[ Upstream commit 2fd5b4b0e7b440602455b79977bfa64dea101e6c ]
Similar to VHE, calculate the value of cptr_el2 from scratch on
activate traps. This removes the need to store cptr_el2 in every
vcpu structure. Moreover, some traps, such as whether the guest
owns the fp registers, need to be set on every vcpu run.
Reported-by: James Clark <james.clark@linaro.org>
Fixes: 5294afdbf45a ("KVM: arm64: Exclude FP ownership from kvm_vcpu_arch")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20241216105057.579031-13-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f9dd00de1e53a47763dfad601635d18542c3836d ]
The shared hyp switch header has a number of static functions which
might not be used by all files that include the header, and when unused
they will provoke compiler warnings, e.g.
| In file included from arch/arm64/kvm/hyp/nvhe/hyp-main.c:8:
| ./arch/arm64/kvm/hyp/include/hyp/switch.h:703:13: warning: 'kvm_hyp_handle_dabt_low' defined but not used [-Wunused-function]
| 703 | static bool kvm_hyp_handle_dabt_low(struct kvm_vcpu *vcpu, u64 *exit_code)
| | ^~~~~~~~~~~~~~~~~~~~~~~
| ./arch/arm64/kvm/hyp/include/hyp/switch.h:682:13: warning: 'kvm_hyp_handle_cp15_32' defined but not used [-Wunused-function]
| 682 | static bool kvm_hyp_handle_cp15_32(struct kvm_vcpu *vcpu, u64 *exit_code)
| | ^~~~~~~~~~~~~~~~~~~~~~
| ./arch/arm64/kvm/hyp/include/hyp/switch.h:662:13: warning: 'kvm_hyp_handle_sysreg' defined but not used [-Wunused-function]
| 662 | static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code)
| | ^~~~~~~~~~~~~~~~~~~~~
| ./arch/arm64/kvm/hyp/include/hyp/switch.h:458:13: warning: 'kvm_hyp_handle_fpsimd' defined but not used [-Wunused-function]
| 458 | static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
| | ^~~~~~~~~~~~~~~~~~~~~
| ./arch/arm64/kvm/hyp/include/hyp/switch.h:329:13: warning: 'kvm_hyp_handle_mops' defined but not used [-Wunused-function]
| 329 | static bool kvm_hyp_handle_mops(struct kvm_vcpu *vcpu, u64 *exit_code)
| | ^~~~~~~~~~~~~~~~~~~
Mark these functions as 'inline' to suppress this warning. This
shouldn't result in any functional change.
At the same time, avoid the use of __alias() in the header and alias
kvm_hyp_handle_iabt_low() and kvm_hyp_handle_watchpt_low() to
kvm_hyp_handle_memory_fault() using CPP, matching the style in the rest
of the kernel. For consistency, kvm_hyp_handle_memory_fault() is also
marked as 'inline'.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-8-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9b66195063c5a145843547b1d692bd189be85287 ]
The hyp exit handling logic is largely shared between VHE and nVHE/hVHE,
with common logic in arch/arm64/kvm/hyp/include/hyp/switch.h. The code
in the header depends on function definitions provided by
arch/arm64/kvm/hyp/vhe/switch.c and arch/arm64/kvm/hyp/nvhe/switch.c
when they include the header.
This is an unusual header dependency, and prevents the use of
arch/arm64/kvm/hyp/include/hyp/switch.h in other files as this would
result in compiler warnings regarding missing definitions, e.g.
| In file included from arch/arm64/kvm/hyp/nvhe/hyp-main.c:8:
| ./arch/arm64/kvm/hyp/include/hyp/switch.h:733:31: warning: 'kvm_get_exit_handler_array' used but never defined
| 733 | static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu);
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~
| ./arch/arm64/kvm/hyp/include/hyp/switch.h:735:13: warning: 'early_exit_filter' used but never defined
| 735 | static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code);
| | ^~~~~~~~~~~~~~~~~
Refactor the logic such that the header doesn't depend on anything from
the C files. There should be no functional change as a result of this
patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-7-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 407a99c4654e8ea65393f412c421a55cac539f5b ]
When KVM is in VHE mode, the host kernel tries to save and restore the
configuration of CPACR_EL1.SMEN (i.e. CPTR_EL2.SMEN when HCR_EL2.E2H=1)
across kvm_arch_vcpu_load_fp() and kvm_arch_vcpu_put_fp(), since the
configuration may be clobbered by hyp when running a vCPU. This logic
has historically been broken, and is currently redundant.
