When the fpu code was reworked pcntxt_mask was renamed to
xfeatures_mask. Reflect it in the comment as well.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191101123850.GE1615@uranus.lan
Pull perf fixes from Ingo Molnar:
"Misc fixes: an ABI fix for a reserved field, AMD IBS fixes, an Intel
uncore PMU driver fix and a header typo fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/headers: Fix spelling s/EACCESS/EACCES/, s/privilidge/privilege/
perf/x86/uncore: Fix event group support
perf/x86/amd/ibs: Handle erratum #420 only on the affected CPU family (10h)
perf/x86/amd/ibs: Fix reading of the IBS OpData register and thus precise RIP validity
perf/core: Start rejecting the syscall with attr.__reserved_2 set
Pull EFI fixes from Ingo Molnar:
"Various fixes all over the map: prevent boot crashes on HyperV,
classify UEFI randomness as bootloader randomness, fix EFI boot for
the Raspberry Pi2, fix efi_test permissions, etc"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/efi_test: Lock down /dev/efi_test and require CAP_SYS_ADMIN
x86, efi: Never relocate kernel below lowest acceptable address
efi: libstub/arm: Account for firmware reserved memory at the base of RAM
efi/random: Treat EFI_RNG_PROTOCOL output as bootloader randomness
efi/tpm: Return -EINVAL when determining tpm final events log size fails
efi: Make CONFIG_EFI_RCI2_TABLE selectable on x86 only
x86: fix MMU corner case with AMD nested paging disabled.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"generic:
- fix memory leak on failure to create VM
x86:
- fix MMU corner case with AMD nested paging disabled"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: vmx, svm: always run with EFER.NXE=1 when shadow paging is active
kvm: call kvm_arch_destroy_vm if vm creation fails
kvm: Allocate memslots and buses before calling kvm_arch_init_vm
VMX already does so if the host has SMEP, in order to support the combination of
CR0.WP=1 and CR4.SMEP=1. However, it is perfectly safe to always do so, and in
fact VMX already ends up running with EFER.NXE=1 on old processors that lack the
"load EFER" controls, because it may help avoiding a slow MSR write. Removing
all the conditionals simplifies the code.
SVM does not have similar code, but it should since recent AMD processors do
support SMEP. So this patch also makes the code for the two vendors more similar
while fixing NPT=0, CR0.WP=1 and CR4.SMEP=1 on AMD processors.
Cc: stable@vger.kernel.org
Cc: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, kernel fails to boot on some HyperV VMs when using EFI.
And it's a potential issue on all x86 platforms.
It's caused by broken kernel relocation on EFI systems, when below three
conditions are met:
1. Kernel image is not loaded to the default address (LOAD_PHYSICAL_ADDR)
by the loader.
2. There isn't enough room to contain the kernel, starting from the
default load address (eg. something else occupied part the region).
3. In the memmap provided by EFI firmware, there is a memory region
starts below LOAD_PHYSICAL_ADDR, and suitable for containing the
kernel.
EFI stub will perform a kernel relocation when condition 1 is met. But
due to condition 2, EFI stub can't relocate kernel to the preferred
address, so it fallback to ask EFI firmware to alloc lowest usable memory
region, got the low region mentioned in condition 3, and relocated
kernel there.
It's incorrect to relocate the kernel below LOAD_PHYSICAL_ADDR. This
is the lowest acceptable kernel relocation address.
The first thing goes wrong is in arch/x86/boot/compressed/head_64.S.
Kernel decompression will force use LOAD_PHYSICAL_ADDR as the output
address if kernel is located below it. Then the relocation before
decompression, which move kernel to the end of the decompression buffer,
will overwrite other memory region, as there is no enough memory there.
To fix it, just don't let EFI stub relocate the kernel to any address
lower than lowest acceptable address.
[ ardb: introduce efi_low_alloc_above() to reduce the scope of the change ]
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191029173755.27149-6-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The events in the same group don't start or stop simultaneously.
