For spinning loops people do often use barrier() or cpu_relax().
For most architectures cpu_relax and barrier are the same, but on
some architectures cpu_relax can add some latency.
For example on power,sparc64 and arc, cpu_relax can shift the CPU
towards other hardware threads in an SMT environment.
On s390 cpu_relax does even more, it uses an hypercall to the
hypervisor to give up the timeslice.
In contrast to the SMT yielding this can result in larger latencies.
In some places this latency is unwanted, so another variant
"cpu_relax_lowlatency" was introduced. Before this is used in more
and more places, lets revert the logic and provide a cpu_relax_yield
that can be called in places where yielding is more important than
latency. By default this is the same as cpu_relax on all architectures.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1477386195-32736-2-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The threshold_cpu_callback callbacks looks like one of the notifier and
its arguments are almost the same. Split this out and have one ONLINE
and one DEAD callback. This will come handy later once the main code
gets changed to use the callback mechanism.
Also, handle threshold_cpu_callback_online() return value so we don't
continue if the function fails.
Boris Petkov removed the callback pointer and replaced it with proper
functions.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: rt@linutronix.de
Cc: linux-edac@vger.kernel.org
Link: http://lkml.kernel.org/r/20161110174447.11848-5-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We already have a macro to invoke boot services which on x86 adapts
automatically to the bitness of the EFI firmware: efi_call_early().
The macro allows sharing of functions across arches and bitness variants
as long as those functions only call boot services. However in practice
functions in the EFI stub contain a mix of boot services calls and
protocol calls.
Add an efi_call_proto() macro for bitness-agnostic protocol calls to
allow sharing more code across arches as well as deduplicating 32 bit
and 64 bit code paths.
On x86, implement it using a new efi_table_attr() macro for bitness-
agnostic table lookups. Refactor efi_call_early() to make use of the
same macro. (The resulting object code remains identical.)
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161112213237.8804-8-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The calculation of the hwid_mcatype value in get_smca_bank_info()
became incorrect after applying the following commit:
1ce9cd7f9f0b ("x86/RAS: Simplify SMCA HWID descriptor struct")
This causes the function to not match a bank to its type.
Disassembly of hwid_mcatype calculation after change:
db: 8b 45 e0 mov -0x20(%rbp),%eax
de: 41 89 c4 mov %eax,%r12d
e1: 25 00 00 ff 0f and $0xfff0000,%eax
e6: 41 c1 ec 10 shr $0x10,%r12d
ea: 41 09 c4 or %eax,%r12d
Disassembly of hwid_mcatype calculation in original code:
286: 8b 45 d0 mov -0x30(%rbp),%eax
289: 41 89 c5 mov %eax,%r13d
28c: c1 e8 10 shr $0x10,%eax
28f: 41 81 e5 ff 0f 00 00 and $0xfff,%r13d
296: 41 c1 e5 10 shl $0x10,%r13d
29a: 41 09 c5 or %eax,%r13d
Grouping the arguments to the HWID_MCATYPE() macro fixes the issue.
( Boris suggested adding parentheses in the macro. )
Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following RCU lockdep warning led to adding irq_enter()/irq_exit() into
smp_reschedule_interrupt():
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
no locks held by swapper/1/0.
do_trace_write_msr
native_write_msr
native_apic_msr_eoi_write
smp_reschedule_interrupt
reschedule_interrupt
As Peterz pointed out:
| So now we're making a very frequent interrupt slower because of debug
| code.
|
| The thing is, many many smp_reschedule_interrupt() invocations don't
| actually execute anything much at all and are only sent to tickle the
| return to user path (which does the actual preemption).
|
| Having to do the whole irq_enter/irq_exit dance just for this unlikely
| debug case totally blows.
Use the wrmsr_notrace() variant in native_apic_msr_write_eoi, annotate the
kvm variant with notrace and add a native_apic_eoi callback to the apic
structure so KVM guests are covered as well.
This allows to revert the irq_enter/irq_exit dance in
smp_reschedule_interrupt().
