When the SMP kernel decides to crash_kexec() the local APICs may have
pending interrupts in their vector tables.
The setup routine for the local APIC has a deficient mechanism for
clearing these interrupts, it only handles interrupts that has already
been dispatched to the local core for servicing (the ISR register) safely,
it doesn't consider lower prioritized queued interrupts stored in the IRR
register.
If you have more than one pending interrupt within the same 32 bit word in
the LAPIC vector table registers you may find yourself entering the IO
APIC setup with pending interrupts left in the LAPIC. This is a situation
for wich the IO APIC setup is not prepared. Depending of what/which
interrupt vector/vectors are stuck in the APIC tables your system may show
various degrees of malfunctioning. That was the reason why the
check_timer() failed in our system, the timer interrupts was blocked by
pending interrupts from the old kernel when routed trough the IO APIC.
Additional comment from Jiri Bohac:
==============
If this should go into stable release,
I'd add some kind of limit on the number of iterations, just to be safe from
hard to debug lock-ups:
+if (loops++ > MAX_LOOPS) {
+ printk("LAPIC pending clean-up")
+ break;
+}
while (queued);
with MAX_LOOPS something like 1E9 this would leave plenty of time for the
pending IRQs to be cleared and would and still cause at most a second of delay
if the loop were to lock-up for whatever reason.
[trenn@suse.de:
V2: Use tsc if avail to bail out after 1 sec due to possible virtual
apic_read calls which may take rather long (suggested by: Avi Kivity
<avi@redhat.com>) If no tsc is available bail out quickly after
cpu_khz, if we broke out too early and still have irqs pending (which
should never happen?) we still get a WARN_ON...
V3: - Fixed indentation -> checkpatch clean
- max_loops must be signed
V4: - Fix typo, mixed up tsc and ntsc in first rdtscll() call
V5: Adjust WARN_ON() condition to also catch error in cpu_has_tsc case]
Cc: <jbohac@novell.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Kerstin Jonsson <kerstin.jonsson@ericsson.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
LKML-Reference: <201005241913.o4OJDGWM010865@imap1.linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (269 commits)
KVM: x86: Add missing locking to arch specific vcpu ioctls
KVM: PPC: Add missing vcpu_load()/vcpu_put() in vcpu ioctls
KVM: MMU: Segregate shadow pages with different cr0.wp
KVM: x86: Check LMA bit before set_efer
KVM: Don't allow lmsw to clear cr0.pe
KVM: Add cpuid.txt file
KVM: x86: Tell the guest we'll warn it about tsc stability
x86, paravirt: don't compute pvclock adjustments if we trust the tsc
x86: KVM guest: Try using new kvm clock msrs
KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID
KVM: x86: add new KVMCLOCK cpuid feature
KVM: x86: change msr numbers for kvmclock
x86, paravirt: Add a global synchronization point for pvclock
x86, paravirt: Enable pvclock flags in vcpu_time_info structure
KVM: x86: Inject #GP with the right rip on efer writes
KVM: SVM: Don't allow nested guest to VMMCALL into host
KVM: x86: Fix exception reinjection forced to true
KVM: Fix wallclock version writing race
KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots
KVM: VMX: enable VMXON check with SMX enabled (Intel TXT)
...
Allow kdb to work properly with with earlyprintk=vga by interpreting
the backspace and carriage return output characters. These
interpretation of these characters is used for simple line editing
provided in the kdb shell.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
If the kernel debugger was configured, attached and started with
kgdbwait, the hardware breakpoint registers should get restored by the
kgdb code which is managing the dr registers.
CC: x86@kernel.org
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
It is not possible to use the hw_breakpoint.c API prior to mm_init(),
but it is possible to use hardware breakpoints with the kernel
debugger.
Prior to smp_init() it is possible to simply write to the dr registers
of the boot cpu directly. This can be used up until the
kgdb_arch_late() is invoked, at which point the standard hw_breakpoint.c
API will get used.
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The kernel debugger can operate well before mm_init(), but the x86
hardware breakpoint code which uses the perf api requires that the
kernel allocators are initialized.
This means the kernel debug core needs to provide an optional arch
specific call back to allow the initialization functions to run after
the kernel has been further initialized.
The kdb shell already had a similar restriction with an early
initialization and late initialization. The kdb_init() was moved into
the debug core's version of the late init which is called
dbg_late_init();
CC: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Allow the x86 arch to have early exception processing for the purpose
of debugging via the kgdb.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a triple fault is
to have a low level "first opportunity handler" in the int3 exception
handler.
Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Remove all the references to the kgdb_post_primary_code. This
function serves no useful purpose because you can obtain the same
information from the "struct kgdb_state *ks" from with in the
debugger, if for some reason you want the data.
Also remove the unintentional duplicate assignment for ks->ex_vector.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
These are the minimum changes to the kgdb core in order to enable an
API to connect a new front end (kdb) to the debug core.
This patch introduces the dbg_kdb_mode variable controls where the
user level I/O is routed. It will be routed to the gdbstub (kgdb) or
to the kdb front end which is a simple shell available over the kgdboc
connection.
You can switch back and forth between kdb or the gdb stub mode of
operation dynamically. From gdb stub mode you can blindly type
"$3#33", or from the kdb mode you can enter "kgdb" to switch to the
gdb stub.
The logic in the debug core depends on kdb to look for the typical gdb
connection sequences and return immediately with KGDB_PASS_EVENT if a
gdb serial command sequence is detected. That should allow a
reasonably seamless transition between kdb -> gdb without leaving the
kernel exception state. The two gdb serial queries that kdb is
responsible for detecting are the "?" and "qSupported" packets.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
* 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (22 commits)
ACPI: fix early DSDT dmi check warnings on ia64
ACPICA: Update version to 20100428.
ACPICA: Update/clarify some parameter names associated with acpi_handle
ACPICA: Rename acpi_ex_system_do_suspend->acpi_ex_system_do_sleep
ACPICA: Prevent possible allocation overrun during object copy
ACPICA: Split large file, evgpeblk
ACPICA: Add GPE support for dynamically loaded ACPI tables
ACPICA: Clarify/rename some root table descriptor fields
ACPICA: Update version to 20100331.
ACPICA: Minimize the differences between linux GPE code and ACPICA code base
ACPI: add boot option acpi=copy_dsdt to fix corrupt DSDT
ACPICA: Update DSDT copy/detection.
ACPICA: Add subsystem option to force copy of DSDT to local memory
ACPICA: Add detection of corrupted/replaced DSDT
ACPICA: Add write support for DataTable operation regions
ACPICA: Fix for acpi_reallocate_root_table for incorrect root table copy
ACPICA: Update comments/headers, no functional change
ACPICA: Update version to 20100304
ACPICA: Fix for possible fault in acpi_ex_release_mutex
ACPICA: Standardize integer output for ACPICA warnings/errors
...
* 'timers-for-linus-hpet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hpet: Add reference to chipset erratum documentation for disable-hpet-msi-quirk
x86, hpet: Restrict read back to affected ATI chipsets
If the HV told us we can fully trust the TSC, skip any
correction
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We now added a new set of clock-related msrs in replacement of the old
ones. In theory, we could just try to use them and get a return value
indicating they do not exist, due to our use of kvm_write_msr_save.
However, kvm clock registration happens very early, and if we ever
try to write to a non-existant MSR, we raise a lethal #GP, since our
idt handlers are not in place yet.
So this patch tests for a cpuid feature exported by the host to
decide which set of msrs are supported.
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In recent stress tests, it was found that pvclock-based systems
could seriously warp in smp systems. Using ingo's time-warp-test.c,
I could trigger a scenario as bad as 1.5mi warps a minute in some systems.
(to be fair, it wasn't that bad in most of them). Investigating further, I
found out that such warps were caused by the very offset-based calculation
pvclock is based on.
This happens even on some machines that report constant_tsc in its tsc flags,
specially on multi-socket ones.
Two reads of the same kernel timestamp at approx the same time, will likely
have tsc timestamped in different occasions too. This means the delta we
calculate is unpredictable at best, and can probably be smaller in a cpu
that is legitimately reading clock in a forward ocasion.
Some adjustments on the host could make this window less likely to happen,
but still, it pretty much poses as an intrinsic problem of the mechanism.
A while ago, I though about using a shared variable anyway, to hold clock
last state, but gave up due to the high contention locking was likely
to introduce, possibly rendering the thing useless on big machines. I argue,
however, that locking is not necessary.
We do a read-and-return sequence in pvclock, and between read and return,
the global value can have changed. However, it can only have changed
by means of an addition of a positive value. So if we detected that our
clock timestamp is less than the current global, we know that we need to
return a higher one, even though it is not exactly the one we compared to.
