commit 8376efd31d3d7c44bd05be337adde023cc531fa1 upstream.
Commit 11e63f6d920d added cache flushing for unaligned writes from an
iovec, covering the first and last cache line of a >= 8 byte write and
the first cache line of a < 8 byte write. But an unaligned write of
2-7 bytes can still cover two cache lines, so make sure we flush both
in that case.
Fixes: 11e63f6d920d ("x86, pmem: fix broken __copy_user_nocache ...")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d594aa0277e541bb997aef0bc0a55172d8138340 upstream.
The minimum size for a new stack (512 bytes) setup for arch/x86/boot components
when the bootloader does not setup/provide a stack for the early boot components
is not "enough".
The setup code executing as part of early kernel startup code, uses the stack
beyond 512 bytes and accidentally overwrites and corrupts part of the BSS
section. This is exposed mostly in the early video setup code, where
it was corrupting BSS variables like force_x, force_y, which in-turn affected
kernel parameters such as screen_info (screen_info.orig_video_cols) and
later caused an exception/panic in console_init().
Most recent boot loaders setup the stack for early boot components, so this
stack overwriting into BSS section issue has not been exposed.
Signed-off-by: Ashish Kalra <ashish@bluestacks.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170419152015.10011-1-ashishkalra@Ashishs-MacBook-Pro.local
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 69861e0a52f8733355ce246f0db15e1b240ad667 upstream.
When booted as pv-guest the p2m list presented by the Xen is already
mapped to virtual addresses. In dom0 case the hypervisor might make use
of 2M- or 1G-pages for this mapping. Unfortunately while being properly
aligned in virtual and machine address space, those pages might not be
aligned properly in guest physical address space.
So when trying to obtain the guest physical address of such a page
pud_pfn() and pmd_pfn() must be avoided as those will mask away guest
physical address bits not being zero in this special case.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab007cc94ff9d82f5a8db8363b3becbd946e58cf upstream.
The PML feature is not exposed to guests so we should not be forwarding
the vmexit either.
This commit fixes BSOD 0x20001 (HYPERVISOR_ERROR) when running Hyper-V
enabled Windows Server 2016 in L1 on hardware that supports PML.
Fixes: 843e433057 ("KVM: VMX: Add PML support in VMX")
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1fb883bb827ee8efc1cc9ea0154f953f8a219d38 upstream.
L2 was running with uninitialized PML fields which led to incomplete
dirty bitmap logging. This manifested as all kinds of subtle erratic
behavior of the nested guest.
Fixes: 843e433057 ("KVM: VMX: Add PML support in VMX")
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 80354c29025833acd72ddac1ffa21c6cb50128cd upstream.
The interrupt line used for the watchdog is 12, according to the official
Intel Edison BSP code.
And indeed after fixing it we start getting an interrupt and thus the
watchdog starts working again:
[ 191.699951] Kernel panic - not syncing: Kernel Watchdog
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Cohen <david.a.cohen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 78a3bb9e40 ("x86: intel-mid: add watchdog platform code for Merrifield")
Link: http://lkml.kernel.org/r/20170312150744.45493-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 75013fb16f8484898eaa8d0b08fed942d790f029 upstream.
Fix to the exception table entry check by using probed address
instead of the address of copied instruction.
This bug may cause unexpected kernel panic if user probe an address
where an exception can happen which should be fixup by __ex_table
(e.g. copy_from_user.)
Unless user puts a kprobe on such address, this doesn't
cause any problem.
This bug has been introduced years ago, by commit:
464846888d ("x86/kprobes: Fix a bug which can modify kernel code permanently").
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 464846888d ("x86/kprobes: Fix a bug which can modify kernel code permanently")
Link: http://lkml.kernel.org/r/148829899399.28855.12581062400757221722.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 68dee8e2f2cacc54d038394e70d22411dee89da2 upstream.
commit 8fd524b355 ("x86: Kill bad_dma_address variable") has killed
bad_dma_address variable and used instead of macro DMA_ERROR_CODE
which is always zero. Since dma_addr is unsigned, the statement
dma_addr >= DMA_ERROR_CODE
is always true, and not needed.
arch/x86/kernel/pci-calgary_64.c: In function ‘iommu_free’:
arch/x86/kernel/pci-calgary_64.c:299:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {
Fixes: 8fd524b355 ("x86: Kill bad_dma_address variable")
Signed-off-by: Nikola Pajkovsky <npajkovsky@suse.cz>
Cc: iommu@lists.linux-foundation.org
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Muli Ben-Yehuda <mulix@mulix.org>
Link: http://lkml.kernel.org/r/7612c0f9dd7c1290407dbf8e809def922006920b.1479161177.git.npajkovsky@suse.cz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a9b4f08770b415f30f2fb0f8329a370c8f554aa3 upstream.
commit d32932d02e removed the irq_retrigger callback from the IO-APIC
chip and did not add it to the new IO-APIC-IR irq chip.
