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2 years agoKVM: VMX: Set failure code in prepare_vmcs02()
Dan Carpenter [Tue, 30 Nov 2021 12:53:37 +0000 (15:53 +0300)]
KVM: VMX: Set failure code in prepare_vmcs02()

The error paths in the prepare_vmcs02() function are supposed to set
*entry_failure_code but this path does not.  It leads to using an
uninitialized variable in the caller.

Fixes: b6c8270c1ced ("KVM: nVMX: Load GUEST_IA32_PERF_GLOBAL_CTRL MSR on VM-Entry")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Message-Id: <20211130125337.GB24578@kili>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: ensure APICv is considered inactive if there is no APIC
Paolo Bonzini [Tue, 30 Nov 2021 12:37:45 +0000 (07:37 -0500)]
KVM: ensure APICv is considered inactive if there is no APIC

kvm_vcpu_apicv_active() returns false if a virtual machine has no in-kernel
local APIC, however kvm_apicv_activated might still be true if there are
no reasons to disable APICv; in fact it is quite likely that there is none
because APICv is inhibited by specific configurations of the local APIC
and those configurations cannot be programmed.  This triggers a WARN:

   WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu));

To avoid this, introduce another cause for APICv inhibition, namely the
absence of an in-kernel local APIC.  This cause is enabled by default,
and is dropped by either KVM_CREATE_IRQCHIP or the enabling of
KVM_CAP_IRQCHIP_SPLIT.

Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Fixes: 29d1c9a64e38 ("KVM: x86: Move SVM's APICv sanity check to common x86", 2021-10-22)
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Ignat Korchagin <ignat@cloudflare.com>
Message-Id: <20211130123746.293379-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86/pmu: Fix reserved bits for AMD PerfEvtSeln register
Like Xu [Thu, 18 Nov 2021 13:03:20 +0000 (21:03 +0800)]
KVM: x86/pmu: Fix reserved bits for AMD PerfEvtSeln register

If we run the following perf command in an AMD Milan guest:

  perf stat \
  -e cpu/event=0x1d0/ \
  -e cpu/event=0x1c7/ \
  -e cpu/umask=0x1f,event=0x18e/ \
  -e cpu/umask=0x7,event=0x18e/ \
  -e cpu/umask=0x18,event=0x18e/ \
  ./workload

dmesg will report a #GP warning from an unchecked MSR access
error on MSR_F15H_PERF_CTLx.

This is because according to APM (Revision: 4.03) Figure 13-7,
the bits [35:32] of AMD PerfEvtSeln register is a part of the
event select encoding, which extends the EVENT_SELECT field
from 8 bits to 12 bits.

Opportunistically update pmu->reserved_bits for reserved bit 19.

Reported-by: Jim Mattson <jmattson@google.com>
Fixes: c97977012838 ("KVM: x86/vPMU: Implement AMD vPMU code for KVM")
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20211118130320.95997-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: fix avic_set_running for preemptable kernels
Paolo Bonzini [Tue, 30 Nov 2021 08:46:07 +0000 (03:46 -0500)]
KVM: fix avic_set_running for preemptable kernels

avic_set_running() passes the current CPU to avic_vcpu_load(), albeit
via vcpu->cpu rather than smp_processor_id().  If the thread is migrated
while avic_set_running runs, the call to avic_vcpu_load() can use a stale
value for the processor id.  Avoid this by blocking preemption over the
entire execution of avic_set_running().

Reported-by: Sean Christopherson <seanjc@google.com>
Fixes: af9badde83f5 ("svm: Manage vcpu load/unload when enable AVIC")
Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled
Paolo Bonzini [Tue, 30 Nov 2021 12:36:41 +0000 (07:36 -0500)]
KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled

There is nothing to synchronize if APICv is disabled, since neither
other vCPUs nor assigned devices can set PIR.ON.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: accept signals in sev_lock_two_vms
Paolo Bonzini [Tue, 23 Nov 2021 00:50:36 +0000 (19:50 -0500)]
KVM: SEV: accept signals in sev_lock_two_vms

Generally, kvm->lock is not taken for a long time, but
sev_lock_two_vms is different: it takes vCPU locks
inside, so userspace can hold it back just by calling
a vCPU ioctl.  Play it safe and use mutex_lock_killable.

Message-Id: <20211123005036.2954379-13-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: do not take kvm->lock when destroying
Paolo Bonzini [Tue, 23 Nov 2021 00:50:35 +0000 (19:50 -0500)]
KVM: SEV: do not take kvm->lock when destroying

Taking the lock is useless since there are no other references,
and there are already accesses (e.g. to sev->enc_context_owner)
that do not take it.  So get rid of it.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-12-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: Prohibit migration of a VM that has mirrors
Paolo Bonzini [Tue, 23 Nov 2021 00:50:34 +0000 (19:50 -0500)]
KVM: SEV: Prohibit migration of a VM that has mirrors

VMs that mirror an encryption context rely on the owner to keep the
ASID allocated.  Performing a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
would cause a dangling ASID:

1. copy context from A to B (gets ref to A)
2. move context from A to L (moves ASID from A to L)
3. close L (releases ASID from L, B still references it)

The right way to do the handoff instead is to create a fresh mirror VM
on the destination first:

1. copy context from A to B (gets ref to A)
[later] 2. close B (releases ref to A)
3. move context from A to L (moves ASID from A to L)
4. copy context from L to M

So, catch the situation by adding a count of how many VMs are
mirroring this one's encryption context.

Fixes: 697b9f909d28 ("KVM: SEV: Add support for SEV-ES intra host migration")
Message-Id: <20211123005036.2954379-11-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: Do COPY_ENC_CONTEXT_FROM with both VMs locked
Paolo Bonzini [Tue, 23 Nov 2021 00:50:33 +0000 (19:50 -0500)]
KVM: SEV: Do COPY_ENC_CONTEXT_FROM with both VMs locked

Now that we have a facility to lock two VMs with deadlock
protection, use it for the creation of mirror VMs as well.  One of
COPY_ENC_CONTEXT_FROM(dst, src) and COPY_ENC_CONTEXT_FROM(src, dst)
would always fail, so the combination is nonsensical and it is okay to
return -EBUSY if it is attempted.

This sidesteps the question of what happens if a VM is
MOVE_ENC_CONTEXT_FROM'd at the same time as it is
COPY_ENC_CONTEXT_FROM'd: the locking prevents that from
happening.

Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-10-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoselftests: sev_migrate_tests: add tests for KVM_CAP_VM_COPY_ENC_CONTEXT_FROM
Paolo Bonzini [Tue, 23 Nov 2021 00:50:32 +0000 (19:50 -0500)]
selftests: sev_migrate_tests: add tests for KVM_CAP_VM_COPY_ENC_CONTEXT_FROM

I am putting the tests in sev_migrate_tests because the failure conditions are
very similar and some of the setup code can be reused, too.

The tests cover both successful creation of a mirror VM, and error
conditions.

Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-9-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: move mirror status to destination of KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
Paolo Bonzini [Tue, 23 Nov 2021 00:50:31 +0000 (19:50 -0500)]
KVM: SEV: move mirror status to destination of KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM

Allow intra-host migration of a mirror VM; the destination VM will be
a mirror of the same ASID as the source.

Fixes: 1167986334b9 ("KVM: SEV: Add support for SEV intra host migration")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-8-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: initialize regions_list of a mirror VM
Paolo Bonzini [Tue, 23 Nov 2021 00:50:30 +0000 (19:50 -0500)]
KVM: SEV: initialize regions_list of a mirror VM

This was broken before the introduction of KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM,
but technically harmless because the region list was unused for a mirror
VM.  However, it is untidy and it now causes a NULL pointer access when
attempting to move the encryption context of a mirror VM.

Fixes: 902f83bac915 ("KVM: x86: Support KVM VMs sharing SEV context")
Message-Id: <20211123005036.2954379-7-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: cleanup locking for KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
Paolo Bonzini [Tue, 23 Nov 2021 00:50:29 +0000 (19:50 -0500)]
KVM: SEV: cleanup locking for KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM

Encapsulate the handling of the migration_in_progress flag for both VMs in
two functions sev_lock_two_vms and sev_unlock_two_vms.  It does not matter
if KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM locks the destination struct kvm a bit
later, and this change 1) keeps the cleanup chain of labels smaller 2)
makes it possible for KVM_CAP_VM_COPY_ENC_CONTEXT_FROM to reuse the logic.

Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-6-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: do not use list_replace_init on an empty list
Paolo Bonzini [Tue, 23 Nov 2021 00:50:28 +0000 (19:50 -0500)]
KVM: SEV: do not use list_replace_init on an empty list

list_replace_init cannot be used if the source is an empty list,
because "new->next->prev = new" will overwrite "old->next":

new old
prev = new, next = new prev = old, next = old
new->next = old->next prev = new, next = old prev = old, next = old
new->next->prev = new prev = new, next = old prev = old, next = new
new->prev = old->prev prev = old, next = old prev = old, next = old
new->next->prev = new prev = old, next = old prev = new, next = new

The desired outcome instead would be to leave both old and new the same
as they were (two empty circular lists).  Use list_cut_before, which
already has the necessary check and is documented to discard the
previous contents of the list that will hold the result.

Fixes: 1167986334b9 ("KVM: SEV: Add support for SEV intra host migration")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86: Use a stable condition around all VT-d PI paths
Paolo Bonzini [Tue, 23 Nov 2021 00:43:11 +0000 (19:43 -0500)]
KVM: x86: Use a stable condition around all VT-d PI paths

Currently, checks for whether VT-d PI can be used refer to the current
status of the feature in the current vCPU; or they more or less pick
vCPU 0 in case a specific vCPU is not available.

However, these checks do not attempt to synchronize with changes to
the IRTE.  In particular, there is no path that updates the IRTE when
APICv is re-activated on vCPU 0; and there is no path to wakeup a CPU
that has APICv disabled, if the wakeup occurs because of an IRTE
that points to a posted interrupt.

To fix this, always go through the VT-d PI path as long as there are
assigned devices and APICv is available on both the host and the VM side.
Since the relevant condition was copied over three times, take the hint
and factor it into a separate function.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Message-Id: <20211123004311.2954158-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86: check PIR even for vCPUs with disabled APICv
Paolo Bonzini [Tue, 23 Nov 2021 00:43:10 +0000 (19:43 -0500)]
KVM: x86: check PIR even for vCPUs with disabled APICv

The IRTE for an assigned device can trigger a POSTED_INTR_VECTOR even
if APICv is disabled on the vCPU that receives it.  In that case, the
interrupt will just cause a vmexit and leave the ON bit set together
with the PIR bit corresponding to the interrupt.

Right now, the interrupt would not be delivered until APICv is re-enabled.
However, fixing this is just a matter of always doing the PIR->IRR
synchronization, even if the vCPU has temporarily disabled APICv.

This is not a problem for performance, or if anything it is an
improvement.  First, in the common case where vcpu->arch.apicv_active is
true, one fewer check has to be performed.  Second, static_call_cond will
elide the function call if APICv is not present or disabled.  Finally,
in the case for AMD hardware we can remove the sync_pir_to_irr callback:
it is only needed for apic_has_interrupt_for_ppr, and that function
already has a fallback for !APICv.

