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The kvm_run struct's if_flag is a part of the userspace/kernel API. The
SEV-ES patches failed to set this flag because it's no longer needed by
QEMU (according to the comment in the source code). However, other
hypervisors may make use of this flag. Therefore, set the flag for
guests with encrypted registers (i.e., with guest_state_protected set).
Fixes: f1c6366e3043 ("KVM: SVM: Add required changes to support intercepts under SEV-ES")
Signed-off-by: Marc Orr <marcorr@google.com>
Message-Id: <20211209155257.128747-1-marcorr@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
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After dropping mmu_lock in the TDP MMU, restart the iterator during
tdp_iter_next() and do not advance the iterator. Advancing the iterator
results in skipping the top-level SPTE and all its children, which is
fatal if any of the skipped SPTEs were not visited before yielding.
When zapping all SPTEs, i.e. when min_level == root_level, restarting the
iter and then invoking tdp_iter_next() is always fatal if the current gfn
has as a valid SPTE, as advancing the iterator results in try_step_side()
skipping the current gfn, which wasn't visited before yielding.
Sprinkle WARNs on iter->yielded being true in various helpers that are
often used in conjunction with yielding, and tag the helper with
__must_check to reduce the probabily of improper usage.
Failing to zap a top-level SPTE manifests in one of two ways. If a valid
SPTE is skipped by both kvm_tdp_mmu_zap_all() and kvm_tdp_mmu_put_root(),
the shadow page will be leaked and KVM will WARN accordingly.
WARNING: CPU: 1 PID: 3509 at arch/x86/kvm/mmu/tdp_mmu.c:46 [kvm]
RIP: 0010:kvm_mmu_uninit_tdp_mmu+0x3e/0x50 [kvm]
Call Trace:
<TASK>
kvm_arch_destroy_vm+0x130/0x1b0 [kvm]
kvm_destroy_vm+0x162/0x2a0 [kvm]
kvm_vcpu_release+0x34/0x60 [kvm]
__fput+0x82/0x240
task_work_run+0x5c/0x90
do_exit+0x364/0xa10
? futex_unqueue+0x38/0x60
do_group_exit+0x33/0xa0
get_signal+0x155/0x850
arch_do_signal_or_restart+0xed/0x750
exit_to_user_mode_prepare+0xc5/0x120
syscall_exit_to_user_mode+0x1d/0x40
do_syscall_64+0x48/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
If kvm_tdp_mmu_zap_all() skips a gfn/SPTE but that SPTE is then zapped by
kvm_tdp_mmu_put_root(), KVM triggers a use-after-free in the form of
marking a struct page as dirty/accessed after it has been put back on the
free list. This directly triggers a WARN due to encountering a page with
page_count() == 0, but it can also lead to data corruption and additional
errors in the kernel.
WARNING: CPU: 7 PID: 1995658 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:171
RIP: 0010:kvm_is_zone_device_pfn.part.0+0x9e/0xd0 [kvm]
Call Trace:
<TASK>
kvm_set_pfn_dirty+0x120/0x1d0 [kvm]
__handle_changed_spte+0x92e/0xca0 [kvm]
__handle_changed_spte+0x63c/0xca0 [kvm]
__handle_changed_spte+0x63c/0xca0 [kvm]
__handle_changed_spte+0x63c/0xca0 [kvm]
zap_gfn_range+0x549/0x620 [kvm]
kvm_tdp_mmu_put_root+0x1b6/0x270 [kvm]
mmu_free_root_page+0x219/0x2c0 [kvm]
kvm_mmu_free_roots+0x1b4/0x4e0 [kvm]
kvm_mmu_unload+0x1c/0xa0 [kvm]
kvm_arch_destroy_vm+0x1f2/0x5c0 [kvm]
kvm_put_kvm+0x3b1/0x8b0 [kvm]
kvm_vcpu_release+0x4e/0x70 [kvm]
__fput+0x1f7/0x8c0
task_work_run+0xf8/0x1a0
do_exit+0x97b/0x2230
do_group_exit+0xda/0x2a0
get_signal+0x3be/0x1e50
arch_do_signal_or_restart+0x244/0x17f0
exit_to_user_mode_prepare+0xcb/0x120
syscall_exit_to_user_mode+0x1d/0x40
do_syscall_64+0x4d/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Note, the underlying bug existed even before commit 1af4a96025b3 ("KVM:
x86/mmu: Yield in TDU MMU iter even if no SPTES changed") moved calls to
tdp_mmu_iter_cond_resched() to the beginning of loops, as KVM could still
incorrectly advance past a top-level entry when yielding on a lower-level
entry. But with respect to leaking shadow pages, the bug was introduced
by yielding before processing the current gfn.
Alternatively, tdp_mmu_iter_cond_resched() could simply fall through, or
callers could jump to their "retry" label. The downside of that approach
is that tdp_mmu_iter_cond_resched() _must_ be called before anything else
in the loop, and there's no easy way to enfornce that requirement.
Ideally, KVM would handling the cond_resched() fully within the iterator
macro (the code is actually quite clean) and avoid this entire class of
bugs, but that is extremely difficult do while also supporting yielding
after tdp_mmu_set_spte_atomic() fails. Yielding after failing to set a
SPTE is very desirable as the "owner" of the REMOVED_SPTE isn't strictly
bounded, e.g. if it's zapping a high-level shadow page, the REMOVED_SPTE
may block operations on the SPTE for a significant amount of time.
