37290 Commits

Author SHA1 Message Date
Paolo Bonzini
8cce12b3c8 KVM: nSVM: set fixed bits by hand
SVM generally ignores fixed-1 bits.  Set them manually so that we
do not end up by mistake without those bits set in struct kvm_vcpu;
it is part of userspace API that KVM always returns value with the
bits set.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-27 12:46:36 -05:00
Gabriele Paoloni
25bc65d8dd x86/mce: Do not overwrite no_way_out if mce_end() fails
Currently, if mce_end() fails, no_way_out - the variable denoting
whether the machine can recover from this MCE - is determined by whether
the worst severity that was found across the MCA banks associated with
the current CPU, is of panic severity.

However, at this point no_way_out could have been already set by
mca_start() after looking at all severities of all CPUs that entered the
MCE handler. If mce_end() fails, check first if no_way_out is already
set and, if so, stick to it, otherwise use the local worst value.

 [ bp: Massage. ]

Signed-off-by: Gabriele Paoloni <gabriele.paoloni@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201127161819.3106432-2-gabriele.paoloni@intel.com
2020-11-27 17:38:36 +01:00
Vitaly Kuznetsov
9a2a0d3ca1 kvm: x86/mmu: Fix get_mmio_spte() on CPUs supporting 5-level PT
Commit 95fb5b0258b7 ("kvm: x86/mmu: Support MMIO in the TDP MMU") caused
the following WARNING on an Intel Ice Lake CPU:

 get_mmio_spte: detect reserved bits on spte, addr 0xb80a0, dump hierarchy:
 ------ spte 0xb80a0 level 5.
 ------ spte 0xfcd210107 level 4.
 ------ spte 0x1004c40107 level 3.
 ------ spte 0x1004c41107 level 2.
 ------ spte 0x1db00000000b83b6 level 1.
 WARNING: CPU: 109 PID: 10254 at arch/x86/kvm/mmu/mmu.c:3569 kvm_mmu_page_fault.cold.150+0x54/0x22f [kvm]
...
 Call Trace:
  ? kvm_io_bus_get_first_dev+0x55/0x110 [kvm]
  vcpu_enter_guest+0xaa1/0x16a0 [kvm]
  ? vmx_get_cs_db_l_bits+0x17/0x30 [kvm_intel]
  ? skip_emulated_instruction+0xaa/0x150 [kvm_intel]
  kvm_arch_vcpu_ioctl_run+0xca/0x520 [kvm]

The guest triggering this crashes. Note, this happens with the traditional
MMU and EPT enabled, not with the newly introduced TDP MMU. Turns out,
there was a subtle change in the above mentioned commit. Previously,
walk_shadow_page_get_mmio_spte() was setting 'root' to 'iterator.level'
which is returned by shadow_walk_init() and this equals to
'vcpu->arch.mmu->shadow_root_level'. Now, get_mmio_spte() sets it to
'int root = vcpu->arch.mmu->root_level'.

The difference between 'root_level' and 'shadow_root_level' on CPUs
supporting 5-level page tables is that in some case we don't want to
use 5-level, in particular when 'cpuid_maxphyaddr(vcpu) <= 48'
kvm_mmu_get_tdp_level() returns '4'. In case upper layer is not used,
the corresponding SPTE will fail '__is_rsvd_bits_set()' check.

Revert to using 'shadow_root_level'.

Fixes: 95fb5b0258b7 ("kvm: x86/mmu: Support MMIO in the TDP MMU")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201126110206.2118959-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-27 11:14:27 -05:00
Paolo Bonzini
71cc849b70 KVM: x86: Fix split-irqchip vs interrupt injection window request
kvm_cpu_accept_dm_intr and kvm_vcpu_ready_for_interrupt_injection are
a hodge-podge of conditions, hacked together to get something that
more or less works.  But what is actually needed is much simpler;
in both cases the fundamental question is, do we have a place to stash
an interrupt if userspace does KVM_INTERRUPT?

In userspace irqchip mode, that is !vcpu->arch.interrupt.injected.
Currently kvm_event_needs_reinjection(vcpu) covers it, but it is
unnecessarily restrictive.

In split irqchip mode it's a bit more complicated, we need to check
kvm_apic_accept_pic_intr(vcpu) (the IRQ window exit is basically an INTACK
cycle and thus requires ExtINTs not to be masked) as well as
!pending_userspace_extint(vcpu).  However, there is no need to
check kvm_event_needs_reinjection(vcpu), since split irqchip keeps
pending ExtINT state separate from event injection state, and checking
kvm_cpu_has_interrupt(vcpu) is wrong too since ExtINT has higher
priority than APIC interrupts.  In fact the latter fixes a bug:
when userspace requests an IRQ window vmexit, an interrupt in the
local APIC can cause kvm_cpu_has_interrupt() to be true and thus
kvm_vcpu_ready_for_interrupt_injection() to return false.  When this
happens, vcpu_run does not exit to userspace but the interrupt window
vmexits keep occurring.  The VM loops without any hope of making progress.

Once we try to fix these with something like

     return kvm_arch_interrupt_allowed(vcpu) &&
-        !kvm_cpu_has_interrupt(vcpu) &&
-        !kvm_event_needs_reinjection(vcpu) &&
-        kvm_cpu_accept_dm_intr(vcpu);
+        (!lapic_in_kernel(vcpu)
+         ? !vcpu->arch.interrupt.injected
+         : (kvm_apic_accept_pic_intr(vcpu)
+            && !pending_userspace_extint(v)));

we realize two things.  First, thanks to the previous patch the complex
conditional can reuse !kvm_cpu_has_extint(vcpu).  Second, the interrupt
window request in vcpu_enter_guest()

        bool req_int_win =
                dm_request_for_irq_injection(vcpu) &&
                kvm_cpu_accept_dm_intr(vcpu);

should be kept in sync with kvm_vcpu_ready_for_interrupt_injection():
it is unnecessary to ask the processor for an interrupt window
if we would not be able to return to userspace.  Therefore,
kvm_cpu_accept_dm_intr(vcpu) is basically !kvm_cpu_has_extint(vcpu)
ANDed with the existing check for masked ExtINT.  It all makes sense:

- we can accept an interrupt from userspace if there is a place
  to stash it (and, for irqchip split, ExtINTs are not masked).
  Interrupts from userspace _can_ be accepted even if right now
  EFLAGS.IF=0.

