Dependent-threads mode is the normal KVM mode for pre-POWER9 SMT
processors, where all threads in a core (or subcore) would run the same
partition at the same time, or they would run the host.
This design was mandated by MMU state that is shared between threads in
a processor, so the synchronisation point is in hypervisor real-mode
that has essentially no shared state, so it's safe for multiple threads
to gather and switch to the correct mode.
It is implemented by having the host unplug all secondary threads and
always run in SMT1 mode, and host QEMU threads essentially represent
virtual cores that wake these secondary threads out of unplug when the
ioctl is called to run the guest. This happens via a side-path that is
mostly invisible to the rest of the Linux host and the secondary threads
still appear to be unplugged.
POWER9 / ISA v3.0 has a more flexible MMU design that is independent
per-thread and allows a much simpler KVM implementation. Before the new
"P9 fast path" was added that began to take advantage of this, POWER9
support was implemented in the existing path which has support to run
in the dependent threads mode. So it was not much work to add support to
run POWER9 in this dependent threads mode.
The mode is not required by the POWER9 MMU (although "mixed-mode" hash /
radix MMU limitations of early processors were worked around using this
mode). But it is one way to run SMT guests without running different
guests or guest and host on different threads of the same core, so it
could avoid or reduce some SMT attack surfaces without turning off SMT
entirely.
This security feature has some real, if indeterminate, value. However
the old path is lagging in features (nested HV), and with this series
the new P9 path adds remaining missing features (radix prefetch bug
and hash support, in later patches), so POWER9 dependent threads mode
support would be the only remaining reason to keep that code in and keep
supporting POWER9/POWER10 in the old path. So here we make the call to
drop this feature.
Remove dependent threads mode support for POWER9 and above processors.
Systems can still achieve this security by disabling SMT entirely, but
that would generally come at a larger performance cost for guests.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-23-npiggin@gmail.com
Rather than partition the guest PID space + flush a rogue guest PID to
work around this problem, instead fix it by always disabling the MMU when
switching in or out of guest MMU context in HV mode.
This may be a bit less efficient, but it is a lot less complicated and
allows the P9 path to trivally implement the workaround too. Newer CPUs
are not subject to this issue.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-22-npiggin@gmail.com
Move MMU context switch as late as reasonably possible to minimise code
running with guest context switched in. This becomes more important when
this code may run in real-mode, with later changes.
Move WARN_ON as early as possible so program check interrupts are less
likely to tangle everything up.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-21-npiggin@gmail.com
Almost all logic is moved to C, by introducing a new in_guest mode for
the P9 path that branches very early in the KVM interrupt handler to P9
exit code.
The main P9 entry and exit assembly is now only about 160 lines of low
level stack setup and register save/restore, plus a bad-interrupt
handler.
There are two motivations for this, the first is just make the code more
maintainable being in C. The second is to reduce the amount of code
running in a special KVM mode, "realmode". In quotes because with radix
it is no longer necessarily real-mode in the MMU, but it still has to be
treated specially because it may be in real-mode, and has various
important registers like PID, DEC, TB, etc set to guest. This is hostile
to the rest of Linux and can't use arbitrary kernel functionality or be
instrumented well.
This initial patch is a reasonably faithful conversion of the asm code,
but it does lack any loop to return quickly back into the guest without
switching out of realmode in the case of unimportant or easily handled
interrupts. As explained in previous changes, handling HV interrupts
very quickly in this low level realmode is not so important for P9
performance, and are important to avoid for security, observability,
debugability reasons.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-15-npiggin@gmail.com
In the interest of minimising the amount of code that is run in
"real-mode", don't handle hcalls in real mode in the P9 path. This
requires some new handlers for H_CEDE and xics-on-xive to be added
before xive is pulled or cede logic is checked.
This introduces a change in radix guest behaviour where radix guests
that execute 'sc 1' in userspace now get a privilege fault whereas
previously the 'sc 1' would be reflected as a syscall interrupt to the
guest kernel. That reflection is only required for hash guests that run
PR KVM.
Background:
In POWER8 and earlier processors, it is very expensive to exit from the
HV real mode context of a guest hypervisor interrupt, and switch to host
virtual mode. On those processors, guest->HV interrupts reach the
hypervisor with the MMU off because the MMU is loaded with guest context
(LPCR, SDR1, SLB), and the other threads in the sub-core need to be
pulled out of the guest too. Then the primary must save off guest state,
invalidate SLB and ERAT, and load up host state before the MMU can be
enabled to run in host virtual mode (~= regular Linux mode).
Hash guests also require a lot of hcalls to run due to the nature of the
MMU architecture and paravirtualisation design. The XICS interrupt
controller requires hcalls to run.
So KVM traditionally tries hard to avoid the full exit, by handling
hcalls and other interrupts in real mode as much as possible.
By contrast, POWER9 has independent MMU context per-thread, and in radix
mode the hypervisor is in host virtual memory mode when the HV interrupt
is taken. Radix guests do not require significant hcalls to manage their
translations, and xive guests don't need hcalls to handle interrupts. So
it's much less important for performance to handle hcalls in real mode on
POWER9.
One caveat is that the TCE hcalls are performance critical, real-mode
variants introduced for POWER8 in order to achieve 10GbE performance.
Real mode TCE hcalls were found to be less important on POWER9, which
was able to drive 40GBe networking without them (using the virt mode
hcalls) but performance is still important. These hcalls will benefit
from subsequent guest entry/exit optimisation including possibly a
faster "partial exit" that does not entirely switch to host context to
handle the hcall.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-14-npiggin@gmail.com
Switching the MMU from radix<->radix mode is tricky particularly as the
MMU can remain enabled and requires a certain sequence of SPR updates.
Move these together into their own functions.
This also includes the radix TLB check / flush because it's tied in to
MMU switching due to tlbiel getting LPID from LPIDR.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-13-npiggin@gmail.com
LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
processors, so it must be enabled before HDEC is set.
Rather than set it in the host LPCR then setting HDEC, move the HDEC
update to after the guest MMU context (including LPCR) is loaded.
There shouldn't be much concern with delaying HDEC by some 10s or 100s
of nanoseconds by setting it a bit later.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-10-npiggin@gmail.com
This sets up the same calling convention from interrupt entry to
KVM interrupt handler for system calls as exists for other interrupt
types.
This is a better API, it uses a save area rather than SPR, and it has
more registers free to use. Using a single common API helps maintain
it, and it becomes easier to use in C in a later patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-8-npiggin@gmail.com
System calls / hcalls have a different calling convention than
other interrupts, so there is code in the KVMTEST to massage these
into the same form as other interrupt handlers.
Move this work into the KVM hcall handler. This means teaching KVM
a little more about the low level interrupt handler setup, PACA save
areas, etc., although that's not obviously worse than the current
approach of coming up with an entirely different interrupt register
/ save convention.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-5-npiggin@gmail.com
Similar to commit 25edcc50d7 ("KVM: PPC: Book3S HV: Save and restore
FSCR in the P9 path"), ensure the P7/8 path saves and restores the host
FSCR. The logic explained in that patch actually applies there to the
old path well: a context switch can be made before kvmppc_vcpu_run_hv
restores the host FSCR and returns.
Now both the p9 and the p7/8 paths now save and restore their FSCR, it
no longer needs to be restored at the end of kvmppc_vcpu_run_hv
Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs")
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210526125851.3436735-1-npiggin@gmail.com
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
I believe there are some issues introduced by commit 31651c6071
("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: 31651c6071 ("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>
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: c25fff7171 ("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>