Cc: stable@vger.kernel.org
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Message-Id: <20211123004311.2954158-4-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: VMX: prepare sync_pir_to_irr for running with APICv disabled
Paolo Bonzini [Tue, 23 Nov 2021 00:43:09 +0000 (19:43 -0500)]
KVM: VMX: prepare sync_pir_to_irr for running with APICv disabled

If APICv is disabled for this vCPU, assigned devices may still attempt to
post interrupts.  In that case, we need to cancel the vmentry and deliver
the interrupt with KVM_REQ_EVENT.  Extend the existing code that handles
injection of L1 interrupts into L2 to cover this case as well.

vmx_hwapic_irr_update is only called when APICv is active so it would be
confusing to add a check for vcpu->arch.apicv_active in there.  Instead,
just use vmx_set_rvi directly in vmx_sync_pir_to_irr.

Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123004311.2954158-3-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: selftests: page_table_test: fix calculation of guest_test_phys_mem
Maciej S. Szmigiero [Fri, 26 Nov 2021 15:28:31 +0000 (16:28 +0100)]
KVM: selftests: page_table_test: fix calculation of guest_test_phys_mem

A kvm_page_table_test run with its default settings fails on VMX due to
memory region add failure:
> ==== Test Assertion Failure ====
>  lib/kvm_util.c:952: ret == 0
>  pid=10538 tid=10538 errno=17 - File exists
>     1  0x00000000004057d1: vm_userspace_mem_region_add at kvm_util.c:947
>     2  0x0000000000401ee9: pre_init_before_test at kvm_page_table_test.c:302
>     3   (inlined by) run_test at kvm_page_table_test.c:374
>     4  0x0000000000409754: for_each_guest_mode at guest_modes.c:53
>     5  0x0000000000401860: main at kvm_page_table_test.c:500
>     6  0x00007f82ae2d8554: ?? ??:0
>     7  0x0000000000401894: _start at ??:?
>  KVM_SET_USER_MEMORY_REGION IOCTL failed,
>  rc: -1 errno: 17
>  slot: 1 flags: 0x0
>  guest_phys_addr: 0xc0000000 size: 0x40000000

This is because the memory range that this test is trying to add
(0x0c0000000 - 0x100000000) conflicts with LAPIC mapping at 0x0fee00000.

Looking at the code it seems that guest_test_*phys*_mem variable gets
mistakenly overwritten with guest_test_*virt*_mem while trying to adjust
the former for alignment.
With the correct variable adjusted this test runs successfully.

Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <52e487458c3172923549bbcf9dfccfbe6faea60b.1637940473.git.maciej.szmigiero@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86/mmu: Handle "default" period when selectively waking kthread
Sean Christopherson [Sat, 20 Nov 2021 01:57:06 +0000 (01:57 +0000)]
KVM: x86/mmu: Handle "default" period when selectively waking kthread

Account for the '0' being a default, "let KVM choose" period, when
determining whether or not the recovery worker needs to be awakened in
response to userspace reducing the period.  Failure to do so results in
the worker not being awakened properly, e.g. when changing the period
from '0' to any small-ish value.

Fixes: 57fbbb5cb984 ("kvm: x86: mmu: Make NX huge page recovery period configurable")
Cc: stable@vger.kernel.org
Cc: Junaid Shahid <junaids@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211120015706.3830341-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: MMU: shadow nested paging does not have PKU
Paolo Bonzini [Mon, 22 Nov 2021 18:01:37 +0000 (13:01 -0500)]
KVM: MMU: shadow nested paging does not have PKU

Initialize the mask for PKU permissions as if CR4.PKE=0, avoiding
incorrect interpretations of the nested hypervisor's page tables.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86/mmu: Remove spurious TLB flushes in TDP MMU zap collapsible path
Sean Christopherson [Sat, 20 Nov 2021 04:50:21 +0000 (04:50 +0000)]
KVM: x86/mmu: Remove spurious TLB flushes in TDP MMU zap collapsible path

Drop the "flush" param and return values to/from the TDP MMU's helper for
zapping collapsible SPTEs.  Because the helper runs with mmu_lock held
for read, not write, it uses tdp_mmu_zap_spte_atomic(), and the atomic
zap handles the necessary remote TLB flush.

Similarly, because mmu_lock is dropped and re-acquired between zapping
legacy MMUs and zapping TDP MMUs, kvm_mmu_zap_collapsible_sptes() must
handle remote TLB flushes from the legacy MMU before calling into the TDP
MMU.

Fixes: 08763ffdb3a23 ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211120045046.3940942-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86/mmu: Use yield-safe TDP MMU root iter in MMU notifier unmapping
Sean Christopherson [Sat, 20 Nov 2021 01:50:08 +0000 (01:50 +0000)]
KVM: x86/mmu: Use yield-safe TDP MMU root iter in MMU notifier unmapping

Use the yield-safe variant of the TDP MMU iterator when handling an
unmapping event from the MMU notifier, as most occurences of the event
allow yielding.

Fixes: 41c263d69428 ("KVM: x86/mmu: Allow yielding during MMU notifier unmap/zap, if possible")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211120015008.3780032-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: X86: Use vcpu->arch.walk_mmu for kvm_mmu_invlpg()
Lai Jiangshan [Wed, 24 Nov 2021 12:20:46 +0000 (20:20 +0800)]
KVM: X86: Use vcpu->arch.walk_mmu for kvm_mmu_invlpg()

INVLPG operates on guest virtual address, which are represented by
vcpu->arch.walk_mmu.  In nested virtualization scenarios,
kvm_mmu_invlpg() was using the wrong MMU structure; if L2's invlpg were
emulated by L0 (in practice, it hardly happen) when nested two-dimensional
paging is enabled, the call to ->tlb_flush_gva() would be skipped and
the hardware TLB entry would not be invalidated.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-5-jiangshanlai@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: X86: Fix when shadow_root_level=5 && guest root_level<4
Lai Jiangshan [Wed, 24 Nov 2021 12:20:43 +0000 (20:20 +0800)]
KVM: X86: Fix when shadow_root_level=5 && guest root_level<4

If the is an L1 with nNPT in 32bit, the shadow walk starts with
pae_root.

Fixes: 8276afa6dc25 ("KVM: x86/mmu: Support shadowing NPT when 5-level paging is enabled in host)
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-2-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE
Vitaly Kuznetsov [Tue, 23 Nov 2021 13:59:53 +0000 (14:59 +0100)]
KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE

With the elevated 'KVM_CAP_MAX_VCPUS' value kvm_create_max_vcpus test
may hit RLIMIT_NOFILE limits:

 # ./kvm_create_max_vcpus
 KVM_CAP_MAX_VCPU_ID: 4096
 KVM_CAP_MAX_VCPUS: 1024
 Testing creating 1024 vCPUs, with IDs 0...1023.
 /dev/kvm not available (errno: 24), skipping test

Adjust RLIMIT_NOFILE limits to make sure KVM_CAP_MAX_VCPUS fds can be
opened. Note, raising hard limit ('rlim_max') requires CAP_SYS_RESOURCE
capability which is generally not needed to run kvm selftests (but without
raising the limit the test is doomed to fail anyway).

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211123135953.667434-1-vkuznets@redhat.com>
[Skip the test if the hard limit can be raised. - Paolo]
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN
Vitaly Kuznetsov [Mon, 22 Nov 2021 17:58:18 +0000 (18:58 +0100)]
KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN

Commit fa09ac0b8207 ("KVM: x86: Alert userspace that KVM_SET_CPUID{,2}
after KVM_RUN is broken") officially deprecated KVM_SET_CPUID{,2} ioctls
after first successful KVM_RUN and promissed to make this sequence forbiden
in 5.16. It's time to fulfil the promise.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211122175818.608220-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: selftests: Avoid KVM_SET_CPUID2 after KVM_RUN in hyperv_features test
Vitaly Kuznetsov [Mon, 22 Nov 2021 17:58:17 +0000 (18:58 +0100)]
KVM: selftests: Avoid KVM_SET_CPUID2 after KVM_RUN in hyperv_features test

hyperv_features's sole purpose is to test access to various Hyper-V MSRs
and hypercalls with different CPUID data. As KVM_SET_CPUID2 after KVM_RUN
is deprecated and soon-to-be forbidden, avoid it by re-creating test VM
for each sub-test.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211122175818.608220-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: nVMX: Emulate guest TLB flush on nested VM-Enter with new vpid12
Sean Christopherson [Thu, 25 Nov 2021 01:49:44 +0000 (01:49 +0000)]
KVM: nVMX: Emulate guest TLB flush on nested VM-Enter with new vpid12

Fully emulate a guest TLB flush on nested VM-Enter which changes vpid12,
i.e. L2's VPID, instead of simply doing INVVPID to flush real hardware's
TLB entries for vpid02.  From L1's perspective, changing L2's VPID is
effectively a TLB flush unless "hardware" has previously cached entries
for the new vpid12.  Because KVM tracks only a single vpid12, KVM doesn't
know if the new vpid12 has been used in the past and so must treat it as
a brand new, never been used VPID, i.e. must assume that the new vpid12
represents a TLB flush from L1's perspective.

For example, if L1 and L2 share a CR3, the first VM-Enter to L2 (with a
VPID) is effectively a TLB flush as hardware/KVM has never seen vpid12
and thus can't have cached entries in the TLB for vpid12.

Reported-by: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Fixes: dbbdabd5cd52 ("KVM: nVMX: nested VPID emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125014944.536398-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: nVMX: Abide to KVM_REQ_TLB_FLUSH_GUEST request on nested vmentry/vmexit
Sean Christopherson [Thu, 25 Nov 2021 01:49:43 +0000 (01:49 +0000)]
KVM: nVMX: Abide to KVM_REQ_TLB_FLUSH_GUEST request on nested vmentry/vmexit

Like KVM_REQ_TLB_FLUSH_CURRENT, the GUEST variant needs to be serviced at
nested transitions, as KVM doesn't track requests for L1 vs L2.  E.g. if
there's a pending flush when a nested VM-Exit occurs, then the flush was
requested in the context of L2 and needs to be handled before switching
to L1, otherwise the flush for L2 would effectiely be lost.

Opportunistically add a helper to handle CURRENT and GUEST as a pair, the
logic for when they need to be serviced is identical as both requests are
tied to L1 vs. L2, the only difference is the scope of the flush.

Reported-by: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Fixes: ae0546e4779a ("KVM: nVMX: Sync all PGDs on nested transition with shadow paging")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125014944.536398-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: nVMX: Flush current VPID (L1 vs. L2) for KVM_REQ_TLB_FLUSH_GUEST
Sean Christopherson [Thu, 25 Nov 2021 01:49:43 +0000 (01:49 +0000)]
KVM: nVMX: Flush current VPID (L1 vs. L2) for KVM_REQ_TLB_FLUSH_GUEST

Flush the current VPID when handling KVM_REQ_TLB_FLUSH_GUEST instead of
always flushing vpid01.  Any TLB flush that is triggered when L2 is
active is scoped to L2's VPID (if it has one), e.g. if L2 toggles CR4.PGE
and L1 doesn't intercept PGE writes, then KVM's emulation of the TLB
flush needs to be applied to L2's VPID.

Reported-by: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Fixes: ae0546e4779a ("KVM: nVMX: Sync all PGDs on nested transition with shadow paging")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125014944.536398-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: SEV: expose KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM capability
Paolo Bonzini [Thu, 18 Nov 2021 09:41:34 +0000 (04:41 -0500)]
KVM: SEV: expose KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM capability

The capability, albeit present, was never exposed via KVM_CHECK_EXTENSION.