Fixes: faaf05b00aec ("kvm: x86/mmu: Support zapping SPTEs in the TDP MMU")
Fixes: 1af4a96025b3 ("KVM: x86/mmu: Yield in TDU MMU iter even if no SPTES changed")
Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211214033528.123268-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The fixed counter 3 is used for the Topdown metrics, which hasn't been
enabled for KVM guests. Userspace accessing to it will fail as it's not
included in get_fixed_pmc(). This breaks KVM selftests on ICX+ machines,
which have this counter.
To reproduce it on ICX+ machines, ./state_test reports:
==== Test Assertion Failure ====
lib/x86_64/processor.c:1078: r == nmsrs
pid=4564 tid=4564 - Argument list too long
1 0x000000000040b1b9: vcpu_save_state at processor.c:1077
2 0x0000000000402478: main at state_test.c:209 (discriminator 6)
3 0x00007fbe21ed5f92: ?? ??:0
4 0x000000000040264d: _start at ??:?
Unexpected result from KVM_GET_MSRS, r: 17 (failed MSR was 0x30c)
With this patch, it works well.
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Message-Id: <20211217124934.32893-1-wei.w.wang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Play nice with a NULL shadow page when checking for an obsolete root in
the page fault handler by flagging the page fault as stale if there's no
shadow page associated with the root and KVM_REQ_MMU_RELOAD is pending.
Invalidating memslots, which is the only case where _all_ roots need to
be reloaded, requests all vCPUs to reload their MMUs while holding
mmu_lock for lock.
The "special" roots, e.g. pae_root when KVM uses PAE paging, are not
backed by a shadow page. Running with TDP disabled or with nested NPT
explodes spectaculary due to dereferencing a NULL shadow page pointer.
Skip the KVM_REQ_MMU_RELOAD check if there is a valid shadow page for the
root. Zapping shadow pages in response to guest activity, e.g. when the
guest frees a PGD, can trigger KVM_REQ_MMU_RELOAD even if the current
vCPU isn't using the affected root. I.e. KVM_REQ_MMU_RELOAD can be seen
with a completely valid root shadow page. This is a bit of a moot point
as KVM currently unloads all roots on KVM_REQ_MMU_RELOAD, but that will
be cleaned up in the future.
Fixes: a955cad84cda ("KVM: x86/mmu: Retry page fault if root is invalidated by memslot update")
Cc: stable@vger.kernel.org
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211209060552.2956723-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Host initiated writes to MSR_IA32_PERF_CAPABILITIES should not depend
on guest visible CPUIDs and (incorrect) KVM logic implementing it is
about to change. Also, KVM_SET_CPUID{,2} after KVM_RUN is now forbidden
and causes test to fail.
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: feb627e8d6f6 ("KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211216165213.338923-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The ability to write to MSR_IA32_PERF_CAPABILITIES from the host should
not depend on guest visible CPUID entries, even if just to allow
creating/restoring guest MSRs and CPUIDs in any sequence.
Fixes: 27461da31089 ("KVM: x86/pmu: Support full width counting")
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211216165213.338923-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add an x86 selftest to verify that KVM doesn't WARN or otherwise explode
if userspace modifies RCX during a userspace exit to handle string I/O.
This is a regression test for a user-triggerable WARN introduced by
commit 3b27de271839 ("KVM: x86: split the two parts of emulator_pio_in").
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211025201311.1881846-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Replace a WARN with a comment to call out that userspace can modify RCX
during an exit to userspace to handle string I/O. KVM doesn't actually
support changing the rep count during an exit, i.e. the scenario can be
ignored, but the WARN needs to go as it's trivial to trigger from
userspace.
Cc: stable@vger.kernel.org
Fixes: 3b27de271839 ("KVM: x86: split the two parts of emulator_pio_in")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211025201311.1881846-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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In the SDM:
If the logical processor is in 64-bit mode or if CR4.PCIDE = 1, an
attempt to clear CR0.PG causes a general-protection exception (#GP).
Software should transition to compatibility mode and clear CR4.PCIDE
before attempting to disable paging.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211207095230.53437-1-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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AMD proceessors define an address range that is reserved by HyperTransport
and causes a failure if used for guest physical addresses. Avoid
selftests failures by reserving those guest physical addresses; the
rules are:
- On parts with <40 bits, its fully hidden from software.
- Before Fam17h, it was always 12G just below 1T, even if there was more
RAM above this location. In this case we just not use any RAM above 1T.
- On Fam17h and later, it is variable based on SME, and is either just
below 2^48 (no encryption) or 2^43 (encryption).
Fixes: ef4c9f4f6546 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()")
Cc: stable@vger.kernel.org
Cc: David Matlack <dmatlack@google.com>
Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210805105423.412878-1-pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Do not bail early if there are no bits set in the sparse banks for a
non-sparse, a.k.a. "all CPUs", IPI request. Per the Hyper-V spec, it is
legal to have a variable length of '0', e.g. VP_SET's BankContents in
this case, if the request can be serviced without the extra info.
