform device.
Create a platform device for generic dmic codec driver.
Tzung-Bi Shih [Mon, 18 Oct 2021 10:16:08 +0000 (18:16 +0800)]
ASoC: dt-bindings: mediatek: rename reset controller headers in DT example
Commit f07c776f6d7e ("arm64: dts: mediatek: Move reset controller
constants into common location") moves the reset controller headers.
However, it forgot to rename the DT example in mt8192-afe-pcm.yaml.
Nicolas Frattaroli [Fri, 15 Oct 2021 21:07:29 +0000 (23:07 +0200)]
ASoC: rockchip: i2s-tdm: Fix refcount test
During development of V5 of the i2s-tdm patch series, I replaced
the atomic refcount with a regular integer, as it was only ever
accessed within a spinlock.
Foolishly, I got the semantics of atomic_dec_and_test wrong, which
resulted in a test for 0 actually becoming a test for >0.
The result was that setting the audio frequency broke; switching
from 44100 Hz audio playback to 96000 Hz audio playback would
garble the sound most unpleasantly.
Fix this by checking for --refcount == 0, which is what it should
have been all along.
Uwe Kleine-König [Fri, 15 Oct 2021 07:11:13 +0000 (09:11 +0200)]
ASoC: tlv320aic32x4: Make aic32x4_remove() return void
Up to now aic32x4_remove() returns zero unconditionally. Make it return
void instead which makes it easier to see in the callers that there is
no error to handle.
Also the return value of i2c and spi remove callbacks is ignored anyway.
Kuninori Morimoto [Mon, 18 Oct 2021 02:05:05 +0000 (11:05 +0900)]
ASoC: soc-pcm: tidyup soc_pcm_hw_clean() - step2
DAI active count is not exchanged during for_each_rtd_dais()
loops. We don't need to keep snd_soc_dai_stream_active() as
"active" on soc_pcm_hw_clean(). This patch avoid verbose code.
Linus Torvalds [Mon, 18 Oct 2021 05:39:22 +0000 (19:39 -1000)]
Merge tag 'libata-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata
Pull libata fixes from Damien Le Moal:
"Two fixes for this cycle:
- Fix a null pointer dereference in ahci-platform driver (from Hai)
- Fix uninitialized variables in pata_legacy driver (from Dan)"
* tag 'libata-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
ata: ahci_platform: fix null-ptr-deref in ahci_platform_enable_regulators()
pata_legacy: fix a couple uninitialized variable bugs
Linus Torvalds [Mon, 18 Oct 2021 05:25:20 +0000 (19:25 -1000)]
Merge tag 'block-5.15-2021-10-17' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Bigger than usual for this point in time, the majority is fixing some
issues around BDI lifetimes with the move from the request_queue to
the disk in this release. In detail:
- Series on draining fs IO for del_gendisk() (Christoph)
- NVMe pull request via Christoph:
- fix the abort command id (Keith Busch)
- nvme: fix per-namespace chardev deletion (Adam Manzanares)
- brd locking scope fix (Tetsuo)
- BFQ fix (Paolo)"
* tag 'block-5.15-2021-10-17' of git://git.kernel.dk/linux-block:
block, bfq: reset last_bfqq_created on group change
block: warn when putting the final reference on a registered disk
brd: reduce the brd_devices_mutex scope
kyber: avoid q->disk dereferences in trace points
block: keep q_usage_counter in atomic mode after del_gendisk
block: drain file system I/O on del_gendisk
block: split bio_queue_enter from blk_queue_enter
block: factor out a blk_try_enter_queue helper
block: call submit_bio_checks under q_usage_counter
nvme: fix per-namespace chardev deletion
block/rnbd-clt-sysfs: fix a couple uninitialized variable bugs
nvme-pci: Fix abort command id
Linus Torvalds [Mon, 18 Oct 2021 04:17:19 +0000 (18:17 -1000)]
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio fixes from Michael Tsirkin:
"Fixes up some issues in rc5"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost-vdpa: Fix the wrong input in config_cb
VDUSE: fix documentation underline warning
Revert "virtio-blk: Add validation for block size in config space"
vhost_vdpa: unset vq irq before freeing irq
virtio: write back F_VERSION_1 before validate
Linus Torvalds [Mon, 18 Oct 2021 04:01:32 +0000 (18:01 -1000)]
Merge tag 'powerpc-5.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix a bug where guests on P9 with interrupts passed through could get
stuck in synchronize_irq().
- Fix a bug in KVM on P8 where secondary threads entering a guest would
write outside their allocated stack.
- Fix a bug in KVM on P8 where secondary threads could confuse the host
offline code and cause the guest or host to crash.
Thanks to Cédric Le Goater.
* tag 'powerpc-5.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
KVM: PPC: Book3S HV: Make idle_kvm_start_guest() return 0 if it went to guest
KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
powerpc/xive: Discard disabled interrupts in get_irqchip_state()
Linus Torvalds [Mon, 18 Oct 2021 03:41:39 +0000 (17:41 -1000)]
Merge tag 'objtool_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fixes from Borislav Petkov:
- Update section headers before the respective relocations to not
trigger a safety check in elftoolchain's implementation of libelf
- Do not add garbage data to the .rela.orc_unwind_ip section
* tag 'objtool_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Update section header before relocations
objtool: Check for gelf_update_rel[a] failures
Linus Torvalds [Mon, 18 Oct 2021 03:30:49 +0000 (17:30 -1000)]
Merge tag 'efi-urgent-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Borislav Petkov:
"Forwarded from Ard Biesheuvel through the tip tree. Ard will send
stuff directly in the near future.