OTOH, if we detect we're greater than the current time source, we atomically
replace the value with our new readings. This do causes contention on big
boxes (but big here means *BIG*), but it seems like a good trade off, since
it provide us with a time source guaranteed to be stable wrt time warps.
After this patch is applied, I don't see a single warp in time during 5 days
of execution, in any of the machines I saw them before.
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
CC: Jeremy Fitzhardinge <jeremy@goop.org>
CC: Avi Kivity <avi@redhat.com>
CC: Marcelo Tosatti <mtosatti@redhat.com>
CC: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch removes one padding byte and transform it into a flags
field. New versions of guests using pvclock will query these flags
upon each read.
Flags, however, will only be interpreted when the guest decides to.
It uses the pvclock_valid_flags function to signal that a specific
set of flags should be taken into consideration. Which flags are valid
are usually devised via HV negotiation.
Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Per document, for feature control MSR:
Bit 1 enables VMXON in SMX operation. If the bit is clear, execution
of VMXON in SMX operation causes a general-protection exception.
Bit 2 enables VMXON outside SMX operation. If the bit is clear, execution
of VMXON outside SMX operation causes a general-protection exception.
This patch is to enable this kind of check with SMX for VMXON in KVM.
Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, acpi/irq: Define gsi_end when X86_IO_APIC is undefined
x86, irq: Kill io_apic_renumber_irq
x86, acpi/irq: Handle isa irqs that are not identity mapped to gsi's.
x86, ioapic: Simplify probe_nr_irqs_gsi.
x86, ioapic: Optimize pin_2_irq
x86, ioapic: Move nr_ioapic_registers calculation to mp_register_ioapic.
x86, ioapic: In mpparse use mp_register_ioapic
x86, ioapic: Teach mp_register_ioapic to compute a global gsi_end
x86, ioapic: Fix the types of gsi values
x86, ioapic: Fix io_apic_redir_entries to return the number of entries.
x86, ioapic: Only export mp_find_ioapic and mp_find_ioapic_pin in io_apic.h
x86, acpi/irq: Generalize mp_config_acpi_legacy_irqs
x86, acpi/irq: Fix acpi_sci_ioapic_setup so it has both bus_irq and gsi
x86, acpi/irq: pci device dev->irq is an isa irq not a gsi
x86, acpi/irq: Teach acpi_get_override_irq to take a gsi not an isa_irq
x86, acpi/irq: Introduce apci_isa_irq_to_gsi
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, fpu: Use static_cpu_has() to implement use_xsave()
x86: Add new static_cpu_has() function using alternatives
x86, fpu: Use the proper asm constraint in use_xsave()
x86, fpu: Unbreak FPU emulation
x86: Introduce 'struct fpu' and related API
x86: Eliminate TS_XSAVE
x86-32: Don't set ignore_fpu_irq in simd exception
x86: Merge kernel_math_error() into math_error()
x86: Merge simd_math_error() into math_error()
x86-32: Rework cache flush denied handler
Fix trivial conflict in arch/x86/kernel/process.c
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hypervisor: add missing <linux/module.h>
Modify the VMware balloon driver for the new x86_hyper API
x86, hypervisor: Export the x86_hyper* symbols
x86: Clean up the hypervisor layer
x86, HyperV: fix up the license to mshyperv.c
x86: Detect running on a Microsoft HyperV system
x86, cpu: Make APERF/MPERF a normal table-driven flag
x86, k8: Fix build error when K8_NB is disabled
x86, cacheinfo: Disable index in all four subcaches
x86, cacheinfo: Make L3 cache info per node
x86, cacheinfo: Reorganize AMD L3 cache structure
x86, cacheinfo: Turn off L3 cache index disable feature in virtualized environments
x86, cacheinfo: Unify AMD L3 cache index disable checking
cpufreq: Unify sysfs attribute definition macros
powernow-k8: Fix frequency reporting
x86, cpufreq: Add APERF/MPERF support for AMD processors
x86: Unify APERF/MPERF support
powernow-k8: Add core performance boost support
x86, cpu: Add AMD core boosting feature flag to /proc/cpuinfo
Fix up trivial conflicts in arch/x86/kernel/cpu/intel_cacheinfo.c and
drivers/cpufreq/cpufreq_ondemand.c
* 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Fix LOCK_PREFIX_HERE for uniprocessor build
x86, atomic64: In selftest, distinguish x86-64 from 586+
