This patch bypass the timer_irq_works() check for hyperv guest since:
- It was guaranteed to work.
- timer_irq_works() may fail sometime due to the lpj calibration were inaccurate
in a hyperv guest or a buggy host.
In the future, we should get the tsc frequency from hypervisor and use preset
lpj instead.
[ hpa: I would prefer to not defer things to "the future" in the future... ]
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: <stable@vger.kernel.org>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/1393558229-14755-1-git-send-email-jasowang@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
destroy_timer_on_stack() is hardly the right thing for a delayed
work. We leak a tracking object for the work itself when DEBUG_OBJECTS
is enabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20140323141940.034005322@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There was a potential lock ordering problem with the module kASLR patch
("x86, kaslr: randomize module base load address"). This patch removes
the usage of the module_mutex and creates a new mutex to protect the
module base address offset value.
Chain exists of:
text_mutex --> kprobe_insn_slots.mutex --> module_mutex
[ 0.515561] Possible unsafe locking scenario:
[ 0.515561]
[ 0.515561] CPU0 CPU1
[ 0.515561] ---- ----
[ 0.515561] lock(module_mutex);
[ 0.515561] lock(kprobe_insn_slots.mutex);
[ 0.515561] lock(module_mutex);
[ 0.515561] lock(text_mutex);
[ 0.515561]
[ 0.515561] *** DEADLOCK ***
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andy Honig <ahonig@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* acpi-processor:
ACPI: Move BAD_MADT_ENTRY() to linux/acpi.h
ACPI / processor: Make it possible to get APIC ID via GIC
ACPI / processor: Build idle_boot_override on x86 and ia64
ACPI / processor: Use ACPI_PROCESSOR_DEVICE_HID instead of "ACPI0007"
ACPI / processor: Fix acpi_processor_eval_pdc() return value type
Many Pentium M systems disable PAE but may have a functionally usable PAE
implementation. This adds the "forcepae" parameter which bypasses the boot
check for PAE, and sets the CPU as being PAE capable. Using this parameter
will taint the kernel with TAINT_CPU_OUT_OF_SPEC.
Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Link: http://lkml.kernel.org/r/20140307114040.GA4997@localhost
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Rename TAINT_UNSAFE_SMP to TAINT_CPU_OUT_OF_SPEC, so we can repurpose
the flag to encompass a wider range of pushing the CPU beyond its
warrany.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Link: http://lkml.kernel.org/r/20140226154949.GA770@redhat.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the hpet code in x86 by using this latter form of callback registration.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the amd-uncore code in x86 by using this latter form of callback
registration.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the intel rapl code in x86 by using this latter form of callback
registration.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the intel cacheinfo code in x86 by using this latter form of callback
registration.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the amd-ibs code in x86 by using this latter form of callback
registration.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After fixing the CPU hotplug callback registration code, the callbacks
invoked for each online CPU, during the initialization phase in
thermal_throttle_init_device(), can no longer race with the actual CPU
hotplug notifier callbacks (in thermal_throttle_cpu_callback). Hence the
therm_cpu_lock is unnecessary now. Remove it.
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the thermal throttle code in x86 by using this latter form of callback
registration.
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the mce code in x86 by using this latter form of callback registration.
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the uncore code in intel-x86 by using this latter form of callback
registration.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the vsyscall code in x86 by using this latter form of callback
registration.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the cpuid code in x86 by using this latter form of callback registration.
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Instead, the correct and race-free way of performing the callback
registration is:
cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);
/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);
cpu_notifier_register_done();
Fix the msr code in x86 by using this latter form of callback registration.
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq: (30 commits)
intel_pstate: Set core to min P state during core offline
cpufreq: Add stop CPU callback to cpufreq_driver interface
cpufreq: Remove unnecessary braces
cpufreq: Fix checkpatch errors and warnings
cpufreq: powerpc: add cpufreq transition latency for FSL e500mc SoCs
cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE}
cpufreq: Do not allow ->setpolicy drivers to provide ->target
cpufreq: arm_big_little: set 'physical_cluster' for each CPU
cpufreq: arm_big_little: make vexpress driver depend on bL core driver
cpufreq: SPEAr: Instantiate as platform_driver
cpufreq: Remove unnecessary variable/parameter 'frozen'
cpufreq: Remove cpufreq_generic_exit()
cpufreq: add 'freq_table' in struct cpufreq_policy
cpufreq: Reformat printk() statements
cpufreq: Tegra: Use cpufreq_generic_suspend()
cpufreq: s5pv210: Use cpufreq_generic_suspend()
cpufreq: exynos: Use cpufreq_generic_suspend()
cpufreq: Implement cpufreq_generic_suspend()
cpufreq: suspend governors on system suspend/hibernate
cpufreq: move call to __find_governor() to cpufreq_init_policy()
...
Resource management
- Revert "Insert GART region into resource map"
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Merge tag 'pci-v3.14-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI resource management fix from Bjorn Helgaas:
"This is a fix for an AGP regression exposed by e501b3d87f ("agp:
Support 64-bit APBASE"), which we merged in v3.14-rc1.
We've warned about the conflict between the GART and PCI resources and
cleared out the PCI resource for a long time, but after e501b3d87f,
we still *use* that cleared-out PCI resource. I think the GART
resource is incorrect, so this patch removes it"
* tag 'pci-v3.14-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
Revert "[PATCH] Insert GART region into resource map"
Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have
not been used for some time, so remove them to clean up code a bit.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This reverts commit 56dd669a13, which makes the GART visible in
/proc/iomem. This fixes a regression: e501b3d87f ("agp: Support 64-bit
APBASE") exposed an existing problem with a conflict between the GART
region and a PCI BAR region.