This logic was originally introduced in commit:
861262ab86 ("KVM: arm64: Handle SME host state when running guests")
At the time, the VHE hyp code would reset CPTR_EL2.SMEN to 0b00 when
returning to the host, trapping host access to SME state. Unfortunately,
this was unsafe as the host could take a softirq before calling
kvm_arch_vcpu_put_fp(), and if a softirq handler were to use kernel mode
NEON the resulting attempt to save the live FPSIMD/SVE/SME state would
result in a fatal trap.
That issue was limited to VHE mode. For nVHE/hVHE modes, KVM always
saved/restored the host kernel's CPACR_EL1 value, and configured
CPTR_EL2.TSM to 0b0, ensuring that host usage of SME would not be
trapped.
The issue above was incidentally fixed by commit:
375110ab51 ("KVM: arm64: Fix resetting SME trap values on reset for (h)VHE")
That commit changed the VHE hyp code to configure CPTR_EL2.SMEN to 0b01
when returning to the host, permitting host kernel usage of SME,
avoiding the issue described above. At the time, this was not identified
as a fix for commit 861262ab86.
Now that the host eagerly saves and unbinds its own FPSIMD/SVE/SME
state, there's no need to save/restore the state of the EL0 SME trap.
The kernel can safely save/restore state without trapping, as described
above, and will restore userspace state (including trap controls) before
returning to userspace.
Remove the redundant logic.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-5-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
[Update for rework of flags storage -- broonie]
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 459f059be702056d91537b99a129994aa6ccdd35 ]
When KVM is in VHE mode, the host kernel tries to save and restore the
configuration of CPACR_EL1.ZEN (i.e. CPTR_EL2.ZEN when HCR_EL2.E2H=1)
across kvm_arch_vcpu_load_fp() and kvm_arch_vcpu_put_fp(), since the
configuration may be clobbered by hyp when running a vCPU. This logic is
currently redundant.
The VHE hyp code unconditionally configures CPTR_EL2.ZEN to 0b01 when
returning to the host, permitting host kernel usage of SVE.
Now that the host eagerly saves and unbinds its own FPSIMD/SVE/SME
state, there's no need to save/restore the state of the EL0 SVE trap.
The kernel can safely save/restore state without trapping, as described
above, and will restore userspace state (including trap controls) before
returning to userspace.
Remove the redundant logic.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-4-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
[Rework for refactoring of where the flags are stored -- broonie]
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8eca7f6d5100b6997df4f532090bc3f7e0203bef ]
Now that the host eagerly saves its own FPSIMD/SVE/SME state,
non-protected KVM never needs to save the host FPSIMD/SVE/SME state,
and the code to do this is never used. Protected KVM still needs to
save/restore the host FPSIMD/SVE state to avoid leaking guest state to
the host (and to avoid revealing to the host whether the guest used
FPSIMD/SVE/SME), and that code needs to be retained.
Remove the unused code and data structures.
To avoid the need for a stub copy of kvm_hyp_save_fpsimd_host() in the
VHE hyp code, the nVHE/hVHE version is moved into the shared switch
header, where it is only invoked when KVM is in protected mode.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-3-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fbc7e61195e23f744814e78524b73b59faa54ab4 ]
There are several problems with the way hyp code lazily saves the host's
FPSIMD/SVE state, including:
* Host SVE being discarded unexpectedly due to inconsistent
configuration of TIF_SVE and CPACR_ELx.ZEN. This has been seen to
result in QEMU crashes where SVE is used by memmove(), as reported by
Eric Auger:
https://issues.redhat.com/browse/RHEL-68997
* Host SVE state is discarded *after* modification by ptrace, which was an
unintentional ptrace ABI change introduced with lazy discarding of SVE state.