Here is the ftrace when enabling event group for uncore_iio_0:
# perf stat -e "{uncore_iio_0/event=0x1/,uncore_iio_0/event=0xe/}"
<idle>-0 [000] d.h. 8959.064832: read_msr: a41, value
b2b0b030 //Read counter reg of IIO unit0 counter0
<idle>-0 [000] d.h. 8959.064835: write_msr: a48, value
400001 //Write Ctrl reg of IIO unit0 counter0 to enable
counter0. <------ Although counter0 is enabled, Unit Ctrl is still
freezed. Nothing will count. We are still good here.
<idle>-0 [000] d.h. 8959.064836: read_msr: a40, value
30100 //Read Unit Ctrl reg of IIO unit0
<idle>-0 [000] d.h. 8959.064838: write_msr: a40, value
30000 //Write Unit Ctrl reg of IIO unit0 to enable all
counters in the unit by clear Freeze bit <------Unit0 is un-freezed.
Counter0 has been enabled. Now it starts counting. But counter1 has not
been enabled yet. The issue starts here.
<idle>-0 [000] d.h. 8959.064846: read_msr: a42, value 0
//Read counter reg of IIO unit0 counter1
<idle>-0 [000] d.h. 8959.064847: write_msr: a49, value
40000e //Write Ctrl reg of IIO unit0 counter1 to enable
counter1. <------ Now, counter1 just starts to count. Counter0 has
been running for a while.
Current code un-freezes the Unit Ctrl right after the first counter is
enabled. The subsequent group events always loses some counter values.
Implement pmu_enable and pmu_disable support for uncore, which can help
to batch hardware accesses.
No one uses uncore_enable_box and uncore_disable_box. Remove them.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-drivers-review@eclists.intel.com
Cc: linux-perf@eclists.intel.com
Fixes: 087bfbb032 ("perf/x86: Add generic Intel uncore PMU support")
Link: https://lkml.kernel.org/r/1572014593-31591-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This saves us writing the IBS control MSR twice when disabling the
event.
I searched revision guides for all families since 10h, and did not
find occurrence of erratum #420, nor anything remotely similar:
so we isolate the secondary MSR write to family 10h only.
Also unconditionally update the count mask for IBS Op implementations
that have read & writeable current count (CurCnt) fields in addition
to the MaxCnt field. These bits were reserved on prior
implementations, and therefore shouldn't have negative impact.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: c9574fe0bd ("perf/x86-ibs: Implement workaround for IBS erratum #420")
Link: https://lkml.kernel.org/r/20191023150955.30292-2-kim.phillips@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The loop that reads all the IBS MSRs into *buf stopped one MSR short of
reading the IbsOpData register, which contains the RipInvalid status bit.
Fix the offset_max assignment so the MSR gets read, so the RIP invalid
evaluation is based on what the IBS h/w output, instead of what was
left in memory.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: d47e8238cd ("perf/x86-ibs: Take instruction pointer from ibs sample")
Link: https://lkml.kernel.org/r/20191023150955.30292-1-kim.phillips@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Thomas Gleixner:
"Two fixes for the VMWare guest support:
- Unbreak VMWare platform detection which got wreckaged by converting
an integer constant to a string constant.
- Fix the clang build of the VMWAre hypercall by explicitely
specifying the ouput register for INL instead of using the short
form"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/vmware: Fix platform detection VMWARE_PORT macro
x86/cpu/vmware: Use the full form of INL in VMWARE_HYPERCALL, for clang/llvm
Pull perf fixes from Thomas Gleixner:
"A set of perf fixes:
kernel:
- Unbreak the tracking of auxiliary buffer allocations which got
imbalanced causing recource limit failures.
- Fix the fallout of splitting of ToPA entries which missed to shift
the base entry PA correctly.
- Use the correct context to lookup the AUX event when unmapping the
associated AUX buffer so the event can be stopped and the buffer
reference dropped.
tools:
- Fix buildiid-cache mode setting in copyfile_mode_ns() when copying
/proc/kcore
- Fix freeing id arrays in the event list so the correct event is
closed.
- Sync sched.h anc kvm.h headers with the kernel sources.
- Link jvmti against tools/lib/ctype.o to have weak strlcpy().
- Fix multiple memory and file descriptor leaks, found by coverity in
perf annotate.