There is no harm because the interrupts are resent in software when the
retrigger callback is NULL, but it's less efficient. So restore them.
[ tglx: Massaged changelog ]
Fixes: d32932d02e ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
Signed-off-by: Ruslan Ruslichenko <rruslich@cisco.com>
Cc: xe-linux-external@cisco.com
Link: http://lkml.kernel.org/r/1484662432-13580-1-git-send-email-rruslich@cisco.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 34a477e5297cbaa6ecc6e17c042a866e1cbe80d6 upstream.
On x86-32, with CONFIG_FIRMWARE and multiple CPUs, if you enable function
graph tracing and then suspend to RAM, it will triple fault and reboot when
it resumes.
The first fault happens when booting a secondary CPU:
startup_32_smp()
load_ucode_ap()
prepare_ftrace_return()
ftrace_graph_is_dead()
(accesses 'kill_ftrace_graph')
The early head_32.S code calls into load_ucode_ap(), which has an an
ftrace hook, so it calls prepare_ftrace_return(), which calls
ftrace_graph_is_dead(), which tries to access the global
'kill_ftrace_graph' variable with a virtual address, causing a fault
because the CPU is still in real mode.
The fix is to add a check in prepare_ftrace_return() to make sure it's
running in protected mode before continuing. The check makes sure the
stack pointer is a virtual kernel address. It's a bit of a hack, but
it's not very intrusive and it works well enough.
For reference, here are a few other (more difficult) ways this could
have potentially been fixed:
- Move startup_32_smp()'s call to load_ucode_ap() down to *after* paging
is enabled. (No idea what that would break.)
- Track down load_ucode_ap()'s entire callee tree and mark all the
functions 'notrace'. (Probably not realistic.)
- Pause graph tracing in ftrace_suspend_notifier_call() or bringup_cpu()
or __cpu_up(), and ensure that the pause facility can be queried from
real mode.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>
Cc: linux-acpi@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/5c1272269a580660703ed2eccf44308e790c7a98.1492123841.git.jpoimboe@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c06b6d70feb32d28f04ba37aa3df17973fd37b6b upstream.
On slow platforms with unreliable TSC, such as QEMU emulated machines,
it is possible for the kernel to request the next event in the past. In
that case, in the current implementation of xen_vcpuop_clockevent, we
simply return -ETIME. To be precise the Xen returns -ETIME and we pass
it on. However the result of this is a missed event, which simply causes
the kernel to hang.
Instead it is better to always ask the hypervisor for a timer event,
even if the timeout is in the past. That way there are no lost
interrupts and the kernel survives. To do that, remove the
VCPU_SSHOTTMR_future flag.
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 11e63f6d920d6f2dfd3cd421e939a4aec9a58dcd upstream.
Before we rework the "pmem api" to stop abusing __copy_user_nocache()
for memcpy_to_pmem() we need to fix cases where we may strand dirty data
in the cpu cache. The problem occurs when copy_from_iter_pmem() is used
for arbitrary data transfers from userspace. There is no guarantee that
these transfers, performed by dax_iomap_actor(), will have aligned
destinations or aligned transfer lengths. Backstop the usage
__copy_user_nocache() with explicit cache management in these unaligned
cases.
Yes, copy_from_iter_pmem() is now too big for an inline, but addressing
that is saved for a later patch that moves the entirety of the "pmem
api" into the pmem driver directly.
Fixes: 5de490daec ("pmem: add copy_from_iter_pmem() and clear_pmem()")
Cc: <x86@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 29f72ce3e4d18066ec75c79c857bee0618a3504b upstream.
MCA bank 3 is reserved on systems pre-Fam17h, so it didn't have a name.
However, MCA bank 3 is defined on Fam17h systems and can be accessed
using legacy MSRs. Without a name we get a stack trace on Fam17h systems
when trying to register sysfs files for bank 3 on kernels that don't
recognize Scalable MCA.
Call MCA bank 3 "decode_unit" since this is what it represents on
Fam17h. This will allow kernels without SMCA support to see this bank on
Fam17h+ and prevent the stack trace. This will not affect older systems
since this bank is reserved on them, i.e. it'll be ignored.
Tested on AMD Fam15h and Fam17h systems.
WARNING: CPU: 26 PID: 1 at lib/kobject.c:210 kobject_add_internal
kobject: (ffff88085bb256c0): attempted to be registered with empty name!
...