Low priority fixes but fixes nonetheless:
- update stub diagnostic print that is no longer accurate
- avoid statically allocated buffer for CPER error record decoding
- avoid sleeping on the efi_runtime semaphore when calling the
ResetSystem EFI runtime service"
* tag 'efi-urgent-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: Change down_interruptible() in virt_efi_reset_system() to down_trylock()
efi/cper: use stack buffer for error record decoding
efi/libstub: Simplify "Exiting bootservices" message
Linus Torvalds [Mon, 18 Oct 2021 03:27:22 +0000 (17:27 -1000)]
Merge tag 'x86_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Do not enable AMD memory encryption in Kconfig by default due to
shortcomings of some platforms, leading to boot failures.
- Mask out invalid bits in the MXCSR for 32-bit kernels again because
Thomas and I don't know how to mask out bits properly. Third time's
the charm.
* tag 'x86_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Mask out the invalid MXCSR bits properly
x86/Kconfig: Do not enable AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT automatically
Linus Torvalds [Mon, 18 Oct 2021 03:17:28 +0000 (17:17 -1000)]
Merge tag 'driver-core-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are some small driver core fixes for 5.15-rc6, all of which have
been in linux-next for a while with no reported issues.
They include:
- kernfs negative dentry bugfix
- simple pm bus fixes to resolve reported issues"
* tag 'driver-core-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
drivers: bus: Delete CONFIG_SIMPLE_PM_BUS
drivers: bus: simple-pm-bus: Add support for probing simple bus only devices
driver core: Reject pointless SYNC_STATE_ONLY device links
kernfs: don't create a negative dentry if inactive node exists
Linus Torvalds [Mon, 18 Oct 2021 03:10:00 +0000 (17:10 -1000)]
Merge tag 'staging-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging and IIO driver fixes from Greg KH:
"Here are a number of small IIO and staging driver fixes for 5.15-rc6.
They include:
- vc04_services bugfix for reported problem
- r8188eu array underflow fix
- iio driver fixes for a lot of tiny reported issues.
All of these have been in linux-next for a while with no reported
issues"
* tag 'staging-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: r8188eu: prevent array underflow in rtw_hal_update_ra_mask()
staging: vc04_services: shut up out-of-range warning
iio: light: opt3001: Fixed timeout error when 0 lux
iio: adis16480: fix devices that do not support sleep mode
iio: mtk-auxadc: fix case IIO_CHAN_INFO_PROCESSED
iio: adis16475: fix deadlock on frequency set
iio: ssp_sensors: add more range checking in ssp_parse_dataframe()
iio: ssp_sensors: fix error code in ssp_print_mcu_debug()
iio: adc: ad7793: Fix IRQ flag
iio: adc: ad7780: Fix IRQ flag
iio: adc: ad7192: Add IRQ flag
iio: adc: aspeed: set driver data when adc probe.
iio: adc: rzg2l_adc: add missing clk_disable_unprepare() in rzg2l_adc_pm_runtime_resume()
iio: adc: max1027: Fix the number of max1X31 channels
iio: adc: max1027: Fix wrong shift with 12-bit devices
iio: adc128s052: Fix the error handling path of 'adc128_probe()'
iio: adc: rzg2l_adc: Fix -EBUSY timeout error return
iio: accel: fxls8962af: return IRQ_HANDLED when fifo is flushed
iio: dac: ti-dac5571: fix an error code in probe()
Linus Torvalds [Mon, 18 Oct 2021 03:06:31 +0000 (17:06 -1000)]
Merge tag 'tty-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull serial driver fix from Greg KH:
"Here is a single 8250 Kconfig fix for 5.15-rc6 that resolves a
regression that showed up in 5.15-rc1. It has been in linux-next for a
while with no reported issues"
* tag 'tty-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: 8250: allow disabling of Freescale 16550 compile test
Linus Torvalds [Mon, 18 Oct 2021 02:57:06 +0000 (16:57 -1000)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input fixes from Dmitry Torokhov:
- a new product ID for the xpad joystick driver
- fixes to resistive-adc-touch and snvs_pwrkey drivers
- a change to touchscreen helpers to make clang happier
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: touchscreen - avoid bitwise vs logical OR warning
Input: xpad - add support for another USB ID of Nacon GC-100
Input: resistive-adc-touch - fix division by zero error on z1 == 0
Input: snvs_pwrkey - add clk handling
Paolo Valente [Fri, 15 Oct 2021 14:43:36 +0000 (16:43 +0200)]
block, bfq: reset last_bfqq_created on group change
Since commit 430a67f9d616 ("block, bfq: merge bursts of newly-created
queues"), BFQ maintains a per-group pointer to the last bfq_queue
created. If such a queue, say bfqq, happens to move to a different
group, then bfqq is no more a valid last bfq_queue created for its
previous group. That pointer must then be cleared. Not resetting such
a pointer may also cause UAF, if bfqq happens to also be freed after
being moved to a different group. This commit performs this missing
reset. As such it fixes commit 430a67f9d616 ("block, bfq: merge bursts
of newly-created queues").
Such a missing reset is most likely the cause of the crash reported in [1].
With some analysis, we found that this crash was due to the
above UAF. And such UAF did go away with this commit applied [1].
Anyway, before this commit, that crash happened to be triggered in
conjunction with commit 2d52c58b9c9b ("block, bfq: honor already-setup
queue merges"). The latter was then reverted by commit ebc69e897e17
("Revert "block, bfq: honor already-setup queue merges""). Yet commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") contains
no error related with the above UAF, and can then be restored.