Fixes: 1167986334b9 ("KVM: SEV: Add support for SEV intra host migration")
Cc: Peter Gonda <pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoselftests: sev_migrate_tests: free all VMs
Paolo Bonzini [Wed, 17 Nov 2021 15:49:24 +0000 (10:49 -0500)]
selftests: sev_migrate_tests: free all VMs

Ensure that the ASID are freed promptly, which becomes more important
when more tests are added to this file.

Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoselftests: fix check for circular KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
Paolo Bonzini [Thu, 18 Nov 2021 10:23:20 +0000 (05:23 -0500)]
selftests: fix check for circular KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM

KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM leaves the source VM in a dead state,
so migrating back to the original source VM fails the ioctl.  Adjust
the test.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: x86: ignore APICv if LAPIC is not enabled
Paolo Bonzini [Wed, 17 Nov 2021 12:35:44 +0000 (07:35 -0500)]
KVM: x86: ignore APICv if LAPIC is not enabled

Synchronize the two calls to kvm_x86_sync_pir_to_irr.  The one
in the reenter-guest fast path invoked the callback unconditionally
even if LAPIC is present but disabled.  In this case, there are
no interrupts to deliver, and therefore posted interrupts can
be ignored.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: downgrade two BUG_ONs to WARN_ON_ONCE
Paolo Bonzini [Mon, 22 Nov 2021 23:24:01 +0000 (18:24 -0500)]
KVM: downgrade two BUG_ONs to WARN_ON_ONCE

This is not an unrecoverable situation.  Users of kvm_read_guest_offset_cached
and kvm_write_guest_offset_cached must expect the read/write to fail, and
therefore it is possible to just return early with an error value.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoKVM: VMX: do not use uninitialized gfn_to_hva_cache
Paolo Bonzini [Mon, 22 Nov 2021 23:20:16 +0000 (18:20 -0500)]
KVM: VMX: do not use uninitialized gfn_to_hva_cache

An uninitialized gfn_to_hva_cache has ghc->len == 0, which causes
the accessors to croak very loudly.  While a BUG_ON is definitely
_too_ loud and a bug on its own, there is indeed an issue of using
the caches in such a way that they could not have been initialized,
because ghc->gpa == 0 might match and thus kvm_gfn_to_hva_cache_init
would not be called.

For the vmcs12_cache, the solution is simply to invoke
kvm_gfn_to_hva_cache_init unconditionally: we already know
that the cache does not match the current VMCS pointer.
For the shadow_vmcs12_cache, there is no similar condition
that checks the VMCS link pointer, so invalidate the cache
on VMXON.

Fixes: edf9a9d78975 ("KVM: nVMX: Use a gfn_to_hva_cache for vmptrld")
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reported-by: syzbot+7b7db8bb4db6fd5e157b@syzkaller.appspotmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 years agoMerge branch 'kvm-5.16-fixes-pre-rc2' into HEAD
Paolo Bonzini [Fri, 26 Nov 2021 11:38:50 +0000 (06:38 -0500)]
Merge branch 'kvm-5.16-fixes-pre-rc2' into HEAD

2 years agoMerge tag 'kvmarm-fixes-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git...
Paolo Bonzini [Fri, 26 Nov 2021 10:42:56 +0000 (05:42 -0500)]
Merge tag 'kvmarm-fixes-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.16, take #2

- Fix constant sign extension affecting TCR_EL2 and preventing
  running on ARMv8.7 models due to spurious bits being set

- Fix use of helpers using PSTATE early on exit by always sampling
  it as soon as the exit takes place

- Move pkvm's 32bit handling into a common helper

2 years agoMerge tag 'kvm-riscv-fixes-5.16-1' of https://github.com/kvm-riscv/linux into HEAD
Paolo Bonzini [Fri, 26 Nov 2021 10:42:47 +0000 (05:42 -0500)]
Merge tag 'kvm-riscv-fixes-5.16-1' of https://github.com/kvm-riscv/linux into HEAD

KVM/riscv fixes for 5.16, take #1

- Fix incorrect KVM_MAX_VCPUS value

- Unmap stage2 mapping when deleting/moving a memslot
  (This was due to empty kvm_arch_flush_shadow_memslot())

2 years agoKVM: arm64: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1
Catalin Marinas [Thu, 25 Nov 2021 15:20:14 +0000 (15:20 +0000)]
KVM: arm64: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1

Having a signed (1 << 31) constant for TCR_EL2_RES1 and CPTR_EL2_TCPAC
causes the upper 32-bit to be set to 1 when assigning them to a 64-bit
variable. Bit 32 in TCR_EL2 is no longer RES0 in ARMv8.7: with FEAT_LPA2
it changes the meaning of bits 49:48 and 9:8 in the stage 1 EL2 page
table entries. As a result of the sign-extension, a non-VHE kernel can
no longer boot on a model with ARMv8.7 enabled.

CPTR_EL2 still has the top 32 bits RES0 but we should preempt any future
problems

Make these top bit constants unsigned as per commit 3186b2d79884
("arm64: KVM: Avoid setting the upper 32 bits of VTCR_EL2 to 1").

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Chris January <Chris.January@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211125152014.2806582-1-catalin.marinas@arm.com
3 years agoKVM: arm64: Move pkvm's special 32bit handling into a generic infrastructure
Marc Zyngier [Tue, 16 Nov 2021 12:39:35 +0000 (12:39 +0000)]
KVM: arm64: Move pkvm's special 32bit handling into a generic infrastructure

Protected KVM is trying to turn AArch32 exceptions into an illegal
exception entry. Unfortunately, it does that in a way that is a bit
abrupt, and too early for PSTATE to be available.

Instead, move it to the fixup code, which is a more reasonable place
for it. This will also be useful for the NV code.

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
3 years agoKVM: arm64: Save PSTATE early on exit
Marc Zyngier [Tue, 16 Nov 2021 10:20:06 +0000 (10:20 +0000)]
KVM: arm64: Save PSTATE early on exit

In order to be able to use primitives such as vcpu_mode_is_32bit(),
we need to synchronize the guest PSTATE. However, this is currently
done deep into the bowels of the world-switch code, and we do have
helpers evaluating this much earlier (__vgic_v3_perform_cpuif_access
and handle_aarch32_guest, for example).

Move the saving of the guest pstate into the early fixups, which
cures the first issue. The second one will be addressed separately.

Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
3 years agoRISC-V: KVM: Fix incorrect KVM_MAX_VCPUS value
Anup Patel [Wed, 17 Nov 2021 05:00:29 +0000 (10:30 +0530)]
RISC-V: KVM: Fix incorrect KVM_MAX_VCPUS value

The KVM_MAX_VCPUS value is supposed to be aligned with number of
VMID bits in the hgatp CSR but the current KVM_MAX_VCPUS value
is aligned with number of ASID bits in the satp CSR.

Fixes: 69c9acb307a7 ("RISC-V: Add initial skeletal KVM support")
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
3 years agoKVM: RISC-V: Unmap stage2 mapping when deleting/moving a memslot
Sean Christopherson [Thu, 4 Nov 2021 16:41:06 +0000 (16:41 +0000)]
KVM: RISC-V: Unmap stage2 mapping when deleting/moving a memslot

Unmap stage2 page tables when a memslot is being deleted or moved.  It's
the architectures' responsibility to ensure existing mappings are removed
when kvm_arch_flush_shadow_memslot() returns.

Fixes: 4fe3b990d671 ("RISC-V: KVM: Implement stage2 page table programming")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
3 years agoLinux 5.16-rc2
Linus Torvalds [Sun, 21 Nov 2021 21:47:39 +0000 (13:47 -0800)]
Linux 5.16-rc2

3 years agoMerge tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Sun, 21 Nov 2021 19:25:19 +0000 (11:25 -0800)]
Merge tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:

 - Move the command line preparation and the early command line parsing
   earlier so that the command line parameters which affect
   early_reserve_memory(), e.g. efi=nosftreserve, are taken into
   account. This was broken when the invocation of
   early_reserve_memory() was moved recently.

 - Use an atomic type for the SGX page accounting, which is read and
   written locklessly, to plug various race conditions related to it.

* tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Fix free page accounting
  x86/boot: Pull up cmdline preparation and early param parsing

3 years agoMerge tag 'perf-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Sun, 21 Nov 2021 19:17:50 +0000 (11:17 -0800)]
Merge tag 'perf-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf fixes from Thomas Gleixner:

 - Remove unneded PEBS disabling when taking LBR snapshots to prevent an
   unchecked MSR access error.

 - Fix IIO event constraints for Snowridge and Skylake server chips.

* tag 'perf-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/perf: Fix snapshot_branch_stack warning in VM
  perf/x86/intel/uncore: Fix IIO event constraints for Snowridge
  perf/x86/intel/uncore: Fix IIO event constraints for Skylake Server
  perf/x86/intel/uncore: Fix filter_tid mask for CHA events on Skylake Server

3 years agoMerge tag 'powerpc-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
Linus Torvalds [Sun, 21 Nov 2021 18:26:35 +0000 (10:26 -0800)]
Merge tag 'powerpc-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull more powerpc fixes from Michael Ellerman:

 - Fix a bug in copying of sigset_t for 32-bit systems, which caused X
   to not start.

 - Fix handling of shared LSIs (rare) with the xive interrupt controller
   (Power9/10).

 - Fix missing TOC setup in some KVM code, which could result in oopses
   depending on kernel data layout.

 - Fix DMA mapping when we have persistent memory and only one DMA
   window available.

 - Fix further problems with STRICT_KERNEL_RWX on 8xx, exposed by a
   recent fix.

 - A couple of other minor fixes.

Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Cédric Le Goater,
Christian Zigotzky, Christophe Leroy, Daniel Axtens, Finn Thain, Greg
Kurz, Masahiro Yamada, Nicholas Piggin, and Uwe Kleine-König.

* tag 'powerpc-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/xive: Change IRQ domain to a tree domain
  powerpc/8xx: Fix pinned TLBs with CONFIG_STRICT_KERNEL_RWX
  powerpc/signal32: Fix sigset_t copy
  powerpc/book3e: Fix TLBCAM preset at boot
  powerpc/pseries/ddw: Do not try direct mapping with persistent memory and one window
  powerpc/pseries/ddw: simplify enable_ddw()
  powerpc/pseries/ddw: Revert "Extend upper limit for huge DMA window for persistent memory"
  powerpc/pseries: Fix numa FORM2 parsing fallback code
  powerpc/pseries: rename numa_dist_table to form2_distances
  powerpc: clean vdso32 and vdso64 directories
  powerpc/83xx/mpc8349emitx: Drop unused variable
  KVM: PPC: Book3S HV: Use GLOBAL_TOC for kvmppc_h_set_dabr/xdabr()

3 years agopstore/blk: Use "%lu" to format unsigned long
Geert Uytterhoeven [Thu, 18 Nov 2021 18:26:21 +0000 (10:26 -0800)]
pstore/blk: Use "%lu" to format unsigned long

On 32-bit:

    fs/pstore/blk.c: In function ‘__best_effort_init’:
    include/linux/kern_levels.h:5:18: warning: format ‘%zu’ expects argument of type ‘size_t’, but argument 3 has type ‘long unsigned int’ [-Wformat=]
5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
  |                  ^~~~~~
    include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’
       14 | #define KERN_INFO KERN_SOH "6" /* informational */
  |                   ^~~~~~~~
    include/linux/printk.h:373:9: note: in expansion of macro ‘KERN_INFO’
      373 |  printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
  |         ^~~~~~~~~
    fs/pstore/blk.c:314:3: note: in expansion of macro ‘pr_info’
      314 |   pr_info("attached %s (%zu) (no dedicated panic_write!)\n",
  |   ^~~~~~~

Cc: stable@vger.kernel.org
Fixes: 3265da402703f197 ("pstore/blk: Use the normal block device I/O path")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210629103700.1935012-1-geert@linux-m68k.org
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Sat, 20 Nov 2021 21:17:24 +0000 (13:17 -0800)]
Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "15 patches.