It is possible that for a given invocation of a hypercall that does
accept variable sized input headers that all the header input fits
entirely within the fixed size header. In such cases the variable sized
input header is zero-sized and the corresponding bits in the hypercall
input should be set to zero.
Bailing early results in KVM failing to send IPIs to all CPUs as expected
by the guest.
Fixes: 214ff83d4473 ("KVM: x86: hyperv: implement PV IPI send hypercalls")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211207220926.718794-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Prior to commit 0baedd792713 ("KVM: x86: make Hyper-V PV TLB flush use
tlb_flush_guest()"), kvm_hv_flush_tlb() was using 'KVM_REQ_TLB_FLUSH |
KVM_REQUEST_NO_WAKEUP' when making a request to flush TLBs on other vCPUs
and KVM_REQ_TLB_FLUSH is/was defined as:
(0 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
so KVM_REQUEST_WAIT was lost. Hyper-V TLFS, however, requires that
"This call guarantees that by the time control returns back to the
caller, the observable effects of all flushes on the specified virtual
processors have occurred." and without KVM_REQUEST_WAIT there's a small
chance that the vCPU making the TLB flush will resume running before
all IPIs get delivered to other vCPUs and a stale mapping can get read
there.
Fix the issue by adding KVM_REQUEST_WAIT flag to KVM_REQ_TLB_FLUSH_GUEST:
kvm_hv_flush_tlb() is the sole caller which uses it for
kvm_make_all_cpus_request()/kvm_make_vcpus_request_mask() where
KVM_REQUEST_WAIT makes a difference.
Cc: stable@kernel.org
Fixes: 0baedd792713 ("KVM: x86: make Hyper-V PV TLB flush use tlb_flush_guest()")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211209102937.584397-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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INTERCEPT_x are bit positions, but the code was using the raw value of
INTERCEPT_VINTR (4) instead of BIT(INTERCEPT_VINTR).
This resulted in masking of bit 2 - that is, SMI instead of VINTR.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <49b9571d25588870db5380b0be1a41df4bbaaf93.1638486479.git.maciej.szmigiero@oracle.com>
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When KVM runs as a nested hypervisor on top of Hyper-V it uses Enlightened
VMCS and enables Enlightened MSR Bitmap feature for its L1s and L2s (which
are actually L2s and L3s from Hyper-V's perspective). When MSR bitmap is
updated, KVM has to reset HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP from
clean fields to make Hyper-V aware of the change. For KVM's L1s, this is
done in vmx_disable_intercept_for_msr()/vmx_enable_intercept_for_msr().
MSR bitmap for L2 is build in nested_vmx_prepare_msr_bitmap() by blending
MSR bitmap for L1 and L1's idea of MSR bitmap for L2. KVM, however, doesn't
check if the resulting bitmap is different and never cleans
HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP in eVMCS02. This is incorrect and
may result in Hyper-V missing the update.
The issue could've been solved by calling evmcs_touch_msr_bitmap() for
eVMCS02 from nested_vmx_prepare_msr_bitmap() unconditionally but doing so
would not give any performance benefits (compared to not using Enlightened
MSR Bitmap at all). 3-level nesting is also not a very common setup
nowadays.
Don't enable 'Enlightened MSR Bitmap' feature for KVM's L2s (real L3s) for
now.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211129094704.326635-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Currently, an SEV-ES guest is terminated if the validation of the VMGEXIT
exit code or exit parameters fails.
The VMGEXIT instruction can be issued from userspace, even though
userspace (likely) can't update the GHCB. To prevent userspace from being
able to kill the guest, return an error through the GHCB when validation
fails rather than terminating the guest. For cases where the GHCB can't be
updated (e.g. the GHCB can't be mapped, etc.), just return back to the
guest.
The new error codes are documented in the lasest update to the GHCB
specification.
Fixes: 291bd20d5d88 ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <b57280b5562893e2616257ac9c2d4525a9aeeb42.1638471124.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Use kvzalloc() to allocate KVM's buffer for SEV-ES's GHCB scratch area so
that KVM falls back to __vmalloc() if physically contiguous memory isn't
available. The buffer is purely a KVM software construct, i.e. there's
no need for it to be physically contiguous.
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109222350.2266045-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Return appropriate error codes if setting up the GHCB scratch area for an
SEV-ES guest fails. In particular, returning -EINVAL instead of -ENOMEM
when allocating the kernel buffer could be confusing as userspace would
likely suspect a guest issue.
Fixes: 8f423a80d299 ("KVM: SVM: Support MMIO for an SEV-ES guest")
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109222350.2266045-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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In commit c8c3735997a3 ("parisc: Enhance detection of synchronous cr16
clocksources") I assumed that CPUs on the same physical core are syncronous.
While booting up the kernel on two different C8000 machines, one with a
dual-core PA8800 and one with a dual-core PA8900 CPU, this turned out to be
wrong. The symptom was that I saw a jump in the internal clocks printed to the
syslog and strange overall behaviour. On machines which have 4 cores (2
dual-cores) the problem isn't visible, because the current logic already marked
the cr16 clocksource unstable in this case.
This patch now marks the cr16 interval timers unstable if we have more than one
CPU in the system, and it fixes this issue.