Call Trace:
kobject_add_internal
kobject_add
kobject_create_and_add
threshold_create_device
threshold_init_device
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1490102285-3659-1-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a4866aa812518ed1a37d8ea0c881dc946409de94 upstream.
Under CONFIG_STRICT_DEVMEM, reading System RAM through /dev/mem is
disallowed. However, on x86, the first 1MB was always allowed for BIOS
and similar things, regardless of it actually being System RAM. It was
possible for heap to end up getting allocated in low 1MB RAM, and then
read by things like x86info or dd, which would trip hardened usercopy:
usercopy: kernel memory exposure attempt detected from ffff880000090000 (dma-kmalloc-256) (4096 bytes)
This changes the x86 exception for the low 1MB by reading back zeros for
System RAM areas instead of blindly allowing them. More work is needed to
extend this to mmap, but currently mmap doesn't go through usercopy, so
hardened usercopy won't Oops the kernel.
Reported-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Tested-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 06ce521af9558814b8606c0476c54497cf83a653 upstream.
handle_vmon gets a reference on VMXON region page,
but does not release it. Release the reference.
Found by syzkaller; based on a patch by Dmitry.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16: use skip_emulated_instruction()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6fdc6dd90272ce7e75d744f71535cfbd8d77da81 upstream.
The vsyscall32 sysctl can racy against a concurrent fork when it switches
from disabled to enabled:
arch_setup_additional_pages()
if (vdso32_enabled)
--> No mapping
sysctl.vsysscall32()
--> vdso32_enabled = true
create_elf_tables()
ARCH_DLINFO_IA32
if (vdso32_enabled) {
--> Add VDSO entry with NULL pointer
Make ARCH_DLINFO_IA32 check whether the VDSO mapping has been set up for
the newly forked process or not.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathias Krause <minipli@googlemail.com>
Link: http://lkml.kernel.org/r/20170410151723.602367196@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c06989da39cdb10604d572c8c7ea8c8c97f3c483 upstream.
vdso_enabled can be set to arbitrary integer values via the kernel command
line 'vdso32=' parameter or via 'sysctl abi.vsyscall32'.
load_vdso32() only maps VDSO if vdso_enabled == 1, but ARCH_DLINFO_IA32
merily checks for vdso_enabled != 0. As a consequence the AT_SYSINFO_EHDR
auxiliary vector for the VDSO_ENTRY is emitted with a NULL pointer which
causes a segfault when the application tries to use the VDSO.
Restrict the valid arguments on the command line and the sysctl to 0 and 1.
Fixes: b0b49f2673 ("x86, vdso: Remove compat vdso support")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@redhat.com>
Link: http://lkml.kernel.org/r/1491424561-7187-1-git-send-email-minipli@googlemail.com
Link: http://lkml.kernel.org/r/20170410151723.518412863@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7ecec8503af37de6be4f96b53828d640a968705f upstream.
When relocating the p2m, take special care not to relocate it so
that is overlaps with the current location of the p2m/initrd. This is
needed since the full extent of the current location is not marked as a
reserved region in the e820.
This was seen to happen to a dom0 with a large initial p2m and a small
reserved region in the middle of the initial p2m.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Vitaly Kuznetsov <vkuznets@redhat.com>
[ Upstream commit 59107e2f48831daedc46973ce4988605ab066de3 ]
There is a feature in Hyper-V ('Debug-VM --InjectNonMaskableInterrupt')
which injects NMI to the guest. We may want to crash the guest and do kdump
on this NMI by enabling unknown_nmi_panic. To make kdump succeed we need to
allow the kdump kernel to re-establish VMBus connection so it will see
VMBus devices (storage, network,..).
To properly unload VMBus making it possible to start over during kdump we
need to do the following:
- Send an 'unload' message to the hypervisor. This can be done on any CPU
so we do this the crashing CPU.
- Receive the 'unload finished' reply message. WS2012R2 delivers this
message to the CPU which was used to establish VMBus connection during
module load and this CPU may differ from the CPU sending 'unload'.
Receiving a VMBus message means the following:
- There is a per-CPU slot in memory for one message. This slot can in
theory be accessed by any CPU.
- We get an interrupt on the CPU when a message was placed into the slot.
- When we read the message we need to clear the slot and signal the fact
to the hypervisor. In case there are more messages to this CPU pending
the hypervisor will deliver the next message. The signaling is done by
writing to an MSR so this can only be done on the appropriate CPU.
To avoid doing cross-CPU work on crash we have vmbus_wait_for_unload()
function which checks message slots for all CPUs in a loop waiting for the
'unload finished' messages. However, there is an issue which arises when
these conditions are met:
- We're crashing on a CPU which is different from the one which was used
to initially contact the hypervisor.