The GART addresses are bus addresses, not CPU addresses, and therefore
should not be inserted in iomem_resource.
On many machines, the GART region is addressable by the CPU as well as by
an AGP master, but CPU addressability is not required by the spec. On some
of these machines, the GART is mapped by a PCI BAR, and in that case, the
PCI core automatically inserts it into iomem_resource, just as it does for
all BARs.
Inserting it here means we'll have a conflict if the PCI core later tries
to claim the GART region, so let's drop the insertion here.
The conflict indirectly causes X failures, as reported by Jouni in the
bugzilla below. We detected the conflict even before e501b3d87f, but
after it the AGP code (fix_northbridge()) uses the PCI resource (which is
zeroed because of the conflict) instead of reading the BAR again.
Conflicts:
arch/x86_64/kernel/aperture.c
Fixes: e501b3d87f agp: Support 64-bit APBASE
Link: https://bugzilla.kernel.org/show_bug.cgi?id=72201
Reported-and-tested-by: Jouni Mettälä <jtmettala@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
By coincidence, the VVAR page is at the end of an ELF segment. As a
result, if it ends up being a partial page, the kernel loader will
leave garbage behind at the end of the vvar page. Zero-pad it to a
full page to fix this issue.
This has probably been broken since the VVAR page was introduced.
On QEMU, if you dump the run-time contents of the VVAR page, you can
find entertaining strings from seabios left behind.
It's remotely possible that this is a security bug -- conceivably
there's some BIOS out there that leaves something sensitive in the
few K of memory that is exposed to userspace.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-12-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch add the VDSO time support for the IA32 Emulation Layer.
Due the nature of the kernel headers and the LP64 compiler where the
size of a long and a pointer differs against a 32 bit compiler, there
is some type hacking necessary for optimal performance.
The vsyscall_gtod_data struture must be a rearranged to serve 32- and
64-bit code access at the same time:
- The seqcount_t was replaced by an unsigned, this makes the
vsyscall_gtod_data intedepend of kernel configuration and internal functions.
- All kernel internal structures are replaced by fix size elements
which works for 32- and 64-bit access
- The inner struct clock was removed to pack the whole struct.
The "unsigned seq" would be handled by functions derivated from seqcount_t.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-11-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch move the vsyscall_gtod_data handling out of vsyscall_64.c
into an additonal file vsyscall_gtod.c to make the functionality
available for x86 32 bit kernel.
It also adds a new vsyscall_32.c which setup the VVAR page.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-2-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull perf fixes from Ingo Molnar:
"Misc smaller fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix leak in uncore_type_init failure paths
perf machine: Use map as success in ip__resolve_ams
perf symbols: Fix crash in elf_section_by_name
perf trace: Decode architecture-specific signal numbers
Pull x86 fixes from Peter Anvin:
"Two x86 fixes: Suresh's eager FPU fix, and a fix to the NUMA quirk for
AMD northbridges.
This only includes Suresh's fix patch, not the "mostly a cleanup"
patch which had __init issues"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/amd/numa: Fix northbridge quirk to assign correct NUMA node
x86, fpu: Check tsk_used_math() in kernel_fpu_end() for eager FPU
For systems with multiple servers and routed fabric, all
northbridges get assigned to the first server. Fix this by also
using the node reported from the PCI bus. For single-fabric
systems, the northbriges are on PCI bus 0 by definition, which
are on NUMA node 0 by definition, so this is invarient on most
systems.
Tested on fam10h and fam15h single and multi-fabric systems and
candidate for stable.
Signed-off-by: Daniel J Blueman <daniel@numascale.com>
Acked-by: Steffen Persvold <sp@numascale.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1394710981-3596-1-git-send-email-daniel@numascale.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Replace somewhat arbitrary constants for bits in MSR_IA32_MISC_ENABLE
with verbose but systematic ones. Add _BIT defines for all the rest
of them, too.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Merge the request/release callbacks which are in a separate branch for
consumption by the gpio folks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch fixes a compilation problem (unused variable) with the
new SNB/IVB/HSW uncore IMC code.
[ In -v2 we simplify the fix as suggested by Peter Zjilstra. ]
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140311235329.GA28624@quad
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For non-eager fpu mode, thread's fpu state is allocated during the first
fpu usage (in the context of device not available exception). This
(math_state_restore()) can be a blocking call and hence we enable
interrupts (which were originally disabled when the exception happened),
allocate memory and disable interrupts etc.
But the eager-fpu mode, call's the same math_state_restore() from
kernel_fpu_end(). The assumption being that tsk_used_math() is always
set for the eager-fpu mode and thus avoid the code path of enabling
interrupts, allocating fpu state using blocking call and disable
interrupts etc.
But the below issue was noticed by Maarten Baert, Nate Eldredge and
few others:
If a user process dumps core on an ecrypt fs while aesni-intel is loaded,
we get a BUG() in __find_get_block() complaining that it was called with
interrupts disabled; then all further accesses to our ecrypt fs hang
and we have to reboot.
The aesni-intel code (encrypting the core file that we are writing) needs
the FPU and quite properly wraps its code in kernel_fpu_{begin,end}(),
the latter of which calls math_state_restore(). So after kernel_fpu_end(),
interrupts may be disabled, which nobody seems to expect, and they stay
that way until we eventually get to __find_get_block() which barfs.