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Mike Galbraith <efault@gmx.de>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1478488420-5982-3-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Required to remove the extra irq_enter()/irq_exit() in
smp_reschedule_interrupt().
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: kvm@vger.kernel.org
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/1478488420-5982-2-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add accessor functions and hide the smca_names array. Also, add a
sanity-check to bank HWID assignment in get_smca_bank_info().
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20161104152317.5r276t35df53qk76@pd.tnic
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make it differ more from struct smca_bank_name for better readability.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20161103125556.15482-3-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Call it simply smca_hwid and call local variables "hwid". More readable.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20161103125556.15482-2-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Call the struct simply smca_bank, it's instance ID can be simply ->id.
Makes the code much more readable.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20161103125556.15482-1-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit cc7cc02bada8 ("PCI: Query platform firmware for device power
state") augmented struct pci_platform_pm_ops with a ->get_state hook and
implemented it for acpi_pci_platform_pm, the only pci_platform_pm_ops
existing till v4.7.
However v4.8 introduced another pci_platform_pm_ops for Intel Mobile
Internet Devices with commit 5823d0893ec2 ("x86/platform/intel-mid: Add
Power Management Unit driver"). It is missing the ->get_state hook,
which is fatal since pci_set_platform_pm() enforces its presence. Andy
Shevchenko reports that without the present commit, such a device
"crashes without even a character printed out on serial console and
reboots (since watchdog)".
Retrofit mid_pci_platform_pm with the missing callback to fix the
breakage.
Acked-and-tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: cc7cc02bada8 ("PCI: Query platform firmware for device power state")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: http://lkml.kernel.org/r/7c1567d4c49303a4aada94ba16275cbf56b8976b.1477221514.git.lukas@wunner.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
... to fix this build warning:
In file included from arch/x86/kernel/cpu/intel_rdt.c:33:0:
./arch/x86/include/asm/intel_rdt.h:56:25: warning: ‘struct kernfs_open_file’ declared inside parameter list will not be visible outside of this definition or declaration
int (*seq_show)(struct kernfs_open_file *of,
^~~~~~~~~~~~~~~~
...
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <h.peter.anvin@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V Shankar <ravi.v.shankar@intel.com>
Cc: Sai Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Link: http://lkml.kernel.org/r/20161102165117.23545-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
during the merge window. The rest are fixes for MIPS, s390 and nested VMX.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"One NULL pointer dereference, and two fixes for regressions introduced
during the merge window.
The rest are fixes for MIPS, s390 and nested VMX"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: x86: Check memopp before dereference (CVE-2016-8630)
kvm: nVMX: VMCLEAR an active shadow VMCS after last use
KVM: x86: drop TSC offsetting kvm_x86_ops to fix KVM_GET/SET_CLOCK
KVM: x86: fix wbinvd_dirty_mask use-after-free
kvm/x86: Show WRMSR data is in hex
kvm: nVMX: Fix kernel panics induced by illegal INVEPT/INVVPID types
KVM: document lock orders
KVM: fix OOPS on flush_work
KVM: s390: Fix STHYI buffer alignment for diag224
KVM: MIPS: Precalculate MMIO load resume PC
KVM: MIPS: Make ERET handle ERL before EXL
KVM: MIPS: Fix lazy user ASID regenerate for SMP
The user of page_track might needs extra information, so pass
the kvm_page_track_notifier_node to callbacks.
Signed-off-by: Jike Song <jike.song@intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When a memory slot is being moved or removed users of page track
can be notified. So users can drop write-protection for the pages
in that memory slot.
This notifier type is needed by KVMGT to sync up its shadow page
table when memory slot is being moved or removed.
Register the notifier type track_flush_slot to receive memslot move
and remove event.
Reviewed-by: Xiao Guangrong <guangrong.xiao@intel.com>
Signed-off-by: Chen Xiaoguang <xiaoguang.chen@intel.com>
[Squashed commits to avoid bisection breakage and reworded the subject.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
These are never used by the host, but they can still be reflected to
the guest.
Tested-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When a memory slot is being moved or removed users of page track
can be notified. So users can drop write-protection for the pages
in that memory slot.