  Subsystems affected by this patch series: ipc, hexagon, mm (swap,
  slab-generic, kmemleak, hugetlb, kasan, damon, and highmem), and proc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  proc/vmcore: fix clearing user buffer by properly using clear_user()
  kmap_local: don't assume kmap PTEs are linear arrays in memory
  mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
  mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
  kasan: test: silence intentional read overflow warnings
  hugetlb, userfaultfd: fix reservation restore on userfaultfd error
  hugetlb: fix hugetlb cgroup refcounting during mremap
  mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag
  hexagon: ignore vmlinux.lds
  hexagon: clean up timer-regs.h
  hexagon: export raw I/O routines for modules
  mm: emit the "free" trace report before freeing memory in kmem_cache_free()
  shm: extend forced shm destroy to support objects from several IPC nses
  ipc: WARN if trying to remove ipc object which is absent
  mm/swap.c:put_pages_list(): reinitialise the page list

3 years agoMerge tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-block
Linus Torvalds [Sat, 20 Nov 2021 19:05:10 +0000 (11:05 -0800)]
Merge tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Flip a cap check to avoid a selinux error (Alistair)

 - Fix for a regression this merge window where we can miss a queue ref
   put (me)

 - Un-mark pstore-blk as broken, as the condition that triggered that
   change has been rectified (Kees)

 - Queue quiesce and sync fixes (Ming)

 - FUA insertion fix (Ming)

 - blk-cgroup error path put fix (Yu)

* tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-block:
  blk-mq: don't insert FUA request with data into scheduler queue
  blk-cgroup: fix missing put device in error path from blkg_conf_pref()
  block: avoid to quiesce queue in elevator_init_mq
  Revert "mark pstore-blk as broken"
  blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()
  block: fix missing queue put in error path
  block: Check ADMIN before NICE for IOPRIO_CLASS_RT

3 years agoMerge tag 'pinctrl-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
Linus Torvalds [Sat, 20 Nov 2021 18:59:03 +0000 (10:59 -0800)]
Merge tag 'pinctrl-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl

Pull pin control fixes from Linus Walleij:
 "There is an ACPI stubs fix which is ACKed by the ACPI maintainer for
  merging through my tree.

  One item stand out and that is that I delete the <linux/sdb.h> header
  that is used by nothing. I deleted this subsystem (through the GPIO
  tree) a while back so I feel responsible for tidying up the floor.

  Other than that it is the usual mistakes, a bit noisy around build
  issue and Kconfig then driver fixes.

  Specifics:

   - Fix some stubs causing compile issues for ACPI.

   - Fix some wakeups on AMD IRQs shared between GPIO and SCI.

   - Fix a build warning in the Tegra driver.

   - Fix a Kconfig issue in the Qualcomm driver.

   - Add a missing include the RALink driver.

   - Return a valid type for the Apple pinctrl IRQs.

   - Implement some Qualcomm SDM845 dual-edge errata.

   - Remove the unused <linux/sdb.h> header. (The subsystem was once
     deleted by the pinctrl maintainer...)

   - Fix a duplicate initialized in the Tegra driver.

   - Fix register offsets for UFS and SDC in the Qualcomm SM8350 driver"

* tag 'pinctrl-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: qcom: sm8350: Correct UFS and SDC offsets
  pinctrl: tegra194: remove duplicate initializer again
  Remove unused header <linux/sdb.h>
  pinctrl: qcom: sdm845: Enable dual edge errata
  pinctrl: apple: Always return valid type in apple_gpio_irq_type
  pinctrl: ralink: include 'ralink_regs.h' in 'pinctrl-mt7620.c'
  pinctrl: qcom: fix unmet dependencies on GPIOLIB for GPIOLIB_IRQCHIP
  pinctrl: tegra: Return const pointer from tegra_pinctrl_get_group()
  pinctrl: amd: Fix wakeups when IRQ is shared with SCI
  ACPI: Add stubs for wakeup handler functions

3 years agoMerge tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Linus Torvalds [Sat, 20 Nov 2021 18:55:50 +0000 (10:55 -0800)]
Merge tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Add missing Kconfig option for ftrace direct multi sample, so it can
   be compiled again, and also add s390 support for this sample.

 - Update Christian Borntraeger's email address.

 - Various fixes for memory layout setup. Besides other this makes it
   possible to load shared DCSS segments again.

 - Fix copy to user space of swapped kdump oldmem.

 - Remove -mstack-guard and -mstack-size compile options when building
   vdso binaries. This can happen when CONFIG_VMAP_STACK is disabled and
   results in broken vdso code which causes more or less random
   exceptions. Also remove the not needed -nostdlib option.

 - Fix memory leak on cpu hotplug and return code handling in kexec
   code.

 - Wire up futex_waitv system call.

 - Replace snprintf with sysfs_emit where appropriate.

* tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  ftrace/samples: add s390 support for ftrace direct multi sample
  ftrace/samples: add missing Kconfig option for ftrace direct multi sample
  MAINTAINERS: update email address of Christian Borntraeger
  s390/kexec: fix memory leak of ipl report buffer
  s390/kexec: fix return code handling
  s390/dump: fix copying to user-space of swapped kdump oldmem
  s390: wire up sys_futex_waitv system call
  s390/vdso: filter out -mstack-guard and -mstack-size
  s390/vdso: remove -nostdlib compiler flag
  s390: replace snprintf in show functions with sysfs_emit
  s390/boot: simplify and fix kernel memory layout setup
  s390/setup: re-arrange memblock setup
  s390/setup: avoid using memblock_enforce_memory_limit
  s390/setup: avoid reserving memory above identity mapping

3 years agoMerge tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Linus Torvalds [Sat, 20 Nov 2021 18:47:16 +0000 (10:47 -0800)]
Merge tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three small cifs/smb3 fixes: two to address minor coverity issues and
  one cleanup"

* tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: introduce cifs_ses_mark_for_reconnect() helper
  cifs: protect srv_count with cifs_tcp_ses_lock
  cifs: move debug print out of spinlock

3 years agoproc/vmcore: fix clearing user buffer by properly using clear_user()
David Hildenbrand [Sat, 20 Nov 2021 00:43:58 +0000 (16:43 -0800)]
proc/vmcore: fix clearing user buffer by properly using clear_user()

To clear a user buffer we cannot simply use memset, we have to use
clear_user().  With a virtio-mem device that registers a vmcore_cb and
has some logically unplugged memory inside an added Linux memory block,
I can easily trigger a BUG by copying the vmcore via "cp":

  systemd[1]: Starting Kdump Vmcore Save Service...
  kdump[420]: Kdump is using the default log level(3).
  kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[465]: saving vmcore-dmesg.txt complete
  kdump[467]: saving vmcore
  BUG: unable to handle page fault for address: 00007f2374e01000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867
  Oops: 0003 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014
  RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86
  Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81
  RSP: 0018:ffffc9000073be08 EFLAGS: 00010212
  RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000
  RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008
  RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50
  R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000
  R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8
  FS:  00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0
  Call Trace:
   read_vmcore+0x236/0x2c0
   proc_reg_read+0x55/0xa0
   vfs_read+0x95/0x190
   ksys_read+0x4f/0xc0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access
Prevention (SMAP)", which is used to detect wrong access from the kernel
to user buffers like this: SMAP triggers a permissions violation on
wrong access.  In the x86-64 variant of clear_user(), SMAP is properly
handled via clac()+stac().

To fix, properly use clear_user() when we're dealing with a user buffer.

Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com
Fixes: 6f36767f699f ("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokmap_local: don't assume kmap PTEs are linear arrays in memory
Ard Biesheuvel [Sat, 20 Nov 2021 00:43:55 +0000 (16:43 -0800)]
kmap_local: don't assume kmap PTEs are linear arrays in memory

The kmap_local conversion broke the ARM architecture, because the new
code assumes that all PTEs used for creating kmaps form a linear array
in memory, and uses array indexing to look up the kmap PTE belonging to
a certain kmap index.

On ARM, this cannot work, not only because the PTE pages may be
non-adjacent in memory, but also because ARM/!LPAE interleaves hardware
entries and extended entries (carrying software-only bits) in a way that
is not compatible with array indexing.

Fortunately, this only seems to affect configurations with more than 8
CPUs, due to the way the per-CPU kmap slots are organized in memory.

Work around this by permitting an architecture to set a Kconfig symbol
that signifies that the kmap PTEs do not form a lineary array in memory,
and so the only way to locate the appropriate one is to walk the page
tables.

Link: https://lore.kernel.org/linux-arm-kernel/20211026131249.3731275-1-ardb@kernel.org/
Link: https://lkml.kernel.org/r/20211116094737.7391-1-ardb@kernel.org
Fixes: 2c9c7433c6d8 ("ARM: highmem: Switch to generic kmap atomic")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reported-by: Quanyang Wang <quanyang.wang@windriver.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/damon/dbgfs: fix missed use of damon_dbgfs_lock
SeongJae Park [Sat, 20 Nov 2021 00:43:52 +0000 (16:43 -0800)]
mm/damon/dbgfs: fix missed use of damon_dbgfs_lock

DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and
dbgfs_dirs using damon_dbgfs_lock.  However, some of the code is
accessing the variables without the protection.  This fixes it by
protecting all such accesses.

Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org
Fixes: 9e7cd59f2791 ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
SeongJae Park [Sat, 20 Nov 2021 00:43:49 +0000 (16:43 -0800)]
mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation

Patch series "DAMON fixes".

This patch (of 2):

DAMON users can trigger below warning in '__alloc_pages()' by invoking
write() to some DAMON debugfs files with arbitrarily high count
argument, because DAMON debugfs interface allocates some buffers based
on the user-specified 'count'.

        if (unlikely(order >= MAX_ORDER)) {
                WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
                return NULL;
        }

Because the DAMON debugfs interface code checks failure of the
'kmalloc()', this commit simply suppresses the warnings by adding
'__GFP_NOWARN' flag.

Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org
Fixes: ba056afad928 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: test: silence intentional read overflow warnings
Kees Cook [Sat, 20 Nov 2021 00:43:46 +0000 (16:43 -0800)]
kasan: test: silence intentional read overflow warnings

As done in commit 8eabbebeb3f3 ("kasan: test: bypass __alloc_size
checks") for __write_overflow warnings, also silence some more cases
that trip the __read_overflow warnings seen in 5.16-rc1[1]:

  In file included from include/linux/string.h:253,
                   from include/linux/bitmap.h:10,
                   from include/linux/cpumask.h:12,
                   from include/linux/mm_types_task.h:14,
                   from include/linux/mm_types.h:5,
                   from include/linux/page-flags.h:13,
                   from arch/arm64/include/asm/mte.h:14,
                   from arch/arm64/include/asm/pgtable.h:12,
                   from include/linux/pgtable.h:6,
                   from include/linux/kasan.h:29,
                   from lib/test_kasan.c:10:
  In function 'memcmp',
      inlined from 'kasan_memcmp' at lib/test_kasan.c:897:2:
  include/linux/fortify-string.h:263:25: error: call to '__read_overflow' declared with attribute error: detected read beyond size of object (1st parameter)
    263 |                         __read_overflow();
        |                         ^~~~~~~~~~~~~~~~~
  In function 'memchr',
      inlined from 'kasan_memchr' at lib/test_kasan.c:872:2:
  include/linux/fortify-string.h:277:17: error: call to '__read_overflow' declared with attribute error: detected read beyond size of object (1st parameter)
    277 |                 __read_overflow();
        |                 ^~~~~~~~~~~~~~~~~

[1] http://kisskb.ellerman.id.au/kisskb/buildresult/14660585/log/

Link: https://lkml.kernel.org/r/20211116004111.3171781-1-keescook@chromium.org
Fixes: 8eabbebeb3f3 ("kasan: test: bypass __alloc_size checks")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohugetlb, userfaultfd: fix reservation restore on userfaultfd error
Mina Almasry [Sat, 20 Nov 2021 00:43:43 +0000 (16:43 -0800)]
hugetlb, userfaultfd: fix reservation restore on userfaultfd error

Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we
bail out using "goto out_release_unlock;" in the cases where idx >=
size, or !huge_pte_none(), the code will detect that new_pagecache_page
== false, and so call restore_reserve_on_error().  In this case I see
restore_reserve_on_error() delete the reservation, and the following
call to remove_inode_hugepages() will increment h->resv_hugepages
causing a 100% reproducible leak.

We should treat the is_continue case similar to adding a page into the
pagecache and set new_pagecache_page to true, to indicate that there is
no reservation to restore on the error path, and we need not call
restore_reserve_on_error().  Rename new_pagecache_page to
page_in_pagecache to make that clear.

Link: https://lkml.kernel.org/r/20211117193825.378528-1-almasrymina@google.com
Fixes: cf07c9264d62 ("hugetlb: don't pass page cache pages to restore_reserve_on_error")
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reported-by: James Houghton <jthoughton@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Wei Xu <weixugc@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohugetlb: fix hugetlb cgroup refcounting during mremap
Bui Quang Minh [Sat, 20 Nov 2021 00:43:40 +0000 (16:43 -0800)]
hugetlb: fix hugetlb cgroup refcounting during mremap

When hugetlb_vm_op_open() is called during copy_vma(), we may take the
reference to resv_map->css.  Later, when clearing the reservation
pointer of old_vma after transferring it to new_vma, we forget to drop
the reference to resv_map->css.  This leads to a reference leak of css.

Fixes this by adding a check to drop reservation css reference in
clear_vma_resv_huge_pages()

Link: https://lkml.kernel.org/r/20211113154412.91134-1-minhquangbui99@gmail.com
Fixes: 27acd37034800f ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag
Rustam Kovhaev [Sat, 20 Nov 2021 00:43:37 +0000 (16:43 -0800)]
mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag

When kmemleak is enabled for SLOB, system does not boot and does not
print anything to the console.  At the very early stage in the boot
process we hit infinite recursion from kmemleak_init() and eventually
kernel crashes.

kmemleak_init() specifies SLAB_NOLEAKTRACE for KMEM_CACHE(), but
kmem_cache_create_usercopy() removes it because CACHE_CREATE_MASK is not
valid for SLOB.

Let's fix CACHE_CREATE_MASK and make kmemleak work with SLOB

Link: https://lkml.kernel.org/r/20211115020850.3154366-1-rkovhaev@gmail.com
Fixes: 5dbe1fb359cd ("slab: Ignore internal flags in cache creation")
Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Glauber Costa <glommer@parallels.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohexagon: ignore vmlinux.lds
Nathan Chancellor [Sat, 20 Nov 2021 00:43:34 +0000 (16:43 -0800)]
hexagon: ignore vmlinux.lds

After building allmodconfig, there is an untracked vmlinux.lds file in
arch/hexagon/kernel:

    $ git ls-files . --exclude-standard --others
    arch/hexagon/kernel/vmlinux.lds

Ignore it as all other architectures have.

Link: https://lkml.kernel.org/r/20211115174250.1994179-4-nathan@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohexagon: clean up timer-regs.h
Nathan Chancellor [Sat, 20 Nov 2021 00:43:31 +0000 (16:43 -0800)]
hexagon: clean up timer-regs.h

When building allmodconfig, there is a warning about TIMER_ENABLE being
redefined:

  drivers/clocksource/timer-oxnas-rps.c:39:9: error: 'TIMER_ENABLE' macro redefined [-Werror,-Wmacro-redefined]
  #define TIMER_ENABLE            BIT(7)
          ^
  arch/hexagon/include/asm/timer-regs.h:13:9: note: previous definition is here
  #define TIMER_ENABLE            0
           ^
  1 error generated.

The values in this header are only used in one file each, if they are
used at all.  Remove the header and sink all of the constants into their
respective files.

TCX0_CLK_RATE is only used in arch/hexagon/include/asm/timex.h

TIMER_ENABLE, RTOS_TIMER_INT, RTOS_TIMER_REGS_ADDR are only used in
arch/hexagon/kernel/time.c.

SLEEP_CLK_RATE and TIMER_CLR_ON_MATCH have both been unused since the
file's introduction in commit 726245470493 ("Hexagon: Add time and timer
functions").

TIMER_ENABLE is redefined as BIT(0) so the shift is moved into the
definition, rather than its use.

Link: https://lkml.kernel.org/r/20211115174250.1994179-3-nathan@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Brian Cain <bcain@codeaurora.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohexagon: export raw I/O routines for modules
Nathan Chancellor [Sat, 20 Nov 2021 00:43:28 +0000 (16:43 -0800)]
hexagon: export raw I/O routines for modules

Patch series "Fixes for ARCH=hexagon allmodconfig", v2.

This series fixes some issues noticed with ARCH=hexagon allmodconfig.

This patch (of 3):

When building ARCH=hexagon allmodconfig, the following errors occur:

  ERROR: modpost: "__raw_readsl" [drivers/i3c/master/svc-i3c-master.ko] undefined!
  ERROR: modpost: "__raw_writesl" [drivers/i3c/master/dw-i3c-master.ko] undefined!
  ERROR: modpost: "__raw_readsl" [drivers/i3c/master/dw-i3c-master.ko] undefined!
  ERROR: modpost: "__raw_writesl" [drivers/i3c/master/i3c-master-cdns.ko] undefined!
  ERROR: modpost: "__raw_readsl" [drivers/i3c/master/i3c-master-cdns.ko] undefined!

Export these symbols so that modules can use them without any errors.

Link: https://lkml.kernel.org/r/20211115174250.1994179-1-nathan@kernel.org
Link: https://lkml.kernel.org/r/20211115174250.1994179-2-nathan@kernel.org
Fixes: 79440acd71d8 ("Hexagon: Provide basic implementation and/or stubs for I/O routines.")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Brian Cain <bcain@codeaurora.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: emit the "free" trace report before freeing memory in kmem_cache_free()
Yunfeng Ye [Sat, 20 Nov 2021 00:43:25 +0000 (16:43 -0800)]
mm: emit the "free" trace report before freeing memory in kmem_cache_free()

After the memory is freed, it can be immediately allocated by other
CPUs, before the "free" trace report has been emitted.  This causes
inaccurate traces.

For example, if the following sequence of events occurs:

    CPU 0                 CPU 1

  (1) alloc xxxxxx
  (2) free  xxxxxx
                         (3) alloc xxxxxx
                         (4) free  xxxxxx

Then they will be inaccurately reported via tracing, so that they appear
to have happened in this order:

    CPU 0                 CPU 1

  (1) alloc xxxxxx
                         (2) alloc xxxxxx
  (3) free  xxxxxx
                         (4) free  xxxxxx

This makes it look like CPU 1 somehow managed to allocate memory that
CPU 0 still had allocated for itself.

In order to avoid this, emit the "free xxxxxx" tracing report just
before the actual call to free the memory, instead of just after it.

Link: https://lkml.kernel.org/r/374eb75d-7404-8721-4e1e-65b0e5b17279@huawei.com
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoshm: extend forced shm destroy to support objects from several IPC nses
Alexander Mikhalitsyn [Sat, 20 Nov 2021 00:43:21 +0000 (16:43 -0800)]
shm: extend forced shm destroy to support objects from several IPC nses

Currently, the exit_shm() function not designed to work properly when
task->sysvshm.shm_clist holds shm objects from different IPC namespaces.

This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it
leads to use-after-free (reproducer exists).

This is an attempt to fix the problem by extending exit_shm mechanism to
handle shm's destroy from several IPC ns'es.

To achieve that we do several things:

1. add a namespace (non-refcounted) pointer to the struct shmid_kernel

2. during new shm object creation (newseg()/shmget syscall) we
   initialize this pointer by current task IPC ns

3. exit_shm() fully reworked such that it traverses over all shp's in
   task->sysvshm.shm_clist and gets IPC namespace not from current task
   as it was before but from shp's object itself, then call
   shm_destroy(shp, ns).

Note: We need to be really careful here, because as it was said before
(1), our pointer to IPC ns non-refcnt'ed.  To be on the safe side we
using special helper get_ipc_ns_not_zero() which allows to get IPC ns
refcounter only if IPC ns not in the "state of destruction".

Q/A

Q: Why can we access shp->ns memory using non-refcounted pointer?
A: Because shp object lifetime is always shorther than IPC namespace
   lifetime, so, if we get shp object from the task->sysvshm.shm_clist
   while holding task_lock(task) nobody can steal our namespace.

Q: Does this patch change semantics of unshare/setns/clone syscalls?
A: No. It's just fixes non-covered case when process may leave IPC
   namespace without getting task->sysvshm.shm_clist list cleaned up.

Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife.com
Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com
Fixes: ce71c5b3476 ("shm: make exit_shm work proportional to task activity")
Co-developed-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoipc: WARN if trying to remove ipc object which is absent
Alexander Mikhalitsyn [Sat, 20 Nov 2021 00:43:18 +0000 (16:43 -0800)]
ipc: WARN if trying to remove ipc object which is absent

Patch series "shm: shm_rmid_forced feature fixes".

Some time ago I met kernel crash after CRIU restore procedure,
fortunately, it was CRIU restore, so, I had dump files and could do
restore many times and crash reproduced easily.  After some
investigation I've constructed the minimal reproducer.  It was found
that it's use-after-free and it happens only if sysctl
kernel.shm_rmid_forced = 1.

The key of the problem is that the exit_shm() function not handles shp's
object destroy when task->sysvshm.shm_clist contains items from
different IPC namespaces.  In most cases this list will contain only
items from one IPC namespace.

How can this list contain object from different namespaces? The
exit_shm() function is designed to clean up this list always when
process leaves IPC namespace.  But we made a mistake a long time ago and
did not add a exit_shm() call into the setns() syscall procedures.

The first idea was just to add this call to setns() syscall but it
obviously changes semantics of setns() syscall and that's
userspace-visible change.  So, I gave up on this idea.

The first real attempt to address the issue was just to omit forced
destroy if we meet shp object not from current task IPC namespace [1].
But that was not the best idea because task->sysvshm.shm_clist was
protected by rwsem which belongs to current task IPC namespace.  It
means that list corruption may occur.