- Fix leaks in error handling paths in 'perf c2c', 'perf kmem', found
by a static analysis tool"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/aux: Fix AUX output stopping
perf/aux: Fix tracking of auxiliary trace buffer allocation
perf/x86/intel/pt: Fix base for single entry topa
perf kmem: Fix memory leak in compact_gfp_flags()
tools headers UAPI: Sync sched.h with the kernel
tools headers kvm: Sync kvm.h headers with the kernel sources
tools headers kvm: Sync kvm headers with the kernel sources
tools headers kvm: Sync kvm headers with the kernel sources
perf c2c: Fix memory leak in build_cl_output()
perf tools: Fix mode setting in copyfile_mode_ns()
perf annotate: Fix multiple memory and file descriptor leaks
perf tools: Fix resource leak of closedir() on the error paths
perf evlist: Fix fix for freed id arrays
perf jvmti: Link against tools/lib/ctype.h to have weak strlcpy()
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Merge tag 'for-linus-5.4-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixlet from Juergen Gross:
"Just one patch for issuing a deprecation warning for 32-bit Xen pv
guests"
* tag 'for-linus-5.4-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: issue deprecation warning for 32-bit pv guest
Support for the kernel as Xen 32-bit PV guest will soon be removed.
Issue a warning when booted as such.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
If the "virtualize APIC accesses" VM-execution control is set in the
VMCS, the APIC virtualization hardware is triggered when a page walk
in VMX non-root mode terminates at a PTE wherein the address of the 4k
page frame matches the APIC-access address specified in the VMCS. On
hardware, the APIC-access address may be any valid 4k-aligned physical
address.
KVM's nVMX implementation enforces the additional constraint that the
APIC-access address specified in the vmcs12 must be backed by
a "struct page" in L1. If not, L0 will simply clear the "virtualize
APIC accesses" VM-execution control in the vmcs02.
The problem with this approach is that the L1 guest has arranged the
vmcs12 EPT tables--or shadow page tables, if the "enable EPT"
VM-execution control is clear in the vmcs12--so that the L2 guest
physical address(es)--or L2 guest linear address(es)--that reference
the L2 APIC map to the APIC-access address specified in the
vmcs12. Without the "virtualize APIC accesses" VM-execution control in
the vmcs02, the APIC accesses in the L2 guest will directly access the
APIC-access page in L1.
When there is no mapping whatsoever for the APIC-access address in L1,
the L2 VM just loses the intended APIC virtualization. However, when
the APIC-access address is mapped to an MMIO region in L1, the L2
guest gets direct access to the L1 MMIO device. For example, if the
APIC-access address specified in the vmcs12 is 0xfee00000, then L2
gets direct access to L1's APIC.
Since this vmcs12 configuration is something that KVM cannot
faithfully emulate, the appropriate response is to exit to userspace
with KVM_INTERNAL_ERROR_EMULATION.
Fixes: fe3ef05c75 ("KVM: nVMX: Prepare vmcs02 from vmcs01 and vmcs12")
Reported-by: Dan Cross <dcross@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Guest physical APIC ID may not equal to vcpu->vcpu_id in some case.
We may set the wrong physical id in avic_handle_ldr_update as we
always use vcpu->vcpu_id. Get physical APIC ID from vAPIC page
instead.
Export and use kvm_xapic_id here and in avic_handle_apic_id_update
as suggested by Vitaly.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After resetting the vCPU, the kvmclock MSR keeps the previous value but it is
not enabled. This can be confusing, so fix it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use BUG_ON instead of a if condition followed by BUG.
Generated by: scripts/coccinelle/misc/bugon.cocci
Fixes: 4b526de50e ("KVM: x86: Check kvm_rebooting in kvm_spurious_fault()")
CC: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit bf653b78f9 ("KVM: vmx: Introduce handle_unexpected_vmexit
and handle WAITPKG vmexit") introduced specialized handling of
specific exit-reasons that should not be raised by CPU because
KVM configures VMCS such that they should never be raised.
However, since commit 7396d337cf ("KVM: x86: Return to userspace
with internal error on unexpected exit reason"), VMX & SVM
exit handlers were modified to generically handle all unexpected
exit-reasons by returning to userspace with internal error.