- in order to tell userspace we will inject its interrupt ("IRQ
  window open" i.e. kvm_vcpu_ready_for_interrupt_injection), both
  KVM and the vCPU need to be ready to accept the interrupt.

... and this is what the patch implements.

Reported-by: David Woodhouse <dwmw@amazon.co.uk>
Analyzed-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Tested-by: David Woodhouse <dwmw@amazon.co.uk>
2020-11-27 09:27:28 -05:00
Paolo Bonzini
72c3bcdcda KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extint
Centralize handling of interrupts from the userspace APIC
in kvm_cpu_has_extint and kvm_cpu_get_extint, since
userspace APIC interrupts are handled more or less the
same as ExtINTs are with split irqchip.  This removes
duplicated code from kvm_cpu_has_injectable_intr and
kvm_cpu_has_interrupt, and makes the code more similar
between kvm_cpu_has_{extint,interrupt} on one side
and kvm_cpu_get_{extint,interrupt} on the other.

Cc: stable@vger.kernel.org
Reviewed-by: Filippo Sironi <sironi@amazon.de>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Tested-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-27 09:19:52 -05:00
Alex Shi
638920a66a x86/PCI: Make a kernel-doc comment a normal one
The comment is using kernel-doc markup but that comment isn't a
kernel-doc comment so make it a normal one to avoid:

  arch/x86/pci/i386.c:373: warning: Function parameter or member \
	  'pcibios_assign_resources' not described in 'fs_initcall'

 [ bp: Massage and fixup comment while at it. ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1605257895-5536-5-git-send-email-alex.shi@linux.alibaba.com
2020-11-27 13:43:09 +01:00
Ingo Molnar
a787bdaff8 Merge branch 'linus' into sched/core, to resolve semantic conflict
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-27 11:10:50 +01:00
Peter Zijlstra
20c7775aec Merge remote-tracking branch 'origin/master' into perf/core
Further perf/core patches will depend on:

  d3f7b1bb2040 ("mm/gup: fix gup_fast with dynamic page table folding")

which is already in Linus' tree.
2020-11-26 13:16:55 +01:00
Sean Christopherson
8539d3f067 x86/asm: Drop unused RDPID macro
Drop the GAS-compatible RDPID macro. RDPID is unsafe in the kernel
because KVM loads guest's TSC_AUX on VM-entry and may not restore the
host's value until the CPU returns to userspace.

See

  6a3ea3e68b8a ("x86/entry/64: Do not use RDPID in paranoid entry to accomodate KVM")

for details.

It can always be resurrected from git history, if needed.

 [ bp: Massage commit message. ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201027214532.1792-1-sean.j.christopherson@intel.com
2020-11-26 12:58:56 +01:00
Justin Ernst
9a3c425cfd x86/platform/uv: Add and export uv_bios_* functions
Add additional uv_bios_call() variant functions to expose information
needed by the new uv_sysfs driver. This includes the addition of several
new data types defined by UV BIOS and used in the new functions.

Signed-off-by: Justin Ernst <justin.ernst@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lkml.kernel.org/r/20201125175444.279074-3-justin.ernst@hpe.com
2020-11-26 12:50:44 +01:00
Justin Ernst
8f061abbf5 x86/platform/uv: Remove existing /sys/firmware/sgi_uv/ interface
Remove existing interface at /sys/firmware/sgi_uv/, created by
arch/x86/platform/uv/uv_sysfs.c

This interface includes:
/sys/firmware/sgi_uv/coherence_id
/sys/firmware/sgi_uv/partition_id

Both coherence_id and partition_id will be re-introduced via a
new uv_sysfs driver.

Signed-off-by: Justin Ernst <justin.ernst@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lkml.kernel.org/r/20201125175444.279074-2-justin.ernst@hpe.com
2020-11-26 12:08:17 +01:00
Anand K Mistry
33fc379df7 x86/speculation: Fix prctl() when spectre_v2_user={seccomp,prctl},ibpb
When spectre_v2_user={seccomp,prctl},ibpb is specified on the command
line, IBPB is force-enabled and STIPB is conditionally-enabled (or not
available).

However, since

  21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.")

the spectre_v2_user_ibpb variable is set to SPECTRE_V2_USER_{PRCTL,SECCOMP}
instead of SPECTRE_V2_USER_STRICT, which is the actual behaviour.
Because the issuing of IBPB relies on the switch_mm_*_ibpb static
branches, the mitigations behave as expected.

Since

  1978b3a53a74 ("x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP")

this discrepency caused the misreporting of IB speculation via prctl().

On CPUs with STIBP always-on and spectre_v2_user=seccomp,ibpb,
prctl(PR_GET_SPECULATION_CTRL) would return PR_SPEC_PRCTL |
PR_SPEC_ENABLE instead of PR_SPEC_DISABLE since both IBPB and STIPB are
always on. It also allowed prctl(PR_SET_SPECULATION_CTRL) to set the IB
speculation mode, even though the flag is ignored.

Similarly, for CPUs without SMT, prctl(PR_GET_SPECULATION_CTRL) should
also return PR_SPEC_DISABLE since IBPB is always on and STIBP is not
available.