Christoph Hellwig [Thu, 14 Oct 2021 13:02:31 +0000 (15:02 +0200)]
block: warn when putting the final reference on a registered disk
Warn when the last reference on a live disk is put without calling
del_gendisk first. There are some BDI related bug reports that look
like a case of this, so make sure we have the proper instrumentation
to catch it.
As with commit 8b52d8be86d72308 ("loop: reorder loop_exit"),
unregister_blkdev() needs to be called first in order to avoid calling
brd_alloc() from brd_probe() after brd_del_one() from brd_exit(). Then,
we can avoid holding global mutex during add_disk()/del_gendisk() as with
commit 1c500ad706383f1a ("loop: reduce the loop_ctl_mutex scope").
Nicolas Frattaroli [Sat, 16 Oct 2021 10:53:51 +0000 (12:53 +0200)]
ASoC: dt-bindings: rockchip: i2s-tdm: Drop rockchip,cru property
This property was only needed for a driver hack, which we can
remove. Since the bindings were not in any kernel release yet, we
are able to just drop the property instead of silently accepting
and ignoring it.
Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Message-Id: <20211016105354.116513-3-frattaroli.nicolas@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Nicolas Frattaroli [Sat, 16 Oct 2021 10:53:50 +0000 (12:53 +0200)]
ASoC: rockchip: i2s-tdm: Strip out direct CRU use
In cases where both rx and tx lrck are synced to the same source,
the resets for rx and tx need to be triggered simultaneously,
according to the downstream driver.
As there is no reset API to atomically bulk (de)assert two resets
at once, what the driver did was implement half a reset controller
specific to Rockchip, which tried to write the registers for the
resets within one write ideally or several writes within an irqsave
section.
This of course violates abstractions quite badly. The driver should
not write to the CRU's registers directly.
In practice, for the cases I tested the driver with, which is audio
playback, replacing the synchronised asserts with just individual
ones does not seem to make any difference.
If it turns out that this breaks something in the future, it should
be fixed through the specification and implementation of an atomic
bulk reset API, not with a CRU hack.
Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Message-Id: <20211016105354.116513-2-frattaroli.nicolas@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Linus Torvalds [Sat, 16 Oct 2021 18:11:07 +0000 (11:11 -0700)]
Merge tag 'perf-tools-fixes-for-v5.15-2021-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull perf tools fixes from Arnaldo Carvalho de Melo:
- Fix 'perf test evsel' build error on !x86 architectures
- Fix libperf's test_stat_cpu mixup of CPU numbers and CPU indexes
- Output offsets for decompressed records, not just useless zeros
* tag 'perf-tools-fixes-for-v5.15-2021-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
libperf tests: Fix test_stat_cpu
libperf test evsel: Fix build error on !x86 architectures
perf report: Output non-zero offset for decompressed records
Linus Torvalds [Sat, 16 Oct 2021 17:51:41 +0000 (10:51 -0700)]
Merge tag 'trace-v5.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Tracing fixes for 5.15:
- Fix defined but not use warning/error for osnoise function
- Fix memory leak in event probe
- Fix memblock leak in bootconfig
- Fix the API of event probes to be like kprobes
- Added test to check removal of event probe API
- Fix recordmcount.pl for nds32 failed build
* tag 'trace-v5.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
nds32/ftrace: Fix Error: invalid operands (*UND* and *UND* sections) for `^'
selftests/ftrace: Update test for more eprobe removal process
tracing: Fix event probe removal from dynamic events
tracing: Fix missing * in comment block
bootconfig: init: Fix memblock leak in xbc_make_cmdline()
tracing: Fix memory leak in eprobe_register()
tracing: Fix missing osnoise tracer on max_latency
Linus Torvalds [Sat, 16 Oct 2021 17:22:08 +0000 (10:22 -0700)]
Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk driver fixes from Stephen Boyd:
"Clk driver fixes for critical issues found in the past few weeks:
- Select gdsc config so qcom sm6350 driver probes
- Fix a register offset in qcom gcc-sm6115 so the correct clk is
controlled
- Fix inverted logic in Renesas RZ/G2L .is_enabled()
- Mark some more clks critical in Renesas clk driver
- Remove a duplicate clk in the agilex driver"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: qcom: add select QCOM_GDSC for SM6350
clk: qcom: gcc-sm6115: Fix offset for hlos1_vote_turing_mmu_tbu0_gdsc
clk: socfpga: agilex: fix duplicate s2f_user0_clk
clk: renesas: rzg2l: Fix clk status function
clk: renesas: r9a07g044: Mark IA55_CLK and DMAC_ACLK critical
Linus Torvalds [Sat, 16 Oct 2021 16:14:55 +0000 (09:14 -0700)]
Merge tag 's390-5.15-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:
- Maintainers and reviewers changes:
* Cornelia decided to free up her time and step down from vfio-ccw
maintainer and s390 kvm reviewer duties
* Add Alexander Gordeev as s390 arch code reviewer
- Fix broken strrchr implementation
* tag 's390-5.15-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: add Alexander Gordeev as reviewer
s390: fix strrchr() implementation
vfio-ccw: step down as maintainer
KVM: s390: remove myself as reviewer
Linus Torvalds [Sat, 16 Oct 2021 16:12:18 +0000 (09:12 -0700)]
Merge tag 'csky-for-linus-5.15-rc6' of git://github.com/c-sky/csky-linux
Pull csky fixes from Guo Ren:
"Only 5 fixups:
- Make HAVE_TCM depend on !COMPILE_TEST
- bitops: Remove duplicate __clear_bit define
- Select ARCH_WANT_FRAME_POINTERS only if compiler supports it
- Fixup regs.sr broken in ptrace
- don't let sigreturn play with priveleged bits of status register"