* The host FPMR value can be discarded when running a non-protected VM,
where FPMR support is not exposed to a VM, and that VM uses
FPSIMD/SVE. In these cases the hyp code does not save the host's FPMR
before unbinding the host's FPSIMD/SVE/SME state, leaving a stale
value in memory.
Avoid these by eagerly saving and "flushing" the host's FPSIMD/SVE/SME
state when loading a vCPU such that KVM does not need to save any of the
host's FPSIMD/SVE/SME state. For clarity, fpsimd_kvm_prepare() is
removed and the necessary call to fpsimd_save_and_flush_cpu_state() is
placed in kvm_arch_vcpu_load_fp(). As 'fpsimd_state' and 'fpmr_ptr'
should not be used, they are set to NULL; all uses of these will be
removed in subsequent patches.
Historical problems go back at least as far as v5.17, e.g. erroneous
assumptions about TIF_SVE being clear in commit:
8383741ab2 ("KVM: arm64: Get rid of host SVE tracking/saving")
... and so this eager save+flush probably needs to be backported to ALL
stable trees.
Fixes: 93ae6b01ba ("KVM: arm64: Discard any SVE state when entering KVM guests")
Fixes: 8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")
Fixes: ef3be86021c3bdf3 ("KVM: arm64: Add save/restore support for FPMR")
Reported-by: Eric Auger <eauger@redhat.com>
Reported-by: Wilco Dijkstra <wilco.dijkstra@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-2-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
[ Mark: Handle vcpu/host flag conflict, remove host_data_ptr() ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 62021cc36a ]
Now that we are explicitly telling the host FP code which register state
it needs to save we can remove the manipulation of TIF_SVE from the KVM
code, simplifying it and allowing us to optimise our handling of normal
tasks. Remove the manipulation of TIF_SVE from KVM and instead rely on
to_save to ensure we save the correct data for it.
There should be no functional or performance impact from this change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221115094640.112848-5-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit deeb8f9a80 ]
In order to avoid needlessly saving and restoring the guest registers KVM
relies on the host FPSMID code to save the guest registers when we context
switch away from the guest. This is done by binding the KVM guest state to
the CPU on top of the task state that was originally there, then carefully
managing the TIF_SVE flag for the task to cause the host to save the full
SVE state when needed regardless of the needs of the host task. This works
well enough but isn't terribly direct about what is going on and makes it
much more complicated to try to optimise what we're doing with the SVE
register state.
Let's instead have KVM pass in the register state it wants saving when it
binds to the CPU. We introduce a new FP_STATE_CURRENT for use
during normal task binding to indicate that we should base our
decisions on the current task. This should not be used when
actually saving. Ideally we might want to use a separate enum for
the type to save but this enum and the enum values would then
need to be named which has problems with clarity and ambiguity.
In order to ease any future debugging that might be required this patch
does not actually update any of the decision making about what to save,
it merely starts tracking the new information and warns if the requested
state is not what we would otherwise have decided to save.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221115094640.112848-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit baa8515281 ]
When we save the state for the floating point registers this can be done
in the form visible through either the FPSIMD V registers or the SVE Z and
P registers. At present we track which format is currently used based on
TIF_SVE and the SME streaming mode state but particularly in the SVE case
this limits our options for optimising things, especially around syscalls.
Introduce a new enum which we place together with saved floating point
state in both thread_struct and the KVM guest state which explicitly
states which format is active and keep it up to date when we change it.
At present we do not use this state except to verify that it has the
expected value when loading the state, future patches will introduce
functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221115094640.112848-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: fix conflicts due to earlier backports ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 93ae6b01ba ]
Since 8383741ab2 (KVM: arm64: Get rid of host SVE tracking/saving)
KVM has not tracked the host SVE state, relying on the fact that we
currently disable SVE whenever we perform a syscall. This may not be true
in future since performance optimisation may result in us keeping SVE
enabled in order to avoid needing to take access traps to reenable it.
Handle this by clearing TIF_SVE and converting the stored task state to
FPSIMD format when preparing to run the guest. This is done with a new
call fpsimd_kvm_prepare() to keep the direct state manipulation
functions internal to fpsimd.c.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221115094640.112848-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: trivial backport to v6.1 ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c0dd8a9253fadfb8e5357217d085f1989da4ef0a upstream.