Fixes: c8c3735997a3 ("parisc: Enhance detection of synchronous cr16 clocksources")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.15+
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On newer debian releases the debian-provided "installkernel" script is
installed in /usr/sbin. Fix the kernel install.sh script to look for the
script in this directory as well.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v3.13+
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Commit d81ae8aac85c ("sched/uclamp: Fix initialization of struct
uclamp_rq") introduced a bug where uclamp_max of the rq is not reset to
match the woken up task's uclamp_max when the rq is idle.
The code was relying on rq->uclamp_max initialized to zero, so on first
enqueue
static inline void uclamp_rq_inc_id(struct rq *rq, struct task_struct *p,
enum uclamp_id clamp_id)
{
...
if (uc_se->value > READ_ONCE(uc_rq->value))
WRITE_ONCE(uc_rq->value, uc_se->value);
}
was actually resetting it. But since commit d81ae8aac85c changed the
default to 1024, this no longer works. And since rq->uclamp_flags is
also initialized to 0, neither above code path nor uclamp_idle_reset()
update the rq->uclamp_max on first wake up from idle.
This is only visible from first wake up(s) until the first dequeue to
idle after enabling the static key. And it only matters if the
uclamp_max of this task is < 1024 since only then its uclamp_max will be
effectively ignored.
Fix it by properly initializing rq->uclamp_flags = UCLAMP_FLAG_IDLE to
ensure uclamp_idle_reset() is called which then will update the rq
uclamp_max value as expected.
Fixes: d81ae8aac85c ("sched/uclamp: Fix initialization of struct uclamp_rq")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lkml.kernel.org/r/20211202112033.1705279-1-qais.yousef@arm.com
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__setup() callbacks expect 1 for success and 0 for failure. Correct the
usage here to reflect that.
Fixes: 826bfeb37bb4 ("preempt/dynamic: Support dynamic preempt with preempt= boot option")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211203233203.133581-1-ahalaney@redhat.com
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server->dstaddr can change when the DNS mapping for the
server hostname changes. But conn_id is a u64 counter
that is incremented each time a new TCP connection
is setup. So use only that as a key.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
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The fscache client cookie uses the server address
(and port) as the cookie key. This is a problem when
nosharesock is used. Two different connections will
use duplicate cookies. Avoid this by adding
server->conn_id to the key, so that it's guaranteed
that cookie will not be duplicated.
Also, for secondary channels of a session, copy the
fscache pointer from the primary channel. The primary
channel is guaranteed not to go away as long as secondary
channels are in use. Also addresses minor problem found
by kernel test robot.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
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The logic for initializing tcon->resource_id is done inside
cifs_root_iget. fscache super cookie relies on this for aux
data. So we need to push the fscache initialization to this
later point during mount.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Fix missed refcounting of IPC tcon used for getting domain-based DFS
root referrals. We want to keep it alive as long as mount is active
and can be refreshed. For standalone DFS root referrals it wouldn't
be a problem as the client ends up having an IPC tcon for both mount
and cache.
Fixes: c88f7dcd6d64 ("cifs: support nested dfs links over reconnect")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
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In the native case, PER_CPU_VAR(cpu_tss_rw + TSS_sp0) is the
trampoline stack. But XEN pv doesn't use trampoline stack, so
PER_CPU_VAR(cpu_tss_rw + TSS_sp0) is also the kernel stack.
In that case, source and destination stacks are identical, which means
that reusing swapgs_restore_regs_and_return_to_usermode() in XEN pv
would cause %rsp to move up to the top of the kernel stack and leave the
IRET frame below %rsp.
This is dangerous as it can be corrupted if #NMI / #MC hit as either of
these events occurring in the middle of the stack pushing would clobber
data on the (original) stack.
And, with XEN pv, swapgs_restore_regs_and_return_to_usermode() pushing
the IRET frame on to the original address is useless and error-prone
when there is any future attempt to modify the code.
[ bp: Massage commit message. ]
Fixes: 7f2590a110b8 ("x86/entry/64: Use a per-CPU trampoline stack for IDT entries")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lkml.kernel.org/r/20211126101209.8613-4-jiangshanlai@gmail.com
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The commit
c75890700455 ("x86/entry/64: Remove unneeded kernel CR3 switching")
removed a CR3 write in the faulting path of load_gs_index().
But the path's FENCE_SWAPGS_USER_ENTRY has no fence operation if PTI is
enabled, see spectre_v1_select_mitigation().
Rather, it depended on the serializing CR3 write of SWITCH_TO_KERNEL_CR3
and since it got removed, add a FENCE_SWAPGS_KERNEL_ENTRY call to make
sure speculation is blocked.
[ bp: Massage commit message and comment. ]
Fixes: c75890700455 ("x86/entry/64: Remove unneeded kernel CR3 switching")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211126101209.8613-3-jiangshanlai@gmail.com
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Jann Horn points out that there is another possible race wrt Unix domain
socket garbage collection, somewhat reminiscent of the one fixed in
commit cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK").
See the extended comment about the garbage collection requirements added
to unix_peek_fds() by that commit for details.
The race comes from how we can locklessly look up a file descriptor just
as it is in the process of being closed, and with the right artificial
timing (Jann added a few strategic 'mdelay(500)' calls to do that), the
Unix domain socket garbage collector could see the reference count
decrement of the close() happen before fget() took its reference to the
file and the file was attached onto a new file descriptor.