* tag 'csky-for-linus-5.15-rc6' of git://github.com/c-sky/csky-linux:
csky: Make HAVE_TCM depend on !COMPILE_TEST
csky: bitops: Remove duplicate __clear_bit define
csky: Select ARCH_WANT_FRAME_POINTERS only if compiler supports it
csky: Fixup regs.sr broken in ptrace
csky: don't let sigreturn play with priveleged bits of status register
Linus Torvalds [Sat, 16 Oct 2021 16:05:58 +0000 (09:05 -0700)]
Merge tag 'arm-soc-fixes-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC fixes from Arnd Bergmann:
"A small number fixes this time, mostly touching actual code:
- Add platform device for i.MX System Reset Controller (SRC) to
fix a regression caused by fw_devlink change
- A fixup for a boot regression caused by my own rework for the
Qualcomm SCM driver
- Multiple bugfixes for the Arm FFA and optee firmware drivers,
addressing problems when they are built as a loadable module
- Four dts bugfixes for the Broadcom SoC used in Raspberry pi,
addressing VEC (video encoder), MDIO bus controller
#address-cells/#size-cells, SDIO voltage and PCIe host bridge
dtc warnings"
* tag 'arm-soc-fixes-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
ARM: imx: register reset controller from a platform driver
iommu/arm: fix ARM_SMMU_QCOM compilation
ARM: dts: bcm2711-rpi-4-b: Fix usb's unit address
ARM: dts: bcm2711-rpi-4-b: Fix pcie0's unit address formatting
tee: optee: Fix missing devices unregister during optee_remove
ARM: dts: bcm2711-rpi-4-b: fix sd_io_1v8_reg regulator states
ARM: dts: bcm2711: fix MDIO #address- and #size-cells
ARM: dts: bcm283x: Fix VEC address for BCM2711
firmware: arm_ffa: Fix __ffa_devices_unregister
firmware: arm_ffa: Add missing remove callback to ffa_bus_type
Nathan Chancellor [Fri, 15 Oct 2021 20:13:06 +0000 (13:13 -0700)]
Input: touchscreen - avoid bitwise vs logical OR warning
A new warning in clang points out a few places in this driver where a
bitwise OR is being used with boolean types:
drivers/input/touchscreen.c:81:17: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
data_present = touchscreen_get_prop_u32(dev, "touchscreen-min-x",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This use of a bitwise OR is intentional, as bitwise operations do not
short circuit, which allows all the calls to touchscreen_get_prop_u32()
to happen so that the last parameter is initialized while coalescing the
results of the calls to make a decision after they are all evaluated.
To make this clearer to the compiler, use the '|=' operator to assign
the result of each touchscreen_get_prop_u32() call to data_present,
which keeps the meaning of the code the same but makes it obvious that
every one of these calls is expected to happen.
Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20211014205757.3474635-1-nathan@kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Michael Cullen [Fri, 15 Oct 2021 20:17:50 +0000 (13:17 -0700)]
Input: xpad - add support for another USB ID of Nacon GC-100
The Nacon GX100XF is already mapped, but it seems there is a Nacon
GC-100 (identified as NC5136Wht PCGC-100WHITE though I believe other
colours exist) with a different USB ID when in XInput mode.
Uwe Kleine-König [Sat, 16 Oct 2021 04:19:33 +0000 (21:19 -0700)]
Input: snvs_pwrkey - add clk handling
On i.MX7S and i.MX8M* (but not i.MX6*) the pwrkey device has an
associated clock. Accessing the registers requires that this clock is
enabled. Binding the driver on at least i.MX7S and i.MX8MP while not
having the clock enabled results in a complete hang of the machine.
(This usually only happens if snvs_pwrkey is built as a module and the
rtc-snvs driver isn't already bound because at bootup the required clk
is on and only gets disabled when the clk framework disables unused clks
late during boot.)
This completes the fix in commit 135be16d3505 ("ARM: dts: imx7s: add
snvs clock to pwrkey").
Christoph Hellwig [Tue, 12 Oct 2021 09:33:01 +0000 (11:33 +0200)]
kyber: avoid q->disk dereferences in trace points
q->disk becomes invalid after the gendisk is removed. Work around this
by caching the dev_t for the tracepoints. The real fix would be to
properly tear down the I/O schedulers with the gendisk, but that is
a much more invasive change.
Christoph Hellwig [Wed, 29 Sep 2021 07:12:41 +0000 (09:12 +0200)]
block: keep q_usage_counter in atomic mode after del_gendisk
Don't switch back to percpu mode to avoid the double RCU grace period
when tearing down SCSI devices. After removing the disk only passthrough
commands can be send anyway.
Suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20210929071241.934472-6-hch@lst.de Tested-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Christoph Hellwig [Wed, 29 Sep 2021 07:12:40 +0000 (09:12 +0200)]
block: drain file system I/O on del_gendisk
Instead of delaying draining of file system I/O related items like the
blk-qos queues, the integrity read workqueue and timeouts only when the
request_queue is removed, do that when del_gendisk is called. This is
important for SCSI where the upper level drivers that control the gendisk
are separate entities, and the disk can be freed much earlier than the
request_queue, or can even be unbound without tearing down the queue.
Fixes: edb0872f44ec ("block: move the bdi from the request_queue to the gendisk") Reported-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20210929071241.934472-5-hch@lst.de Tested-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Christoph Hellwig [Wed, 29 Sep 2021 07:12:39 +0000 (09:12 +0200)]
block: split bio_queue_enter from blk_queue_enter
To prepare for fixing a gendisk shutdown race, open code the
blk_queue_enter logic in bio_queue_enter. This also removes the
pointless flags translation.
Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20210929071241.934472-4-hch@lst.de Tested-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Christoph Hellwig [Wed, 29 Sep 2021 07:12:38 +0000 (09:12 +0200)]
block: factor out a blk_try_enter_queue helper
Factor out the code to try to get q_usage_counter without blocking into
a separate helper. Both to improve code readability and to prepare for
splitting bio_queue_enter from blk_queue_enter.
Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20210929071241.934472-3-hch@lst.de Tested-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Christoph Hellwig [Wed, 29 Sep 2021 07:12:37 +0000 (09:12 +0200)]
block: call submit_bio_checks under q_usage_counter
Ensure all bios check the current values of the queue under freeze
protection, i.e. to make sure the zero capacity set by del_gendisk
is actually seen before dispatching to the driver.
Steven Rostedt [Thu, 14 Oct 2021 18:35:07 +0000 (14:35 -0400)]
nds32/ftrace: Fix Error: invalid operands (*UND* and *UND* sections) for `^'
I received a build failure for a new patch I'm working on the nds32
architecture, and when I went to test it, I couldn't get to my build error,
because it failed to build with a bunch of:
Error: invalid operands (*UND* and *UND* sections) for `^'
issues with various files. Those files were temporary asm files that looked
like: kernel/.tmp_mc_fork.s
I decided to look deeper, and found that the "mc" portion of that name
stood for "mcount", and was created by the recordmcount.pl script. One that
I wrote over a decade ago. Once I knew the source of the problem, I was
able to investigate it further.
The way the recordmcount.pl script works (BTW, there's a C version that
simply modifies the ELF object) is by doing an "objdump" on the object
file. Looks for all the calls to "mcount", and creates an offset of those
locations from some global variable it can use (usually a global function
name, found with <.*>:). Creates a asm file that is a table of references
to these locations, using the found variable/function. Compiles it and
links it back into the original object file. This asm file is called
".tmp_mc_<object_base_name>.s".
The problem here is that the objdump produced by the nds32 object file,
contains things that look like:
Building csky:allmodconfig results in the following build errors.
arch/csky/mm/tcm.c:9:2: error:
#error "You should define ITCM_RAM_BASE"
9 | #error "You should define ITCM_RAM_BASE"
| ^~~~~
arch/csky/mm/tcm.c:14:2: error:
#error "You should define DTCM_RAM_BASE"
14 | #error "You should define DTCM_RAM_BASE"
| ^~~~~
arch/csky/mm/tcm.c:18:2: error:
#error "You should define correct DTCM_RAM_BASE"
18 | #error "You should define correct DTCM_RAM_BASE"
This is seen with compile tests since those enable HAVE_TCM,
but do not provide useful default values for ITCM_RAM_BASE or
DTCM_RAM_BASE. Disable HAVE_TCM for commpile tests to avoid
the error.
Building csky:allmodconfig results in the following build error.
In file included from ./include/linux/bitops.h:33,
from ./include/linux/log2.h:12,
from kernel/bounds.c:13:
./arch/csky/include/asm/bitops.h:77: error: "__clear_bit" redefined
Since commit 9248e52fec95 ("locking/atomic: simplify non-atomic wrappers"),
__clear_bit is defined in include/asm-generic/bitops/non-atomic.h,
and the define in the csky include file is no longer necessary or useful.
Remove it.
gpr_get() return the entire pt_regs (include sr) to userspace, if we
don't restore the C bit in gpr_set, it may break the ALU result in
that context. So the C flag bit is part of gpr context, that's why
riscv totally remove the C bit in the ISA. That makes sr reg clear
from userspace to supervisor privilege.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org
Al Viro [Fri, 24 Sep 2021 00:35:42 +0000 (00:35 +0000)]
csky: don't let sigreturn play with priveleged bits of status register
csky restore_sigcontext() blindly overwrites regs->sr with the value
it finds in sigcontext. Attacker can store whatever they want in there,
which includes things like S-bit. Userland shouldn't be able to set
that, or anything other than C flag (bit 0).
Do the same thing other architectures with protected bits in flags
register do - preserve everything that shouldn't be settable in
user mode, picking the rest from the value saved is sigcontext.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: stable@vger.kernel.org
Mark Brown [Fri, 15 Oct 2021 19:40:27 +0000 (20:40 +0100)]
Merge series "ASoC: Add Audio Graph Card2 support" from Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>:
Hi Mark
We already have Audio-Graph-Card which is Of-Graph base general sound
card driver. Basically it supports basic CPU-Codec connection, and is
also supporting DPCM connection. Because it was forcibly expanded to
DPCM, DT parsing is very limited and very difficult to add new features
on it, for example Multi-CPU/Codec support, Codec2Codec support, etc.
This patch adds more flexible new Audio-Graph-Card2 driver for it.
Audio-Graph-Card and Audio-Graph-Card2 are similar, but don't have
full compatibility.
The reason why I need Audio-Graph-Card2 instead of updating Audio-Graph-Card
is that it is very difficult to keep compatibility.
Audio-Graph-Card2 supports Normal/DPCM/Codec2Codec Connection wich
Single/Multi DAIs. And it is possible to Customizing.
This patch-set adds Audio-Graph-Card2 driver and its custom driver
sample, and DT settings sample which can be used for testing.
To enable testing/debuging, this patch-set also adds Test-Component
driver. We already have Dummy Component and/or Dummy DAI on soc-utils,
but 1) we can't use it from DT, 2) it do nothing.