The page_link lower bits of the first sg could contain something like
SG_END, if we are mapping a single VRAM page or contiguous blob which
fits into one sg entry. Rather pull out the struct page, and use that in
our check to know if we mapped struct pages vs VRAM.
Fixes: f44ffd677f ("drm/amdgpu: add support for exporting VRAM using DMA-buf v3")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4e3d9508c056d7e0a56b58d5c81253e2a0d22b6c upstream.
The user can set any speed value.
If speed is greater than UINT_MAX/8, division by zero is possible.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 031db09017 ("drm/amd/powerplay/vega20: enable fan RPM and pwm settings V2")
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f23e9116ebb71b63fe9cec0dcac792aa9af30b0c upstream.
The user can set any speed value.
If speed is greater than UINT_MAX/8, division by zero is possible.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: c05d1c4015 ("drm/amd/swsmu: add aldebaran smu13 ip support (v3)")
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7c246a05df51c52fe0852ce56ba10c41e6ed1f39 upstream.
The user can set any speed value.
If speed is greater than UINT_MAX/8, division by zero is possible.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: c52dcf4919 ("drm/amd/pp: Avoid divide-by-zero in fan_ctrl_set_fan_speed_rpm")
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7ba88b5cccc1a99c1afb96e31e7eedac9907704c upstream.
The user can set any speed value.
If speed is greater than UINT_MAX/8, division by zero is possible.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 1e866f1fe5 ("drm/amd/pm: Prevent divide by zero")
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit da7dc714a8f8e1c9fc33c57cd63583779a3bef71)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4b8c3c0d17c07f301011e2908fecd2ebdcfe3d1c upstream.
The user can set any speed value.
If speed is greater than UINT_MAX/8, division by zero is possible.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: c52dcf4919 ("drm/amd/pp: Avoid divide-by-zero in fan_ctrl_set_fan_speed_rpm")
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7d641c2b83275d3b0424127b2e0d2d0f7dd82aef upstream.
The user can set any speed value.
If speed is greater than UINT_MAX/8, division by zero is possible.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: b64625a303 ("drm/amd/pm: correct the address of Arcturus fan related registers")
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f561db72a663f8a73c2250bf3244ce1ce221bed7 upstream.
It was observed on sc7180 (A618 gpu) that GPU votes for GX rail and CNOC
BCM nodes were not removed after GPU suspend. This was because we
skipped sending 'prepare-slumber' request to gmu during suspend sequence
in some cases. So, make sure we always call prepare-slumber hfi during
suspend. Also, calling prepare-slumber without a prior oob-gpu handshake
messes up gmu firmware's internal state. So, do that when required.
Fixes: 4b565ca5a2 ("drm/msm: Add A6XX device support")
Cc: stable@vger.kernel.org
Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/639569/
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4d098000ac193f359e6b8ca4801dbdbd6a27b41f upstream.
There are conditions, albeit somewhat unlikely, under which right hand
expressions, calculating the end of time period in functions like
repaper_frame_fixed_repeat(), may overflow.
For instance, if 'factor10x' in repaper_get_temperature() is high
enough (170), as is 'epd->stage_time' in repaper_probe(), then the
resulting value of 'end' will not fit in unsigned int expression.
Mitigate this by casting 'epd->factored_stage_time' to wider type before
any multiplication is done.
Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.
Fixes: 3589211e9b ("drm/tinydrm: Add RePaper e-ink driver")
Cc: stable@vger.kernel.org
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Signed-off-by: Alex Lanzano <lanzano.alex@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250116134801.22067-1-n.zhandarovich@fintech.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 96a720db59ab330c8562b2437153faa45dac705f upstream.
There was a mistake in the SNR uncore spec. The counter increments for
every 32 bytes of data sent from the IO agent to the SOC, not 4 bytes
which was documented in the spec.
The event list has been updated:
"EventName": "UNC_IIO_BANDWIDTH_IN.PART0_FREERUN",
"BriefDescription": "Free running counter that increments for every 32
bytes of data sent from the IO agent to the SOC",
Update the scale of the IIO bandwidth in free running counters as well.