This notifier type is needed by KVMGT to sync up its shadow page
table when memory slot is being moved or removed.
Register the notifier type track_flush_slot to receive memslot move
and remove event.
Reviewed-by: Xiao Guangrong <guangrong.xiao@intel.com>
Signed-off-by: Chen Xiaoguang <xiaoguang.chen@intel.com>
[Squashed commits to avoid bisection breakage and reworded the subject.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Since commit a545ab6a0085 ("kvm: x86: add tsc_offset field to struct
kvm_vcpu_arch", 2016-09-07) the offset between host and L1 TSC is
cached and need not be fished out of the VMCS or VMCB. This means
that we can implement adjust_tsc_offset_guest and read_l1_tsc
entirely in generic code. The simplification is particularly
significant for VMX code, where vmx->nested.vmcs01_tsc_offset
was duplicating what is now in vcpu->arch.tsc_offset. Therefore
the vmcs01_tsc_offset can be dropped completely.
More importantly, this fixes KVM_GET_CLOCK/KVM_SET_CLOCK
which, after commit 108b249c453d ("KVM: x86: introduce get_kvmclock_ns",
2016-09-01) called read_l1_tsc while the VMCS was not loaded.
It thus returned bogus values on Intel CPUs.
Fixes: 108b249c453dd7132599ab6dc7e435a7036c193f
Reported-by: Roman Kagan <rkagan@virtuozzo.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The kernel doesn't use clts() any more. Remove it and all of its
paravirt infrastructure.
A careful reader may notice that xen_clts() appears to have been
buggy -- it didn't update xen_cr0_value.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/3d3c8ca62f17579b9849a013d71e59a4d5d1b079.1477951965.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It has no callers any more, and it was always a bit confusing, as
there is no STTS instruction.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/04247401710b230849e58bf2112ce4fd0b9840e1.1477951965.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that Linux never sets CR0.TS, lguest doesn't need to support it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/8a7bf2c11231c082258fd67705d0f275639b8475.1477951965.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that lazy FPU is gone, we don't use CR0.TS (except possibly in
KVM guest mode). Remove irq_ts_save(), irq_ts_restore(), and all of
their callers.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/70b9b9e7ba70659bedcb08aba63d0f9214f338f2.1477951965.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Hook the x86 scheduler code to update closid based on whether the current
task is assigned to a specific closid or running on a CPU assigned to a
specific closid.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-10-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Last of the per resource group files. Also mode 0644. This one shows
the resources available to the group. Syntax depends on whether the
"cdp" mount option was given. With code/data prioritization disabled
it is simply a list of masks for each cache domain. Initial value
allows access to all of the L3 cache on all domains. E.g. on a 2 socket
Broadwell:
L3:0=fffff;1=fffff
With CDP enabled, separate masks for data and instructions are provided:
L3DATA:0=fffff;1=fffff
L3CODE:0=fffff;1=fffff
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-9-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Now we populate each directory with a read/write (mode 0644) file
named "cpus". This is used to over-ride the resources available
to processes in the default resource group when running on specific
CPUs. Each "cpus" file reads as a cpumask showing which CPUs belong
to this resource group. Initially all online CPUs are assigned to
the default group. They can be added to other groups by writing a
cpumask to the "cpus" file in the directory for the resource group
(which will remove them from the previous group to which they were
assigned). CPU online/offline operations will delete CPUs that go
offline from whatever group they are in and add new CPUs to the
default group.
If there are CPUs assigned to a group when the directory is removed,
they are returned to the default group.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-7-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Resource control groups are represented as directories in the resctrl
file system. The root directory describes the default resources available
to tasks that have not been assigned specific resources. Other directories
can be created at the root level to make new resource groups. It is not
permitted to make directories within other directories.
Hardware uses a CLOSID (Class of service ID) to determine which resource
limits are currently in effect. The exact number available is enumerated
by CPUID leaf 0x10, but on current implementations it is a small number.
We implement a simple bitmask allocator for CLOSIDs.
Each resource control group uses one CLOSID, which limits the total number
of directories that can be created.