- The CPU which was used for the initial contact is blocked with interrupts
disabled and there is a message pending in the message slot.
In this case we won't be able to read the 'unload finished' message on the
crashing CPU. This is reproducible when we receive unknown NMIs on all CPUs
simultaneously: the first CPU entering panic() will proceed to crash and
all other CPUs will stop themselves with interrupts disabled.
The suggested solution is to handle unknown NMIs for Hyper-V guests on the
first CPU which gets them only. This will allow us to rely on VMBus
interrupt handler being able to receive the 'unload finish' message in
case it is delivered to a different CPU.
The issue is not reproducible on WS2016 as Debug-VM delivers NMI to the
boot CPU only, WS2012R2 and earlier Hyper-V versions are affected.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: devel@linuxdriverproject.org
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Link: http://lkml.kernel.org/r/20161202100720.28121-1-vkuznets@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Dan Streetman <ddstreet@ieee.org>
[ Upstream commit c74fd80f2f41d05f350bb478151021f88551afe8 ]
Revert the main part of commit:
af42b8d12f ("xen: fix MSI setup and teardown for PV on HVM guests")
That commit introduced reading the pci device's msi message data to see
if a pirq was previously configured for the device's msi/msix, and re-use
that pirq. At the time, that was the correct behavior. However, a
later change to Qemu caused it to call into the Xen hypervisor to unmap
all pirqs for a pci device, when the pci device disables its MSI/MSIX
vectors; specifically the Qemu commit:
c976437c7dba9c7444fb41df45468968aaa326ad
("qemu-xen: free all the pirqs for msi/msix when driver unload")
Once Qemu added this pirq unmapping, it was no longer correct for the
kernel to re-use the pirq number cached in the pci device msi message
data. All Qemu releases since 2.1.0 contain the patch that unmaps the
pirqs when the pci device disables its MSI/MSIX vectors.
This bug is causing failures to initialize multiple NVMe controllers
under Xen, because the NVMe driver sets up a single MSIX vector for
each controller (concurrently), and then after using that to talk to
the controller for some configuration data, it disables the single MSIX
vector and re-configures all the MSIX vectors it needs. So the MSIX
setup code tries to re-use the cached pirq from the first vector
for each controller, but the hypervisor has already given away that
pirq to another controller, and its initialization fails.
This is discussed in more detail at:
https://lists.xen.org/archives/html/xen-devel/2017-01/msg00447.html
Fixes: af42b8d12f ("xen: fix MSI setup and teardown for PV on HVM guests")
Signed-off-by: Dan Streetman <dan.streetman@canonical.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 707e59ba494372a90d245f18b0c78982caa88e48 upstream.
The following commit:
1fb3a8b2cf ("xen/spinlock: Fix locking path engaging too soon under PVHVM.")
... moved the initalization of the kicker interrupt until after
native_cpu_up() is called.
However, when using qspinlocks, a CPU may try to kick another CPU that is
spinning (because it has not yet initialized its kicker interrupt), resulting
in the following crash during boot:
kernel BUG at /build/linux-Ay7j_C/linux-4.4.0/drivers/xen/events/events_base.c:1210!
invalid opcode: 0000 [#1] SMP
...
RIP: 0010:[<ffffffff814c97c9>] [<ffffffff814c97c9>] xen_send_IPI_one+0x59/0x60
...
Call Trace:
[<ffffffff8102be9e>] xen_qlock_kick+0xe/0x10
[<ffffffff810cabc2>] __pv_queued_spin_unlock+0xb2/0xf0
[<ffffffff810ca6d1>] ? __raw_callee_save___pv_queued_spin_unlock+0x11/0x20
[<ffffffff81052936>] ? check_tsc_warp+0x76/0x150
[<ffffffff81052aa6>] check_tsc_sync_source+0x96/0x160
[<ffffffff81051e28>] native_cpu_up+0x3d8/0x9f0
[<ffffffff8102b315>] xen_hvm_cpu_up+0x35/0x80
[<ffffffff8108198c>] _cpu_up+0x13c/0x180
[<ffffffff81081a4a>] cpu_up+0x7a/0xa0
[<ffffffff81f80dfc>] smp_init+0x7f/0x81
[<ffffffff81f5a121>] kernel_init_freeable+0xef/0x212
[<ffffffff81817f30>] ? rest_init+0x80/0x80
[<ffffffff81817f3e>] kernel_init+0xe/0xe0
[<ffffffff8182488f>] ret_from_fork+0x3f/0x70
[<ffffffff81817f30>] ? rest_init+0x80/0x80
To fix this, only send the kick if the target CPU's interrupt has been
initialized. This check isn't racy, because the target is waiting for
the spinlock, so it won't have initialized the interrupt in the
meantime.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3a020a723c65eb8ffa7c237faca26521a024e582 upstream.
ghash_clmulni_intel fails to load on Linux 4.3+ with the following message:
"modprobe: ERROR: could not insert 'ghash_clmulni_intel': Invalid argument"
After 8996eafdc ("crypto: ahash - ensure statesize is non-zero") all ahash
drivers are required to implement import()/export(), and must have a non-
zero statesize.
