Pull device mapper fixes from Mikulas Patocka:
- always update the array size in realloc_argv on success
- dm-integrity: fix a warning on invalid table line
- dm-bufio: don't schedule in atomic context
- Fix W=1 build with clang
* tag 'for-6.15/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm: always update the array size in realloc_argv on success
dm-integrity: fix a warning on invalid table line
dm-bufio: don't schedule in atomic context
dm table: Fix W=1 build warning when mempool_needs_integrity is unused
Using "depends on" and "select" for the same Kconfig symbol is known to
cause circular dependencies (cmp. "Kconfig recursive dependency
limitations" in Documentation/kbuild/kconfig-language.rst.
DRM drivers are selecting drm helpers so do the same for
DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
Fixes following circular dependency reported on x86 for the downstream
Asahi Linux tree:
error: recursive dependency detected!
symbol DRM_KMS_HELPER is selected by DRM_GEM_SHMEM_HELPER
symbol DRM_GEM_SHMEM_HELPER is selected by RUST_DRM_GEM_SHMEM_HELPER
symbol RUST_DRM_GEM_SHMEM_HELPER is selected by DRM_ASAHI
symbol DRM_ASAHI depends on RUST
symbol RUST depends on CALL_PADDING
symbol CALL_PADDING depends on OBJTOOL
symbol OBJTOOL is selected by STACK_VALIDATION
symbol STACK_VALIDATION depends on UNWINDER_FRAME_POINTER
symbol UNWINDER_FRAME_POINTER is part of choice block at arch/x86/Kconfig.debug:224
symbol <choice> unknown is visible depending on UNWINDER_GUESS
symbol UNWINDER_GUESS prompt is visible depending on STACKDEPOT
symbol STACKDEPOT is selected by DRM_DEBUG_DP_MST_TOPOLOGY_REFS
symbol DRM_DEBUG_DP_MST_TOPOLOGY_REFS depends on DRM_KMS_HELPER
Fixes: 12a280c728 ("drm/dp_mst: Add topology ref history tracking for debugging")
Cc: stable@vger.kernel.org
Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250304-drm_debug_dp_mst_topo_kconfig-v1-1-e16fd152f258@jannau.net
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Calling drm_crtc_vblank_on() drm_crtc_helper_funcs' atomic_enable is
expected to enable vblank interrupts. It may have been avoided here to
due to drm_crtc_vblank_get()'s error behavior after
drm_crtc_vblank_reset(). With that fixed in the preceding change the
driver can call drm_crtc_vblank_on() from adp_crtc_atomic_enable().
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Janne Grunau <j@jannau.net>
Link: https://lore.kernel.org/r/20250428-drm_adp_fixes-v2-3-912e081e55d8@jannau.net
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
drm_crtc_vblank_get() may fail when it's called before
drm_crtc_vblank_on() on a resetted CRTC. This occurs in
drm_crtc_helper_funcs' atomic_flush() calls after
drm_atomic_helper_crtc_reset() for example directly after probe. Send
the vblank event directly in such cases. Avoids following warning in
the subsequent drm_crtc_vblank_put() call from the vblank irq handler as
below:
adp 228200000.display-pipe: [drm] drm_WARN_ON(atomic_read(&vblank->refcount) == 0)
WARNING: CPU: 5 PID: 1206 at drivers/gpu/drm/drm_vblank.c:1247 drm_vblank_put+0x158/0x170
...
Call trace:
drm_vblank_put+0x158/0x170 (P)
drm_crtc_vblank_put+0x24/0x38
adp_fe_irq+0xd8/0xe8 [adpdrm]
__handle_irq_event_percpu+0x94/0x318
handle_irq_event+0x54/0xd0
handle_fasteoi_irq+0xa8/0x240
handle_irq_desc+0x3c/0x68
generic_handle_domain_irq+0x24/0x40
Modifying `crtc->state->event` here is fine as crtc->mutex is locked by
the non-async atomic commit. In retrospect this looks so obvious that it
doesn't warrant a comment in the file.
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://lore.kernel.org/r/20250428-drm_adp_fixes-v2-2-912e081e55d8@jannau.net
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Check request KVM_REQ_MMU_FREE_OBSOLETE_ROOTS to free obsolete roots in
kvm_mmu_reload() to prevent kvm_mmu_reload() from seeing a stale obsolete
root.