Added new Test-Component can be used from DT, and it can indicate called
function name. We can use it to trace callback order, understanding
ALSA SoC behavior, etc, etc...
Sample DT settings of Audio Graph Card2 is using Test-Component as CPU/Codec DAI.
You can easily try to use/test it if you added below line to your DT file.
Your .config needs to have below CONFIGs to use/test it.
It will probe sample Sound Card which has Normal/DPCM/Multi/Codec2Codec
connections.
v2 -> v3
- Rename audio-graph-card2 to rich-graph-card
- Rename DSP to DPCM not to confuse
- Normal/DPCM/Codec2Codec can use Single/Multi DAIs.
- use dpcm/multi/codec2codec node instead of using extra compatible
- Sample DTSI patch is separated to Single/Multi.
Srinivas Kandagatla [Thu, 14 Oct 2021 16:13:30 +0000 (17:13 +0100)]
ASoC: soc-component: improve error reporting for register access
Currently errors on register read/write/update are reported with
an error code and the corresponding function but does not provide
any details on the which register number did it actually fail.
register number can give better clue and it should be easy to
locate the code and fix.
This patch adds Codec2Codec-Multi sample to audio-graph-card2-custom-sample.dtsi.
Because it can use very basic connection only for now,
it can use only
- 2channels
- S32_LE format
Test-Component driver has "IN" and "OUT" widget. Thus the route is
This patch adds Codec2Codec-Single sample to audio-graph-card2-custom-sample.dtsi.
Because it can use very basic connection only for now,
it can use only
- 2channels
- S32_LE format
Test-Component driver has "IN" and "OUT" widget. Thus the route is
+--+
| | <-- Codec6 <-- IN
| | --> Codec7 --> OUT
+--+
One note here is that it will start works when it boot.
In other words we can't stop it so far.
We need to update driver for it in the future.
This patch adds DPCM link Multi-CPU/Codec sample to
audio-graph-card2-custom-sample.dtsi.
This sample is assuming MIXer connection.
One note is that Multi-FE is not supported on ASoC
Kuninori Morimoto [Tue, 12 Oct 2021 04:56:14 +0000 (13:56 +0900)]
ASoC: audio-graph-card2-custom-sample.dtsi: add Sample DT for Normal (Single)
Audio Graph Card2 settings is a little bit difficult for beginner,
and Customizing it also difficult/confusable too.
So, this patch adds sample for it.
You can easily use it by adding below line on your DT file,
and select CONFIGs to your .config.
This patch uses audio-graph-card2 base custom sample driver.
You can directly use audio-graph-card2 instead of custom sample driver
by modifing compatible.
Sample custom driver will indicate customized print.
It is using Test-Component driver for CPU/Codec.
It can indicate more detail print of each behavior if user want to.
In such case, you need to update compatible to "xxx-nv" or "xxx-vv".
Kuninori Morimoto [Tue, 12 Oct 2021 04:56:07 +0000 (13:56 +0900)]
ASoC: add Audio Graph Card2 Custom Sample
audio-graph-card2 has customizing support.
This means user can re-use audio-graph-card2 DT parsing, and possible
to expand to own special handling.
This patch adds Audio Graph Card2 Customize Sample Driver.
It can re-use audio-graph-card2 parsing by calling
audio_graph2_parse_of(...), and user can expand each functions by
using hooks.
Kuninori Morimoto [Tue, 12 Oct 2021 04:55:33 +0000 (13:55 +0900)]
ASoC: audio-graph-card2: add Codec2Codec support
This patch adds Codec2Codec support to audio-graph-card2.
It can use Codec2Codec but very simple case only for now.
It doesn't have "SWITCH" control yet, thus it start automatically
when it was probed, and can't stop, so far.
Thus it needs to be updated around widgets/routing handling,
and you need to understand that it is under experimental.
Codec has SND_SOC_DAPM_INPUT() (= IN) / SND_SOC_DAPM_OUTPUT(= OUT)
widgets in below case.
It is assuming 2channel, S32_LE format for now.
It needs to be updated, too.
It needs "codec2codec" node (= B), needs to have routing (= A),
need to indicate CPU side at links (= X).
ports@0 is for CPU side (= X), port@1 is Codec side (= Y).
It needs to have "rate" (= C)
+--+
| |<-- Codec0 <-- IN
| |--> Codec1 --> OUT
+--+
Kuninori Morimoto [Tue, 12 Oct 2021 04:55:12 +0000 (13:55 +0900)]
ASoC: audio-graph-card2: add DPCM support
This patch adds DPCM support to audio-graph-card2.
It uses "dpcm" node (= D), needs to have routing (= A),
need to indicate both FE/BE at links (= B, C).
dpcm ports@0 is for FE (= B), port@1 is for BE (= C).
remote-endpoint can use both Single/Multi connection.
Kuninori Morimoto [Tue, 12 Oct 2021 04:55:03 +0000 (13:55 +0900)]
ASoC: audio-graph-card2: add Multi CPU/Codec support
This patch adds Multi CPU/Codec support to audio-graph-card2.
Multi CPU/Codec will have connection part (= X) and CPU/Codec list part (= Y).
links indicates connection part of CPU side (= A).
Kuninori Morimoto [Tue, 12 Oct 2021 04:54:46 +0000 (13:54 +0900)]
ASoC: add Audio Graph Card2 driver
We already have audio-graph-card which is Of-graph base of general
sound card driver.
It is supporting DPCM connection, but was forcibly expanded.
Thus, it is very difficult to add new features on it, for example
Multi CPU/Codec support, Codec2Codec support, etc.