This patch has been tested with the algif_hash interface. The calculated
digest values, after several rounds of import()s and export()s, match those
calculated by tcrypt.
Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5dc855d44c2ad960a86f593c60461f1ae1566b6d upstream.
If one thread mmaps a perf event while another thread in the same mm
is in some context where active_mm != mm (which can happen in the
scheduler, for example), refresh_pce() would write the wrong value
to CR4.PCE. This broke some PAPI tests.
Reported-and-tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 7911d3f7af ("perf/x86: Only allow rdpmc if a perf_event is mapped")
Link: http://lkml.kernel.org/r/0c5b38a76ea50e405f9abe07a13dfaef87c173a1.1489694270.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit be3606ff739d1c1be36389f8737c577ad87e1f57 upstream.
The kernel doesn't boot with both PROFILE_ANNOTATED_BRANCHES=y and KASAN=y
options selected. With branch profiling enabled we end up calling
ftrace_likely_update() before kasan_early_init(). ftrace_likely_update() is
built with KASAN instrumentation, so calling it before kasan has been
initialized leads to crash.
Use DISABLE_BRANCH_PROFILING define to make sure that we don't call
ftrace_likely_update() from early code before kasan_early_init().
Fixes: ef7f0d6a6c ("x86_64: add KASan support")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: lkp@01.org
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: http://lkml.kernel.org/r/20170313163337.1704-1-aryabinin@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 96794e4ed4d758272c486e1529e431efb7045265 upstream.
Guest segment selector is 16 bit field and guest segment base is natural
width field. Fix two incorrect invocations accordingly.
Without this patch, build fails when aggressive inlining is used with ICC.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4e59516a12a6ef6dcb660cb3a3f70c64bd60cfec upstream.
Between loading the new VMCS and enabling PML, the CPU was unpinned.
If the vCPU thread were migrated to another CPU in the interim (e.g.,
due to preemption or sleeping alloc_page), then the VMWRITEs to enable
PML would target the wrong VMCS -- or no VMCS at all:
[ 2087.266950] vmwrite error: reg 200e value 3fe1d52000 (err -506126336)
[ 2087.267062] vmwrite error: reg 812 value 1ff (err 511)
[ 2087.267125] vmwrite error: reg 401e value 12229c00 (err 304258048)
This patch ensures that the VMCS remains current while enabling PML by
doing the VMWRITEs while the CPU is pinned. Allocation of the PML buffer
is hoisted out of the critical section.
Signed-off-by: Peter Feiner <pfeiner@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Herongguang (Stephen)" <herongguang.he@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 47512cfd0d7a8bd6ab71d01cd89fca19eb2093eb upstream.
The goldfish platform code registers the platform device unconditionally
which causes havoc in several ways if the goldfish_pdev_bus driver is
enabled:
- Access to the hardcoded physical memory region, which is either not
available or contains stuff which is completely unrelated.
- Prevents that the interrupt of the serial port can be requested
- In case of a spurious interrupt it goes into a infinite loop in the
interrupt handler of the pdev_bus driver (which needs to be fixed
seperately).
Add a 'goldfish' command line option to make the registration opt-in when
the platform is compiled in.
I'm seriously grumpy about this engineering trainwreck, which has seven
SOBs from Intel developers for 50 lines of code. And none of them figured
out that this is broken. Impressive fail!
Fixes: ddd70cf93d ("goldfish: platform device for x86")
Reported-by: Gabriel C <nix.or.die@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d966564fcdc19e13eb6ba1fbe6b8101070339c3d upstream.
This reverts commit 020eb3daaba2857b32c4cf4c82f503d6a00a67de.
Gabriel C reports that it causes his machine to not boot, and we haven't
tracked down the reason for it yet. Since the bug it fixes has been
around for a longish time, we're better off reverting the fix for now.
Gabriel says:
"It hangs early and freezes with a lot RCU warnings.
I bisected it down to :
> Ruslan Ruslichenko (1):
> x86/ioapic: Restore IO-APIC irq_chip retrigger callback
Reverting this one fixes the problem for me..