This is all (intentionally) correct on the 'struct file *' side, with
RCU lookups and lockless reference counting very much part of the
design. Getting that reference count out of order isn't a problem per
se.
But the garbage collector can get confused by seeing this situation of
having seen a file not having any remaining external references and then
seeing it being attached to an fd.
In commit cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK") the
fix was to serialize the file descriptor install with the garbage
collector by taking and releasing the unix_gc_lock.
That's not really an option here, but since this all happens when we are
in the process of looking up a file descriptor, we can instead simply
just re-check that the file hasn't been closed in the meantime, and just
re-do the lookup if we raced with a concurrent close() of the same file
descriptor.
Reported-and-tested-by: Jann Horn <jannh@google.com>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit
18ec54fdd6d18 ("x86/speculation: Prepare entry code for Spectre v1 swapgs mitigations")
added FENCE_SWAPGS_{KERNEL|USER}_ENTRY for conditional SWAPGS. In
paranoid_entry(), it uses only FENCE_SWAPGS_KERNEL_ENTRY for both
branches. This is because the fence is required for both cases since the
CR3 write is conditional even when PTI is enabled.
But
96b2371413e8f ("x86/entry/64: Switch CR3 before SWAPGS in paranoid entry")
changed the order of SWAPGS and the CR3 write. And it missed the needed
FENCE_SWAPGS_KERNEL_ENTRY for the user gsbase case.
Add it back by changing the branches so that FENCE_SWAPGS_KERNEL_ENTRY
can cover both branches.
[ bp: Massage, fix typos, remove obsolete comment while at it. ]
Fixes: 96b2371413e8f ("x86/entry/64: Switch CR3 before SWAPGS in paranoid entry")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211126101209.8613-2-jiangshanlai@gmail.com
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Properly type the operands being passed to __put_user()/__get_user().
Otherwise, these routines truncate data for dependent instructions
(e.g., INSW) and only read/write one byte.
This has been tested by sending a string with REP OUTSW to a port and
then reading it back in with REP INSW on the same port.
Previous behavior was to only send and receive the first char of the
size. For example, word operations for "abcd" would only read/write
"ac". With change, the full string is now written and read back.
Fixes: f980f9c31a923 (x86/sev-es: Compile early handler code into kernel image)
Signed-off-by: Michael Sterritt <sterritt@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Reviewed-by: Peter Gonda <pgonda@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20211119232757.176201-1-sterritt@google.com
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The dtpm_descr variable in init_dtpm() is not used after commit
f751db8adaea ("powercap/drivers/dtpm: Disable DTPM at boot time"),
so drop it.
Fixes: f751db8adaea ("powercap/drivers/dtpm: Disable DTPM at boot time")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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We don't want to be retrying task_work creation failure if there's
an actual signal pending for the parent task. If we do, then we can
enter an infinite loop of perpetually retrying and each retry failing
with -ERESTARTNOINTR because a signal is pending.
Fixes: 3146cba99aa2 ("io-wq: make worker creation resilient against signals")
Reported-by: Florian Fischer <florian.fl.fischer@fau.de>
Link: https://lore.kernel.org/io-uring/20211202165606.mqryio4yzubl7ms5@pasture/
Tested-by: Florian Fischer <florian.fl.fischer@fau.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There is a small window in time during resume where the hardware
flow control signal RTS can be asserted (which allows a sender to
resume sending data to the UART) but the baud rate has not yet
been restored. This will cause corrupted data and FRAMING, OVERRUN
and BREAK errors. This is happening because the MCTRL register is
shadowed in uart_port struct and is later used during resume to set
the MCTRL register during both serial8250_do_startup() and
uart_resume_port(). Unfortunately, serial8250_do_startup()
happens before the UART baud rate is restored. The fix is to clear
the shadowed mctrl value at the end of suspend and restore it at the
end of resume.
Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Link: https://lore.kernel.org/r/20211201201402.47446-1-alcooperx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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In cdnsp_endpoint_init(), cdnsp_ring_alloc() is assigned to pep->ring
and there is a dereference of it in cdnsp_endpoint_init(), which could
lead to a NULL pointer dereference on failure of cdnsp_ring_alloc().
Fix this bug by adding a check of pep->ring.
This bug was found by a static analyzer. The analysis employs
differential checking to identify inconsistent security operations
(e.g., checks or kfrees) between two code paths and confirms that the
inconsistent operations are not recovered in the current function or
the callers, so they constitute bugs.
Note that, as a bug found by static analysis, it can be a false
positive or hard to trigger. Multiple researchers have cross-reviewed
the bug.
Builds with CONFIG_USB_CDNSP_GADGET=y show no new warnings,
and our static analyzer no longer warns about this code.
Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Cc: stable <stable@vger.kernel.org>
Acked-by: Pawel Laszczak <pawell@cadence.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
Link: https://lore.kernel.org/r/20211130172700.206650-1-zhou1615@umn.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This issue was found at android12 MTP.
1. MTP submit many out urb request.
2. Cancel left requests (>20) when enough data get from host
3. Send ACK by IN endpoint.
4. MTP submit new out urb request.
5. 4's urb never complete.