 [ bp: Massage commit message. ]

Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.")
Fixes: 1978b3a53a74 ("x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP")
Signed-off-by: Anand K Mistry <amistry@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201110123349.1.Id0cbf996d2151f4c143c90f9028651a5b49a5908@changeid
2020-11-25 20:17:09 +01:00
Lu Baolu
e2be2a833a x86/tboot: Don't disable swiotlb when iommu is forced on
After commit 327d5b2fee91c ("iommu/vt-d: Allow 32bit devices to uses DMA
domain"), swiotlb could also be used for direct memory access if IOMMU
is enabled but a device is configured to pass through the DMA translation.
Keep swiotlb when IOMMU is forced on, otherwise, some devices won't work
if "iommu=pt" kernel parameter is used.

Fixes: 327d5b2fee91 ("iommu/vt-d: Allow 32bit devices to uses DMA domain")
Reported-and-tested-by: Adrian Huang <ahuang12@lenovo.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20201125014124.4070776-1-baolu.lu@linux.intel.com
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=210237
Signed-off-by: Will Deacon <will@kernel.org>
2020-11-25 12:07:32 +00:00
Peter Zijlstra
545b8c8df4 smp: Cleanup smp_call_function*()
Get rid of the __call_single_node union and cleanup the API a little
to avoid external code relying on the structure layout as much.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
2020-11-24 16:47:49 +01:00
Peter Zijlstra
58c644ba51 sched/idle: Fix arch_cpu_idle() vs tracing
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.

Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.

(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)

Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-24 16:47:35 +01:00
Thomas Gleixner
7e015a2798 x86/crashdump/32: Simplify copy_oldmem_page()
Replace kmap_atomic_pfn() with kmap_local_pfn() which is preemptible and
can take page faults.

Remove the indirection of the dump page and the related cruft which is not
longer required.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201118204007.670851839@linutronix.de
2020-11-24 14:42:09 +01:00
Thomas Gleixner
14df326702 x86: Support kmap_local() forced debugging
kmap_local() and related interfaces are NOOPs on 64bit and only create
temporary fixmaps for highmem pages on 32bit. That means the test coverage
for this code is pretty small.

CONFIG_KMAP_LOCAL can be enabled independent from CONFIG_HIGHMEM, which
allows to provide support for enforced kmap_local() debugging even on
64bit.

For 32bit the support is unconditional, for 64bit it's only supported when
CONFIG_NR_CPUS <= 4096 as supporting it for 8192 CPUs would require to set
up yet another fixmap PGT.

If CONFIG_KMAP_LOCAL_FORCE_DEBUG is enabled then kmap_local()/kmap_atomic()
will use the temporary fixmap mapping path.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201118204007.169209557@linutronix.de
2020-11-24 14:42:09 +01:00
Xiaochen Shen
7589992469 x86/resctrl: Add necessary kernfs_put() calls to prevent refcount leak
On resource group creation via a mkdir an extra kernfs_node reference is
obtained by kernfs_get() to ensure that the rdtgroup structure remains
accessible for the rdtgroup_kn_unlock() calls where it is removed on
deletion. Currently the extra kernfs_node reference count is only
dropped by kernfs_put() in rdtgroup_kn_unlock() while the rdtgroup
structure is removed in a few other locations that lack the matching
reference drop.

In call paths of rmdir and umount, when a control group is removed,
kernfs_remove() is called to remove the whole kernfs nodes tree of the
control group (including the kernfs nodes trees of all child monitoring
groups), and then rdtgroup structure is freed by kfree(). The rdtgroup
structures of all child monitoring groups under the control group are
freed by kfree() in free_all_child_rdtgrp().

Before calling kfree() to free the rdtgroup structures, the kernfs node
of the control group itself as well as the kernfs nodes of all child
monitoring groups still take the extra references which will never be
dropped to 0 and the kernfs nodes will never be freed. It leads to
reference count leak and kernfs_node_cache memory leak.

For example, reference count leak is observed in these two cases:
  (1) mount -t resctrl resctrl /sys/fs/resctrl
      mkdir /sys/fs/resctrl/c1
      mkdir /sys/fs/resctrl/c1/mon_groups/m1
      umount /sys/fs/resctrl

  (2) mkdir /sys/fs/resctrl/c1
      mkdir /sys/fs/resctrl/c1/mon_groups/m1
      rmdir /sys/fs/resctrl/c1

The same reference count leak issue also exists in the error exit paths
of mkdir in mkdir_rdt_prepare() and rdtgroup_mkdir_ctrl_mon().

Fix this issue by following changes to make sure the extra kernfs_node
reference on rdtgroup is dropped before freeing the rdtgroup structure.
  (1) Introduce rdtgroup removal helper rdtgroup_remove() to wrap up
  kernfs_put() and kfree().

  (2) Call rdtgroup_remove() in rdtgroup removal path where the rdtgroup
  structure is about to be freed by kfree().

  (3) Call rdtgroup_remove() or kernfs_put() as appropriate in the error
  exit paths of mkdir where an extra reference is taken by kernfs_get().

Fixes: f3cbeacaa06e ("x86/intel_rdt/cqm: Add rmdir support")
Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files")
Fixes: 60cf5e101fd4 ("x86/intel_rdt: Add mkdir to resctrl file system")
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1604085088-31707-1-git-send-email-xiaochen.shen@intel.com
2020-11-24 12:13:37 +01:00
Xiaochen Shen
fd8d9db355 x86/resctrl: Remove superfluous kernfs_get() calls to prevent refcount leak
Willem reported growing of kernfs_node_cache entries in slabtop when
repeatedly creating and removing resctrl subdirectories as well as when
repeatedly mounting and unmounting the resctrl filesystem.