The box is a PRIMERGY TX200 S5 , 2 socket , 2 x E5520 CPU(s) installed"
and Ruslan and Thomas are currently stumped.
Reported-and-bisected-by: Gabriel C <nix.or.die@gmail.com>
Cc: Ruslan Ruslichenko <rruslich@cisco.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aaaec6fc755447a1d056765b11b24d8ff2b81366 upstream.
The recent commit which prevents double activation of interrupts unearthed
interesting code in x86. The code (ab)uses irq_domain_activate_irq() to
reconfigure an already activated interrupt. That trips over the prevention
code now.
Fix it by deactivating the interrupt before activating the new configuration.
Fixes: 08d85f3ea99f1 "irqdomain: Avoid activating interrupts more than once"
Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701311901580.3457@nanos
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00c87e9a70a17b355b81c36adedf05e84f54e10d upstream.
Saving unsupported state prevents migration when the new host does not
support a XSAVE feature of the original host, even if the feature is not
exposed to the guest.
We've masked host features with guest-visible features before, with
4344ee981e ("KVM: x86: only copy XSAVE state for the supported
features") and dropped it when implementing XSAVES. Do it again.
Fixes: df1daba7d1 ("KVM: x86: support XSAVES usage in the host")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 020eb3daaba2857b32c4cf4c82f503d6a00a67de upstream.
commit d32932d02e removed the irq_retrigger callback from the IO-APIC
chip and did not add it to the new IO-APIC-IR irq chip.
Unfortunately the software resend fallback is not enabled on X86, so edge
interrupts which are received during the lazy disabled state of the
interrupt line are not retriggered and therefor lost.
Restore the callbacks.
[ tglx: Massaged changelog ]
Fixes: d32932d02e ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
Signed-off-by: Ruslan Ruslichenko <rruslich@cisco.com>
Cc: xe-linux-external@cisco.com
Link: http://lkml.kernel.org/r/1484662432-13580-1-git-send-email-rruslich@cisco.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 89e9f7bcd8744ea25fcf0ac671b8d72c10d7d790 upstream.
Martin reported that the Supermicro X8DTH-i/6/iF/6F advertises incorrect
host bridge windows via _CRS:
pci_root PNP0A08:00: host bridge window [io 0xf000-0xffff]
pci_root PNP0A08:01: host bridge window [io 0xf000-0xffff]
Both bridges advertise the 0xf000-0xffff window, which cannot be correct.
Work around this by ignoring _CRS on this system. The downside is that we
may not assign resources correctly to hot-added PCI devices (if they are
possible on this system).
Link: https://bugzilla.kernel.org/show_bug.cgi?id=42606
Reported-by: Martin Burnicki <martin.burnicki@meinberg.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8329e818f14926a6040df86b2668568bde342ebf upstream.
Matt Fleming reported seeing crashes when enabling and disabling
function profiling which uses function graph tracer. Later Namhyung Kim
hit a similar issue and he found that the issue was due to the jmp to
ftrace_stub in ftrace_graph_call was only two bytes, and when it was
changed to jump to the tracing code, it overwrote the ftrace_stub that
was after it.
Masami Hiramatsu bisected this down to a binutils change:
8dcea93252a9ea7dff57e85220a719e2a5e8ab41 is the first bad commit
commit 8dcea93252a9ea7dff57e85220a719e2a5e8ab41
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri May 15 03:17:31 2015 -0700
Add -mshared option to x86 ELF assembler
This patch adds -mshared option to x86 ELF assembler. By default,
assembler will optimize out non-PLT relocations against defined non-weak
global branch targets with default visibility. The -mshared option tells
the assembler to generate code which may go into a shared library
where all non-weak global branch targets with default visibility can
be preempted. The resulting code is slightly bigger. This option
only affects the handling of branch instructions.
Declaring ftrace_stub as a weak call prevents gas from using two byte
jumps to it, which would be converted to a jump to the function graph
code.
Link: http://lkml.kernel.org/r/20160516230035.1dbae571@gandalf.local.home
Reported-by: Matt Fleming <matt@codeblueprint.co.uk>
Reported-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dd853fd216d1485ed3045ff772079cc8689a9a4a upstream.
A negative number can be specified in the cmdline which will be used as
setup_clear_cpu_cap() argument. With that we can clear/set some bit in
memory predceeding boot_cpu_data/cpu_caps_cleared which may cause kernel
to misbehave. This patch adds lower bound check to setup_disablecpuid().