Fixes: 210cc5f9db ("perf/x86/intel/uncore: Add uncore support for Snow Ridge server")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250416142426.3933977-1-kan.liang@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 71dcc11c2cd9e434c34a63154ecadca21c135ddd upstream.
Currently when a user samples user space GPRs (--user-regs option) with
PEBS, the user space GPRs actually always come from software PMI
instead of from PEBS hardware. This leads to the sampled GPRs to
possibly be inaccurate for single PEBS record case because of the
skid between counter overflow and GPRs sampling on PMI.
For the large PEBS case, it is even worse. If user sets the
exclude_kernel attribute, large PEBS would be used to sample user space
GPRs, but since PEBS GPRs group is not really enabled, it leads to all
samples in the large PEBS record to share the same piece of user space
GPRs, like this reproducer shows:
$ perf record -e branches:pu --user-regs=ip,ax -c 100000 ./foo
$ perf report -D | grep "AX"
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
.... AX 0x000000003a0d4ead
So enable GPRs group for user space GPRs sampling and prioritize reading
GPRs from PEBS. If the PEBS sampled GPRs is not user space GPRs (single
PEBS record case), perf_sample_regs_user() modifies them to user space
GPRs.
[ mingo: Clarified the changelog. ]
Fixes: c22497f583 ("perf/x86/intel: Support adaptive PEBS v4")
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250415104135.318169-2-dapeng1.mi@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 45f5dcdd049719fb999393b30679605f16ebce14 upstream.
struct rdma_cm_id has member "struct work_struct net_work"
that is reused for enqueuing cma_netevent_work_handler()s
onto cma_wq.
Below crash[1] can occur if more than one call to
cma_netevent_callback() occurs in quick succession,
which further enqueues cma_netevent_work_handler()s for the
same rdma_cm_id, overwriting any previously queued work-item(s)
that was just scheduled to run i.e. there is no guarantee
the queued work item may run between two successive calls
to cma_netevent_callback() and the 2nd INIT_WORK would overwrite
the 1st work item (for the same rdma_cm_id), despite grabbing
id_table_lock during enqueue.
Also drgn analysis [2] indicates the work item was likely overwritten.
Fix this by moving the INIT_WORK() to __rdma_create_id(),
so that it doesn't race with any existing queue_work() or
its worker thread.
[1] Trimmed crash stack:
=============================================
BUG: kernel NULL pointer dereference, address: 0000000000000008
kworker/u256:6 ... 6.12.0-0...
Workqueue: cma_netevent_work_handler [rdma_cm] (rdma_cm)
RIP: 0010:process_one_work+0xba/0x31a
Call Trace:
worker_thread+0x266/0x3a0
kthread+0xcf/0x100
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1a/0x30
=============================================
[2] drgn crash analysis:
>>> trace = prog.crashed_thread().stack_trace()
>>> trace
(0) crash_setup_regs (./arch/x86/include/asm/kexec.h:111:15)
(1) __crash_kexec (kernel/crash_core.c:122:4)
(2) panic (kernel/panic.c:399:3)
(3) oops_end (arch/x86/kernel/dumpstack.c:382:3)
...
(8) process_one_work (kernel/workqueue.c:3168:2)
(9) process_scheduled_works (kernel/workqueue.c:3310:3)
(10) worker_thread (kernel/workqueue.c:3391:4)
(11) kthread (kernel/kthread.c:389:9)
Line workqueue.c:3168 for this kernel version is in process_one_work():
3168 strscpy(worker->desc, pwq->wq->name, WORKER_DESC_LEN);
>>> trace[8]["work"]
*(struct work_struct *)0xffff92577d0a21d8 = {
.data = (atomic_long_t){
.counter = (s64)536870912, <=== Note
},
.entry = (struct list_head){
.next = (struct list_head *)0xffff924d075924c0,
.prev = (struct list_head *)0xffff924d075924c0,
},
.func = (work_func_t)cma_netevent_work_handler+0x0 = 0xffffffffc2cec280,
}
Suspicion is that pwq is NULL:
>>> trace[8]["pwq"]
(struct pool_workqueue *)<absent>
In process_one_work(), pwq is assigned from:
struct pool_workqueue *pwq = get_work_pwq(work);
and get_work_pwq() is:
static struct pool_workqueue *get_work_pwq(struct work_struct *work)
{
unsigned long data = atomic_long_read(&work->data);
if (data & WORK_STRUCT_PWQ)
return work_struct_pwq(data);
else
return NULL;
}
WORK_STRUCT_PWQ is 0x4:
>>> print(repr(prog['WORK_STRUCT_PWQ']))
Object(prog, 'enum work_flags', value=4)
But work->data is 536870912 which is 0x20000000.