Second approach is just extend exit_shm() to properly handle shp's from
different IPC namespaces [2].  This is really non-trivial thing, I've
put a lot of effort into that but not believed that it's possible to
make it fully safe, clean and clear.

Thanks to the efforts of Manfred Spraul working an elegant solution was
designed.  Thanks a lot, Manfred!

Eric also suggested the way to address the issue in ("[RFC][PATCH] shm:
In shm_exit destroy all created and never attached segments") Eric's
idea was to maintain a list of shm_clists one per IPC namespace, use
lock-less lists.  But there is some extra memory consumption-related
concerns.

An alternative solution which was suggested by me was implemented in
("shm: reset shm_clist on setns but omit forced shm destroy").  The idea
is pretty simple, we add exit_shm() syscall to setns() but DO NOT
destroy shm segments even if sysctl kernel.shm_rmid_forced = 1, we just
clean up the task->sysvshm.shm_clist list.

This chages semantics of setns() syscall a little bit but in comparision
to the "naive" solution when we just add exit_shm() without any special
exclusions this looks like a safer option.

[1] https://lkml.org/lkml/2021/7/6/1108
[2] https://lkml.org/lkml/2021/7/14/736

This patch (of 2):

Let's produce a warning if we trying to remove non-existing IPC object
from IPC namespace kht/idr structures.

This allows us to catch possible bugs when the ipc_rmid() function was
called with inconsistent struct ipc_ids*, struct kern_ipc_perm*
arguments.

Link: https://lkml.kernel.org/r/20211027224348.611025-1-alexander.mikhalitsyn@virtuozzo.com
Link: https://lkml.kernel.org/r/20211027224348.611025-2-alexander.mikhalitsyn@virtuozzo.com
Co-developed-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/swap.c:put_pages_list(): reinitialise the page list
Matthew Wilcox [Sat, 20 Nov 2021 00:43:15 +0000 (16:43 -0800)]
mm/swap.c:put_pages_list(): reinitialise the page list

While free_unref_page_list() puts pages onto the CPU local LRU list, it
does not remove them from the list they were passed in on.  That makes
the list_head appear to be non-empty, and would lead to various
corruption problems if we didn't have an assertion that the list was
empty.

Reinitialise the list after calling free_unref_page_list() to avoid this
problem.

Link: https://lkml.kernel.org/r/YYp40A2lNrxaZji8@casper.infradead.org
Fixes: 8a64e0c511aa ("mm: optimise put_pages_list()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Steve French <stfrench@microsoft.com>
Reported-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Steve French <stfrench@microsoft.com>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyeoncheol Lee <hyc.lee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoMerge tag 'libata-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal...
Linus Torvalds [Fri, 19 Nov 2021 22:15:14 +0000 (14:15 -0800)]
Merge tag 'libata-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata

Pull libata fixes from Damien Le Moal:

 - Prevent accesses to unsupported log pages as that causes device scan
   failures with LLDDs using libsas (from me).

 - A couple of fixes for AMD AHCI adapters handling of low power modes
   and resume (from Mario).

 - Fix a compilation warning (from me).

* tag 'libata-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: libata-sata: Declare ata_ncq_sdev_attrs static
  ata: libahci: Adjust behavior when StorageD3Enable _DSD is set
  ata: ahci: Add Green Sardine vendor ID as board_ahci_mobile
  ata: libata: add missing ata_identify_page_supported() calls
  ata: libata: improve ata_read_log_page() error message

3 years agoMerge tag 'trace-v5.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...
Linus Torvalds [Fri, 19 Nov 2021 21:50:48 +0000 (13:50 -0800)]
Merge tag 'trace-v5.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix double free in destroy_hist_field

 - Harden memset() of trace_iterator structure

 - Do not warn in trace printk check when test buffer fills up

* tag 'trace-v5.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Don't use out-of-sync va_list in event printing
  tracing: Use memset_startat() to zero struct trace_iterator
  tracing/histogram: Fix UAF in destroy_hist_field()

3 years agoMerge tag 'perf-tools-fixes-for-v5.16-2021-11-19' of git://git.kernel.org/pub/scm...
Linus Torvalds [Fri, 19 Nov 2021 20:47:29 +0000 (12:47 -0800)]
Merge tag 'perf-tools-fixes-for-v5.16-2021-11-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix the 'local_weight', 'weight' (memory access latency),
   'local_ins_lat', 'ins_lat' (instruction latency) and 'pstage_cyc'
   (pipeline stage cycles) sort key sample aggregation.

 - Fix 'perf test' entry for watchpoints on s/390.

 - Fix branch_stack entry endianness check in the 'perf test' sample
   parsing test.

 - Fix ARM SPE handling on 'perf inject'.

 - Fix memory leaks detected with ASan.

 - Fix build on arm64 related to reallocarray() availability.

 - Sync copies of kernel headers: cpufeatures, kvm, MIPS syscalltable
   (futex_waitv).

* tag 'perf-tools-fixes-for-v5.16-2021-11-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf evsel: Fix memory leaks relating to unit
  perf report: Fix memory leaks around perf_tip()
  perf hist: Fix memory leak of a perf_hpp_fmt
  tools headers UAPI: Sync MIPS syscall table file changed by new futex_waitv syscall
  tools build: Fix removal of feature-sync-compare-and-swap feature detection
  perf inject: Fix ARM SPE handling
  perf bench: Fix two memory leaks detected with ASan
  perf test sample-parsing: Fix branch_stack entry endianness check
  tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources
  perf sort: Fix the 'p_stage_cyc' sort key behavior
  perf sort: Fix the 'ins_lat' sort key behavior
  perf sort: Fix the 'weight' sort key behavior
  perf tools: Set COMPAT_NEED_REALLOCARRAY for CONFIG_AUXTRACE=1
  perf tests wp: Remove unused functions on s390
  tools headers UAPI: Sync linux/kvm.h with the kernel sources
  tools headers cpufeatures: Sync with the kernel sources

3 years agoMerge tag 'riscv-for-linus-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Fri, 19 Nov 2021 19:40:14 +0000 (11:40 -0800)]
Merge tag 'riscv-for-linus-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:
 "I have two patches for 5.16:

   - allow external modules to be built against read-only source trees

   - turn KVM on in the defconfigs

  The second one isn't technically a fix, but it got tied up pending
  some defconfig cleanups that ended up finding some larger issues. I
  figured it'd be better to get the config changes some more testing,
  but didn't want to hold up turning KVM on for that"

* tag 'riscv-for-linus-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: fix building external modules
  RISC-V: Enable KVM in RV64 and RV32 defconfigs as a module

3 years agoMerge branch 'SA_IMMUTABLE-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux...
Linus Torvalds [Fri, 19 Nov 2021 19:33:31 +0000 (11:33 -0800)]
Merge branch 'SA_IMMUTABLE-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull exit-vs-signal handling fixes from Eric Biederman:
 "This is a small set of changes where debuggers were no longer able to
  intercept synchronous SIGTRAP and SIGSEGV, introduced by the exit
  cleanups.

  This is essentially the change you suggested with all of i's dotted
  and the t's crossed so that ptrace can intercept all of the cases it
  has been able to intercept the past, and all of the cases that made it
  to exit without giving ptrace a chance still don't give ptrace a
  chance"

* 'SA_IMMUTABLE-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Replace force_fatal_sig with force_exit_sig when in doubt
  signal: Don't always set SA_IMMUTABLE for forced signals

3 years agoMerge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Linus Torvalds [Fri, 19 Nov 2021 19:19:58 +0000 (11:19 -0800)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "Six fixes, five in drivers (ufs, qla2xxx, iscsi) and one core change
  to fix a regression in user space device state setting, which is used
  by the iscsi daemons to effect device recovery"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qla2xxx: Fix mailbox direction flags in qla2xxx_get_adapter_id()
  scsi: ufs: core: Fix another task management completion race
  scsi: ufs: core: Fix task management completion timeout race
  scsi: core: sysfs: Fix hang when device state is set via sysfs
  scsi: iscsi: Unblock session then wake up error handler
  scsi: ufs: core: Improve SCSI abort handling

3 years agoMerge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Linus Torvalds [Fri, 19 Nov 2021 19:07:13 +0000 (11:07 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull rdma fixes from Jason Gunthorpe:
 "There are a few big regression items from the merge window suggesting
  that people are testing rc1's but not testing the for-next branches:

   - Warnings fixes

   - Crash in hf1 when creating QPs and setting counters

   - Some old mlx4 cards fail to probe due to missing counters

   - Syzkaller crash in the new counters code"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  MAINTAINERS: Update for VMware PVRDMA driver
  RDMA/nldev: Check stat attribute before accessing it
  RDMA/mlx4: Do not fail the registration on port stats
  IB/hfi1: Properly allocate rdma counter desc memory
  RDMA/core: Set send and receive CQ before forwarding to the driver
  RDMA/netlink: Add __maybe_unused to static inline in C file

3 years agoMerge tag 'gpio-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Fri, 19 Nov 2021 19:02:09 +0000 (11:02 -0800)]
Merge tag 'gpio-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio fixes from Bartosz Golaszewski:

 - fix a coccicheck warning in gpio-virtio

 - fix gpio selftests build issues

 - fix a Kconfig issue in gpio-rockchip

* tag 'gpio-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: rockchip: needs GENERIC_IRQ_CHIP to fix build errors
  selftests: gpio: restore CFLAGS options
  selftests: gpio: fix uninitialised variable warning
  selftests: gpio: fix gpio compiling error
  gpio: virtio: remove unneeded semicolon

3 years agoMerge tag 'drm-fixes-2021-11-19' of git://anongit.freedesktop.org/drm/drm
Linus Torvalds [Fri, 19 Nov 2021 18:50:11 +0000 (10:50 -0800)]
Merge tag 'drm-fixes-2021-11-19' of git://anongit.freedesktop.org/drm/drm

Pull drm fixes from Dave Airlie:
 "This week's fixes, pretty quiet, about right for rc2. amdgpu is the
  bulk of them but the scheduler ones have been reported in a few places
  I think.