For eager fpu, most the time, tsk_used_math() is true. At few instances
during thread exit, signal return handling etc, tsk_used_math() might
be false.
In kernel_fpu_end(), for eager-fpu, call math_state_restore()
only if tsk_used_math() is set. Otherwise, don't bother. Kernel code
path which cleared tsk_used_math() knows what needs to be done
with the fpu state.
Reported-by: Maarten Baert <maarten-baert@hotmail.com>
Reported-by: Nate Eldredge <nate@thatsmathematics.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Suresh Siddha <sbsiddha@gmail.com>
Link: http://lkml.kernel.org/r/1391410583.3801.6.camel@europa
Cc: George Spelvin <linux@horizon.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This was an optimization that made memcpy type benchmarks a little
faster on ancient (Circa 1998) IDT Winchip CPUs. In real-life
workloads, it wasn't even noticable, and I doubt anyone is running
benchmarks on 16 year old silicon any more.
Given this code has likely seen very little use over the last decade,
let's just remove it.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
apic_icr_write() and its users in smpboot.c were apparently
written under the assumption that this code would only run
during early boot. But nowadays we also execute it when onlining
a CPU later on while the system is fully running. That will make
wakeup_cpu_via_init_nmi and, thus, also native_apic_icr_write
run in plain process context. If we migrate the caller to a
different CPU at the wrong time or interrupt it and write to
ICR/ICR2 to send unrelated IPIs, we can end up sending INIT,
SIPI or NMIs to wrong CPUs.
Fix this by disabling interrupts during the write to the ICR
halves and disable preemption around waiting for ICR
availability and using it.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-By: Igor Mammedov <imammedo@redhat.com>
Link: http://lkml.kernel.org/r/52E6AFFE.3030004@siemens.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 028a690a1e "i386: Remove unneeded test of 'task' in
dump_trace()" correctly removed the unneeded 'task != NULL'
check because it would be set to current if it was NULL.
Commit 2bc5f927d4 "i386: split out dumpstack code from
traps_32.c" moved the code from traps_32.c to its own file
dump_stack.c for preparation of the i386 / x86_64 merge.
Commit 8a541665b9 "dumpstack: x86: various small unification
steps" worked to make i386 and x86_64 dump_stack logic similar.
But this actually reverted the correct change from
028a690a1e.
Commit d0caf29250 "x86/dumpstack: Remove unneeded check in
dump_trace()" removed the unneeded "task != NULL" check for
x86_64 but left that same unneeded check for i386, that was
added because x86_64 had it!
This chain of events ironically had i386 add back the unneeded
task != NULL check because x86_64 did it, and then the fix for
x86_64 was fixed by Dan. And even more ironically, it was Dan's
smatch bot that told me that a change to dump_stack_32 I made
may be wrong if current can be NULL (it can't), as there was a
check for it by assigning task to current, and then checking if
task is NULL.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Cc: Jesper Juhl <jesper.juhl@gmail.com>
Link: http://lkml.kernel.org/r/20140307105242.79a0befd@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The error path of uncore_type_init() frees up any allocations
that were made along the way, but it relies upon type->pmus
being set, which only happens if the function succeeds. As
type->pmus remains null in this case, the call to
uncore_type_exit will do nothing.
Moving the assignment earlier will allow us to actually free
those allocations should something go awry.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140306172028.GA552@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
411cf180fa perf/x86/uncore: fix initialization of cpumask
introduced the function uncore_cpumask_init(), which is only
called in __init intel_uncore_init(). But it is not marked
with __init, which produces the following warning:
WARNING: vmlinux.o(.text+0x2464a): Section mismatch in reference from the function uncore_cpumask_init() to the function .init.text:uncore_cpu_setup()
The function uncore_cpumask_init() references
the function __init uncore_cpu_setup().
This is often because uncore_cpumask_init lacks a __init
annotation or the annotation of uncore_cpu_setup is wrong.
This patch marks uncore_cpumask_init() with __init.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1394013516-4964-1-git-send-email-yangds.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch restores the changes of commit dff38e3e93 "x86: Use inline
assembler instead of global register variable to get sp". They got lost
in commit 198d208df4 "x86: Keep thread_info on thread stack in x86_32"
while moving the code to arch/x86/kernel/irq_32.c.
Quoting Andi from commit dff38e3e93:
"""
LTO in gcc 4.6/47. has trouble with global register variables. They were
used to read the stack pointer. Use a simple inline assembler statement
with a mov instead.
This also helps LLVM/clang, which does not support global register
variables.
"""
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Link: http://lkml.kernel.org/r/1394178752-18047-1-git-send-email-minipli@googlemail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
It's an enum, not a #define, you can't use it in asm files.
Introduced in commit 5fa10196bd ("x86: Ignore NMIs that come in during
early boot"), and sadly I didn't compile-test things like I should have
before pushing out.
My weak excuse is that the x86 tree generally doesn't introduce stupid
things like this (and the ARM pull afterwards doesn't cause me to do a
compile-test either, since I don't cross-compile).
Cc: Don Zickus <dzickus@redhat.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don Zickus reports:
A customer generated an external NMI using their iLO to test kdump
worked. Unfortunately, the machine hung. Disabling the nmi_watchdog
made things work.
I speculated the external NMI fired, caused the machine to panic (as
expected) and the perf NMI from the watchdog came in and was latched.
My guess was this somehow caused the hang.
----
It appears that the latched NMI stays latched until the early page
table generation on 64 bits, which causes exceptions to happen which
end in IRET, which re-enable NMI. Therefore, ignore NMIs that come in
during early execution, until we have proper exception handling.