So, get_work_pwq() returns NULL and we crash in process_one_work():
3168 strscpy(worker->desc, pwq->wq->name, WORKER_DESC_LEN);
=============================================
Fixes: 925d046e7e ("RDMA/core: Add a netevent notifier to cma")
Cc: stable@vger.kernel.org
Co-developed-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Sharath Srinivasan <sharath.srinivasan@oracle.com>
Reviewed-by: Patrisious Haddad <phaddad@nvidia.com>
Link: https://patch.msgid.link/bf0082f9-5b25-4593-92c6-d130aa8ba439@oracle.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d94c12bd97d567de342fd32599e7cd9e50bfa140 upstream.
The call to read_word_at_a_time() in sized_strscpy() is problematic
with MTE because it may trigger a tag check fault when reading
across a tag granule (16 bytes) boundary. To make this code
MTE compatible, let's start using load_unaligned_zeropad()
on architectures where it is available (i.e. architectures that
define CONFIG_DCACHE_WORD_ACCESS). Because load_unaligned_zeropad()
takes care of page boundaries as well as tag granule boundaries,
also disable the code preventing crossing page boundaries when using
load_unaligned_zeropad().
Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/If4b22e43b5a4ca49726b4bf98ada827fdf755548
Fixes: 94ab5b61ee ("kasan, arm64: enable CONFIG_KASAN_HW_TAGS")
Cc: stable@vger.kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250403000703.2584581-2-pcc@google.com
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 262b73ef442e68e53220b9d6fc5a0d08b557fa42 upstream.
The following Python script results in unexpected behaviour when run on
a CIFS filesystem against a Windows Server:
# Create file
fd = os.open('test', os.O_WRONLY|os.O_CREAT)
os.write(fd, b'foo')
os.close(fd)
# Open and close the file to leave a pending deferred close
fd = os.open('test', os.O_RDONLY|os.O_DIRECT)
os.close(fd)
# Try to open the file via a hard link
os.link('test', 'new')
newfd = os.open('new', os.O_RDONLY|os.O_DIRECT)
The final open returns EINVAL due to the server returning
STATUS_INVALID_PARAMETER. The root cause of this is that the client
caches lease keys per inode, but the spec requires them to be related to
the filename which causes problems when hard links are involved:
From MS-SMB2 section 3.3.5.9.11:
"The server MUST attempt to locate a Lease by performing a lookup in the
LeaseTable.LeaseList using the LeaseKey in the
SMB2_CREATE_REQUEST_LEASE_V2 as the lookup key. If a lease is found,
Lease.FileDeleteOnClose is FALSE, and Lease.Filename does not match the
file name for the incoming request, the request MUST be failed with
STATUS_INVALID_PARAMETER"
On client side, we first check the context of file open, if it hits above
conditions, we first close all opening files which are belong to the same
inode, then we do open the hard link file.
Cc: stable@vger.kernel.org
Signed-off-by: Chunjie Zhu <chunjie.zhu@cloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit adf53771a3123df99ca26e38818760fbcf5c05d0 upstream.
When building with CONFIG_FORTIFY_SOURCE=y and W=1, there is a warning
because of the memcpy() in syscall_get_arguments():
In file included from include/linux/string.h:392,
from include/linux/bitmap.h:13,
from include/linux/cpumask.h:12,
from arch/riscv/include/asm/processor.h:55,
from include/linux/sched.h:13,
from kernel/ptrace.c:13:
In function 'fortify_memcpy_chk',
inlined from 'syscall_get_arguments.isra' at arch/riscv/include/asm/syscall.h:66:2:
include/linux/fortify-string.h:580:25: error: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning]
580 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
The fortified memcpy() routine enforces that the source is not overread
and the destination is not overwritten if the size of either field and
the size of the copy are known at compile time. The memcpy() in
syscall_get_arguments() intentionally overreads from a1 to a5 in
'struct pt_regs' but this is bigger than the size of a1.