On resource group (control as well as monitoring) creation via a mkdir
an extra kernfs_node reference is obtained to ensure that the rdtgroup
structure remains accessible for the rdtgroup_kn_unlock() calls where it
is removed on deletion. The kernfs_node reference count is dropped by
kernfs_put() in rdtgroup_kn_unlock().

With the above explaining the need for one kernfs_get()/kernfs_put()
pair in resctrl there are more places where a kernfs_node reference is
obtained without a corresponding release. The excessive amount of
reference count on kernfs nodes will never be dropped to 0 and the
kernfs nodes will never be freed in the call paths of rmdir and umount.
It leads to reference count leak and kernfs_node_cache memory leak.

Remove the superfluous kernfs_get() calls and expand the existing
comments surrounding the remaining kernfs_get()/kernfs_put() pair that
remains in use.

Superfluous kernfs_get() calls are removed from two areas:

  (1) In call paths of mount and mkdir, when kernfs nodes for "info",
  "mon_groups" and "mon_data" directories and sub-directories are
  created, the reference count of newly created kernfs node is set to 1.
  But after kernfs_create_dir() returns, superfluous kernfs_get() are
  called to take an additional reference.

  (2) kernfs_get() calls in rmdir call paths.

Fixes: 17eafd076291 ("x86/intel_rdt: Split resource group removal in two")
Fixes: 4af4a88e0c92 ("x86/intel_rdt/cqm: Add mount,umount support")
Fixes: f3cbeacaa06e ("x86/intel_rdt/cqm: Add rmdir support")
Fixes: d89b7379015f ("x86/intel_rdt/cqm: Add mon_data")
Fixes: c7d9aac61311 ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring")
Fixes: 5dc1d5c6bac2 ("x86/intel_rdt: Simplify info and base file lists")
Fixes: 60cf5e101fd4 ("x86/intel_rdt: Add mkdir to resctrl file system")
Fixes: 4e978d06dedb ("x86/intel_rdt: Add "info" files to resctrl file system")
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Willem de Bruijn <willemb@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1604085053-31639-1-git-send-email-xiaochen.shen@intel.com
2020-11-24 12:03:04 +01:00
Borislav Petkov
afe76eca86 x86/sgx: Fix sgx_ioc_enclave_provision() kernel-doc comment
Fix

  ./arch/x86/kernel/cpu/sgx/ioctl.c:666: warning: Function parameter or member \
	  'encl' not described in 'sgx_ioc_enclave_provision'
  ./arch/x86/kernel/cpu/sgx/ioctl.c:666: warning: Excess function parameter \
	  'enclave' description in 'sgx_ioc_enclave_provision'

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201123181922.0c009406@canb.auug.org.au
2020-11-24 10:46:01 +01:00
Peter Collingbourne
23acdc76f1 signal: clear non-uapi flag bits when passing/returning sa_flags
Previously we were not clearing non-uapi flag bits in
sigaction.sa_flags when storing the userspace-provided sa_flags or
when returning them via oldact. Start doing so.

This allows userspace to detect missing support for flag bits and
allows the kernel to use non-uapi bits internally, as we are already
doing in arch/x86 for two flag bits. Now that this change is in
place, we no longer need the code in arch/x86 that was hiding these
bits from userspace, so remove it.

This is technically a userspace-visible behavior change for sigaction, as
the unknown bits returned via oldact.sa_flags are no longer set. However,
we are free to define the behavior for unknown bits exactly because
their behavior is currently undefined, so for now we can define the
meaning of each of them to be "clear the bit in oldact.sa_flags unless
the bit becomes known in the future". Furthermore, this behavior is
consistent with OpenBSD [1], illumos [2] and XNU [3] (FreeBSD [4] and
NetBSD [5] fail the syscall if unknown bits are set). So there is some
precedent for this behavior in other kernels, and in particular in XNU,
which is probably the most popular kernel among those that I looked at,
which means that this change is less likely to be a compatibility issue.

Link: [1] f634a6a4b5/sys/kern/kern_sig.c (L278)
Link: [2] 76f19f5fdc/usr/src/uts/common/syscall/sigaction.c (L86)
Link: [3] a449c6a3b8/bsd/kern/kern_sig.c (L480)
Link: [4] eded70c370/sys/kern/kern_sig.c (L699)
Link: [5] 3365779bec/sys/kern/sys_sig.c (L473)
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://linux-review.googlesource.com/id/I35aab6f5be932505d90f3b3450c083b4db1eca86
Link: https://lkml.kernel.org/r/878dbcb5f47bc9b11881c81f745c0bef5c23f97f.1605235762.git.pcc@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-11-23 10:31:05 -06:00
Peter Collingbourne
1d82b7898f arch: move SA_* definitions to generic headers
Most architectures with the exception of alpha, mips, parisc and
sparc use the same values for these flags. Move their definitions into
asm-generic/signal-defs.h and allow the architectures with non-standard
values to override them. Also, document the non-standard flag values
in order to make it easier to add new generic flags in the future.

