Cascade Lake Xeon parts have the same model number as Skylake Xeon
parts, so they are tagged with the intel_pebs_isolation
quirk. However, as with Skylake Xeon H0 stepping parts, the PEBS
isolation issue is fixed in all microcode versions.
Add the Cascade Lake Xeon steppings (5, 6, and 7) to the
isolation_ucodes[] table so that these parts benefit from Andi's
optimization in commit 9b545c04ab ("perf/x86/kvm: Avoid unnecessary
work in guest filtering").
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20210205191324.2889006-1-jmattson@google.com
send_call_function_single_ipi() may wake an idle CPU without sending an
IPI. The woken up CPU will process the SMP-functions in
flush_smp_call_function_from_idle(). Any raised softirq from within the
SMP-function call will not be processed.
Should the CPU have no tasks assigned, then it will go back to idle with
pending softirqs and the NOHZ will rightfully complain.
Process pending softirqs on return from flush_smp_call_function_queue().
Fixes: b2a02fc43a ("smp: Optimize send_call_function_single_ipi()")
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210123201027.3262800-2-bigeasy@linutronix.de
Commit 997acaf6b4 ("lockdep: report broken irq restoration") makes
compiling s390 fail because the irq enable/disable functions are now
no longer fully contained in header files.
Fixes: 997acaf6b4 ("lockdep: report broken irq restoration")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Merely enabling CONFIG_COMPILE_TEST should not enable additional code.
To fix this, restrict the automatic enabling of GPIO_MXS to ARCH_MXS,
and ask the user in case of compile-testing.
Fixes: 6876ca311b ("gpio: mxs: add COMPILE_TEST support for GPIO_MXS")
Cc: <stable@vger.kernel.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Right now, the case of the kernel trying to execute from user memory
is treated more or less just like the kernel getting a page fault on a
user access. In the failure path, it checks for erratum #93, tries to
otherwise fix up the error, and then oopses.
If it manages to jump to the user address space, with or without SMEP,
it should not try to resolve the page fault. This is an error, pure and
simple. Rearrange the code so that this case is caught early, check for
erratum #93, and bail out.
[ bp: Massage commit message. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/ab8719c7afb8bd501c4eee0e36493150fbbe5f6a.1612924255.git.luto@kernel.org
In general, page fault errors for WRUSS should be just like get_user(),
etc. Fix three bugs in this area:
There is a comment that says that, if the kernel can't handle a page fault
on a user address due to OOM, the OOM-kill-and-retry logic would be
skipped. The code checked kernel *privilege*, not kernel mode, so it
missed WRUSS. This means that the kernel would malfunction if it got OOM
on a WRUSS fault -- this would be a kernel-mode, user-privilege fault, and
the OOM killer would be invoked and the handler would retry the faulting
instruction.
A failed user access from kernel while a fatal signal is pending should
fail even if the instruction in question was WRUSS.
do_sigbus() should not send SIGBUS for WRUSS -- it should handle it like
any other kernel mode failure.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/a7b7bcea730bd4069e6b7e629236bb2cf526c2fb.1612924255.git.luto@kernel.org
mm_fault_error() is logically just the end of do_user_addr_fault().
Combine the functions. This makes the code easier to read.
Most of the churn here is from renaming hw_error_code to error_code in
do_user_addr_fault().
This makes no difference at all to the generated code (objdump -dr) as
compared to changing noinline to __always_inline in the definition of
mm_fault_error().
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/dedc4d9c9b047e51ce38b991bd23971a28af4e7b.1612924255.git.luto@kernel.org
printk_safe_flush_on_panic() caused the following deadlock on our
server:
CPU0: CPU1:
panic rcu_dump_cpu_stacks
kdump_nmi_shootdown_cpus nmi_trigger_cpumask_backtrace
register_nmi_handler(crash_nmi_callback) printk_safe_flush
__printk_safe_flush
raw_spin_lock_irqsave(&read_lock)
// send NMI to other processors
apic_send_IPI_allbutself(NMI_VECTOR)
// NMI interrupt, dead loop
crash_nmi_callback
printk_safe_flush_on_panic
printk_safe_flush
__printk_safe_flush
// deadlock
raw_spin_lock_irqsave(&read_lock)
DEADLOCK: read_lock is taken on CPU1 and will never get released.
It happens when panic() stops a CPU by NMI while it has been in
the middle of printk_safe_flush().