Reported-and-tested-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1394221143-29713-1-git-send-email-dzickus@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.5+, older with some backport effort
Ftrace modifies function calls using Int3 breakpoints on x86.
The breakpoints are handled only when the patching is in progress.
If something goes wrong, there is a recovery code that removes
the breakpoints. If this fails, the system might get silently
rebooted when a remaining break is not handled or an invalid
instruction is proceed.
We should BUG() when the breakpoint could not be removed. Otherwise,
the system silently crashes when the function finishes the Int3
handler is disabled.
Note that we need to modify remove_breakpoint() to return non-zero
value only when there is an error. The return value was ignored before,
so it does not cause any troubles.
Link: http://lkml.kernel.org/r/1393258342-29978-4-git-send-email-pmladek@suse.cz
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As the data parameter is not really used by any ftrace_dyn_arch_init,
remove that from ftrace_dyn_arch_init. This also removes the addr
local variable from ftrace_init which is now unused.
Note the documentation was imprecise as it did not suggest to set
(*data) to 0.
Link: http://lkml.kernel.org/r/1393268401-24379-4-git-send-email-jslaby@suse.cz
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
No architecture uses the "data" parameter in ftrace_dyn_arch_init() in any
way, it just sets the value to 0. And this is used as a return value
in the caller -- ftrace_init, which just checks the retval against
zero.
Note there is also "return 0" in every ftrace_dyn_arch_init. So it is
enough to check the retval and remove all the indirect sets of data on
all archs.
Link: http://lkml.kernel.org/r/1393268401-24379-3-git-send-email-jslaby@suse.cz
Cc: linux-arch@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Having ftrace_write() return -EPERM on failure, as that's what the callers
return, then we can clean up the code a bit. That is, instead of:
if (ftrace_write(...))
return -EPERM;
return 0;
or
if (ftrace_write(...)) {
ret = -EPERM;
goto_out;
}
We can instead have:
return ftrace_write(...);
or
ret = ftrace_write(...);
if (ret)
goto out;
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The dump_trace() function in dumpstack_64.c is hard to follow.
The test for exception stack is processed differently than the
test for irq stack, and the normal stack is outside completely.
By restructuring this code to have all the stacks determined by
a single function that returns an enum of the following:
STACK_IS_NORMAL
STACK_IS_EXCEPTION
STACK_IS_IRQ
STACK_IS_UNKNOWN
and has the logic of each within a switch statement.
This should make the code much easier to read and understand.
Link: http://lkml.kernel.org/r/20110806012354.684598995@goodmis.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140206144322.086050042@goodmis.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86_64 uses a per_cpu variable kernel_stack to always point to
the thread stack of current. This is where the thread_info is stored
and is accessed from this location even when the irq or exception stack
is in use. This removes the complexity of having to maintain the
thread info on the stack when interrupts are running and having to
copy the preempt_count and other fields to the interrupt stack.
x86_32 uses the old method of copying the thread_info from the thread
stack to the exception stack just before executing the exception.
Having the two different requires #ifdefs and also the x86_32 way
is a bit of a pain to maintain. By converting x86_32 to the same
method of x86_64, we can remove #ifdefs, clean up the x86_32 code
a little, and remove the overhead of the copy.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20110806012354.263834829@goodmis.org
Link: http://lkml.kernel.org/r/20140206144321.852942014@goodmis.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The i386 thread_info contains a previous_esp field that is used
to daisy chain the different stacks for dump_stack()
(ie. irq, softirq, thread stacks).
The goal is to eventual make i386 handling of thread_info the same
as x86_64, which means that the thread_info will not be in the stack
but as a per_cpu variable. We will no longer depend on thread_info
being able to daisy chain different stacks as it will only exist
in one location (the thread stack).
By moving previous_esp to the end of thread_info and referencing
it as an offset instead of using a thread_info field, this becomes
a stepping stone to moving the thread_info.
The offset to get to the previous stack is rather ugly in this
patch, but this is only temporary and the prev_esp will be changed
in the next commit. This commit is more for sanity checks of the
change.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Robert Richter <rric@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20110806012353.891757693@goodmis.org
Link: http://lkml.kernel.org/r/20140206144321.608754481@goodmis.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Only CF9_COND is appropriate for inclusion in the default chain, not
CF9; the latter will poke that register unconditionally, whereas
CF9_COND will at least look for PCI configuration method #1 or #2
first (a weak check, but better than nothing.)
CF9 should be used for explicit system configuration (command line or
DMI) only.
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Link: http://lkml.kernel.org/r/53130A46.1010801@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Reboot is the last service linux OS provides to the end user. We are
supposed to make this function more robust than today. This patch adds
all of the known reboot methods into the default attempt list. The
machines requiring reboot=efi or reboot=p or reboot=bios get a chance
to reboot automatically now.
If there is a new reboot method emerged, we are supposed to add it to
the default list as well, instead of adding the endless dmidecode entry.
If one method required is in the default list in this patch but the
machine reboot still hangs, that means some methods ahead of the
required method cause the system hangs, then reboot the machine by
passing reboot= arguments and submit the reboot dmidecode table quirk.
We are supposed to remove the reboot dmidecode table from the kernel,
but to be safe, we keep it. This patch prevents us from adding more.
If you happened to have a machine listed in the reboot dmidecode
table and this patch makes reboot work on your machine, please submit
a patch to remove the quirk.