x86-32: Fix atomic64_inc_not_zero return value convention
lib: Fix atomic64_inc_not_zero test
lib: Fix atomic64_add_unless return value convention
x86-32: Fix atomic64_add_unless return value convention
lib: Fix atomic64_add_unless test
x86: Implement atomic[64]_dec_if_positive()
lib: Only test atomic64_dec_if_positive on archs having it
x86-32: Rewrite 32-bit atomic64 functions in assembly
lib: Add self-test for atomic64_t
x86-32: Allow UP/SMP lock replacement in cmpxchg64
x86: Add support for lock prefix in alternatives
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Use .cfi_sections for assembly code
x86-64: Reduce SMP locks table size
x86, asm: Introduce and use percpu_inc()
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
perf tools: Add mode to build without newt support
perf symbols: symbol inconsistency message should be done only at verbose=1
perf tui: Add explicit -lslang option
perf options: Type check all the remaining OPT_ variants
perf options: Type check OPT_BOOLEAN and fix the offenders
perf options: Check v type in OPT_U?INTEGER
perf options: Introduce OPT_UINTEGER
perf tui: Add workaround for slang < 2.1.4
perf record: Fix bug mismatch with -c option definition
perf options: Introduce OPT_U64
perf tui: Add help window to show key associations
perf tui: Make <- exit menus too
perf newt: Add single key shortcuts for zoom into DSO and threads
perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
perf newt: Fix the 'A'/'a' shortcut for annotate
perf newt: Make <- exit the ui_browser
x86, perf: P4 PMU - fix counters management logic
perf newt: Make <- zoom out filters
perf report: Report number of events, not samples
perf hist: Clarify events_stats fields usage
...
Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: Reduce stack_trace usage
lockdep: No need to disable preemption in debug atomic ops
lockdep: Actually _dec_ in debug_atomic_dec
lockdep: Provide off case for redundant_hardirqs_on increment
lockdep: Simplify debug atomic ops
lockdep: Fix redundant_hardirqs_on incremented with irqs enabled
lockstat: Make lockstat counting per cpu
i8253: Convert i8253_lock to raw_spinlock
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/amd-iommu: Add amd_iommu=off command line option
iommu-api: Remove iommu_{un}map_range functions
x86/amd-iommu: Implement ->{un}map callbacks for iommu-api
x86/amd-iommu: Make amd_iommu_iova_to_phys aware of multiple page sizes
x86/amd-iommu: Make iommu_unmap_page and fetch_pte aware of page sizes
x86/amd-iommu: Make iommu_map_page and alloc_pte aware of page sizes
kvm: Change kvm_iommu_map_pages to map large pages
VT-d: Change {un}map_range functions to implement {un}map interface
iommu-api: Add ->{un}map callbacks to iommu_ops
iommu-api: Add iommu_map and iommu_unmap functions
iommu-api: Rename ->{un}map function pointers to ->{un}map_range
(At the moment the "SB700 Family Product Errata" document is available
at http://support.amd.com/us/Embedded_TechDocs/46837.pdf)
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100517164324.GB10254@alberich.amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Moorestown does not have BIOS provided MP tables, we can save some time
by avoiding scaning of these tables. e.g.
[ 0.000000] Scan SMP from c0000000 for 1024 bytes.
[ 0.000000] Scan SMP from c009fc00 for 1024 bytes.
[ 0.000000] Scan SMP from c00f0000 for 65536 bytes.
[ 0.000000] Scan SMP from c00bfff0 for 1024 bytes.
Searching EBDA with the base at 0x40E will also result in random pointer
deferencing within 1MB. This can be a problem in Lincroft if the pointer
hits VGA area and VGA mode is not enabled.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
LKML-Reference: <1273873281-17489-8-git-send-email-jacob.jun.pan@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Jaswinder reported this #GP:
|
| Message from syslogd@ht at May 14 09:39:32 ...
| kernel:[ 314.908612] EIP: [<c100ccca>]
| x86_perf_event_set_period+0x19d/0x1b2 SS:ESP 0068:edac3d70
|
Ming has narrowed it down to a comparision issue
between arguments with different sizes and
signs. As result event index reached a wrong
value which in turn led to a GP fault.
At the same time it was found that p4_next_cntr
has broken logic and should return the counter
index only if it was not yet borrowed for
another event.