Since kvm_mmu_reload() can be called outside the
vcpu_enter_guest() path (e.g., kvm_arch_vcpu_pre_fault_memory()), it may be
invoked after a root has been marked obsolete and before vcpu_enter_guest()
is invoked to process KVM_REQ_MMU_FREE_OBSOLETE_ROOTS and set root.hpa to
invalid. This causes kvm_mmu_reload() to fail to load a new root, which
can lead to kvm_arch_vcpu_pre_fault_memory() being stuck in the while
loop in kvm_tdp_map_page() since RET_PF_RETRY is always returned due to
is_page_fault_stale().
Keep the existing check of KVM_REQ_MMU_FREE_OBSOLETE_ROOTS in
vcpu_enter_guest() since the cost of kvm_check_request() is negligible,
especially a check that's guarded by kvm_request_pending().
Export symbol of kvm_mmu_free_obsolete_roots() as kvm_mmu_reload() is
inline and may be called outside of kvm.ko.
Fixes: 6e01b7601d ("KVM: x86: Implement kvm_arch_vcpu_pre_fault_memory()")
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Link: https://lore.kernel.org/r/20250318013333.5817-1-yan.y.zhao@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Pull powerpc fixes from Madhavan Srinivasan:
- fix to handle patchable function entries during module load
- fix to align vmemmap start to page size
- fixes to handle compilation errors and warnings
Thanks to Anthony Iliopoulos, Donet Tom, Ritesh Harjani (IBM), Venkat
Rao Bagalkote, and Stephen Rothwell.
* tag 'powerpc-6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/boot: Fix dash warning
powerpc/boot: Check for ld-option support
powerpc: Add check to select PPC_RADIX_BROADCAST_TLBIE
powerpc64/ftrace: fix module loading without patchable function entries
book3s64/radix : Align section vmemmap start address to PAGE_SIZE
book3s64/radix: Fix compile errors when CONFIG_ARCH_WANT_OPTIMIZE_DAX_VMEMMAP=n
Pull hyperv fixes from Wei Liu:
- Bug fixes for the Hyper-V driver and kvp_daemon
* tag 'hyperv-fixes-signed-20250427' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
Drivers: hv: Fix bad ref to hv_synic_eventring_tail when CPU goes offline
tools/hv: update route parsing in kvp daemon
Drivers: hv: Fix bad pointer dereference in hv_get_partition_id
realloc_argv() was only updating the array size if it was called with
old_argv already allocated. The first time it was called to create an
argv array, it would allocate the array but return the array size as
zero. dm_split_args() would think that it couldn't store any arguments
in the array and would call realloc_argv() again, causing it to
reallocate the initial slots (this time using GPF_KERNEL) and finally
return a size. Aside from being wasteful, this could cause deadlocks on
targets that need to process messages without starting new IO. Instead,
realloc_argv should always update the allocated array size on success.
Fixes: a065192655 ("dm table: don't copy from a NULL pointer in realloc_argv()")
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
On the Lenovo ThinkPad X201, when Intel VT-d is enabled in the BIOS, the
kernel boots with errors related to DMAR, the graphical interface appeared
quite choppy, and the system resets erratically within a minute after it
booted:
DMAR: DRHD: handling fault status reg 3
DMAR: [DMA Write NO_PASID] Request device [00:02.0] fault addr 0xb97ff000
[fault reason 0x05] PTE Write access is not set
Upon comparing boot logs with VT-d on/off, I found that the Intel Calpella
quirk (`quirk_calpella_no_shadow_gtt()') correctly applied the igfx IOMMU
disable/quirk correctly:
pci 0000:00:00.0: DMAR: BIOS has allocated no shadow GTT; disabling IOMMU
for graphics
Whereas with VT-d on, it went into the "else" branch, which then
triggered the DMAR handling fault above:
... else if (!disable_igfx_iommu) {
/* we have to ensure the gfx device is idle before we flush */
pci_info(dev, "Disabling batched IOTLB flush on Ironlake\n");
iommu_set_dma_strict();
}
Now, this is not exactly scientific, but moving 0x0044 to quirk_iommu_igfx
seems to have fixed the aforementioned issue. Running a few `git blame'
runs on the function, I have found that the quirk was originally
introduced as a fix specific to ThinkPad X201:
commit 9eecabcb9a ("intel-iommu: Abort IOMMU setup for igfx if BIOS gave
no shadow GTT space")
Which was later revised twice to the "else" branch we saw above:
- 2011: commit 6fbcfb3e46 ("intel-iommu: Workaround IOTLB hang on
Ironlake GPU")
- 2024: commit ba00196ca4 ("iommu/vt-d: Decouple igfx_off from graphic
identity mapping")
I'm uncertain whether further testings on this particular laptops were
done in 2011 and (honestly I'm not sure) 2024, but I would be happy to do
some distro-specific testing if that's what would be required to verify
this patch.