Normally, this could be solved by wrapping a1 through a5 with
struct_group() but there was already a struct_group() applied to these
members in commit bba547810c66 ("riscv: tracing: Fix
__write_overflow_field in ftrace_partial_regs()").
Just avoid memcpy() altogether and write the copying of args from regs
manually, which clears up the warning at the expense of three extra
lines of code.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Dmitry V. Levin <ldv@strace.io>
Fixes: e2c0cdfba7 ("RISC-V: User-facing API")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250409-riscv-avoid-fortify-warning-syscall_get_arguments-v1-1-7853436d4755@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a93ff742820f75bf8bb3fcf21d9f25ca6eb3d4c6 upstream.
The user can set any value for 'deadtime'. This affects the arithmetic
expression 'req->deadtime * SMB_ECHO_INTERVAL', which is subject to
overflow. The added check makes the server behavior more predictable.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Cc: stable@vger.kernel.org
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1e440d5b25b7efccb3defe542a73c51005799a5f upstream.
krb_authenticate frees sess->user and does not set the pointer
to NULL. It calls ksmbd_krb5_authenticate to reinitialise
sess->user but that function may return without doing so. If
that happens then smb2_sess_setup, which calls krb_authenticate,
will be accessing free'd memory when it later uses sess->user.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Heelan <seanheelan@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8ab1b16023961dc640023b10436d282f905835ad upstream.
filemap_get_folios_contig() is supposed to return distinct folios found
within [start, end]. Large folios in the Xarray become multi-index
entries. xas_next() can iterate through the sub-indexes before finding a
sibling entry and breaking out of the loop.
This can result in a returned folio_batch containing an indeterminate
number of duplicate folios, which forces the callers to skeptically handle
the returned batch. This is inefficient and incurs a large maintenance
overhead.
We can fix this by calling xas_advance() after we have successfully adding
a folio to the batch to ensure our Xarray is positioned such that it will
correctly find the next folio - similar to filemap_get_read_batch().
Link: https://lkml.kernel.org/r/Z-8s1-kiIDkzgRbc@fedora
Fixes: 35b471467f ("filemap: add filemap_get_folios_contig()")
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reported-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Closes: https://lkml.kernel.org/r/b714e4de-2583-4035-b829-72cfb5eb6fc6@gmx.com
Tested-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e7bc0010ceb403d025100698586c8e760921d471 upstream.
The original commit message and the wording "uncork" in the code comment
indicate that it is expected that the suppressed event instances are
automatically sent after unsuppressing.
This is not the case, instead they are discarded.
In effect this means that no "changed" events are emitted on the device
itself by default.
While each discovered partition does trigger a changed event on the
device, devices without partitions don't have any event emitted.
This makes udev miss the device creation and prompted workarounds in
userspace. See the linked util-linux/losetup bug.
Explicitly emit the events and drop the confusingly worded comments.
Link: https://github.com/util-linux/util-linux/issues/2434
Fixes: 498ef5c777 ("loop: suppress uevents while reconfiguring the device")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250415-loop-uevent-changed-v2-1-0c4e6a923b2a@linutronix.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0405d4b63d082861f4eaff9d39c78ee9dc34f845 upstream.
syzbot reported a slab-out-of-bounds Read in isofs_fh_to_parent. [1]
The handle_bytes value passed in by the reproducing program is equal to 12.
In handle_to_path(), only 12 bytes of memory are allocated for the structure
file_handle->f_handle member, which causes an out-of-bounds access when
accessing the member parent_block of the structure isofs_fid in isofs,
because accessing parent_block requires at least 16 bytes of f_handle.
Here, fh_len is used to indirectly confirm that the value of handle_bytes
is greater than 3 before accessing parent_block.