Boris Petkov reproduced a crash:
[ 1.234575] BUG: unable to handle kernel paging request at ffffffff858bd540
[ 1.236535] IP: memcpy_erms+0x6/0x10
Signed-off-by: Lukasz Odzioba <lukasz.odzioba@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andi.kleen@intel.com
Cc: bp@alien8.de
Cc: dave.hansen@linux.intel.com
Cc: luto@kernel.org
Cc: slaoub@gmail.com
Fixes: ac72e7888a ("x86: add generic clearcpuid=... option")
Link: http://lkml.kernel.org/r/1482933340-11857-1-git-send-email-lukasz.odzioba@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 129a72a0d3c8e139a04512325384fe5ac119e74d upstream.
Introduces segemented_write_std.
Switches from emulated reads/writes to standard read/writes in fxsave,
fxrstor, sgdt, and sidt. This fixes CVE-2017-2584, a longstanding
kernel memory leak.
Since commit 283c95d0e389 ("KVM: x86: emulate FXSAVE and FXRSTOR",
2016-11-09), which is luckily not yet in any final release, this would
also be an exploitable kernel memory *write*!
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: 96051572c8
Fixes: 283c95d0e3891b64087706b344a4b545d04a6e62
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 283c95d0e3891b64087706b344a4b545d04a6e62 upstream.
Internal errors were reported on 16 bit fxsave and fxrstor with ipxe.
Old Intels don't have unrestricted_guest, so we have to emulate them.
The patch takes advantage of the hardware implementation.
AMD and Intel differ in saving and restoring other fields in first 32
bytes. A test wrote 0xff to the fxsave area, 0 to upper bits of MCSXR
in the fxsave area, executed fxrstor, rewrote the fxsave area to 0xee,
and executed fxsave:
Intel (Nehalem):
7f 1f 7f 7f ff 00 ff 07 ff ff ff ff ff ff 00 00
ff ff ff ff ff ff 00 00 ff ff 00 00 ff ff 00 00
Intel (Haswell -- deprecated FPU CS and FPU DS):
7f 1f 7f 7f ff 00 ff 07 ff ff ff ff 00 00 00 00
ff ff ff ff 00 00 00 00 ff ff 00 00 ff ff 00 00
AMD (Opteron 2300-series):
7f 1f 7f 7f ff 00 ee ee ee ee ee ee ee ee ee ee
ee ee ee ee ee ee ee ee ff ff 00 00 ff ff 02 00
fxsave/fxrstor will only be emulated on early Intels, so KVM can't do
much to improve the situation.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aabba3c6abd50b05b1fc2c6ec44244aa6bcda576 upstream.
Move the existing exception handling for inline assembly into a macro
and switch its return values to X86EMUL type.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cef84c302fe051744b983a92764d3fcca933415d upstream.
KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled).
These are implemented with delayed_work structs which can still be
pending when the KVM module is unloaded. We've seen this cause kernel
panics when the kvm_intel module is quickly reloaded.
Use the new static_key_deferred_flush() API to flush pending updates on
module unload.
Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 33ab91103b3415e12457e3104f0e4517ce12d0f3 upstream.
This is CVE-2017-2583. On Intel this causes a failed vmentry because
SS's type is neither 3 nor 7 (even though the manual says this check is
only done for usable SS, and the dmesg splat says that SS is unusable!).
On AMD it's worse: svm.c is confused and sets CPL to 0 in the vmcb.
The fix fabricates a data segment descriptor when SS is set to a null
selector, so that CPL and SS.DPL are set correctly in the VMCS/vmcb.
Furthermore, only allow setting SS to a NULL selector if SS.RPL < 3;
this in turn ensures CPL < 3 because RPL must be equal to CPL.
Thanks to Andy Lutomirski and Willy Tarreau for help in analyzing
the bug and deciphering the manuals.
Reported-by: Xiaohan Zhang <zhangxiaohan1@huawei.com>
Fixes: 79d5b4c3cd
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6ef4e07ecd2db21025c446327ecf34414366498b upstream.
Otherwise, mismatch between the smm bit in hflags and the MMU role
can cause a NULL pointer dereference.
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 847fa1a6d3d00f3bdf68ef5fa4a786f644a0dd67 upstream.
With new binutils, gcc may get smart with its optimization and change a jmp
from a 5 byte jump to a 2 byte one even though it was jumping to a global
function. But that global function existed within a 2 byte radius, and gcc
was able to optimize it. Unfortunately, that jump was also being modified
when function graph tracing begins. Since ftrace expected that jump to be 5
bytes, but it was only two, it overwrote code after the jump, causing a
crash.
This was fixed for x86_64 with commit 8329e818f149, with the same subject as
this commit, but nothing was done for x86_32.
Fixes: d61f82d066 ("ftrace: use dynamic patching for updating mcount calls")
Reported-by: Colin Ian King <colin.king@canonical.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef85b67385436ddc1998f45f1d6a210f935b3388 upstream.