This patch adds more flexible new Audio Graph Card2 driver for it.
audio-graph-card and audio-graph-card2 are similar, but don't have
full compatibility.
Audio Graph Card2 supports very generic connection, but some users
want to have its own settings, for example PLL settings, etc.
For such case, it has customizing support.
In users own driver, it can use Audio Graph Card2 parsing by using
audio_graph2_parse_of(), and doing its own customizing.
Because Audio Graph Card2 is still under experimental stage,
it will indicate such warning when probing, and the DT syntax
might be changed.
audio-graph-card2 will support DPCM/Multi/Codec2Codec,
and these will use almost same DT settings which uses
ports0 and ports1.
This patch adds asoc_graph_is_ports0() which checks
port is under port0 or not.
Kuninori Morimoto [Tue, 12 Oct 2021 04:53:38 +0000 (13:53 +0900)]
ASoC: test-component: add Test Component for Sound debug/test
We already have dummy-codec, dummy-platform.
But its issues are
1) we don't have dummy-cpu,
2) we can't select it via DeviceTree
3) It do nothing
Sometimes we want to have Dummy Sound Component for debugging,
for testing, for learning Framework behavior, etc, etc...
This patch adds Test-Component driver for it.
User can select CPU Component by using "test-cpu" compatible,
and can select Codec Component by using "test-codec" compatible.
It doesn't support Platform so far, but is easy to add.
We can verbose print to know its progress if user selected
xxx-verbose compatible driver.
for example,
test-cpu : silent Component, silent DAI
test-cpu-verbose-component : verbose Component, silent DAI
test-cpu-verbose-dai : silent Component, verbose DAI
test-cpu-verbose : verbose Component, verbose DAI
Linus Torvalds [Fri, 15 Oct 2021 14:27:20 +0000 (10:27 -0400)]
Merge tag 'gpio-fixes-for-v5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
- fix module autoloading on gpio-74x164 after a revert of OF modaliases
- fix problems with the bias setting in gpio-pca953x
- fix a use-after-free bug in gpio-mockup by using software nodes
* tag 'gpio-fixes-for-v5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpio: mockup: Convert to use software nodes
gpio: pca953x: Improve bias setting
gpio: 74x164: Add SPI device ID table
Linus Torvalds [Fri, 15 Oct 2021 14:21:46 +0000 (10:21 -0400)]
Merge tag 'spi-fix-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"A few small fixes.
Mostly driver specific but there's one in the core which fixes a
deadlock when adding devices on spi-mux that's triggered because
spi-mux is a SPI device which is itself a SPI controller and so can
instantiate devices when registered.
We were using a global lock to protect against reusing chip selects
but they're a per controller thing so moving the lock per controller
resolves that"
* tag 'spi-fix-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi-mux: Fix false-positive lockdep splats
spi: Fix deadlock when adding SPI controllers on SPI buses
spi: bcm-qspi: clear MSPI spifie interrupt during probe
spi: spi-nxp-fspi: don't depend on a specific node name erratum workaround
spi: mediatek: skip delays if they are 0
spi: atmel: Fix PDC transfer setup bug
spi: spidev: Add SPI ID table
spi: Use 'flash' node name instead of 'spi-flash' in example
Linus Torvalds [Fri, 15 Oct 2021 14:20:18 +0000 (10:20 -0400)]
Merge tag 'regulator-fix-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fix from Mark Brown:
"Just a trivial fix to the MAINTAINERS file for an update missed during
conversion of the DT bindings to YAML format"
* tag 'regulator-fix-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
MAINTAINERS: rectify entry for SY8106A REGULATOR DRIVER
Linus Torvalds [Fri, 15 Oct 2021 14:09:09 +0000 (10:09 -0400)]
Merge tag 'drm-fixes-2021-10-15-1' of git://anongit.freedesktop.org/drm/drm
Pull drm fixes from Dave Airlie:
"It has a few scattered msm and i915 fixes, a few core fixes and a
mediatek feature revert.
I've had to pick a bunch of patches into this, as the drm-misc-fixes
tree had a bunch of vc4 patches I wasn't comfortable with sending to
you at least as part of this, they were delayed due to your reverts.
If it's really useful as fixes I'll do a separate pull.
Summary:
Core:
- clamp fbdev size
- edid cap blocks read to avoid out of bounds
panel:
- fix missing crc32 dependency
msm:
- Fix a new crash on dev file close if the dev file was opened when
GPU is not loaded (such as missing fw in initrd)
- Switch to single drm_sched_entity per priority level per drm_file
to unbreak multi-context userspace
- Serialize GMU access to fix GMU OOB errors
- Various error path fixes
- A couple integer overflow fixes
- Fix mdp5 cursor plane WARNs
i915:
- Fix ACPI object leak
- Fix context leak in user proto-context creation
- Fix missing i915_sw_fence_fini call
hyperv:
- hide hw pointer
nouveau:
- fix engine selection bit
r128:
- fix UML build
rcar-du:
- unconncted LVDS regression fix
mediatek:
- revert CMDQ refinement patches"
* tag 'drm-fixes-2021-10-15-1' of git://anongit.freedesktop.org/drm/drm: (34 commits)
drm/panel: olimex-lcd-olinuxino: select CRC32
drm/r128: fix build for UML
drm/nouveau/fifo: Reinstate the correct engine bit programming
drm/hyperv: Fix double mouse pointers
drm/fbdev: Clamp fbdev surface size if too large
drm/edid: In connector_bad_edid() cap num_of_ext by num_blocks read
drm/i915: Free the returned object of acpi_evaluate_dsm()
drm/i915: Fix bug in user proto-context creation that leaked contexts
drm: rcar-du: Don't create encoder for unconnected LVDS outputs
drm/msm/dsi: fix off by one in dsi_bus_clk_enable error handling
drm/msm/dsi: Fix an error code in msm_dsi_modeset_init()
drm/msm/dsi: dsi_phy_14nm: Take ready-bit into account in poll_for_ready
drm/msm/dsi/phy: fix clock names in 28nm_8960 phy
drm/msm/dpu: Fix address of SM8150 PINGPONG5 IRQ register
drm/msm: Do not run snapshot on non-DPU devices
drm/msm/a3xx: fix error handling in a3xx_gpu_init()
drm/msm/a4xx: fix error handling in a4xx_gpu_init()
drm/msm: Fix null pointer dereference on pointer edp
drm/msm/mdp5: fix cursor-related warnings
drm/msm: Avoid potential overflow in timeout_to_jiffies()
...