The default reboot order with this patch is now:
ACPI > KBD > ACPI > KBD > EFI > CF9_COND > BIOS
Because BIOS and TRIPLE are mutually exclusive (either will either
work or hang the machine) that method is not included.
[ hpa: as with any changes to the reboot order, this patch will have
to be monitored carefully for regressions. ]
Signed-off-by: Aubrey Li <aubrey.li@intel.com>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Link: http://lkml.kernel.org/r/53130A46.1010801@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Compiling last minute changes without setting the proper config
options is not really clever.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
causes a crash during boot - Borislav Petkov
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Merge tag 'efi-urgent' into x86/urgent
* Disable the new EFI 1:1 virtual mapping for SGI UV because using it
causes a crash during boot - Borislav Petkov
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Alex reported hitting the following BUG after the EFI 1:1 virtual
mapping work was merged,
kernel BUG at arch/x86/mm/init_64.c:351!
invalid opcode: 0000 [#1] SMP
Call Trace:
[<ffffffff818aa71d>] init_extra_mapping_uc+0x13/0x15
[<ffffffff818a5e20>] uv_system_init+0x22b/0x124b
[<ffffffff8108b886>] ? clockevents_register_device+0x138/0x13d
[<ffffffff81028dbb>] ? setup_APIC_timer+0xc5/0xc7
[<ffffffff8108b620>] ? clockevent_delta2ns+0xb/0xd
[<ffffffff818a3a92>] ? setup_boot_APIC_clock+0x4a8/0x4b7
[<ffffffff8153d955>] ? printk+0x72/0x74
[<ffffffff818a1757>] native_smp_prepare_cpus+0x389/0x3d6
[<ffffffff818957bc>] kernel_init_freeable+0xb7/0x1fb
[<ffffffff81535530>] ? rest_init+0x74/0x74
[<ffffffff81535539>] kernel_init+0x9/0xff
[<ffffffff81541dfc>] ret_from_fork+0x7c/0xb0
[<ffffffff81535530>] ? rest_init+0x74/0x74
Getting this thing to work with the new mapping scheme would need more
work, so automatically switch to the old memmap layout for SGI UV.
Acked-by: Russ Anderson <rja@sgi.com>
Cc: Alex Thorlton <athorlton@sgi.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reported-by: fengguang.wu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linuxdrivers <devel@linuxdriverproject.org>
Cc: x86 <x86@kernel.org>
Commit 1aec16967 (x86: Hyperv: Cleanup the irq mess) removed the
ability to build the hyperv stuff as a module. Bring it back.
Reported-by: fengguang.wu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linuxdrivers <devel@linuxdriverproject.org>
Cc: x86 <x86@kernel.org>
The vmbus/hyperv interrupt handling is another complete trainwreck and
probably the worst of all currently in tree.
If CONFIG_HYPERV=y then the interrupt delivery to the vmbus happens
via the direct HYPERVISOR_CALLBACK_VECTOR. So far so good, but:
The driver requests first a normal device interrupt. The only reason
to do so is to increment the interrupt stats of that device
interrupt. For no reason it also installs a private flow handler.
We have proper accounting mechanisms for direct vectors, but of
course it's too much effort to add that 5 lines of code.
Aside of that the alloc_intr_gate() is not protected against
reallocation which makes module reload impossible.
Solution to the problem is simple to rip out the whole mess and
implement it correctly.
First of all move all that code to arch/x86/kernel/cpu/mshyperv.c and
merily install the HYPERVISOR_CALLBACK_VECTOR with proper reallocation
protection and use the proper direct vector accounting mechanism.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linuxdrivers <devel@linuxdriverproject.org>
Cc: x86 <x86@kernel.org>
Link: http://lkml.kernel.org/r/20140223212739.028307673@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
HyperV abuses a device interrupt to account for the
HYPERVISOR_CALLBACK_VECTOR.
Provide proper accounting as we have for the other vectors as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: x86 <x86@kernel.org>
Link: http://lkml.kernel.org/r/20140223212738.681855582@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
As we grow support for more EFI architectures they're going to want the
ability to query which EFI features are available on the running system.
Instead of storing this information in an architecture-specific place,
stick it in the global 'struct efi', which is already the central
location for EFI state.
While we're at it, let's change the return value of efi_enabled() to be
bool and replace all references to 'facility' with 'feature', which is
the usual word used to describe the attributes of the running system.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
If a failure occurs while modifying ftrace function, it bails out and will
remove the tracepoints to be back to what the code originally was.
There is missing the final sync run across the CPUs after the fix up is done
and before the ftrace int3 handler flag is reset.
Here's the description of the problem:
CPU0 CPU1
---- ----
remove_breakpoint();
modifying_ftrace_code = 0;
[still sees breakpoint]
<takes trap>
[sees modifying_ftrace_code as zero]
[no breakpoint handler]
[goto failed case]
[trap exception - kernel breakpoint, no
handler]
BUG()
Link: http://lkml.kernel.org/r/1393258342-29978-2-git-send-email-pmladek@suse.cz
Fixes: 8a4d0a687a "ftrace: Use breakpoint method to update ftrace caller"
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If a failure occurs while enabling a trace, it bails out and will remove
the tracepoints to be back to what the code originally was. But the fix
up had some bugs in it. By injecting a failure in the code, the fix up
ran to completion, but shortly afterward the system rebooted.
There was two bugs here.
The first was that there was no final sync run across the CPUs after the
fix up was done, and before the ftrace int3 handler flag was reset. That
means that other CPUs could still see the breakpoint and trigger on it
long after the flag was cleared, and the int3 handler would think it was
a spurious interrupt. Worse yet, the int3 handler could hit other breakpoints
because the ftrace int3 handler flag would have prevented the int3 handler
from going further.