Handle the lock the same way as logbuf_lock. The printk_safe buffers
are flushed only when both locks can be safely taken. It can avoid
the deadlock _in this particular case_ at expense of losing contents
of printk_safe buffers.
Note: It would actually be safe to re-init the locks when all CPUs were
stopped by NMI. But it would require passing this information
from arch-specific code. It is not worth the complexity.
Especially because logbuf_lock and printk_safe buffers have been
obsoleted by the lockless ring buffer.
Fixes: cf9b1106c8 ("printk/nmi: flush NMI messages on the system panic")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: <stable@vger.kernel.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210210034823.64867-1-songmuchun@bytedance.com
The value we receive from ACPI is a long long unsigned integer but the
values should be treated as signed char. When comparing the received
value with ACPI_PPAG_MIN_LB/HB, we were doing an unsigned comparison,
so the negative value would actually be treated as a very high number.
To solve this issue, assign the value to our table of s8's before
making the comparison, so the value is already converted when we do
so.
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210210135352.b0ec69f312bc.If77fd9c61a96aa7ef2ac96d935b7efd7df502399@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
The recent rework of probe_kernel_address() and its conversion to
get_kernel_nofault() inadvertently broke is_prefetch(). Before this
change, probe_kernel_address() was used as a sloppy "read user or
kernel memory" helper, but it doesn't do that any more. The new
get_kernel_nofault() reads *kernel* memory only, which completely broke
is_prefetch() for user access.
Adjust the code to the correct accessor based on access mode. The
manual address bounds check is no longer necessary, since the accessor
helpers (get_user() / get_kernel_nofault()) do the right thing all by
themselves. As a bonus, by using the correct accessor, the open-coded
address bounds check is not needed anymore.
[ bp: Massage commit message. ]
Fixes: eab0c6089b ("maccess: unify the probe kernel arch hooks")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/b91f7f92f3367d2d3a88eec3b09c6aab1b2dc8ef.1612924255.git.luto@kernel.org
The ucode TLV data may be read-only and should be treated as const
pointers, but currently a few code forcibly cast to the writable
pointer unnecessarily. This gave developers a wrong impression as if
it can be modified, resulting in crashing regressions already a couple
of times.
This patch adds the const prefix to those cast pointers, so that such
attempt can be caught more easily in future.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20210112132449.22243-3-tiwai@suse.de
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Aspeed's u-boot sdk has been updated with the SoC IDs for the AST2605
variant, as well as A2 and A3 variants of the 2600 family.
>From u-boot's arch/arm/mach-aspeed/ast2600/scu_info.c:
SOC_ID("AST2600-A0", 0x0500030305000303),
SOC_ID("AST2600-A1", 0x0501030305010303),
SOC_ID("AST2620-A1", 0x0501020305010203),
SOC_ID("AST2600-A2", 0x0502030305010303),
SOC_ID("AST2620-A2", 0x0502020305010203),
SOC_ID("AST2605-A2", 0x0502010305010103),
SOC_ID("AST2600-A3", 0x0503030305030303),
SOC_ID("AST2620-A3", 0x0503020305030203),
SOC_ID("AST2605-A3", 0x0503010305030103),
Fixes: e0218dca57 ("soc: aspeed: Add soc info driver")
Link: https://lore.kernel.org/r/20210210114651.334324-1-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
POPF is a rather expensive operation, so don't use it for restoring
irq flags. Instead, test whether interrupts are enabled in the flags
parameter and enable interrupts via STI in that case.
This results in the restore_fl paravirt op to be no longer needed.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210120135555.32594-7-jgross@suse.com
USERGS_SYSRET64 is used to return from a syscall via SYSRET, but
a Xen PV guest will nevertheless use the IRET hypercall, as there
is no sysret PV hypercall defined.
So instead of testing all the prerequisites for doing a sysret and
then mangling the stack for Xen PV again for doing an iret just use
the iret exit from the beginning.
This can easily be done via an ALTERNATIVE like it is done for the
sysenter compat case already.
It should be noted that this drops the optimization in Xen for not
restoring a few registers when returning to user mode, but it seems
as if the saved instructions in the kernel more than compensate for
this drop (a kernel build in a Xen PV guest was slightly faster with
this patch applied).
While at it remove the stale sysret32 remnants.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210120135555.32594-6-jgross@suse.com