P.S., I also see IDs 0x0040, 0x0062, and 0x006a listed under the same
`quirk_calpella_no_shadow_gtt()' quirk, but I'm not sure how similar these
chipsets are (if they share the same issue with VT-d or even, indeed, if
this issue is specific to a bug in the Lenovo BIOS). With regards to
0x0062, it seems to be a Centrino wireless card, but not a chipset?
I have also listed a couple (distro and kernel) bug reports below as
references (some of them are from 7-8 years ago!), as they seem to be
similar issue found on different Westmere/Ironlake, Haswell, and Broadwell
hardware setups.
Cc: stable@vger.kernel.org
Fixes: 6fbcfb3e46 ("intel-iommu: Workaround IOTLB hang on Ironlake GPU")
Fixes: ba00196ca4 ("iommu/vt-d: Decouple igfx_off from graphic identity mapping")
Link: https://groups.google.com/g/qubes-users/c/4NP4goUds2c?pli=1
Link: https://bugs.archlinux.org/task/65362
Link: https://bbs.archlinux.org/viewtopic.php?id=230323
Reported-by: Wenhao Sun <weiguangtwk@outlook.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=197029
Signed-off-by: Mingcong Bai <jeffbai@aosc.io>
Link: https://lore.kernel.org/r/20250415133330.12528-1-jeffbai@aosc.io
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Lei Chen raised an issue with CLOCK_MONOTONIC_COARSE seeing time
inconsistencies. Lei tracked down that this was being caused by the
adjustment:
tk->tkr_mono.xtime_nsec -= offset;
which is made to compensate for the unaccumulated cycles in offset when the
multiplicator is adjusted forward, so that the non-_COARSE clockids don't
see inconsistencies.
However, the _COARSE clockid getter functions use the adjusted xtime_nsec
value directly and do not compensate the negative offset via the
clocksource delta multiplied with the new multiplicator. In that case the
caller can observe time going backwards in consecutive calls.
By design, this negative adjustment should be fine, because the logic run
from timekeeping_adjust() is done after it accumulated approximately
multiplicator * interval_cycles
into xtime_nsec. The accumulated value is always larger then the
mult_adj * offset
value, which is subtracted from xtime_nsec. Both operations are done
together under the tk_core.lock, so the net change to xtime_nsec is always
always be positive.
However, do_adjtimex() calls into timekeeping_advance() as well, to
apply the NTP frequency adjustment immediately. In this case,
timekeeping_advance() does not return early when the offset is smaller
then interval_cycles. In that case there is no time accumulated into
xtime_nsec. But the subsequent call into timekeeping_adjust(), which
modifies the multiplicator, subtracts from xtime_nsec to correct for the
new multiplicator.
Here because there was no accumulation, xtime_nsec becomes smaller than
before, which opens a window up to the next accumulation, where the
_COARSE clockid getters, which don't compensate for the offset, can
observe the inconsistency.
This has been tried to be fixed by forwarding the timekeeper in the case
that adjtimex() adjusts the multiplier, which resets the offset to zero:
757b000f7b ("timekeeping: Fix possible inconsistencies in _COARSE clockids")
That works correctly, but unfortunately causes a regression on the
adjtimex() side. There are two issues:
1) The forwarding of the base time moves the update out of the original
period and establishes a new one.
2) The clearing of the accumulated NTP error is changing the behaviour as
well.