A consequence of this change is that on powerpc and x86, the constants'
values aside from SA_RESETHAND change signedness from unsigned
to signed. This is not expected to impact realistic use of these
constants. In particular the typical use of the constants where they
are or'ed together and assigned to sa_flags (or another int variable)
would not be affected.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://linux-review.googlesource.com/id/Ia3849f18b8009bf41faca374e701cdca36974528
Link: https://lkml.kernel.org/r/b6d0d1ec34f9ee93e1105f14f288fba5f89d1f24.1605235762.git.pcc@google.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-11-23 10:31:05 -06:00
Linus Torvalds
48da330589 A single fix for the x86 perf sysfs interfaces which used kobject
attributes instead of device attributes and therefore making Clangs control
 flow integrity checker upset.
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Merge tag 'perf-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fix from Thomas Gleixner:
 "A single fix for the x86 perf sysfs interfaces which used kobject
  attributes instead of device attributes and therefore making clang's
  control flow integrity checker upset"

* tag 'perf-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: fix sysfs type mismatches
2020-11-22 13:23:43 -08:00
Linus Torvalds
68d3fa235f Couple of EFI fixes for v5.10:
- fix memory leak in efivarfs driver
 - fix HYP mode issue in 32-bit ARM version of the EFI stub when built in
   Thumb2 mode
 - avoid leaking EFI pgd pages on allocation failure
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Merge tag 'efi-urgent-for-v5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Borislav Petkov:
 "Forwarded EFI fixes from Ard Biesheuvel:

   - fix memory leak in efivarfs driver

   - fix HYP mode issue in 32-bit ARM version of the EFI stub when built
     in Thumb2 mode

   - avoid leaking EFI pgd pages on allocation failure"

* tag 'efi-urgent-for-v5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/x86: Free efi_pgd with free_pages()
  efivarfs: fix memory leak in efivarfs_create()
  efi/arm: set HSCTLR Thumb2 bit correctly for HVC calls from HYP
2020-11-22 13:05:48 -08:00
Linus Torvalds
7d53be55c9 * An IOMMU VT-d build fix when CONFIG_PCI_ATS=n along with a revert of
same because the proper one is going through the IOMMU tree. (Thomas Gleixner)
 
 * An Intel microcode loader fix to save the correct microcode patch to
   apply during resume. (Chen Yu)
 
 * A fix to not access user memory of other processes when dumping opcode
   bytes. (Thomas Gleixner)
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Merge tag 'x86_urgent_for_v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - An IOMMU VT-d build fix when CONFIG_PCI_ATS=n along with a revert of
   same because the proper one is going through the IOMMU tree (Thomas
   Gleixner)

 - An Intel microcode loader fix to save the correct microcode patch to
   apply during resume (Chen Yu)

 - A fix to not access user memory of other processes when dumping
   opcode bytes (Thomas Gleixner)

* tag 'x86_urgent_for_v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "iommu/vt-d: Take CONFIG_PCI_ATS into account"
  x86/dumpstack: Do not try to access user space code of other tasks
  x86/microcode/intel: Check patch signature before saving microcode for early loading
  iommu/vt-d: Take CONFIG_PCI_ATS into account
2020-11-22 12:55:50 -08:00
Dan Williams
a927bd6ba9 mm: fix phys_to_target_node() and memory_add_physaddr_to_nid() exports
The core-mm has a default __weak implementation of phys_to_target_node()
to mirror the weak definition of memory_add_physaddr_to_nid().  That
symbol is exported for modules.  However, while the export in
mm/memory_hotplug.c exported the symbol in the configuration cases of:

	CONFIG_NUMA_KEEP_MEMINFO=y
	CONFIG_MEMORY_HOTPLUG=y

...and:

	CONFIG_NUMA_KEEP_MEMINFO=n
	CONFIG_MEMORY_HOTPLUG=y

...it failed to export the symbol in the case of:

	CONFIG_NUMA_KEEP_MEMINFO=y
	CONFIG_MEMORY_HOTPLUG=n

Not only is that broken, but Christoph points out that the kernel should
not be exporting any __weak symbol, which means that
memory_add_physaddr_to_nid() example that phys_to_target_node() copied
is broken too.

Rework the definition of phys_to_target_node() and
memory_add_physaddr_to_nid() to not require weak symbols.  Move to the
common arch override design-pattern of an asm header defining a symbol
to replace the default implementation.

The only common header that all memory_add_physaddr_to_nid() producing
architectures implement is asm/sparsemem.h.  In fact, powerpc already
defines its memory_add_physaddr_to_nid() helper in sparsemem.h.
Double-down on that observation and define phys_to_target_node() where
necessary in asm/sparsemem.h.  An alternate consideration that was
discarded was to put this override in asm/numa.h, but that entangles
with the definition of MAX_NUMNODES relative to the inclusion of
linux/nodemask.h, and requires powerpc to grow a new header.

The dependency on NUMA_KEEP_MEMINFO for DEV_DAX_HMEM_DEVICES is invalid
now that the symbol is properly exported / stubbed in all combinations
of CONFIG_NUMA_KEEP_MEMINFO and CONFIG_MEMORY_HOTPLUG.

[dan.j.williams@intel.com: v4]
  Link: https://lkml.kernel.org/r/160461461867.1505359.5301571728749534585.stgit@dwillia2-desk3.amr.corp.intel.com
[dan.j.williams@intel.com: powerpc: fix create_section_mapping compile warning]
  Link: https://lkml.kernel.org/r/160558386174.2948926.2740149041249041764.stgit@dwillia2-desk3.amr.corp.intel.com

Fixes: a035b6bf863e ("mm/memory_hotplug: introduce default phys_to_target_node() implementation")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lkml.kernel.org/r/160447639846.1133764.7044090803980177548.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-22 10:48:22 -08:00
Smita Koralahalli
4a24d80b8c x86/mce, cper: Pass x86 CPER through the MCA handling chain
The kernel uses ACPI Boot Error Record Table (BERT) to report fatal
errors that occurred in a previous boot. The MCA errors in the BERT are
reported using the x86 Processor Error Common Platform Error Record
(CPER) format. Currently, the record prints out the raw MSR values and
AMD relies on the raw record to provide MCA information.

Extract the raw MSR values of MCA registers from the BERT and feed them
into mce_log() to decode them properly.

The implementation is SMCA-specific as the raw MCA register values are
given in the register offset order of the SMCA address space.