[1]
BUG: KASAN: slab-out-of-bounds in isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183
Read of size 4 at addr ffff0000cc030d94 by task syz-executor215/6466
CPU: 1 UID: 0 PID: 6466 Comm: syz-executor215 Not tainted 6.14.0-rc7-syzkaller-ga2392f333575 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0x198/0x550 mm/kasan/report.c:521
kasan_report+0xd8/0x138 mm/kasan/report.c:634
__asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380
isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183
exportfs_decode_fh_raw+0x2dc/0x608 fs/exportfs/expfs.c:523
do_handle_to_path+0xa0/0x198 fs/fhandle.c:257
handle_to_path fs/fhandle.c:385 [inline]
do_handle_open+0x8cc/0xb8c fs/fhandle.c:403
__do_sys_open_by_handle_at fs/fhandle.c:443 [inline]
__se_sys_open_by_handle_at fs/fhandle.c:434 [inline]
__arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Allocated by task 6466:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x40/0x78 mm/kasan/common.c:68
kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4294 [inline]
__kmalloc_noprof+0x32c/0x54c mm/slub.c:4306
kmalloc_noprof include/linux/slab.h:905 [inline]
handle_to_path fs/fhandle.c:357 [inline]
do_handle_open+0x5a4/0xb8c fs/fhandle.c:403
__do_sys_open_by_handle_at fs/fhandle.c:443 [inline]
__se_sys_open_by_handle_at fs/fhandle.c:434 [inline]
__arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Reported-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4d7cd7dd0ce1aa8d5c65
Tested-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/tencent_9C8CB8A7E7C6C512C7065DC98B6EDF6EC606@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dc08c58696f8555e4a802f1f23c894a330d80ab7 upstream.
Currently, displaying the btrfs subvol mount option doesn't escape ','.
This makes parsing /proc/self/mounts and /proc/self/mountinfo
ambiguous for subvolume names that contain commas. The text after the
comma could be mistaken for another option (think "subvol=foo,ro", where
ro is actually part of the subvolumes name).
Replace the manual escape characters list with a call to
seq_show_option(). Thanks to Calvin Walton for suggesting this approach.
Fixes: c8d3fe028f ("Btrfs: show subvol= and subvolid= in /proc/mounts")
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Johannes Kimmel <kernel@bareminimum.eu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a1d14d931bf700c1025db8c46d6731aa5cf440f9 ]
A deadlock warning occurred when invoking nfs4_put_stid following a failed
dl_recall queue operation:
T1 T2
nfs4_laundromat
nfs4_get_client_reaplist
nfs4_anylock_blockers
__break_lease
spin_lock // ctx->flc_lock
spin_lock // clp->cl_lock
nfs4_lockowner_has_blockers
locks_owner_has_blockers
spin_lock // flctx->flc_lock
nfsd_break_deleg_cb
nfsd_break_one_deleg
nfs4_put_stid
refcount_dec_and_lock
spin_lock // clp->cl_lock
When a file is opened, an nfs4_delegation is allocated with sc_count
initialized to 1, and the file_lease holds a reference to the delegation.
The file_lease is then associated with the file through kernel_setlease.
The disassociation is performed in nfsd4_delegreturn via the following
call chain:
nfsd4_delegreturn --> destroy_delegation --> destroy_unhashed_deleg -->
nfs4_unlock_deleg_lease --> kernel_setlease --> generic_delete_lease
The corresponding sc_count reference will be released after this
disassociation.
Since nfsd_break_one_deleg executes while holding the flc_lock, the
disassociation process becomes blocked when attempting to acquire flc_lock
in generic_delete_lease. This means:
1) sc_count in nfsd_break_one_deleg will not be decremented to 0;
2) The nfs4_put_stid called by nfsd_break_one_deleg will not attempt to
acquire cl_lock;
3) Consequently, no deadlock condition is created.
Given that sc_count in nfsd_break_one_deleg remains non-zero, we can
safely perform refcount_dec on sc_count directly. This approach
effectively avoids triggering deadlock warnings.
Fixes: 230ca758453c ("nfsd: put dl_stid if fail to queue dl_recall")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