User-space expects that multiplier/frequency updates are in effect, when the
syscall returns, so delaying the update to the next tick is not solving the
problem either.
Commit 757b000f7b was reverted so that the established expectations of
user space implementations (ntpd, chronyd) are restored, but that obviously
brought the inconsistencies back.
One of the initial approaches to fix this was to establish a separate
storage for the coarse time getter nanoseconds part by calculating it from
the offset. That was dropped on the floor because not having yet another
state to maintain was simpler. But given the result of the above exercise,
this solution turns out to be the right one. Bring it back in a slightly
modified form.
Thus introduce timekeeper::coarse_nsec and store that nanoseconds part in
it, switch the time getter functions and the VDSO update to use that value.
coarse_nsec is set on operations which forward or initialize the timekeeper
and after time was accumulated during a tick. If there is no accumulation
the timestamp is unchanged.
This leaves the adjtimex() behaviour unmodified and prevents coarse time
from going backwards.
[ jstultz: Simplified the coarse_nsec calculation and kept behavior so
coarse clockids aren't adjusted on each inter-tick adjtimex
call, slightly reworked the comments and commit message ]
Fixes: da15cfdae0 ("time: Introduce CLOCK_REALTIME_COARSE")
Reported-by: Lei Chen <lei.chen@smartx.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/all/20250419054706.2319105-1-jstultz@google.com
Closes: https://lore.kernel.org/lkml/20250310030004.3705801-1-lei.chen@smartx.com/
Fix missing .cpuidle.text section assignment for r4k_wait() to correct
backtracing with nmi_backtrace().
Fixes: 97c8580e85 ("MIPS: Annotate cpu_wait implementations with __cpuidle")
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
MIPS re-enables interrupts on its idle routine and performs
a TIF_NEED_RESCHED check afterwards before putting the CPU to sleep.
The IRQs firing between the check and the 'wait' instruction may set the
TIF_NEED_RESCHED flag. In order to deal with this possible race, IRQs
interrupting __r4k_wait() rollback their return address to the
beginning of __r4k_wait() so that TIF_NEED_RESCHED is checked
again before going back to sleep.
However idle IRQs can also queue timers that may require a tick
reprogramming through a new generic idle loop iteration but those timers
would go unnoticed here because __r4k_wait() only checks
TIF_NEED_RESCHED. It doesn't check for pending timers.
Fix this with fast-forwarding idle IRQs return address to the end of the
idle routine instead of the beginning, so that the generic idle loop
handles both TIF_NEED_RESCHED and pending timers.
CONFIG_CPU_MICROMIPS has been removed along with the nop instructions.
There, NOPs are 2 byte in size, so change the code with 3 _ssnop which are
always 4 byte and remove the ifdef. Added ehb to make sure the hazard
is always cleared.
Fixes: c65a5480ff ("[MIPS] Fix potential latency problem due to non-atomic cpu_wait.")
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
This hardware has ALC274 codec with speaker NID 0x17 and line out
NID 0x16 for audio output. The line out is routed correctly but
the speaker is not. Thus the volume can't be controlled.
This patch removes DAC NID 0x06 (without volume control) from the
connection list for speaker NID 0x17. Routing both speaker and line
out pins to DAC NID 0x02 which controls the output volume.