 [ bp: Massage. ]

[ Fix a build breakage in patch v1. ]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lkml.kernel.org/r/20201119182938.151155-1-Smita.KoralahalliChannabasappa@amd.com
2020-11-21 12:05:41 +01:00
Uros Bizjak
ab09b58e4b x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg
Use TEST %reg,%reg which sets the zero flag in the same way as CMP
$0,%reg, but the encoding uses one byte less.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20201029160258.139216-1-ubizjak@gmail.com
2020-11-21 10:26:25 +01:00
Kees Cook
25db91209a x86: Enable seccomp architecture tracking
Provide seccomp internals with the details to calculate which syscall
table the running kernel is expecting to deal with. This allows for
efficient architecture pinning and paves the way for constant-action
bitmaps.

Co-developed-by: YiFei Zhu <yifeifz2@illinois.edu>
Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/da58c3733d95c4f2115dd94225dfbe2573ba4d87.1602431034.git.yifeifz2@illinois.edu
2020-11-20 11:16:34 -08:00
Linus Torvalds
4ccf7a01e8 xen: branch for v5.10-rc5
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Merge tag 'for-linus-5.10b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fix from Juergen Gross:
 "A single fix for avoiding WARN splats when booting a Xen guest with
  nosmt"

* tag 'for-linus-5.10b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: don't unbind uninitialized lock_kicker_irq
2020-11-20 10:30:48 -08:00
Linus Torvalds
fc8299f9f3 iommu fixes for -rc5
- Fix boot when intel iommu initialisation fails under TXT (tboot)
 
 - Fix intel iommu compilation error when DMAR is enabled without ATS
 
 - Temporarily update IOMMU MAINTAINERs entry
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Merge tag 'iommu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull iommu fixes from Will Deacon:
 "Two straightforward vt-d fixes:

   - Fix boot when intel iommu initialisation fails under TXT (tboot)

   - Fix intel iommu compilation error when DMAR is enabled without ATS

  and temporarily update IOMMU MAINTAINERs entry"

* tag 'iommu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  MAINTAINERS: Temporarily add myself to the IOMMU entry
  iommu/vt-d: Fix compile error with CONFIG_PCI_ATS not set
  iommu/vt-d: Avoid panic if iommu init fails in tboot system
2020-11-20 10:20:16 -08:00
Wang Qing
61b39ad9a7 x86/head64: Remove duplicate include
Remove duplicate header include.

Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1604893542-20961-1-git-send-email-wangqing@vivo.com
2020-11-20 17:43:15 +01:00
Lukas Bulwahn
bab202ab87 x86/mm: Declare 'start' variable where it is used
It is not required to initialize the local variable start in
memory_map_top_down(), as the variable will be initialized in any path
before it is used.

make clang-analyzer on x86_64 tinyconfig reports:

  arch/x86/mm/init.c:612:15: warning: Although the value stored to 'start' \
  is used in the enclosing expression, the value is never actually read \
  from 'start' [clang-analyzer-deadcode.DeadStores]

Move the variable declaration into the loop, where it is used.

No code changed:

  # arch/x86/mm/init.o:

   text    data     bss     dec     hex filename
   7105    1424   26768   35297    89e1 init.o.before
   7105    1424   26768   35297    89e1 init.o.after

md5:
   a8d76c1bb5fce9cae251780a7ee7730f  init.o.before.asm
   a8d76c1bb5fce9cae251780a7ee7730f  init.o.after.asm

 [ bp: Massage. ]

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20200928100004.25674-1-lukas.bulwahn@gmail.com
2020-11-20 12:49:00 +01:00
Eric Biggers
a24d22b225 crypto: sha - split sha.h into sha1.h and sha2.h
Currently <crypto/sha.h> contains declarations for both SHA-1 and SHA-2,
and <crypto/sha3.h> contains declarations for SHA-3.

This organization is inconsistent, but more importantly SHA-1 is no
longer considered to be cryptographically secure.  So to the extent
possible, SHA-1 shouldn't be grouped together with any of the other SHA
versions, and usage of it should be phased out.

Therefore, split <crypto/sha.h> into two headers <crypto/sha1.h> and
<crypto/sha2.h>, and make everyone explicitly specify whether they want
the declarations for SHA-1, SHA-2, or both.

This avoids making the SHA-1 declarations visible to files that don't
want anything to do with SHA-1.  It also prepares for potentially moving
sha1.h into a new insecure/ or dangerous/ directory.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-11-20 14:45:33 +11:00
Paul E. McKenney
7fc91fc845 Merge branches 'cpuinfo.2020.11.06a', 'doc.2020.11.06a', 'fixes.2020.11.19b', 'lockdep.2020.11.02a', 'tasks.2020.11.06a' and 'torture.2020.11.06a' into HEAD
cpuinfo.2020.11.06a: Speedups for /proc/cpuinfo.
doc.2020.11.06a: Documentation updates.
fixes.2020.11.19b: Miscellaneous fixes.
lockdep.2020.11.02a: Lockdep-RCU updates to avoid "unused variable".
tasks.2020.11.06a: Tasks-RCU updates.
torture.2020.11.06a': Torture-test updates.
2020-11-19 19:37:47 -08:00
Paul E. McKenney
29368e0939 x86/smpboot: Move rcu_cpu_starting() earlier
The call to rcu_cpu_starting() in mtrr_ap_init() is not early enough
in the CPU-hotplug onlining process, which results in lockdep splats
as follows:

=============================
WARNING: suspicious RCU usage
5.9.0+ #268 Not tainted
-----------------------------
kernel/kprobes.c:300 RCU-list traversed in non-reader section!!

other info that might help us debug this:

RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
no locks held by swapper/1/0.

stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0+ #268
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 dump_stack+0x77/0x97
 __is_insn_slot_addr+0x15d/0x170
 kernel_text_address+0xba/0xe0
 ? get_stack_info+0x22/0xa0
 __kernel_text_address+0x9/0x30
 show_trace_log_lvl+0x17d/0x380
 ? dump_stack+0x77/0x97
 dump_stack+0x77/0x97
 __lock_acquire+0xdf7/0x1bf0
 lock_acquire+0x258/0x3d0
 ? vprintk_emit+0x6d/0x2c0
 _raw_spin_lock+0x27/0x40
 ? vprintk_emit+0x6d/0x2c0
 vprintk_emit+0x6d/0x2c0
 printk+0x4d/0x69
 start_secondary+0x1c/0x100
 secondary_startup_64_no_verify+0xb8/0xbb

This is avoided by moving the call to rcu_cpu_starting up near
the beginning of the start_secondary() function.  Note that the
raw_smp_processor_id() is required in order to avoid calling into lockdep
before RCU has declared the CPU to be watched for readers.

Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/
Reported-by: Qian Cai <cai@redhat.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19 19:37:16 -08:00
Rikard Falkeborn
2002d29513 x86/resctrl: Constify kernfs_ops
The only usage of the kf_ops field in the rftype struct is to pass
it as argument to __kernfs_create_file(), which accepts a pointer to
const. Make it a pointer to const. This makes it possible to make
rdtgroup_kf_single_ops and kf_mondata_ops const, which allows the
compiler to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/20201110230228.801785-1-rikard.falkeborn@gmail.com
2020-11-19 18:23:45 +01:00
Ben Gardon
b9a98c3437 kvm: x86/mmu: Add TDP MMU SPTE changed trace point
Add an extremely verbose trace point to the TDP MMU to log all SPTE
changes, regardless of callstack / motivation. This is useful when a
complete picture of the paging structure is needed or a change cannot be
explained with the other, existing trace points.

Tested: ran the demand paging selftest on an Intel Skylake machine with
	all the trace points used by the TDP MMU enabled and observed
	them firing with expected values.

This patch can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/3813

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201027175944.1183301-2-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-19 10:57:16 -05:00
Ben Gardon
33dd3574f5 kvm: x86/mmu: Add existing trace points to TDP MMU
The TDP MMU was initially implemented without some of the usual
tracepoints found in mmu.c. Correct this discrepancy by adding the
missing trace points to the TDP MMU.

Tested: ran the demand paging selftest on an Intel Skylake machine with
	all the trace points used by the TDP MMU enabled and observed
	them firing with expected values.

This patch can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/3812

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201027175944.1183301-1-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-19 10:57:16 -05:00
Yazen Ghannam
cb09a37972 x86/topology: Set cpu_die_id only if DIE_TYPE found
CPUID Leaf 0x1F defines a DIE_TYPE level (nb: ECX[8:15] level type == 0x5),
but CPUID Leaf 0xB does not. However, detect_extended_topology() will
set struct cpuinfo_x86.cpu_die_id regardless of whether a valid Die ID
was found.

Only set cpu_die_id if a DIE_TYPE level is found. CPU topology code may
use another value for cpu_die_id, e.g. the AMD NodeId on AMD-based
systems. Code ordering should be maintained so that the CPUID Leaf 0x1F
Die ID value will take precedence on systems that may use another value.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201109210659.754018-5-Yazen.Ghannam@amd.com
2020-11-19 11:43:25 +01:00
Yazen Ghannam
db970bd231 x86/CPU/AMD: Remove amd_get_nb_id()
The Last Level Cache ID is returned by amd_get_nb_id(). In practice,
this value is the same as the AMD NodeId for callers of this function.
The NodeId is saved in struct cpuinfo_x86.cpu_die_id.

Replace calls to amd_get_nb_id() with the logical CPU's cpu_die_id and
remove the function.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201109210659.754018-3-Yazen.Ghannam@amd.com
2020-11-19 11:43:17 +01:00
Yazen Ghannam
028c221ed1 x86/CPU/AMD: Save AMD NodeId as cpu_die_id
AMD systems provide a "NodeId" value that represents a global ID
indicating to which "Node" a logical CPU belongs. The "Node" is a
physical structure equivalent to a Die, and it should not be confused
with logical structures like NUMA nodes. Logical nodes can be adjusted
based on firmware or other settings whereas the physical nodes/dies are
fixed based on hardware topology.

The NodeId value can be used when a physical ID is needed by software.

Save the AMD NodeId to struct cpuinfo_x86.cpu_die_id. Use the value
from CPUID or MSR as appropriate. Default to phys_proc_id otherwise.
Do so for both AMD and Hygon systems.

Drop the node_id parameter from cacheinfo_*_init_llc_id() as it is no
longer needed.

Update the x86 topology documentation.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201109210659.754018-2-Yazen.Ghannam@amd.com
2020-11-19 11:43:13 +01:00
Frederic Weisbecker
d1f250e220 x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK
A lot of ground work has been performed on x86 entry code. Fragile path
between user_enter() and user_exit() have IRQs disabled. Uses of RCU and
intrumentation in these fragile areas have been explicitly annotated
and protected.

This architecture doesn't need exception_enter()/exception_exit()
anymore and has therefore earned CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201117151637.259084-6-frederic@kernel.org
2020-11-19 11:25:42 +01:00
Jarkko Sakkinen
14132a5b80 x86/sgx: Return -ERESTARTSYS in sgx_ioc_enclave_add_pages()
Return -ERESTARTSYS instead of -EINTR in sgx_ioc_enclave_add_pages()
when interrupted before any pages have been processed. At this point
ioctl can be obviously safely restarted.