Therefore, there is no need for specialized handling of specific
unexpected exit-reasons (This specialized handling also introduced
inconsistency for these exit-reasons to silently skip guest instruction
instead of return to userspace on internal-error).
Fixes: bf653b78f9 ("KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit")
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When the RDPID instruction is supported on the host, enumerate it in
KVM_GET_SUPPORTED_CPUID.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The platform detection VMWARE_PORT macro uses the VMWARE_HYPERVISOR_PORT
definition, but expects it to be an integer. However, when it was moved
to the new vmware.h include file, it was changed to be a string to better
fit into the VMWARE_HYPERCALL set of macros. This obviously breaks the
platform detection VMWARE_PORT functionality.
Change the VMWARE_HYPERVISOR_PORT and VMWARE_HYPERVISOR_PORT_HB
definitions to be integers, and use __stringify() for their stringified
form when needed.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: b4dd4f6e36 ("Add a header file for hypercall definitions")
Link: https://lkml.kernel.org/r/20191021172403.3085-3-thomas_os@shipmail.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
LLVM's assembler doesn't accept the short form INL instruction:
inl (%%dx)
but instead insists on the output register to be explicitly specified.
This was previously fixed for the VMWARE_PORT macro. Fix it also for
the VMWARE_HYPERCALL macro.
Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: clang-built-linux@googlegroups.com
Fixes: b4dd4f6e36 ("Add a header file for hypercall definitions")
Link: https://lkml.kernel.org/r/20191021172403.3085-2-thomas_os@shipmail.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Jan reported failing ltp test for PT:
https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/tracing/pt_test/pt_test.c
It looks like the reason is this new commit added in this v5.4 merge window:
38bb8d77d0 ("perf/x86/intel/pt: Split ToPA metadata and page layout")
which did not keep the TOPA_SHIFT for entry base.
Add it back.
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 38bb8d77d0 ("perf/x86/intel/pt: Split ToPA metadata and page layout")
Link: https://lkml.kernel.org/r/20191019220726.12213-1-jolsa@kernel.org
[ Minor changelog edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Thomas Gleixner:
"A small set of x86 fixes:
- Prevent a NULL pointer dereference in the X2APIC code in case of a
CPU hotplug failure.
- Prevent boot failures on HP superdome machines by invalidating the
level2 kernel pagetable entries outside of the kernel area as
invalid so BIOS reserved space won't be touched unintentionally.
Also ensure that memory holes are rounded up to the next PMD
boundary correctly.
- Enable X2APIC support on Hyper-V to prevent boot failures.
- Set the paravirt name when running on Hyper-V for consistency
- Move a function under the appropriate ifdef guard to prevent build
warnings"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot/acpi: Move get_cmdline_acpi_rsdp() under #ifdef guard
x86/hyperv: Set pv_info.name to "Hyper-V"
x86/apic/x2apic: Fix a NULL pointer deref when handling a dying cpu
x86/hyperv: Make vapic support x2apic mode
x86/boot/64: Round memory hole size up to next PMD page
x86/boot/64: Make level2_kernel_pgt pages invalid outside kernel area
When building with "EXTRA_CFLAGS=-Wall" gcc warns:
arch/x86/boot/compressed/acpi.c:29:30: warning: get_cmdline_acpi_rsdp defined but not used [-Wunused-function]
get_cmdline_acpi_rsdp() is only used when CONFIG_RANDOMIZE_BASE and
CONFIG_MEMORY_HOTREMOVE are both enabled, so any build where one of these
config options is disabled has this issue.
Move the function under the same ifdef guard as the call site.