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
Link: https://patch.msgid.link/20250425103618.534951-1-chris.chiu@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Pull PCI fixes from Bjorn Helgaas:
- When releasing a start-aligned resource, e.g., a bridge window, save
start/end/flags for the next assignment attempt; fixes a v6.15-rc1
regression (Ilpo Järvinen)
- Move set_pcie_speed.sh from TEST_PROGS to TEST_FILE; fixes a bwctrl
selftest v6.15-rc1 regression (Ilpo Järvinen)
- Add Manivannan Sadhasivam as maintainer of native host bridge and
endpoint drivers (Manivannan Sadhasivam)
- In endpoint test driver, defer IRQ allocation from .probe() until
ioctl() to fix a regression on platforms where the Vendor/Device ID
match doesn't include driver_data (Niklas Cassel)
* tag 'pci-v6.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
misc: pci_endpoint_test: Defer IRQ allocation until ioctl(PCITEST_SET_IRQTYPE)
MAINTAINERS: Move Manivannan Sadhasivam as PCI Native host bridge and endpoint maintainer
selftests/pcie_bwctrl: Fix test progs list
PCI: Restore assigned resources fully after release
Pull nfsd fix from Chuck Lever:
- Revert a v6.15 patch due to a report of SELinux test failures
* tag 'nfsd-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
Revert "sunrpc: clean cache_detail immediately when flush is written frequently"
Pull misc x86 fixes from Ingo Molnar:
- Fix 32-bit kernel boot crash if passed physical memory with more than
32 address bits
- Fix Xen PV crash
- Work around build bug in certain limited build environments
- Fix CTEST instruction decoding in insn_decoder_test
* tag 'x86-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/insn: Fix CTEST instruction decoding
x86/boot: Work around broken busybox 'truncate' tool
x86/mm: Fix _pgd_alloc() for Xen PV mode
x86/e820: Discard high memory that can't be addressed by 32-bit systems
Pull scheduler fix from Ingo Molnar:
"Fix sporadic crashes in dequeue_entities() due to ... bad math.
[ Arguably if pick_eevdf()/pick_next_entity() was less trusting of
complex math being correct it could have de-escalated a crash into
a warning, but that's for a different patch ]"
* tag 'sched-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/eevdf: Fix se->slice being set to U64_MAX and resulting crash
Pull misc perf events fixes from Ingo Molnar:
- Use POLLERR for events in error state, instead of the ambiguous
POLLHUP error value
- Fix non-sampling (counting) events on certain x86 platforms
* tag 'perf-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix non-sampling (counting) events on certain x86 platforms
perf/core: Change to POLLERR for pinned events with error
Pull irq fix from Ingo Molnar:
"Fix crashes in the gic-v2m irqchip driver, caused by an incorrect
__init annotation"
* tag 'irq-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v2m: Prevent use after free of gicv2m_get_fwnode()
Pull LoongArch fixes from Huacai Chen:
"Add a missing Kconfig option, fix some bugs in exception handlers,
memory management and KVM"
* tag 'loongarch-fixes-6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
LoongArch: KVM: Fix PMU pass-through issue if VM exits to host finally
LoongArch: KVM: Fully clear some CSRs when VM reboot
LoongArch: KVM: Fix multiple typos of KVM code
LoongArch: Return NULL from huge_pte_offset() for invalid PMD
LoongArch: Remove a bogus reference to ZONE_DMA
LoongArch: Handle fp, lsx, lasx and lbt assembly symbols
LoongArch: Make do_xyz() exception handlers more robust
LoongArch: Make regs_irqs_disabled() more clear
LoongArch: Select ARCH_USE_MEMTEST
Pull OpenRISC updates from Stafford Horne:
- Support for cacheinfo API to expose OpenRISC cache info via sysfs,
this also translated to some cleanups to OpenRISC cache flush and
invalidate API's
- Documentation updates for new mailing list and toolchain binaries
* tag 'for-linus' of https://github.com/openrisc/linux:
Documentation: openrisc: Update toolchain binaries URL
Documentation: openrisc: Update mailing list
openrisc: Add cacheinfo support
openrisc: Introduce new utility functions to flush and invalidate caches
openrisc: Refactor struct cpuinfo_or1k to reduce duplication
Ondrej reports that certain SELinux tests are failing after commit
fc2a169c56 ("sunrpc: clean cache_detail immediately when flush is
written frequently"), merged during the v6.15 merge window.
Reported-by: Ondrej Mosnacek <omosnace@redhat.com>
Fixes: fc2a169c56 ("sunrpc: clean cache_detail immediately when flush is written frequently")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pull kunit fix from Kees Cook:
"A single fix for the kunit lib/tests/ relocation:
- Ensure prime numbers tests are included in KUnit test runs (Mark Brown)"
* tag 'move-lib-kunit-v6.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
lib: Ensure prime numbers tests are included in KUnit test runs
Pull drm fixes from Dave Airlie:
"Weekly drm fixes, mostly amdgpu, with some exynos cleanups and a
couple of minor fixes, seems a bit quiet, but probably some lag from
Easter holidays.