Here's a description of the issue:
CPU0 CPU1
---- ----
remove_breakpoint();
modifying_ftrace_code = 0;
[still sees breakpoint]
<takes trap>
[sees modifying_ftrace_code as zero]
[no breakpoint handler]
[goto failed case]
[trap exception - kernel breakpoint, no
handler]
BUG()
The second bug was that the removal of the breakpoints required the
"within()" logic updates instead of accessing the ip address directly.
As the kernel text is mapped read-only when CONFIG_DEBUG_RODATA is set, and
the removal of the breakpoint is a modification of the kernel text.
The ftrace_write() includes the "within()" logic, where as, the
probe_kernel_write() does not. This prevented the breakpoint from being
removed at all.
Link: http://lkml.kernel.org/r/1392650573-3390-1-git-send-email-pmladek@suse.cz
Reported-by: Petr Mladek <pmladek@suse.cz>
Tested-by: Petr Mladek <pmladek@suse.cz>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull perf fixes from Ingo Molnar:
"Misc fixes, most of them on the tooling side"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix strict alias issue for find_first_bit
perf tools: fix BFD detection on opensuse
perf: Fix hotplug splat
perf/x86: Fix event scheduling
perf symbols: Destroy unused symsrcs
perf annotate: Check availability of annotate when processing samples
Extend ECC decoding support for F16h M30h. Tested on F16h M30h with ECC
turned on using mce_amd_inj module and the patch works fine.
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Link: http://lkml.kernel.org/r/1392913726-16961-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Tested-by: Arindam Nath <Arindam.Nath@amd.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
We call this "clflush" in /proc/cpuinfo, and have
cpu_has_clflush()... let's be consistent and just call it that.
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-mlytfzjkvuf739okyn40p8a5@git.kernel.org
The NUMAQ support seems to be unmaintained, remove it.
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/n/530CFD6C.7040705@zytor.com
The SGI Visual Workstation seems to be dead; remove support so we
don't have to continue maintaining it.
Cc: Andrey Panin <pazke@donpac.ru>
Cc: Michael Reed <mdr@sgi.com>
Link: http://lkml.kernel.org/r/530CFD6C.7040705@zytor.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Add a few comments on the ->add(), ->del() and ->*_txn()
implementation.
Requested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-he3819318c245j7t5e1e22tr@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince "Super Tester" Weaver reported a new round of syscall fuzzing (Trinity) failures,
with perf WARN_ON()s triggering. He also provided traces of the failures.
This is I think the relevant bit:
> pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_disable: x86_pmu_disable
> pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_state: Events: {
> pec_1076_warn-2804 [000] d... 147.926156: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null))
> pec_1076_warn-2804 [000] d... 147.926158: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926159: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926160: x86_pmu_state: n_events: 1, n_added: 0, n_txn: 1
> pec_1076_warn-2804 [000] d... 147.926161: x86_pmu_state: Assignment: {
> pec_1076_warn-2804 [000] d... 147.926162: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926163: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926166: collect_events: Adding event: 1 (ffff880119ec8800)
So we add the insn:p event (fd[23]).
At this point we should have:
n_events = 2, n_added = 1, n_txn = 1
> pec_1076_warn-2804 [000] d... 147.926170: collect_events: Adding event: 0 (ffff8800c9e01800)
> pec_1076_warn-2804 [000] d... 147.926172: collect_events: Adding event: 4 (ffff8800cbab2c00)
We try and add the {BP,cycles,br_insn} group (fd[3], fd[4], fd[15]).
These events are 0:cycles and 4:br_insn, the BP event isn't x86_pmu so
that's not visible.
group_sched_in()
pmu->start_txn() /* nop - BP pmu */
event_sched_in()
event->pmu->add()
So here we should end up with:
0: n_events = 3, n_added = 2, n_txn = 2
4: n_events = 4, n_added = 3, n_txn = 3
But seeing the below state on x86_pmu_enable(), the must have failed,
because the 0 and 4 events aren't there anymore.
Looking at group_sched_in(), since the BP is the leader, its
event_sched_in() must have succeeded, for otherwise we would not have
seen the sibling adds.
But since neither 0 or 4 are in the below state; their event_sched_in()
must have failed; but I don't see why, the complete state: 0,0,1:p,4
fits perfectly fine on a core2.
However, since we try and schedule 4 it means the 0 event must have
succeeded! Therefore the 4 event must have failed, its failure will
have put group_sched_in() into the fail path, which will call:
event_sched_out()
event->pmu->del()
on 0 and the BP event.
Now x86_pmu_del() will reduce n_events; but it will not reduce n_added;
giving what we see below:
n_event = 2, n_added = 2, n_txn = 2
> pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_enable: x86_pmu_enable
> pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_state: Events: {
> pec_1076_warn-2804 [000] d... 147.926179: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null))
> pec_1076_warn-2804 [000] d... 147.926181: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926182: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: n_events: 2, n_added: 2, n_txn: 2
> pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: Assignment: {
> pec_1076_warn-2804 [000] d... 147.926186: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: 1->0 tag: 1 config: 1 (ffff880119ec8800)
> pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926190: x86_pmu_enable: S0: hwc->idx: 33, hwc->last_cpu: 0, hwc->last_tag: 1 hwc->state: 0
So the problem is that x86_pmu_del(), when called from a
group_sched_in() that fails (for whatever reason), and without x86_pmu
TXN support (because the leader is !x86_pmu), will corrupt the n_added
state.