When L2 exits to L0 due to "exception or NMI", software exceptions
(#BP and #OF) for which L1 has requested an intercept should be
handled by L1 rather than L0. Previously, only hardware exceptions
were forwarded to L1.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7f612a7f0bc13a2361a152862435b7941156b6af upstream.
Lukasz reported that perf stat counters overflow handling is broken on KNL/SLM.
Both these parts have full_width_write set, and that does indeed have
a problem. In order to deal with counter wrap, we must sample the
counter at at least half the counter period (see also the sampling
theorem) such that we can unambiguously reconstruct the count.
However commit:
069e0c3c40 ("perf/x86/intel: Support full width counting")
sets the sampling interval to the full period, not half.
Fixing that exposes another issue, in that we must not sign extend the
delta value when we shift it right; the counter cannot have
decremented after all.
With both these issues fixed, counter overflow functions correctly
again.
Reported-by: Lukasz Odzioba <lukasz.odzioba@intel.com>
Tested-by: Liang, Kan <kan.liang@intel.com>
Tested-by: Odzioba, Lukasz <lukasz.odzioba@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: 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: 069e0c3c40 ("perf/x86/intel: Support full width counting")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fc0e81b2bea0ebceb71889b61d2240856141c9ee upstream.
On the 80486 DX, it seems that some exceptions may leave garbage in
the high bits of CS. This causes sporadic failures in which
early_fixup_exception() refuses to fix up an exception.
As far as I can tell, this has been buggy for a long time, but the
problem seems to have been exacerbated by commits:
1e02ce4ccc ("x86: Store a per-cpu shadow copy of CR4")
e1bfc11c5a6f ("x86/init: Fix cr4_init_shadow() on CR4-less machines")
This appears to have broken for as long as we've had early
exception handling.
[ This backport should apply to kernels from 3.4 - 4.5. ]
Fixes: 4c5023a3fa ("x86-32: Handle exception table entries during early boot")
Cc: H. Peter Anvin <hpa@zytor.com>
Reported-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2117d5398c81554fbf803f5fd1dc55eb78216c0c upstream.
em_jmp_far and em_ret_far assumed that setting IP can only fail in 64
bit mode, but syzkaller proved otherwise (and SDM agrees).
Code segment was restored upon failure, but it was left uninitialized
outside of long mode, which could lead to a leak of host kernel stack.
We could have fixed that by always saving and restoring the CS, but we
take a simpler approach and just break any guest that manages to fail
as the error recovery is error-prone and modern CPUs don't need emulator
for this.
Found by syzkaller:
WARNING: CPU: 2 PID: 3668 at arch/x86/kvm/emulate.c:2217 em_ret_far+0x428/0x480
Kernel panic - not syncing: panic_on_warn set ...
CPU: 2 PID: 3668 Comm: syz-executor Not tainted 4.9.0-rc4+ #49
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[...]
Call Trace:
[...] __dump_stack lib/dump_stack.c:15
[...] dump_stack+0xb3/0x118 lib/dump_stack.c:51
[...] panic+0x1b7/0x3a3 kernel/panic.c:179
[...] __warn+0x1c4/0x1e0 kernel/panic.c:542
[...] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
[...] em_ret_far+0x428/0x480 arch/x86/kvm/emulate.c:2217
[...] em_ret_far_imm+0x17/0x70 arch/x86/kvm/emulate.c:2227
[...] x86_emulate_insn+0x87a/0x3730 arch/x86/kvm/emulate.c:5294
[...] x86_emulate_instruction+0x520/0x1ba0 arch/x86/kvm/x86.c:5545
[...] emulate_instruction arch/x86/include/asm/kvm_host.h:1116
[...] complete_emulated_io arch/x86/kvm/x86.c:6870
[...] complete_emulated_mmio+0x4e9/0x710 arch/x86/kvm/x86.c:6934
[...] kvm_arch_vcpu_ioctl_run+0x3b7a/0x5a90 arch/x86/kvm/x86.c:6978
[...] kvm_vcpu_ioctl+0x61e/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557
[...] vfs_ioctl fs/ioctl.c:43
[...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679
[...] SYSC_ioctl fs/ioctl.c:694
[...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
[...] entry_SYSCALL_64_fastpath+0x1f/0xc2
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: d1442d85cc ("KVM: x86: Handle errors when RIP is set during far jumps")
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 90944e40ba1838de4b2a9290cf273f9d76bd3bdd upstream.
If the gcc is configured to do -fPIE by default then the build aborts
later with:
| Unsupported relocation type: unknown type rel type name (29)
Tagging it stable so it is possible to compile recent stable kernels as
well.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