amdgpu:
- P2P DMA fixes
- Display reset fixes
- DCN 3.5 fixes
- ACPI EDID fix
- LTTPR fix
- mode_valid() fix
exynos:
- fix spelling error
- remove redundant error handling in exynos_drm_vidi.c module
- marks struct decon_data as const in the exynos7_drm_decon driver
since it is only read
- Remove unnecessary checking in exynos_drm_drv.c module
meson:
- Fix VCLK calculation
panel:
- jd9365a: Fix reset polarity"
* tag 'drm-fixes-2025-04-26' of https://gitlab.freedesktop.org/drm/kernel:
drm/exynos: Fix spelling mistake "enqueu" -> "enqueue"
drm/exynos: exynos7_drm_decon: Consstify struct decon_data
drm/exynos: fixed a spelling error
drm/exynos/vidi: Remove redundant error handling in vidi_get_modes()
drm/exynos: Remove unnecessary checking
drm/amd/display: do not copy invalid CRTC timing info
drm/amd/display: Default IPS to RCG_IN_ACTIVE_IPS2_IN_OFF
drm/amd/display: Use 16ms AUX read interval for LTTPR with old sinks
drm/amd/display: Fix ACPI edid parsing on some Lenovo systems
drm/amdgpu: Allow P2P access through XGMI
drm/amd/display: Enable urgent latency adjustment on DCN35
drm/amd/display: Force full update in gpu reset
drm/amd/display: Fix gpu reset in multidisplay config
drm/amdgpu: Don't pin VRAM without DMABUF_MOVE_NOTIFY
drm/amdgpu: Use allowed_domains for pinning dmabufs
drm: panel: jd9365da: fix reset signal polarity in unprepare
drm/meson: use unsigned long long / Hz for frequency types
Revert "drm/meson: vclk: fix calculation of 59.94 fractional rates"
There is a code path in dequeue_entities() that can set the slice of a
sched_entity to U64_MAX, which sometimes results in a crash.
The offending case is when dequeue_entities() is called to dequeue a
delayed group entity, and then the entity's parent's dequeue is delayed.
In that case:
1. In the if (entity_is_task(se)) else block at the beginning of
dequeue_entities(), slice is set to
cfs_rq_min_slice(group_cfs_rq(se)). If the entity was delayed, then
it has no queued tasks, so cfs_rq_min_slice() returns U64_MAX.
2. The first for_each_sched_entity() loop dequeues the entity.
3. If the entity was its parent's only child, then the next iteration
tries to dequeue the parent.
4. If the parent's dequeue needs to be delayed, then it breaks from the
first for_each_sched_entity() loop _without updating slice_.
5. The second for_each_sched_entity() loop sets the parent's ->slice to
the saved slice, which is still U64_MAX.
This throws off subsequent calculations with potentially catastrophic
results. A manifestation we saw in production was:
6. In update_entity_lag(), se->slice is used to calculate limit, which
ends up as a huge negative number.
7. limit is used in se->vlag = clamp(vlag, -limit, limit). Because limit
is negative, vlag > limit, so se->vlag is set to the same huge
negative number.
8. In place_entity(), se->vlag is scaled, which overflows and results in
another huge (positive or negative) number.
9. The adjusted lag is subtracted from se->vruntime, which increases or
decreases se->vruntime by a huge number.
10. pick_eevdf() calls entity_eligible()/vruntime_eligible(), which
incorrectly returns false because the vruntime is so far from the
other vruntimes on the queue, causing the
(vruntime - cfs_rq->min_vruntime) * load calulation to overflow.
11. Nothing appears to be eligible, so pick_eevdf() returns NULL.
12. pick_next_entity() tries to dereference the return value of
pick_eevdf() and crashes.
Dumping the cfs_rq states from the core dumps with drgn showed tell-tale
huge vruntime ranges and bogus vlag values, and I also traced se->slice
being set to U64_MAX on live systems (which was usually "benign" since
the rest of the runqueue needed to be in a particular state to crash).
Fix it in dequeue_entities() by always setting slice from the first
non-empty cfs_rq.
Fixes: aef6987d89 ("sched/eevdf: Propagate min_slice up the cgroup hierarchy")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/f0c2d1072be229e1bdddc73c0703919a8b00c652.1745570998.git.osandov@fb.com
Kent Overstreet