  Otherwise just some minor i915 fixes and a few other scattered around:

  scheduler:
   - two refcounting fixes

  cma-helper:
   - use correct free path for noncoherent

  efifb:
   - probing fix

  amdgpu:
   - Better debugging info for SMU msgs
   - Better error reporting when adding IP blocks
   - Fix UVD powergating regression on CZ
   - Clock reporting fix for navi1x
   - OLED panel backlight fix
   - Fix scaling on VGA/DVI for non-DC display code
   - Fix GLFCLK handling for RGP on some APUs
   - fix potential memory leak

  amdkfd:
   - GPU reset fix

  i915:
   - return error handling fix
   - ADL-P display fix
   - TGL DSI display clocks fix

  nouveau:
   - infoframe corruption fix

  sun4i:
   - Kconfig fix"

* tag 'drm-fixes-2021-11-19' of git://anongit.freedesktop.org/drm/drm:
  drm/amd/amdgpu: fix potential memleak
  drm/amd/amdkfd: Fix kernel panic when reset failed and been triggered again
  drm/amd/pm: add GFXCLK/SCLK clocks level print support for APUs
  drm/amdgpu: fix set scaling mode Full/Full aspect/Center not works on vga and dvi connectors
  drm/amd/display: Fix OLED brightness control on eDP
  drm/amd/pm: Remove artificial freq level on Navi1x
  drm/amd/pm: avoid duplicate powergate/ungate setting
  drm/amdgpu: add error print when failing to add IP block(v2)
  drm/amd/pm: Enhanced reporting also for a stuck command
  drm/i915/guc: fix NULL vs IS_ERR() checking
  drm/i915/dsi/xelpd: Fix the bit mask for wakeup GB
  Revert "drm/i915/tgl/dsi: Gate the ddi clocks after pll mapping"
  fbdev: Prevent probing generic drivers if a FB is already registered
  drm/scheduler: fix drm_sched_job_add_implicit_dependencies harder
  drm/scheduler: fix drm_sched_job_add_implicit_dependencies
  drm/sun4i: fix unmet dependency on RESET_CONTROLLER for PHY_SUN6I_MIPI_DPHY
  drm/cma-helper: Release non-coherent memory with dma_free_noncoherent()
  drm/nouveau: hdmigv100.c: fix corrupted HDMI Vendor InfoFrame

3 years agox86: Pin task-stack in __get_wchan()
Peter Zijlstra [Fri, 19 Nov 2021 09:29:47 +0000 (10:29 +0100)]
x86: Pin task-stack in __get_wchan()

When commit 80472ff2479d ("x86: Fix __get_wchan() for !STACKTRACE")
moved from stacktrace to native unwind_*() usage, the
try_get_task_stack() got lost, leading to use-after-free issues for
dying tasks.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Fixes: 80472ff2479d ("x86: Fix __get_wchan() for !STACKTRACE")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215031
Link: https://lore.kernel.org/stable/YZV02RCRVHIa144u@fedora64.linuxtx.org/
Reported-by: Justin Forbes <jmforbes@linuxtx.org>
Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agosignal: Replace force_fatal_sig with force_exit_sig when in doubt
Eric W. Biederman [Thu, 18 Nov 2021 20:23:21 +0000 (14:23 -0600)]
signal: Replace force_fatal_sig with force_exit_sig when in doubt

Recently to prevent issues with SECCOMP_RET_KILL and similar signals
being changed before they are delivered SA_IMMUTABLE was added.

Unfortunately this broke debuggers[1][2] which reasonably expect
to be able to trap synchronous SIGTRAP and SIGSEGV even when
the target process is not configured to handle those signals.

Add force_exit_sig and use it instead of force_fatal_sig where
historically the code has directly called do_exit.  This has the
implementation benefits of going through the signal exit path
(including generating core dumps) without the danger of allowing
userspace to ignore or change these signals.

This avoids userspace regressions as older kernels exited with do_exit
which debuggers also can not intercept.

In the future is should be possible to improve the quality of
implementation of the kernel by changing some of these force_exit_sig
calls to force_fatal_sig.  That can be done where it matters on
a case-by-case basis with careful analysis.

Reported-by: Kyle Huey <me@kylehuey.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
[1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com
[2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020
Fixes: a2a2dd8f85de ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Fixes: 856705c39f8a ("signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die")
Fixes: fc99908855da ("signal/powerpc: On swapcontext failure force SIGSEGV")
Fixes: 21d81bf71bfe ("signal/s390: Use force_sigsegv in default_trap_handler")
Fixes: e98d91d2e629 ("signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig")
Fixes: 908486441621 ("signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails")
Fixes: eed3b85106a0 ("signal/x86: In emulate_vsyscall force a signal instead of calling do_exit")
Fixes: cac0eb1efcc3 ("signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.")
Fixes: 05466dc15414 ("exit/syscall_user_dispatch: Send ordinary signals on failure")
Link: https://lkml.kernel.org/r/871r3dqfv8.fsf_-_@email.froward.int.ebiederm.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
3 years agosignal: Don't always set SA_IMMUTABLE for forced signals
Eric W. Biederman [Thu, 18 Nov 2021 17:11:13 +0000 (11:11 -0600)]
signal: Don't always set SA_IMMUTABLE for forced signals

Recently to prevent issues with SECCOMP_RET_KILL and similar signals
being changed before they are delivered SA_IMMUTABLE was added.

Unfortunately this broke debuggers[1][2] which reasonably expect to be
able to trap synchronous SIGTRAP and SIGSEGV even when the target
process is not configured to handle those signals.

Update force_sig_to_task to support both the case when we can allow
the debugger to intercept and possibly ignore the signal and the case
when it is not safe to let userspace know about the signal until the
process has exited.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Kyle Huey <me@kylehuey.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Cc: stable@vger.kernel.org
[1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com
[2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020
Fixes: a2a2dd8f85de ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Link: https://lkml.kernel.org/r/877dd5qfw5.fsf_-_@email.froward.int.ebiederm.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
3 years agoMAINTAINERS: Update for VMware PVRDMA driver
Bryan Tan [Fri, 19 Nov 2021 11:19:30 +0000 (03:19 -0800)]
MAINTAINERS: Update for VMware PVRDMA driver

Update maintainer info for the VMware PVRDMA driver.

Link: https://lore.kernel.org/r/1637320770-44878-1-git-send-email-bryantan@vmware.com
Reviewed-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
Signed-off-by: Bryan Tan <bryantan@vmware.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
3 years agoblk-mq: don't insert FUA request with data into scheduler queue
Ming Lei [Thu, 18 Nov 2021 15:30:41 +0000 (23:30 +0800)]
blk-mq: don't insert FUA request with data into scheduler queue

We never insert flush request into scheduler queue before.

Recently commit d55e1f141323 ("blk-mq: don't handle non-flush requests in
blk_insert_flush") tries to handle FUA data request as normal request.
This way has caused warning[1] in mq-deadline dd_exit_sched() or io hang in
case of kyber since RQF_ELVPRIV isn't set for flush request, then
->finish_request won't be called.

Fix the issue by inserting FUA data request with blk_mq_request_bypass_insert()
when the device supports FUA, just like what we did before.

[1] https://lore.kernel.org/linux-block/CAHj4cs-_vkTW=dAzbZYGxpEWSpzpcmaNeY1R=vH311+9vMUSdg@mail.gmail.com/

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Fixes: d55e1f141323 ("blk-mq: don't handle non-flush requests in blk_insert_flush")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20211118153041.2163228-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
3 years agoblk-cgroup: fix missing put device in error path from blkg_conf_pref()
Yu Kuai [Tue, 2 Nov 2021 02:07:05 +0000 (10:07 +0800)]
blk-cgroup: fix missing put device in error path from blkg_conf_pref()

If blk_queue_enter() failed due to queue is dying, the
blkdev_put_no_open() is needed because blkcg_conf_open_bdev() succeeded.

Fixes: 5bdf84ba8864 ("blk-cgroup: synchronize blkg creation against policy deactivation")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20211102020705.2321858-1-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
3 years agoriscv: fix building external modules
Andreas Schwab [Tue, 2 Nov 2021 15:51:43 +0000 (16:51 +0100)]
riscv: fix building external modules

When building external modules, vdso_prepare should not be run.  If the
kernel sources are read-only, it will fail.

Fixes: bc078acb69cb ("riscv: explicitly use symbol offsets for VDSO")
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
3 years agoRISC-V: Enable KVM in RV64 and RV32 defconfigs as a module
Anup Patel [Wed, 17 Nov 2021 08:47:05 +0000 (14:17 +0530)]
RISC-V: Enable KVM in RV64 and RV32 defconfigs as a module

Let's enable KVM RISC-V in RV64 and RV32 defconfigs as module
so that it always built along with the default kernel image.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
3 years agoMerge tag 'amd-drm-fixes-5.16-2021-11-17' of https://gitlab.freedesktop.org/agd5f...
Dave Airlie [Fri, 19 Nov 2021 04:23:14 +0000 (14:23 +1000)]
Merge tag 'amd-drm-fixes-5.16-2021-11-17' of https://gitlab.freedesktop.org/agd5f/linux into drm-fixes

amd-drm-fixes-5.16-2021-11-17:

amdgpu:
- Better debugging info for SMU msgs
- Better error reporting when adding IP blocks
- Fix UVD powergating regression on CZ
- Clock reporting fix for navi1x
- OLED panel backlight fix
- Fix scaling on VGA/DVI for non-DC display code
- Fix GLFCLK handling for RGP on some APUs
- fix potential memory leak

amdkfd:
- GPU reset fix

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211118041638.20831-1-alexander.deucher@amd.com
3 years agoMerge tag 'drm-intel-fixes-2021-11-18' of git://anongit.freedesktop.org/drm/drm-intel...
Dave Airlie [Fri, 19 Nov 2021 03:36:53 +0000 (13:36 +1000)]
Merge tag 'drm-intel-fixes-2021-11-18' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

One quick fix for return error handling, one fix for ADL-P display
and one revert targeting stable 5.4, for TGL's DSI display clocks

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/YZbUPIHpR1S3JZ2b@intel.com
3 years agoMerge tag 'drm-misc-fixes-2021-11-18' of git://anongit.freedesktop.org/drm/drm-misc...
Dave Airlie [Fri, 19 Nov 2021 03:28:54 +0000 (13:28 +1000)]
Merge tag 'drm-misc-fixes-2021-11-18' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

A infoframe corruption fix for nouveau, a wrong free function usage fix
for GEM CMA helpers, a Kconfig dependency fix for sun4i, two fixes for
drm/scheduler refcounting and a probing fix for efifb.

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211118075447.5rn6zaulnrequqnm@gilmour
3 years agotracing: Don't use out-of-sync va_list in event printing
Nikita Yushchenko [Thu, 18 Nov 2021 14:55:16 +0000 (17:55 +0300)]
tracing: Don't use out-of-sync va_list in event printing

If trace_seq becomes full, trace_seq_vprintf() no longer consumes
arguments from va_list, making va_list out of sync with format
processing by trace_check_vprintf().

This causes va_arg() in trace_check_vprintf() to return wrong
positional argument, which results into a WARN_ON_ONCE() hit.

ftrace_stress_test from LTP triggers this situation.

Fix it by explicitly avoiding further use if va_list at the point
when it's consistency can no longer be guaranteed.

Link: https://lkml.kernel.org/r/20211118145516.13219-1-nikita.yushchenko@virtuozzo.com
Signed-off-by: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
3 years agotracing: Use memset_startat() to zero struct trace_iterator
Kees Cook [Thu, 18 Nov 2021 20:22:17 +0000 (12:22 -0800)]
tracing: Use memset_startat() to zero struct trace_iterator

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() to avoid confusing memset() about writing beyond
the target struct member.

Link: https://lkml.kernel.org/r/20211118202217.1285588-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
3 years agoMerge tag 'zstd-for-linus-5.16-rc1' of git://github.com/terrelln/linux
Linus Torvalds [Fri, 19 Nov 2021 01:09:05 +0000 (17:09 -0800)]
Merge tag 'zstd-for-linus-5.16-rc1' of git://github.com/terrelln/linux

Pull zstd fixes from Nick Terrell:
 "Fix stack usage on parisc & improve code size bloat

  This contains three commits:

   1. Fixes a minor unused variable warning reported by Kernel test
      robot [0].

   2. Improves the reported code bloat (-88KB / 374KB) [1] by outlining
      some functions that are unlikely to be used in performance
      sensitive workloads.

   3. Fixes the reported excess stack usage on parisc [2] by removing
      -O3 from zstd's compilation flags. -O3 triggered bugs in the
      hppa-linux-gnu gcc-8 compiler. -O2 performance is acceptable:
      neutral compression, about -1% decompression speed. We also reduce
      code bloat (-105KB / 374KB).