TRACE LOG:
MtpServer-2157 [000] d..3 1287.150391: cdns3_ep_dequeue: ep1out: req: 00000000299e6836, req buff 000000009df42287, length: 0/16384 zsi, status: -115, trb: [start:87, end:87: virt addr 0x80004000ffd50420], flags:1 SID: 0
MtpServer-2157 [000] d..3 1287.150410: cdns3_gadget_giveback: ep1out: req: 00000000299e6836, req buff 000000009df42287, length: 0/16384 zsi, status: -104, trb: [start:87, end:87: virt addr 0x80004000ffd50420], flags:0 SID: 0
MtpServer-2157 [000] d..3 1287.150433: cdns3_ep_dequeue: ep1out: req: 0000000080b7bde6, req buff 000000009ed5c556, length: 0/16384 zsi, status: -115, trb: [start:88, end:88: virt addr 0x80004000ffd5042c], flags:1 SID: 0
MtpServer-2157 [000] d..3 1287.150446: cdns3_gadget_giveback: ep1out: req: 0000000080b7bde6, req buff 000000009ed5c556, length: 0/16384 zsi, status: -104, trb: [start:88, end:88: virt addr 0x80004000ffd5042c], flags:0 SID: 0
....
MtpServer-2157 [000] d..1 1293.630410: cdns3_alloc_request: ep1out: req: 00000000afbccb7d, req buff 0000000000000000, length: 0/0 zsi, status: 0, trb: [start:0, end:0: virt addr (null)], flags:0 SID: 0
MtpServer-2157 [000] d..2 1293.630421: cdns3_ep_queue: ep1out: req: 00000000afbccb7d, req buff 00000000871caf90, length: 0/512 zsi, status: -115, trb: [start:0, end:0: virt addr (null)], flags:0 SID: 0
MtpServer-2157 [000] d..2 1293.630445: cdns3_wa1: WA1: ep1out set guard
MtpServer-2157 [000] d..2 1293.630450: cdns3_wa1: WA1: ep1out restore cycle bit
MtpServer-2157 [000] d..2 1293.630453: cdns3_prepare_trb: ep1out: trb 000000007317b3ee, dma buf: 0xffd5bc00, size: 512, burst: 128 ctrl: 0x00000424 (C=0, T=0, ISP, IOC, Normal) SID:0 LAST_SID:0
MtpServer-2157 [000] d..2 1293.630460: cdns3_doorbell_epx: ep1out, ep_trbaddr ffd50414
....
irq/241-5b13000-2154 [000] d..1 1293.680849: cdns3_epx_irq: IRQ for ep1out: 01000408 ISP , ep_traddr: ffd508ac ep_last_sid: 00000000 use_streams: 0
irq/241-5b13000-2154 [000] d..1 1293.680858: cdns3_complete_trb: ep1out: trb 0000000021a11b54, dma buf: 0xffd50420, size: 16384, burst: 128 ctrl: 0x00001810 (C=0, T=0, CHAIN, LINK) SID:0 LAST_SID:0
irq/241-5b13000-2154 [000] d..1 1293.680865: cdns3_request_handled: Req: 00000000afbccb7d not handled, DMA pos: 185, ep deq: 88, ep enq: 185, start trb: 184, end trb: 184
Actually DMA pos already bigger than previous submit request afbccb7d's TRB (184-184). The reason of (not handled) is that deq position is wrong.
The TRB link is below when irq happen.
DEQ LINK LINK LINK LINK LINK .... TRB(afbccb7d):START DMA(EP_TRADDR).
Original code check LINK TRB, but DEQ just move one step.
LINK DEQ LINK LINK LINK LINK .... TRB(afbccb7d):START DMA(EP_TRADDR).
This patch skip all LINK TRB and sync DEQ to trb's start.
LINK LINK LINK LINK LINK .... DEQ = TRB(afbccb7d):START DMA(EP_TRADDR).
Acked-by: Peter Chen <peter.chen@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jun Li <jun.li@nxp.com>
Link: https://lore.kernel.org/r/20211130154239.8029-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Stub from the spec:
"4.5.2.2.4.2 Exiting from AttachWait.SNK State
A Sink shall transition to Unattached.SNK when the state of both
the CC1 and CC2 pins is SNK.Open for at least tPDDebounce.
A DRP shall transition to Unattached.SRC when the state of both
the CC1 and CC2 pins is SNK.Open for at least tPDDebounce."
This change makes TCPM to wait in SNK_DEBOUNCED state until
CC1 and CC2 pins is SNK.Open for at least tPDDebounce. Previously,
TCPM resets the port if vbus is not present in PD_T_PS_SOURCE_ON.
This causes TCPM to loop continuously when connected to a
faulty power source that does not present vbus. Waiting in
SNK_DEBOUNCED also ensures that TCPM is adherant to
"4.5.2.2.4.2 Exiting from AttachWait.SNK State" requirements.