Reported-and-Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20140221150312.GF3104@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Randomize the load address of modules in the kernel to make kASLR
effective for modules. Modules can only be loaded within a particular
range of virtual address space. This patch adds 10 bits of entropy to
the load address by adding 1-1024 * PAGE_SIZE to the beginning range
where modules are loaded.
The single base offset was chosen because randomizing each module
load ends up wasting/fragmenting memory too much. Prior approaches to
minimizing fragmentation while doing randomization tend to result in
worse entropy than just doing a single base address offset.
Example kASLR boot without this change, with a single module loaded:
---[ Modules ]---
0xffffffffc0000000-0xffffffffc0001000 4K ro GLB x pte
0xffffffffc0001000-0xffffffffc0002000 4K ro GLB NX pte
0xffffffffc0002000-0xffffffffc0004000 8K RW GLB NX pte
0xffffffffc0004000-0xffffffffc0200000 2032K pte
0xffffffffc0200000-0xffffffffff000000 1006M pmd
---[ End Modules ]---
Example kASLR boot after this change, same module loaded:
---[ Modules ]---
0xffffffffc0000000-0xffffffffc0200000 2M pmd
0xffffffffc0200000-0xffffffffc03bf000 1788K pte
0xffffffffc03bf000-0xffffffffc03c0000 4K ro GLB x pte
0xffffffffc03c0000-0xffffffffc03c1000 4K ro GLB NX pte
0xffffffffc03c1000-0xffffffffc03c3000 8K RW GLB NX pte
0xffffffffc03c3000-0xffffffffc0400000 244K pte
0xffffffffc0400000-0xffffffffff000000 1004M pmd
---[ End Modules ]---
Signed-off-by: Andy Honig <ahonig@google.com>
Link: http://lkml.kernel.org/r/20140226005916.GA27083@www.outflux.net
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Include kASLR offset in VMCOREINFO ELF notes to assist in debugging.
[ hpa: pushing this for v3.14 to avoid having a kernel version with
kASLR where we can't debug output. ]
Signed-off-by: Eugene Surovegin <surovegin@google.com>
Link: http://lkml.kernel.org/r/20140123173120.GA25474@www.outflux.net
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 fixes from Thomas Gleixner:
- a bugfix which prevents a divide by 0 panic when the newly introduced
try_msr_calibrate_tsc() fails
- enablement of the Baytrail platform to utilize the newfangled msr
based calibration
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: tsc: Add missing Baytrail frequency to the table
x86, tsc: Fallback to normal calibration if fast MSR calibration fails
These days hv_clock allocation is memblock based (i.e. the percpu
allocator is not involved), which means that the physical address
of each of the per-cpu hv_clock areas is guaranteed to remain
unchanged through all its lifetime and we do not need to update
its location after CPU bring-up.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch updates the CBOX PMU filters mapping tables for SNB-EP
and IVT (model 45 and 62 respectively).
The NID umask always comes in addition to another umask.
When set, the NID filter is applied.
The current mapping tables were missing some code/umask
combinations to account for the NID umask. This patch
fixes that.
Cc: mingo@elte.hu
Cc: ak@linux.intel.com
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140219131018.GA24475@quad
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The current code simply assumes Intel Arch PerfMon v2+ to have
the IA32_PERF_CAPABILITIES MSR; the SDM specifies that we should check
CPUID[1].ECX[15] (aka, FEATURE_PDCM) instead.
This was found by KVM which implements v2+ but didn't provide the
capabilities MSR. Change the code to DTRT; KVM will also implement the
MSR and return 0.
Cc: pbonzini@redhat.com
Reported-by: "Michael S. Tsirkin" <mst@redhat.com>
Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140203132903.GI8874@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When using BTS on Core i7-4*, I get the below kernel warning.
$ perf record -c 1 -e branches:u ls
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317893] Uhhuh. NMI received for unknown reason 31 on CPU 2.
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317920] Do you have a strange power saving mode enabled?
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317945] Dazed and confused, but trying to continue
Make intel_pmu_handle_irq() take the full exit path when returning early.
Cc: eranian@google.com
Cc: peterz@infradead.org
Cc: mingo@kernel.org
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392425048-5309-1-git-send-email-andi@firstfloor.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch is needed because that PMU uses 32-bit free
running counters with no interrupt capabilities.
On SNB/IVB/HSW, we used 20GB/s theoretical peak to calculate
the hrtimer timeout necessary to avoid missing an overflow.
That delay is set to 5s to be on the cautious side.
The SNB IMC uses free running counters, which are handled
via pseudo fixed counters. The SNB IMC PMU implementation
supports an arbitrary number of events, because the counters
are read-only. Therefore it is not possible to track active
counters. Instead we put active events on a linked list which
is then used by the hrtimer handler to update the SW counts.
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: ak@linux.intel.com
Cc: zheng.z.yan@intel.com
Cc: peterz@infradead.org
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392132015-14521-8-git-send-email-eranian@google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch makes the hrtimer timeout configurable per PMU
box. Not all counters have necessarily the same width and
rate, thus the default timeout of 60s may need to be adjusted.
This patch adds box->hrtimer_duration. It is set to default
when the box is allocated. It can be overriden when the box
is initialized.
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: ak@linux.intel.com
Cc: zheng.z.yan@intel.com
Cc: peterz@infradead.org
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392132015-14521-5-git-send-email-eranian@google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On certain processors, the uncore PMU boxes may only be
msr-bsed or PCI-based. But in both cases, the cpumask,
suggesting on which CPUs to monitor to get full coverage
of the particular PMU, must be created.