[ tglx: Add context to the changelog so it becomes useful ]
Fixes: 41fa1ee9c6 ("acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1569719633-32164-1-git-send-email-zhenzhong.duan@oracle.com
Michael reported that the x86/hyperv initialization code prints the
following dmesg when running in a VM on Hyper-V:
[ 0.000738] Booting paravirtualized kernel on bare hardware
Let the x86/hyperv initialization code set pv_info.name to "Hyper-V" so
dmesg reports correctly:
[ 0.000172] Booting paravirtualized kernel on Hyper-V
[ tglx: Folded build fix provided by Yue ]
Reported-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Link: https://lkml.kernel.org/r/20191015103502.13156-1-parri.andrea@gmail.com
Check that the per-cpu cluster mask pointer has been set prior to
clearing a dying cpu's bit. The per-cpu pointer is not set until the
target cpu reaches smp_callin() during CPUHP_BRINGUP_CPU, whereas the
teardown function, x2apic_dead_cpu(), is associated with the earlier
CPUHP_X2APIC_PREPARE. If an error occurs before the cpu is awakened,
e.g. if do_boot_cpu() itself fails, x2apic_dead_cpu() will dereference
the NULL pointer and cause a panic.
smpboot: do_boot_cpu failed(-22) to wakeup CPU#1
BUG: kernel NULL pointer dereference, address: 0000000000000008
RIP: 0010:x2apic_dead_cpu+0x1a/0x30
Call Trace:
cpuhp_invoke_callback+0x9a/0x580
_cpu_up+0x10d/0x140
do_cpu_up+0x69/0xb0
smp_init+0x63/0xa9
kernel_init_freeable+0xd7/0x229
? rest_init+0xa0/0xa0
kernel_init+0xa/0x100
ret_from_fork+0x35/0x40
Fixes: 023a611748 ("x86/apic/x2apic: Simplify cluster management")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20191001205019.5789-1-sean.j.christopherson@intel.com
Now that there's Hyper-V IOMMU driver, Linux can switch to x2apic mode
when supported by the vcpus.
However, the apic access functions for Hyper-V enlightened apic assume
xapic mode only.
As a result, Linux fails to bring up secondary cpus when run as a guest
in QEMU/KVM with both hv_apic and x2apic enabled.
According to Michael Kelley, when in x2apic mode, the Hyper-V synthetic
apic MSRs behave exactly the same as the corresponding architectural
x2apic MSRs, so there's no need to override the apic accessors. The
only exception is hv_apic_eoi_write, which benefits from lazy EOI when
available; however, its implementation works for both xapic and x2apic
modes.
Fixes: 29217a4746 ("iommu/hyper-v: Add Hyper-V stub IOMMU driver")
Fixes: 6b48cb5f83 ("X86/Hyper-V: Enlighten APIC access")
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20191010123258.16919-1-rkagan@virtuozzo.com
Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, but also a couple of updates for new Intel
models (which are technically hw-enablement, but to users it's a fix
to perf behavior on those new CPUs - hope this is fine), an AUX
inheritance fix, event time-sharing fix, and a fix for lost non-perf
NMI events on AMD systems"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
perf/x86/cstate: Add Tiger Lake CPU support
perf/x86/msr: Add Tiger Lake CPU support
perf/x86/intel: Add Tiger Lake CPU support
perf/x86/cstate: Update C-state counters for Ice Lake
perf/x86/msr: Add new CPU model numbers for Ice Lake
perf/x86/cstate: Add Comet Lake CPU support
perf/x86/msr: Add Comet Lake CPU support
perf/x86/intel: Add Comet Lake CPU support
perf/x86/amd: Change/fix NMI latency mitigation to use a timestamp
perf/core: Fix corner case in perf_rotate_context()
perf/core: Rework memory accounting in perf_mmap()
perf/core: Fix inheritance of aux_output groups
perf annotate: Don't return -1 for error when doing BPF disassembly
perf annotate: Return appropriate error code for allocation failures
perf annotate: Fix arch specific ->init() failure errors
perf annotate: Propagate the symbol__annotate() error return
perf annotate: Fix the signedness of failure returns
perf annotate: Propagate perf_env__arch() error
perf evsel: Fall back to global 'perf_env' in perf_evsel__env()
perf tools: Propagate get_cpuid() error
...