Resource groups can be removed using rmdir.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-6-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use kernfs as basis for our user interface filesystem. This patch
supports mount/umount, and one mount parameter "cdp" to enable code/data
prioritization (though all we do at this point is ensure that the system
can support CDP). The file system is not populated yet in this patch.
[ tglx: Fixed up a few nits and added cdp handling in case of error ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-4-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We use the cpu hotplug notifier to catch each cpu in turn and look at
its cache topology w.r.t each of the resource groups. As we discover
new resources, we initialize the bitmask array for each to the default
(full access) value.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-3-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
PQR_ASSOC MSR contains the RMID used for preformance monitoring of cache
occupancy and memory bandwidth. The upper 32bit of this MSR contain the
CLOSID for cache allocation. So we need to share the information between
the two facilities.
Move the rdt data structure declaration into the shared header file and
make the per cpu data structure containing the MSR values global.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477142405-32078-10-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Some Haswell generation CPUs support RDT, but they don't enumerate this via
CPUID. Use rdmsr_safe() and wrmsr_safe() to probe the MSRs on cpu model 63
(INTEL_FAM6_HASWELL_X)
Move the relevant defines into a common header file which is shared between
RDT/CQM and RDT/Allocation to avoid duplication.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477142405-32078-8-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A recent change to the mm code in:
87744ab3832b mm: fix cache mode tracking in vm_insert_mixed()
started enforcing checking the memory type against the registered list for
amixed pfn insertion mappings. It happens that the drm drivers for a number
of gpus relied on this being broken. Currently the driver only inserted
VRAM mappings into the tracking table when they came from the kernel,
and userspace mappings never landed in the table. This led to a regression
where all the mapping end up as UC instead of WC now.
I've considered a number of solutions but since this needs to be fixed
in fixes and not next, and some of the solutions were going to introduce
overhead that hadn't been there before I didn't consider them viable at
this stage. These mainly concerned hooking into the TTM io reserve APIs,
but these API have a bunch of fast paths I didn't want to unwind to add
this to.
The solution I've decided on is to add a new API like the arch_phys_wc
APIs (these would have worked but wc_del didn't take a range), and
use them from the drivers to add a WC compatible mapping to the table
for all VRAM on those GPUs. This means we can then create userspace
mapping that won't get degraded to UC.
v1.1: use CONFIG_X86_PAT + add some comments in io.h
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: x86@kernel.org
Cc: mcgrof@suse.com
Cc: Dan Williams <dan.j.williams@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
For mostly historical reasons, the x86 oops dump shows the raw stack
values:
...
[registers]
Stack:
ffff880079af7350 ffff880079905400 0000000000000000 ffffc900008f3ae0
ffffffffa0196610 0000000000000001 00010000ffffffff 0000000087654321
0000000000000002 0000000000000000 0000000000000000 0000000000000000
Call Trace:
...
This seems to be an artifact from long ago, and probably isn't needed
anymore. It generally just adds noise to the dump, and it can be
actively harmful because it leaks kernel addresses.
Linus says:
"The stack dump actually goes back to forever, and it used to be
useful back in 1992 or so. But it used to be useful mainly because
stacks were simpler and we didn't have very good call traces anyway. I
definitely remember having used them - I just do not remember having
used them in the last ten+ years.
Of course, it's still true that if you can trigger an oops, you've
likely already lost the security game, but since the stack dump is so
useless, let's aim to just remove it and make games like the above
harder."
This also removes the related 'kstack=' cmdline option and the
'kstack_depth_to_print' sysctl.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e83bd50df52d8fe88e94d2566426ae40d813bf8f.1477405374.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Printing kernel text addresses in stack dumps is of questionable value,
especially now that address randomization is becoming common.
It can be a security issue because it leaks kernel addresses. It also
affects the usefulness of the stack dump. Linus says:
"I actually spend time cleaning up commit messages in logs, because
useless data that isn't actually information (random hex numbers) is
actively detrimental.
It makes commit logs less legible.
It also makes it harder to parse dumps.
It's not useful. That makes it actively bad.