  After this our code bloat is cut from 374KB to 105KB with gcc-11. If
  we wanted to cut the remaining 105KB we'd likely have to trade
  signicant performance, so I want to say that this is enough for now.

  We should be able to get further gains without sacrificing speed, but
  that will take some significant optimization effort, and isn't
  suitable for a quick fix. I've opened an upstream issue [3] to track
  the code size, and try to avoid future regressions, and improve it in
  the long term"

Link: https://lore.kernel.org/linux-mm/202111120312.833wII4i-lkp@intel.com/T/
Link: https://lkml.org/lkml/2021/11/15/710
Link: https://lkml.org/lkml/2021/11/14/189
Link: https://github.com/facebook/zstd/issues/2867
Link: https://lore.kernel.org/r/20211117014949.1169186-1-nickrterrell@gmail.com/
Link: https://lore.kernel.org/r/20211117201459.1194876-1-nickrterrell@gmail.com/
* tag 'zstd-for-linus-5.16-rc1' of git://github.com/terrelln/linux:
  lib: zstd: Don't add -O3 to cflags
  lib: zstd: Don't inline functions in zstd_opt.c
  lib: zstd: Fix unused variable warning

3 years agoMerge tag 'thermal-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
Linus Torvalds [Thu, 18 Nov 2021 22:52:24 +0000 (14:52 -0800)]
Merge tag 'thermal-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull thermal control fixes from Rafael Wysocki:
 "These fix the handling of thermal zones during system resume and
  disable building of the int340x thermal driver on 32-bit.

  Specifics:

   - Prevent the previous high and low thermal zone trip values from
     being retained over a system suspend-resume cycle (Manaf
     Meethalavalappu Pallikunhi)

   - Prevent the int340x thermal driver from being built in 32-bit
     kernel configurations, because running it on 32-bit is questionable
     (Arnd Bergmann)"

* tag 'thermal-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: core: Reset previous low and high trip during thermal zone init
  thermal: int340x: Limit Kconfig to 64-bit

3 years agoMerge tag 'pm-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Linus Torvalds [Thu, 18 Nov 2021 22:46:28 +0000 (14:46 -0800)]
Merge tag 'pm-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix a system-wide suspend issue in the DTPM framework and
  improve the Energy Model documentation.

  Specifics:

   - Fix system suspend handling in DTPM when it is enabled, but not
     actually used (Daniel Lezcano)

   - Describe the new cpufreq callback for Energy Model registration and
     explain the "advanced" and "simple" EM variants in the EM
     documentation (Lukasz Luba)"

* tag 'pm-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Documentation: power: Describe 'advanced' and 'simple' EM models
  Documentation: power: Add description about new callback for EM registration
  powercap: DTPM: Fix suspend failure and kernel warning

3 years agoMerge tag 'acpi-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
Linus Torvalds [Thu, 18 Nov 2021 22:42:36 +0000 (14:42 -0800)]
Merge tag 'acpi-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI fix from Rafael Wysocki:
 "Revert the change attempting to release PM resources blocked by unused
  ACPI objects after device enumeration, because it caused boot issues
  to appear on multiple systems"

* tag 'acpi-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPI: scan: Release PM resources blocked by unused objects"

3 years agoMerge tag 'platform-drivers-x86-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Thu, 18 Nov 2021 22:39:40 +0000 (14:39 -0800)]
Merge tag 'platform-drivers-x86-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver fixes from Hans de Goede:
 "Various build- and bug-fixes as well as one hardware-id addition"

* tag 'platform-drivers-x86-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
  platform/x86: thinkpad_acpi: fix documentation for adaptive keyboard
  platform/x86: thinkpad_acpi: Fix WWAN device disabled issue after S3 deep
  platform/x86: thinkpad_acpi: Add support for dual fan control
  platform/x86: think-lmi: Abort probe on analyze failure
  platform/x86: dell-wmi-descriptor: disable by default
  platform/x86: samsung-laptop: Fix typo in a comment
  platform/x86: hp_accel: Fix an error handling path in 'lis3lv02d_probe()'
  platform/x86: amd-pmc: Make CONFIG_AMD_PMC depend on RTC_CLASS
  platform/mellanox: mlxreg-lc: fix error code in mlxreg_lc_create_static_devices()

3 years agoMerge tag 'spi-fix-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brooni...
Linus Torvalds [Thu, 18 Nov 2021 22:35:41 +0000 (14:35 -0800)]
Merge tag 'spi-fix-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A few small fixes for v5.16, one in the core for an issue with
  handling of controller unregistration that was introduced with the
  fixes for registering nested SPI controllers and a few more minor
  device specific ones"

* tag 'spi-fix-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: fix use-after-free of the add_lock mutex
  spi: spi-geni-qcom: fix error handling in spi_geni_grab_gpi_chan()
  spi: lpspi: Silence error message upon deferred probe
  spi: cadence-quadspi: fix write completion support

3 years agolib: zstd: Don't add -O3 to cflags
Nick Terrell [Tue, 16 Nov 2021 23:11:39 +0000 (15:11 -0800)]
lib: zstd: Don't add -O3 to cflags

After the update to zstd-1.4.10 passing -O3 is no longer necessary to
get good performance from zstd. Using the default optimization level -O2
is sufficient to get good performance.

I've measured no significant change to compression speed, and a ~1%
decompression speed loss, which is acceptable.

This fixes the reported parisc -Wframe-larger-than=1536 errors [0]. The
gcc-8-hppa-linux-gnu compiler performed very poorly with -O3, generating
stacks that are ~3KB. With -O2 these same functions generate stacks in
the < 100B, completely fixing the problem. Function size deltas are
listed below:

ZSTD_compressBlock_fast_extDict_generic: 3800 -> 68
ZSTD_compressBlock_fast: 2216 -> 40
ZSTD_compressBlock_fast_dictMatchState: 1848 ->  64
ZSTD_compressBlock_doubleFast_extDict_generic: 3744 -> 76
ZSTD_fillDoubleHashTable: 3252 -> 0
ZSTD_compressBlock_doubleFast: 5856 -> 36
ZSTD_compressBlock_doubleFast_dictMatchState: 5380 -> 84
ZSTD_copmressBlock_lazy2: 2420 -> 72

Additionally, this improves the reported code bloat [1]. With gcc-11
bloat-o-meter shows an 80KB code size improvement:

```
> ../scripts/bloat-o-meter vmlinux.old vmlinux
add/remove: 31/8 grow/shrink: 24/155 up/down: 25734/-107924 (-82190)
Total: Before=6418562, After=6336372, chg -1.28%
```

Compared to before the zstd-1.4.10 update we see a total code size
regression of 105KB, down from 374KB at v5.16-rc1:

```
> ../scripts/bloat-o-meter vmlinux.old vmlinux
add/remove: 292/62 grow/shrink: 56/88 up/down: 235009/-127487 (107522)
Total: Before=6228850, After=6336372, chg +1.73%
```

[0] https://lkml.org/lkml/2021/11/15/710
[1] https://lkml.org/lkml/2021/11/14/189

Link: https://lore.kernel.org/r/20211117014949.1169186-4-nickrterrell@gmail.com/
Link: https://lore.kernel.org/r/20211117201459.1194876-4-nickrterrell@gmail.com/
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Nick Terrell <terrelln@fb.com>
3 years agolib: zstd: Don't inline functions in zstd_opt.c
Nick Terrell [Tue, 16 Nov 2021 04:33:08 +0000 (20:33 -0800)]
lib: zstd: Don't inline functions in zstd_opt.c

`zstd_opt.c` contains the match finder for the highest compression
levels. These levels are already very slow, and are unlikely to be used
in the kernel. If they are used, they shouldn't be used in latency
sensitive workloads, so slowing them down shouldn't be a big deal.

This saves 188 KB of the 288 KB regression reported by Geert Uytterhoeven [0].
I've also opened an issue upstream [1] so that we can properly tackle
the code size issue in `zstd_opt.c` for all users, and can hopefully
remove this hack in the next zstd version we import.

Bloat-o-meter output on x86-64:

```
> ../scripts/bloat-o-meter vmlinux.old vmlinux
add/remove: 6/5 grow/shrink: 1/9 up/down: 16673/-209939 (-193266)
Function                                     old     new   delta
ZSTD_compressBlock_opt_generic.constprop       -    7559   +7559
ZSTD_insertBtAndGetAllMatches                  -    6304   +6304
ZSTD_insertBt1                                 -    1731   +1731
ZSTD_storeSeq                                  -     693    +693
ZSTD_BtGetAllMatches                           -     255    +255
ZSTD_updateRep                                 -     128    +128
ZSTD_updateTree                               96      99      +3
ZSTD_insertAndFindFirstIndexHash3             81       -     -81
ZSTD_setBasePrices.constprop                  98       -     -98
ZSTD_litLengthPrice.constprop                138       -    -138
ZSTD_count                                   362     181    -181
ZSTD_count_2segments                        1407     938    -469
ZSTD_insertBt1.constprop                    2689       -   -2689
ZSTD_compressBlock_btultra2                19990     423  -19567
ZSTD_compressBlock_btultra                 19633      15  -19618
ZSTD_initStats_ultra                       19825       -  -19825
ZSTD_compressBlock_btopt                   20374      12  -20362
ZSTD_compressBlock_btopt_extDict           29984      12  -29972
ZSTD_compressBlock_btultra_extDict         30718      15  -30703
ZSTD_compressBlock_btopt_dictMatchState    32689      12  -32677
ZSTD_compressBlock_btultra_dictMatchState   33574      15  -33559
Total: Before=6611828, After=6418562, chg -2.92%
```

[0] https://lkml.org/lkml/2021/11/14/189
[1] https://github.com/facebook/zstd/issues/2862

Link: https://lore.kernel.org/r/20211117014949.1169186-3-nickrterrell@gmail.com/
Link: https://lore.kernel.org/r/20211117201459.1194876-3-nickrterrell@gmail.com/
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Nick Terrell <terrelln@fb.com>
3 years agolib: zstd: Fix unused variable warning
Nick Terrell [Tue, 16 Nov 2021 03:08:19 +0000 (19:08 -0800)]
lib: zstd: Fix unused variable warning

The variable `litLengthSum` is only used by an `assert()`, so when
asserts are disabled the compiler doesn't see any usage and warns.

This issue is already fixed upstream by PR #2838 [0]. It was reported
by the Kernel test robot in [1].

Another approach would be to change zstd's disabled `assert()`
definition to use the argument in a disabled branch, instead of
ignoring the argument. I've avoided this approach because there are
some small changes necessary to get zstd to build, and I would
want to thoroughly re-test for performance, since that is slightly
changing the code in every function in zstd. It seems like a
trivial change, but some functions are pretty sensitive to small
changes. However, I think it is a valid approach that I would
like to see upstream take, so I've opened Issue #2868 to attempt
this upstream.

Lastly, I've chosen not to use __maybe_unused because all code
in lib/zstd/ must eventually be upstreamed. Upstream zstd can't
use __maybe_unused because it isn't portable across all compilers.

[0] https://github.com/facebook/zstd/pull/2838
[1] https://lore.kernel.org/linux-mm/202111120312.833wII4i-lkp@intel.com/T/
[2] https://github.com/facebook/zstd/issues/2868

Link: https://lore.kernel.org/r/20211117014949.1169186-2-nickrterrell@gmail.com/
Link: https://lore.kernel.org/r/20211117201459.1194876-2-nickrterrell@gmail.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nick Terrell <terrelln@fb.com>