Pull EFI fixes from Ingo Molnar:
"Misc EFI fixes all across the map: CPER error report fixes, fixes to
TPM event log parsing, fix for a kexec hang, a Sparse fix and other
fixes"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/tpm: Fix sanity check of unsigned tbl_size being less than zero
efi/x86: Do not clean dummy variable in kexec path
efi: Make unexported efi_rci2_sysfs_init() static
efi/tpm: Only set 'efi_tpm_final_log_size' after successful event log parsing
efi/tpm: Don't traverse an event log with no events
efi/tpm: Don't access event->count when it isn't mapped
efivar/ssdt: Don't iterate over EFI vars if no SSDT override was specified
efi/cper: Fix endianness of PCIe class code
Pull x86 fixes from Ingo Molnar:
"A handful of fixes: a kexec linking fix, an AMD MWAITX fix, a vmware
guest support fix when built under Clang, and new CPU model number
definitions"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Add Comet Lake to the Intel CPU models header
lib/string: Make memzero_explicit() inline instead of external
x86/cpu/vmware: Use the full form of INL in VMWARE_PORT
x86/asm: Fix MWAITX C-state hint value
Pull x86 license tag fixlets from Ingo Molnar:
"Fix a couple of SPDX tags in x86 headers to follow the canonical
pattern"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Use the correct SPDX License Identifier in headers
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Merge tag 'for-linus-5.4-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
- correct panic handling when running as a Xen guest
- cleanup the Xen grant driver to remove printing a pointer being
always NULL
- remove a soon to be wrong call of of_dma_configure()
* tag 'for-linus-5.4-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: Stop abusing DT of_dma_configure API
xen/grant-table: remove unnecessary printing
x86/xen: Return from panic notifier
Tiger Lake is the followon to Ice Lake. From the perspective of Intel
cstate residency counters, there is nothing changed compared with
Ice Lake.
Share icl_cstates with Ice Lake.
Update the comments for Tiger Lake.
The External Design Specification (EDS) is not published yet. It comes
from an authoritative internal source.
The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-10-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tiger Lake is the followon to Ice Lake. PPERF and SMI_COUNT MSRs are
also supported.
The External Design Specification (EDS) is not published yet. It comes
from an authoritative internal source.
The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-9-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tiger Lake is the followon to Ice Lake. From the perspective of Intel
core PMU, there is little changes compared with Ice Lake, e.g. small
changes in event list. But it doesn't impact on core PMU functionality.
Share the perf code with Ice Lake. The event list patch will be submitted
later separately.
The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-8-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is no Core C3 C-State counter for Ice Lake.
Package C8/C9/C10 C-State counters are added for Ice Lake.
Introduce a new event list, icl_cstates, for Ice Lake.
Update the comments accordingly.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f08c47d1f8 ("perf/x86/intel/cstate: Add Icelake support")
Link: https://lkml.kernel.org/r/1570549810-25049-7-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
PPERF and SMI_COUNT MSRs are also supported by Ice Lake desktop and
server.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-6-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Comet Lake is the new 10th Gen Intel processor. From the perspective of
Intel cstate residency counters, there is nothing changed compared with
Kaby Lake.
Share hswult_cstates with Kaby Lake.
Update the comments for Comet Lake.
Kaby Lake is missed in the comments for some Residency Counters. Update
the comments for Kaby Lake as well.
The External Design Specification (EDS) is not published yet. It comes
from an authoritative internal source.
The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-5-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Comet Lake is the new 10th Gen Intel processor. PPERF and SMI_COUNT MSRs
are also supported.
The External Design Specification (EDS) is not published yet. It comes
from an authoritative internal source.
The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-4-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Comet Lake is the new 10th Gen Intel processor. From the perspective
of Intel PMU, there is nothing changed compared with Sky Lake.
Share the perf code with Sky Lake.
The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-3-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The kernel image map is created using PMD pages, which can include
some extra space beyond what's actually needed. Round the size of the
memory hole we search for up to the next PMD boundary, to be certain
all of the space to be mapped is usable RAM and includes no reserved
areas.
Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: dimitri.sivanich@hpe.com
Cc: Feng Tang <feng.tang@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jordan Borgner <mail@jordan-borgner.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: mike.travis@hpe.com
Cc: russ.anderson@hpe.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Link: https://lkml.kernel.org/r/df4f49f05c0c27f108234eb93db5c613d09ea62e.1569358539.git.steve.wahl@hpe.com
Our hardware (UV aka Superdome Flex) has address ranges marked
reserved by the BIOS. Access to these ranges is caught as an error,
causing the BIOS to halt the system.