However with the current code base, the cpumask was only
created on processor which had at least one MSR-based
uncore PMU. This patch removes that restriction and
ensures the cpumask is created even when there is no
msr-based PMU. For instance, on SNB client where only
a PCI-based memory controller PMU is supported.
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: ak@linux.intel.com
Cc: zheng.z.yan@intel.com
Cc: peterz@infradead.org
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392132015-14521-2-git-send-email-eranian@google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Current ACPI cpu hotplug driver fails to associate hot-added CPUs with
corresponding NUMA node when doing socket online. The code path to
associate CPU with NUMA node is as below:
acpi_processor_add()
->acpi_processor_get_info()
->acpi_processor_hotadd_init()
->acpi_map_lsapic()
->_acpi_map_lsapic()
->acpi_map_cpu2node()
cpu_subsys_online()
->try_online_node()
->node_set_online()
When doing socket online, a new NUMA node is introduced in addition to
hot-added CPU and memory device. And the new NUMA node is marked as
online when onlining hot-added CPUs through sysfs interface
/sys/devices/system/cpu/cpuxx/online.
On the other hand, acpi_map_cpu2node() will only build the CPU to node
map if corresponding NUMA node is already online, so it always fails
to associate hot-added CPUs with corresponding NUMA node because the
NUMA node is still in offline state.
For the fix, we could safely remove the "node_online(node)" check in
function acpi_map_cpu2node() because it's only called for hot-added CPUs
by acpi_processor_hotadd_init().
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1390185115-26850-1-git-send-email-jiang.liu@linux.intel.com
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull DMA-mapping fixes from Marek Szyprowski:
"This contains fixes for incorrect atomic test in dma-mapping subsystem
for ARM and x86 architecture"
* 'fixes-for-v3.14' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
x86: dma-mapping: fix GFP_ATOMIC macro usage
ARM: dma-mapping: fix GFP_ATOMIC macro usage
Linux uses CPUID.MWAIT.EDX to validate the C-states
reported by ACPI, silently discarding states which
are not supported by the HW.
This test is too restrictive, as some HW now uses
sparse sub-state numbering, so the sub-state number
may be higher than the number of sub-states...
Also, rather than silently ignoring an invalid state,
we should complain about a firmware bug.
In practice...
Bay Trail systems originally supported C6-no-shrink as
MWAIT sub-state 0x58, and in CPUID.MWAIT.EDX 0x03000000
indicated that there were 3 MWAIT-C6 sub-states.
So acpi_idle would discard that C-state because 8 >= 3.
Upon discovering this issue, the ucode was updated so that
C6-no-shrink was also exported as 0x51, and the BIOS was
updated to match. However, systems shipped with 0x58,
will never get a BIOS update, and this patch allows
Linux to see C6-no-shrink on early Bay Trail.
Signed-off-by: Len Brown <len.brown@intel.com>
Intel Baytrail is based on Silvermont core so MSR_FSB_FREQ[2:0] == 0 means
that the CPU reference clock runs at 83.3MHz. Add this missing frequency to
the table.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1392810750-18660-2-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we cannot calibrate TSC via MSR based calibration
try_msr_calibrate_tsc() stores zero to fast_calibrate and returns that
to the caller. This value gets then propagated further to clockevents
code resulting division by zero oops like the one below:
divide error: 0000 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.13.0+ #47
task: ffff880075508000 ti: ffff880075506000 task.ti: ffff880075506000
RIP: 0010:[<ffffffff810aec14>] [<ffffffff810aec14>] clockevents_config.part.3+0x24/0xa0
RSP: 0000:ffff880075507e58 EFLAGS: 00010246
RAX: ffffffffffffffff RBX: ffff880079c0cd80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffffffffff
RBP: ffff880075507e70 R08: 0000000000000001 R09: 00000000000000be
R10: 00000000000000bd R11: 0000000000000003 R12: 000000000000b008
R13: 0000000000000008 R14: 000000000000b010 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff880079c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff880079fff000 CR3: 0000000001c0b000 CR4: 00000000001006f0
Stack:
ffff880079c0cd80 000000000000b008 0000000000000008 ffff880075507e88
ffffffff810aecb0 ffff880079c0cd80 ffff880075507e98 ffffffff81030168
ffff880075507ed8 ffffffff81d1104f 00000000000000c3 0000000000000000
Call Trace:
[<ffffffff810aecb0>] clockevents_config_and_register+0x20/0x30
[<ffffffff81030168>] setup_APIC_timer+0xc8/0xd0
[<ffffffff81d1104f>] setup_boot_APIC_clock+0x4cc/0x4d8
[<ffffffff81d0f5de>] native_smp_prepare_cpus+0x3dd/0x3f0
[<ffffffff81d02ee9>] kernel_init_freeable+0xc3/0x205
[<ffffffff8177c910>] ? rest_init+0x90/0x90
[<ffffffff8177c91e>] kernel_init+0xe/0x120
[<ffffffff8178deec>] ret_from_fork+0x7c/0xb0
[<ffffffff8177c910>] ? rest_init+0x90/0x90
Prevent this from happening by:
1) Modifying try_msr_calibrate_tsc() to return calibration value or zero
if it fails.
2) Check this return value in native_calibrate_tsc() and in case of zero
fallback to use normal non-MSR based calibration.
[mw: Added subject and changelog]
Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1392810750-18660-1-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