Reported-by: Haitao Huang <haitao.huang@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201118213932.63341-1-jarkko@kernel.org
2020-11-19 10:51:24 +01:00
Will Deacon
388255ce95 A small set of fixes for x86:
- Cure the fallout from the MSI irqdomain overhaul which missed that the
    Intel IOMMU does not register virtual function devices and therefore
    never reaches the point where the MSI interrupt domain is assigned. This
    makes the VF devices use the non-remapped MSI domain which is trapped by
    the IOMMU/remap unit.
 
  - Remove an extra space in the SGI_UV architecture type procfs output for
    UV5.
 
  - Remove a unused function which was missed when removing the UV BAU TLB
    shootdown handler.
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Merge tag 'x86-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-next/iommu/fixes

Pull in x86 fixes from Thomas, as they include a change to the Intel DMAR
code on which we depend:

* tag 'x86-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  iommu/vt-d: Cure VF irqdomain hickup
  x86/platform/uv: Fix copied UV5 output archtype
  x86/platform/uv: Drop last traces of uv_flush_tlb_others
2020-11-19 09:50:06 +00:00
Borislav Petkov
b023fd5f74 x86/msr: Downgrade unrecognized MSR message
It is a warning and not an error so use pr_warn().

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201118123806.19672-1-bp@alien8.de
2020-11-19 10:46:54 +01:00
David Woodhouse
d1adcfbb52 iommu/amd: Fix IOMMU interrupt generation in X2APIC mode
The AMD IOMMU has two modes for generating its own interrupts.

The first is very much based on PCI MSI, and can be configured by Linux
precisely that way. But like legacy unmapped PCI MSI it's limited to
8 bits of APIC ID.

The second method does not use PCI MSI at all in hardawre, and instead
configures the INTCAPXT registers in the IOMMU directly with the APIC ID
and vector.

In the latter case, the IOMMU driver would still use pci_enable_msi(),
read back (through MMIO) the MSI message that Linux wrote to the PCI MSI
table, then swizzle those bits into the appropriate register.

Historically, this worked because__irq_compose_msi_msg() would silently
generate an invalid MSI message with the high bits of the APIC ID in the
high bits of the MSI address. That hack was intended only for the Intel
IOMMU, and I recently enforced that, introducing a warning in
__irq_msi_compose_msg() if it was invoked with an APIC ID above 255.

Fix the AMD IOMMU not to depend on that hack any more, by having its own
irqdomain and directly putting the bits from the irq_cfg into the right
place in its ->activate() method.

Fixes: 47bea873cf80 "x86/msi: Only use high bits of MSI address for DMAR unit")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/05e3a5ba317f5ff48d2f8356f19e617f8b9d23a4.camel@infradead.org
2020-11-18 20:55:59 +01:00
Dave Hansen
67655b57f8 x86/sgx: Clarify 'laundry_list' locking
Short Version:

The SGX section->laundry_list structure is effectively thread-local, but
declared next to some shared structures. Its semantics are clear as mud.
Fix that. No functional changes. Compile tested only.

Long Version:

The SGX hardware keeps per-page metadata. This can provide things like
permissions, integrity and replay protection. It also prevents things
like having an enclave page mapped multiple times or shared between
enclaves.

But, that presents a problem for kexec()'d kernels (or any other kernel
that does not run immediately after a hardware reset). This is because
the last kernel may have been rude and forgotten to reset pages, which
would trigger the "shared page" sanity check.

To fix this, the SGX code "launders" the pages by running the EREMOVE
instruction on all pages at boot. This is slow and can take a long
time, so it is performed off in the SGX-specific ksgxd instead of being
synchronous at boot. The init code hands the list of pages to launder in
a per-SGX-section list: ->laundry_list. The only code to touch this list
is the init code and ksgxd. This means that no locking is necessary for
->laundry_list.

However, a lock is required for section->page_list, which is accessed
while creating enclaves and by ksgxd. This lock (section->lock) is
acquired by ksgxd while also processing ->laundry_list. It is easy to
confuse the purpose of the locking as being for ->laundry_list and
->page_list.

Rename ->laundry_list to ->init_laundry_list to make it clear that this
is not normally used at runtime. Also add some comments clarifying the
locking, and reorganize 'sgx_epc_section' to put 'lock' near the things
it protects.

Note: init_laundry_list is 128 bytes of wasted space at runtime. It
could theoretically be dynamically allocated and then freed after
the laundering process. But it would take nearly 128 bytes of extra
instructions to do that.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201116222531.4834-1-dave.hansen@intel.com
2020-11-18 18:16:28 +01:00
Arvind Sankar
31d8546033 x86/head/64: Remove unused GET_CR2_INTO() macro
Commit

  4b47cdbda6f1 ("x86/head/64: Move early exception dispatch to C code")

removed the usage of GET_CR2_INTO().

Drop the definition as well, and related definitions in paravirt.h and
asm-offsets.h

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201005151208.2212886-3-nivedita@alum.mit.edu
2020-11-18 18:09:38 +01:00
Jarkko Sakkinen
947c6e11fa x86/sgx: Add ptrace() support for the SGX driver
Enclave memory is normally inaccessible from outside the enclave. This
makes enclaves hard to debug. However, enclaves can be put in a debug
mode when they are being built. In that mode, enclave data *can* be read
and/or written by using the ENCLS[EDBGRD] and ENCLS[EDBGWR] functions.

This is obviously only for debugging and destroys all the protections
present with normal enclaves. But, enclaves know their own debug status
and can adjust their behavior appropriately.

Add a vm_ops->access() implementation which can be used to read and write
memory inside debug enclaves.  This is typically used via ptrace() APIs.

 [ bp: Massage. ]

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-23-jarkko@kernel.org
2020-11-18 18:04:11 +01:00