Initial page tables mapped a large range of physical addresses that
were not checked against the list of BIOS reserved addresses, and
sometimes included reserved addresses in part of the mapped range.
Including the reserved range in the map allowed processor speculative
accesses to the reserved range, triggering a BIOS halt.
Used early in booting, the page table level2_kernel_pgt addresses 1
GiB divided into 2 MiB pages, and it was set up to linearly map a full
1 GiB of physical addresses that included the physical address range
of the kernel image, as chosen by KASLR. But this also included a
large range of unused addresses on either side of the kernel image.
And unlike the kernel image's physical address range, this extra
mapped space was not checked against the BIOS tables of usable RAM
addresses. So there were times when the addresses chosen by KASLR
would result in processor accessible mappings of BIOS reserved
physical addresses.
The kernel code did not directly access any of this extra mapped
space, but having it mapped allowed the processor to issue speculative
accesses into reserved memory, causing system halts.
This was encountered somewhat rarely on a normal system boot, and much
more often when starting the crash kernel if "crashkernel=512M,high"
was specified on the command line (this heavily restricts the physical
address of the crash kernel, in our case usually within 1 GiB of
reserved space).
The solution is to invalidate the pages of this table outside the kernel
image's space before the page table is activated. It fixes this problem
on our hardware.
[ bp: Touchups. ]
Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: dimitri.sivanich@hpe.com
Cc: Feng Tang <feng.tang@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jordan Borgner <mail@jordan-borgner.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: mike.travis@hpe.com
Cc: russ.anderson@hpe.com
Cc: stable@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Link: https://lkml.kernel.org/r/9c011ee51b081534a7a15065b1681d200298b530.1569358539.git.steve.wahl@hpe.com
It turns out that the NMI latency workaround from commit:
6d3edaae16 ("x86/perf/amd: Resolve NMI latency issues for active PMCs")
ends up being too conservative and results in the perf NMI handler claiming
NMIs too easily on AMD hardware when the NMI watchdog is active.
This has an impact, for example, on the hpwdt (HPE watchdog timer) module.
This module can produce an NMI that is used to reset the system. It
registers an NMI handler for the NMI_UNKNOWN type and relies on the fact
that nothing has claimed an NMI so that its handler will be invoked when
the watchdog device produces an NMI. After the referenced commit, the
hpwdt module is unable to process its generated NMI if the NMI watchdog is
active, because the current NMI latency mitigation results in the NMI
being claimed by the perf NMI handler.
Update the AMD perf NMI latency mitigation workaround to, instead, use a
window of time. Whenever a PMC is handled in the perf NMI handler, set a
timestamp which will act as a perf NMI window. Any NMIs arriving within
that window will be claimed by perf. Anything outside that window will
not be claimed by perf. The value for the NMI window is set to 100 msecs.
This is a conservative value that easily covers any NMI latency in the
hardware. While this still results in a window in which the hpwdt module
will not receive its NMI, the window is now much, much smaller.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jerry Hoemann <jerry.hoemann@hpe.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 6d3edaae16 ("x86/perf/amd: Resolve NMI latency issues for active PMCs")
Link: https://lkml.kernel.org/r/Message-ID:
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Comet Lake is the new 10th Gen Intel processor. Add two new CPU model
numbers to the Intel family list.
The CPU model numbers are not published in the SDM yet but they come
from an authoritative internal source.
[ bp: Touch up commit message. ]
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: ak@linux.intel.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1570549810-25049-2-git-send-email-kan.liang@linux.intel.com
LLVM's assembler doesn't accept the short form INL instruction:
inl (%%dx)
but instead insists on the output register to be explicitly specified:
<inline asm>:1:7: error: invalid operand for instruction
inl (%dx)
^
LLVM ERROR: Error parsing inline asm
Use the full form of the instruction to fix the build.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Thomas Hellstrom <thellstrom@vmware.com>
Cc: clang-built-linux@googlegroups.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: "VMware, Inc." <pv-drivers@vmware.com>
Cc: x86-ml <x86@kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/734
Link: https://lkml.kernel.org/r/20191007192129.104336-1-samitolvanen@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As per "AMD64 Architecture Programmer's Manual Volume 3: General-Purpose
and System Instructions", MWAITX EAX[7:4]+1 specifies the optional hint
of the optimized C-state. For C0 state, EAX[7:4] should be set to 0xf.