[ 6169.280751] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected]
[ 6169.280759] state change TOGGLING -> SNK_ATTACH_WAIT [rev2 NONE_AMS]
[ 6169.280771] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev2 NONE_AMS]
[ 6169.282427] CC1: 0 -> 0, CC2: 5 -> 5 [state SNK_ATTACH_WAIT, polarity 0, connected]
[ 6169.450825] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms]
[ 6169.450834] pending state change SNK_DEBOUNCED -> PORT_RESET @ 480 ms [rev2 NONE_AMS]
[ 6169.930892] state change SNK_DEBOUNCED -> PORT_RESET [delayed 480 ms]
[ 6169.931296] disable vbus discharge ret:0
[ 6169.931301] Setting usb_comm capable false
[ 6169.932783] Setting voltage/current limit 0 mV 0 mA
[ 6169.932802] polarity 0
[ 6169.933706] Requesting mux state 0, usb-role 0, orientation 0
[ 6169.936689] cc:=0
[ 6169.936812] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev2 NONE_AMS]
[ 6169.937157] CC1: 0 -> 0, CC2: 5 -> 0 [state PORT_RESET, polarity 0, disconnected]
[ 6170.036880] state change PORT_RESET -> PORT_RESET_WAIT_OFF [delayed 100 ms]
[ 6170.036890] state change PORT_RESET_WAIT_OFF -> SNK_UNATTACHED [rev2 NONE_AMS]
[ 6170.036896] Start toggling
[ 6170.041412] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[ 6170.042973] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected]
[ 6170.042976] state change TOGGLING -> SNK_ATTACH_WAIT [rev2 NONE_AMS]
[ 6170.042981] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev2 NONE_AMS]
[ 6170.213014] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms]
[ 6170.213019] pending state change SNK_DEBOUNCED -> PORT_RESET @ 480 ms [rev2 NONE_AMS]
[ 6170.693068] state change SNK_DEBOUNCED -> PORT_RESET [delayed 480 ms]
[ 6170.693304] disable vbus discharge ret:0
[ 6170.693308] Setting usb_comm capable false
[ 6170.695193] Setting voltage/current limit 0 mV 0 mA
[ 6170.695210] polarity 0
[ 6170.695990] Requesting mux state 0, usb-role 0, orientation 0
[ 6170.701896] cc:=0
[ 6170.702181] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev2 NONE_AMS]
[ 6170.703343] CC1: 0 -> 0, CC2: 5 -> 0 [state PORT_RESET, polarity 0, disconnected]
Fixes: f0690a25a140b8 ("staging: typec: USB Type-C Port Manager (tcpm)")
Cc: stable@vger.kernel.org
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20211130001825.3142830-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This is another branded 8153 device that doesn't work well with LPM:
r8152 2-2.1:1.0 enp0s13f0u2u1: Stop submitting intr, status -71
Disable LPM to resolve the issue.
Signed-off-by: Ole Ernst <olebowle@gmx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211127090546.52072-1-olebowle@gmx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Turns out some xHC controllers require all 64 bits in the CRCR register
to be written to execute a command abort.
The lower 32 bits containing the command abort bit is written first.
In case the command ring stops before we write the upper 32 bits then
hardware may use these upper bits to set the commnd ring dequeue pointer.
Solve this by making sure the upper 32 bits contain a valid command
ring dequeue pointer.
The original patch that only wrote the first 32 to stop the ring went
to stable, so this fix should go there as well.
Fixes: ff0e50d3564f ("xhci: Fix command ring pointer corruption while aborting a command")
Cc: stable@vger.kernel.org
Tested-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20211126122340.1193239-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The trampoline_pgd only maps the 0xfffffff000000000-0xffffffffffffffff
range of kernel memory (with 4-level paging). This range contains the
kernel's text+data+bss mappings and the module mapping space but not the
direct mapping and the vmalloc area.
This is enough to get the application processors out of real-mode, but
for code that switches back to real-mode the trampoline_pgd is missing
important parts of the address space. For example, consider this code
from arch/x86/kernel/reboot.c, function machine_real_restart() for a
64-bit kernel:
#ifdef CONFIG_X86_32
load_cr3(initial_page_table);
#else
write_cr3(real_mode_header->trampoline_pgd);
/* Exiting long mode will fail if CR4.PCIDE is set. */
if (boot_cpu_has(X86_FEATURE_PCID))
cr4_clear_bits(X86_CR4_PCIDE);
#endif
/* Jump to the identity-mapped low memory code */
#ifdef CONFIG_X86_32
asm volatile("jmpl *%0" : :
"rm" (real_mode_header->machine_real_restart_asm),
"a" (type));
#else
asm volatile("ljmpl *%0" : :
"m" (real_mode_header->machine_real_restart_asm),
"D" (type));
#endif
The code switches to the trampoline_pgd, which unmaps the direct mapping
and also the kernel stack. The call to cr4_clear_bits() will find no
stack and crash the machine. The real_mode_header pointer below points
into the direct mapping, and dereferencing it also causes a crash.
The reason this does not crash always is only that kernel mappings are
global and the CR3 switch does not flush those mappings. But if theses
mappings are not in the TLB already, the above code will crash before it
can jump to the real-mode stub.
Extend the trampoline_pgd to contain all kernel mappings to prevent
these crashes and to make code which runs on this page-table more
robust.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20211202153226.22946-5-joro@8bytes.org
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Boris reported that in one of his randconfig builds, objtool got
infinitely stuck. Turns out there's trivial list corruption in the
pv_ops tracking when a function is both in a static table and in a code
assignment.
Avoid re-adding function to the pv_ops[] lists when they're already on
it.