- some typos, wrong returned error codes, dead code, etc"
* tag 'ntfs3_for_5.15' of git://github.com/Paragon-Software-Group/linux-ntfs3: (70 commits)
fs/ntfs3: Check for NULL pointers in ni_try_remove_attr_list
fs/ntfs3: Refactor ntfs_read_mft
fs/ntfs3: Refactor ni_parse_reparse
fs/ntfs3: Refactor ntfs_create_inode
fs/ntfs3: Refactor ntfs_readlink_hlp
fs/ntfs3: Rework ntfs_utf16_to_nls
fs/ntfs3: Fix memory leak if fill_super failed
fs/ntfs3: Keep prealloc for all types of files
fs/ntfs3: Remove unnecessary functions
fs/ntfs3: Forbid FALLOC_FL_PUNCH_HOLE for normal files
fs/ntfs3: Refactoring of ntfs_set_ea
fs/ntfs3: Remove locked argument in ntfs_set_ea
fs/ntfs3: Use available posix_acl_release instead of ntfs_posix_acl_release
fs/ntfs3: Check for NULL if ATTR_EA_INFO is incorrect
fs/ntfs3: Refactoring of ntfs_init_from_boot
fs/ntfs3: Reject mount if boot's cluster size < media sector size
fs/ntfs3: Refactoring lock in ntfs_init_acl
fs/ntfs3: Change posix_acl_equiv_mode to posix_acl_update_mode
fs/ntfs3: Pass flags to ntfs_set_ea in ntfs_set_acl_ex
fs/ntfs3: Refactor ntfs_get_acl_ex for better readability
...
Michael Ellerman [Fri, 15 Oct 2021 12:02:08 +0000 (23:02 +1100)]
KVM: PPC: Book3S HV: Make idle_kvm_start_guest() return 0 if it went to guest
We call idle_kvm_start_guest() from power7_offline() if the thread has
been requested to enter KVM. We pass it the SRR1 value that was returned
from power7_idle_insn() which tells us what sort of wakeup we're
processing.
Depending on the SRR1 value we pass in, the KVM code might enter the
guest, or it might return to us to do some host action if the wakeup
requires it.
If idle_kvm_start_guest() is able to handle the wakeup, and enter the
guest it is supposed to indicate that by returning a zero SRR1 value to
us.
That was the behaviour prior to commit 10d91611f426 ("powerpc/64s:
Reimplement book3s idle code in C"), however in that commit the
handling of SRR1 was reworked, and the zeroing behaviour was lost.
Returning from idle_kvm_start_guest() without zeroing the SRR1 value can
confuse the host offline code, causing the guest to crash and other
weirdness.
Michael Ellerman [Fri, 15 Oct 2021 12:01:48 +0000 (23:01 +1100)]
KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
In commit 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in
C") kvm_start_guest() became idle_kvm_start_guest(). The old code
allocated a stack frame on the emergency stack, but didn't use the
frame to store anything, and also didn't store anything in its caller's
frame.
idle_kvm_start_guest() on the other hand is written more like a normal C
function, it creates a frame on entry, and also stores CR/LR into its
callers frame (per the ABI). The problem is that there is no caller
frame on the emergency stack.
The emergency stack for a given CPU is allocated with:
So emergency_sp actually points to the first address above the emergency
stack allocation for a given CPU, we must not store above it without
first decrementing it to create a frame. This is different to the
regular kernel stack, paca->kstack, which is initialised to point at an
initial frame that is ready to use.
idle_kvm_start_guest() stores the backchain, CR and LR all of which
write outside the allocation for the emergency stack. It then creates a
stack frame and saves the non-volatile registers. Unfortunately the
frame it creates is not large enough to fit the non-volatiles, and so
the saving of the non-volatile registers also writes outside the
emergency stack allocation.
The end result is that we corrupt whatever is at 0-24 bytes, and 112-248
bytes above the emergency stack allocation.
In practice this has gone unnoticed because the memory immediately above
the emergency stack happens to be used for other stack allocations,
either another CPUs mc_emergency_sp or an IRQ stack. See the order of
calls to irqstack_early_init() and emergency_stack_init().
The low addresses of another stack are the top of that stack, and so are
only used if that stack is under extreme pressue, which essentially
never happens in practice - and if it did there's a high likelyhood we'd
crash due to that stack overflowing.
Still, we shouldn't be corrupting someone else's stack, and it is purely
luck that we aren't corrupting something else.
To fix it we save CR/LR into the caller's frame using the existing r1 on
entry, we then create a SWITCH_FRAME_SIZE frame (which has space for
pt_regs) on the emergency stack with the backchain pointing to the
existing stack, and then finally we switch to the new frame on the
emergency stack.