Currently, a value of 0xf is set for EAX[3:0] instead of EAX[7:4]. Fix
this by changing MWAITX_DISABLE_CSTATES from 0xf to 0xf0.
This hasn't had any implications so far because setting reserved bits in
EAX is simply ignored by the CPU.
[ bp: Fixup comment in delay_mwaitx() and massage. ]
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "x86@kernel.org" <x86@kernel.org>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20191007190011.4859-1-Janakarajan.Natarajan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently execution of panic() continues until Xen's panic notifier
(xen_panic_event()) is called at which point we make a hypercall that
never returns.
This means that any notifier that is supposed to be called later as
well as significant part of panic() code (such as pstore writes from
kmsg_dump()) is never executed.
There is no reason for xen_panic_event() to be this last point in
execution since panic()'s emergency_restart() will call into
xen_emergency_restart() from where we can perform our hypercall.
Nevertheless, we will provide xen_legacy_crash boot option that will
preserve original behavior during crash. This option could be used,
for example, if running kernel dumper (which happens after panic
notifiers) is undesirable.
Reported-by: James Dingwall <james@dingwall.me.uk>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
In commit 9f79b78ef7 ("Convert filldir[64]() from __put_user() to
unsafe_put_user()") I made filldir() use unsafe_put_user(), which
improves code generation on x86 enormously.
But because we didn't have a "unsafe_copy_to_user()", the dirent name
copy was also done by hand with unsafe_put_user() in a loop, and it
turns out that a lot of other architectures didn't like that, because
unlike x86, they have various alignment issues.
Most non-x86 architectures trap and fix it up, and some (like xtensa)
will just fail unaligned put_user() accesses unconditionally. Which
makes that "copy using put_user() in a loop" not work for them at all.
I could make that code do explicit alignment etc, but the architectures
that don't like unaligned accesses also don't really use the fancy
"user_access_begin/end()" model, so they might just use the regular old
__copy_to_user() interface.
So this commit takes that looping implementation, turns it into the x86
version of "unsafe_copy_to_user()", and makes other architectures
implement the unsafe copy version as __copy_to_user() (the same way they
do for the other unsafe_xyz() accessor functions).
Note that it only does this for the copying _to_ user space, and we
still don't have a unsafe version of copy_from_user().
That's partly because we have no current users of it, but also partly
because the copy_from_user() case is slightly different and cannot
efficiently be implemented in terms of a unsafe_get_user() loop (because
gcc can't do asm goto with outputs).
It would be trivial to do this using "rep movsb", which would work
really nicely on newer x86 cores, but really badly on some older ones.
Al Viro is looking at cleaning up all our user copy routines to make
this all a non-issue, but for now we have this simple-but-stupid version
for x86 that works fine for the dirent name copy case because those
names are short strings and we simply don't need anything fancier.
Fixes: 9f79b78ef7 ("Convert filldir[64]() from __put_user() to unsafe_put_user()")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-and-tested-by: Tony Luck <tony.luck@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kexec reboot fails randomly in UEFI based KVM guest. The firmware
just resets while calling efi_delete_dummy_variable(); Unfortunately
I don't know how to debug the firmware, it is also possible a potential
problem on real hardware as well although nobody reproduced it.
The intention of the efi_delete_dummy_variable is to trigger garbage collection
when entering virtual mode. But SetVirtualAddressMap can only run once
for each physical reboot, thus kexec_enter_virtual_mode() is not necessarily
a good place to clean a dummy object.
Drop the efi_delete_dummy_variable so that kexec reboot can work.
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Matthew Garrett <mjg59@google.com>
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Talbert <swt@techie.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Link: https://lkml.kernel.org/r/20191002165904.8819-8-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