Fixes: db2b0c5d7b6f ("objtool: Support pv_opsindirect calls for noinstr")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20211202204534.GA16608@worktop.programming.kicks-ass.net
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Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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This workarounds are causing hangs, because I missed the fact that it
needs to be enabled for all cases and disabled when doing a resolve
pass.
So KMD only needs to whitelist it and UMD will be the one setting it
on per case.
This reverts commit 28ec02c9cbebf3feeaf21a59df9dfbc02bda3362.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4145
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Fixes: 28ec02c9cbeb ("drm/i915: Implement Wa_1508744258")
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211119140931.32791-1-jose.souza@intel.com
(cherry picked from commit f3799ff16fcfacd44aee55db162830df461b631f)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
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getrusage(RUSAGE_THREAD) with nohz_full may return shorter utime/stime
than the actual time.
task_cputime_adjusted() snapshots utime and stime and then adjust their
sum to match the scheduler maintained cputime.sum_exec_runtime.
Unfortunately in nohz_full, sum_exec_runtime is only updated once per
second in the worst case, causing a discrepancy against utime and stime
that can be updated anytime by the reader using vtime.
To fix this situation, perform an update of cputime.sum_exec_runtime
when the cputime snapshot reports the task as actually running while
the tick is disabled. The related overhead is then contained within the
relevant situations.
Reported-by: Hasegawa Hitomi <hasegawa-hitomi@fujitsu.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Hasegawa Hitomi <hasegawa-hitomi@fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Acked-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20211026141055.57358-3-frederic@kernel.org
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When at least one CPU runs in nohz_full mode, a dedicated timekeeper CPU
is guaranteed to stay online and to never stop its tick.
Meanwhile on some rare case, the dedicated timekeeper may be running
with interrupts disabled for a while, such as in stop_machine.
If jiffies stop being updated, a nohz_full CPU may end up endlessly
programming the next tick in the past, taking the last jiffies update
monotonic timestamp as a stale base, resulting in an tick storm.
Here is a scenario where it matters:
0) CPU 0 is the timekeeper and CPU 1 a nohz_full CPU.
1) A stop machine callback is queued to execute somewhere.
2) CPU 0 reaches MULTI_STOP_DISABLE_IRQ while CPU 1 is still in
MULTI_STOP_PREPARE. Hence CPU 0 can't do its timekeeping duty. CPU 1
can still take IRQs.
3) CPU 1 receives an IRQ which queues a timer callback one jiffy forward.
4) On IRQ exit, CPU 1 schedules the tick one jiffy forward, taking
last_jiffies_update as a base. But last_jiffies_update hasn't been
updated for 2 jiffies since the timekeeper has interrupts disabled.
5) clockevents_program_event(), which relies on ktime_get(), observes
that the expiration is in the past and therefore programs the min
delta event on the clock.
6) The tick fires immediately, goto 3)
7) Tick storm, the nohz_full CPU is drown and takes ages to reach
MULTI_STOP_DISABLE_IRQ, which is the only way out of this situation.
Solve this with unconditionally updating jiffies if the value is stale
on nohz_full IRQ entry. IRQs and other disturbances are expected to be
rare enough on nohz_full for the unconditional call to ktime_get() to
actually matter.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211026141055.57358-2-frederic@kernel.org
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Currently autoloading for SPI devices does not use the DT ID table, it
uses SPI modalises. Supporting OF modalises is going to be difficult if
not impractical, an attempt was made but has been reverted, so ensure
that module autoloading works for this driver by adding an id_table
listing the SPI IDs for everything.
Fixes: 96c8395e2166 ("spi: Revert modalias changes")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eliminate the follow smatch warning:
net/ipv6/ip6_offload.c:249 ipv6_gro_receive() warn: inconsistent
indenting.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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ipv6_addr_bind/ipv4_addr_bind are function names. Previously, bind test
would not be run by default due to the wrong case names
Fixes: 34d0302ab861 ("selftests: Add ipv6 address bind tests to fcnal-test")
Fixes: 75b2b2b3db4c ("selftests: Add ipv4 address bind tests to fcnal-test")
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Correct an error where setting /proc/sys/net/rds/tcp/rds_tcp_rcvbuf would
instead modify the socket's sk_sndbuf and would leave sk_rcvbuf untouched.
Fixes: c6a58ffed536 ("RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket")
Signed-off-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We need to test against the existing route type, not
the rtm_type in the netlink request.
Fixes: 83f0a0b7285b ("mctp: Specify route types, require rtm_type in RTM_*ROUTE messages")
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Marc Orr
Sean Christopherson
Wei Wang
Vitaly Kuznetsov
Lai Jiangshan
Paolo Bonzini
Maciej S. Szmigiero
Linus Torvalds
Tom Lendacky
Helge Deller
Qais Yousef
Andrew Halaney
Shyam Prasad N
Paulo Alcantara
Michael Sterritt
Rafael J. Wysocki
Jens Axboe
Al Cooper
Zhou Qingyang
Frank Li
Badhri Jagan Sridharan
Ole Ernst
Mathias Nyman
Joerg Roedel
Peter Zijlstra
Heiko Carstens
José Roberto de Souza
Frederic Weisbecker
Florian Fainelli
Jiapeng Chong
Li Zhijian
William Kucharski
Matt Johnston