Reported-by: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Reported-by: Lin Ming <ming.m.lin@intel.com>
Bisected-by: Lin Ming <ming.m.lin@intel.com>
Tested-by: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100514190815.GG13509@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, cacheinfo: Turn off L3 cache index disable feature in virtualized environments
x86, k8: Fix build error when K8_NB is disabled
x86, amd: Check X86_FEATURE_OSVW bit before accessing OSVW MSRs
x86: Fix fake apicid to node mapping for numa emulation
If host CPU is exposed to a guest the OSVW MSRs are not guaranteed
to be present and a GP fault occurs. Thus checking the feature flag is
essential.
Cc: <stable@kernel.org> # .32.x .33.x
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100427101348.GC4489@alberich.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Linear search over all p4 MSRs should be fine if only
we would not use it in events scheduling routine which
is pretty time critical. Lets use hashes. It should speed
scheduling up significantly.
v2: Steven proposed to use more gentle approach than issue
BUG on error, so we use WARN_ONCE now
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <20100512174242.GA5190@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds a command line option to tell the AMD IOMMU
driver to not initialize any IOMMU it finds.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Fix kprobe/x86 to check removed int3 when failing to get kprobe
from hlist. Since we have a time window between checking int3
exists on probed address and getting kprobe on that address,
we can have following scenario:
-------
CPU1 CPU2
hit int3
check int3 exists
remove int3
remove kprobe from hlist
get kprobe from hlist
no kprobe->OOPS!
-------
This patch moves int3 checking if there is no kprobe on that
address for fixing this problem as follows:
------
CPU1 CPU2
hit int3
remove int3
remove kprobe from hlist
get kprobe from hlist
no kprobe->check int3 exists
->rollback&retry
------
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100427223348.2322.9112.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently all fpu state access is through tsk->thread.xstate. Since we wish
to generalize fpu access to non-task contexts, wrap the state in a new
'struct fpu' and convert existing access to use an fpu API.
Signal frame handlers are not converted to the API since they will remain
task context only things.
Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1273135546-29690-3-git-send-email-avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The fpu code currently uses current->thread_info->status & TS_XSAVE as
a way to distinguish between XSAVE capable processors and older processors.
The decision is not really task specific; instead we use the task status to
avoid a global memory reference - the value should be the same across all
threads.
Eliminate this tie-in into the task structure by using an alternative
instruction keyed off the XSAVE cpu feature; this results in shorter and
faster code, without introducing a global memory reference.
[ hpa: in the future, this probably should use an asm jmp ]
Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1273135546-29690-2-git-send-email-avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
EXPORT_SYMBOL() needs <linux/module.h> to be included; fixes modular
builds of the VMware balloon driver, and any future modular drivers
which depends on the hypervisor.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
LKML-Reference: <4BE49778.6060800@zytor.com>
Export x86_hyper and the related specific structures, allowing for
hypervisor identification by modules.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
LKML-Reference: <4BE49778.6060800@zytor.com>
RAW events are special and we should be ready for user passing
in insane event index values.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <20100508112717.315897547@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The caller already has done such a check.
And it was wrong anyway, it had to be '>=' rather than '>'
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <20100508112717.130386882@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Steven reported:
|
| I'm getting:
|
| Pid: 3477, comm: perf Not tainted 2.6.34-rc6 #2727
| Call Trace:
| [<ffffffff811c7565>] debug_smp_processor_id+0xd5/0xf0
| [<ffffffff81019874>] p4_hw_config+0x2b/0x15c
| [<ffffffff8107acbc>] ? trace_hardirqs_on_caller+0x12b/0x14f
| [<ffffffff81019143>] hw_perf_event_init+0x468/0x7be
| [<ffffffff810782fd>] ? debug_mutex_init+0x31/0x3c
| [<ffffffff810c68b2>] T.850+0x273/0x42e
| [<ffffffff810c6cab>] sys_perf_event_open+0x23e/0x3f1
| [<ffffffff81009e6a>] ? sysret_check+0x2e/0x69
| [<ffffffff81009e32>] system_call_fastpath+0x16/0x1b
|
| When running perf record in latest tip/perf/core
|
Due to the fact that p4 counters are shared between HT threads
we synthetically divide the whole set of counters into two
non-intersected subsets. And while we're "borrowing" counters
from these subsets we should not be preempted (well, strictly
speaking in p4_hw_config we just pre-set reference to the
subset which allow to save some cycles in schedule routine
if it happens on the same cpu). So use get_cpu/put_cpu pair.
Also p4_pmu_schedule_events should use smp_processor_id rather
than raw_ version. This allow us to catch up preemption issue
(if there will ever be).
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <20100508112716.963478928@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