I probably look at more oops reports than most people. I have not
found the hex numbers useful for the last five years, because they are
just randomized crap.
The stack content thing just makes code scroll off the screen etc, for
example."
The only real downside to removing these addresses is that they can be
used to disambiguate duplicate symbol names. However such cases are
rare, and the context of the stack dump should be enough to be able to
figure it out.
There's now a 'faddr2line' script which can be used to convert a
function address to a file name and line:
$ ./scripts/faddr2line ~/k/vmlinux write_sysrq_trigger+0x51/0x60
write_sysrq_trigger+0x51/0x60:
write_sysrq_trigger at drivers/tty/sysrq.c:1098
Or gdb can be used:
$ echo "list *write_sysrq_trigger+0x51" |gdb ~/k/vmlinux |grep "is in"
(gdb) 0xffffffff815b5d83 is in driver_probe_device (/home/jpoimboe/git/linux/drivers/base/dd.c:378).
(But note that when there are duplicate symbol names, gdb will only show
the first symbol it finds. faddr2line is recommended over gdb because
it handles duplicates and it also does function size checking.)
Here's an example of what a stack dump looks like after this change:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: sysrq_handle_crash+0x45/0x80
PGD 36bfa067 [ 29.650644] PUD 7aca3067
Oops: 0002 [#1] PREEMPT SMP
Modules linked in: ...
CPU: 1 PID: 786 Comm: bash Tainted: G E 4.9.0-rc1+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
task: ffff880078582a40 task.stack: ffffc90000ba8000
RIP: 0010:sysrq_handle_crash+0x45/0x80
RSP: 0018:ffffc90000babdc8 EFLAGS: 00010296
RAX: ffff880078582a40 RBX: 0000000000000063 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000292
RBP: ffffc90000babdc8 R08: 0000000b31866061 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000007 R14: ffffffff81ee8680 R15: 0000000000000000
FS: 00007ffb43869700(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007a3e9000 CR4: 00000000001406e0
Stack:
ffffc90000babe00 ffffffff81572d08 ffffffff81572bd5 0000000000000002
0000000000000000 ffff880079606600 00007ffb4386e000 ffffc90000babe20
ffffffff81573201 ffff880036a3fd00 fffffffffffffffb ffffc90000babe40
Call Trace:
__handle_sysrq+0x138/0x220
? __handle_sysrq+0x5/0x220
write_sysrq_trigger+0x51/0x60
proc_reg_write+0x42/0x70
__vfs_write+0x37/0x140
? preempt_count_sub+0xa1/0x100
? __sb_start_write+0xf5/0x210
? vfs_write+0x183/0x1a0
vfs_write+0xb8/0x1a0
SyS_write+0x58/0xc0
entry_SYSCALL_64_fastpath+0x1f/0xc2
RIP: 0033:0x7ffb42f55940
RSP: 002b:00007ffd33bb6b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007ffb42f55940
RDX: 0000000000000002 RSI: 00007ffb4386e000 RDI: 0000000000000001
RBP: 0000000000000011 R08: 00007ffb4321ea40 R09: 00007ffb43869700
R10: 00007ffb43869700 R11: 0000000000000246 R12: 0000000000778a10
R13: 00007ffd33bb5c00 R14: 0000000000000007 R15: 0000000000000010
Code: 34 e8 d0 34 bc ff 48 c7 c2 3b 2b 57 81 be 01 00 00 00 48 c7 c7 e0 dd e5 81 e8 a8 55 ba ff c7 05 0e 3f de 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 e8 4c 49 bc ff 84 c0 75 c3 48 c7
RIP: sysrq_handle_crash+0x45/0x80 RSP: ffffc90000babdc8
CR2: 0000000000000000
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/69329cb29b8f324bb5fcea14d61d224807fb6488.1477405374.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yeah, I know, I know, this is a huuge patch and reviewing it is hard.
Sorry but this is the only way I could think of in which I can rewrite
the microcode patches loading procedure without breaking (knowingly) the
driver.
So maybe this patch is easier to review if one looks at the files after
the patch has been applied instead at the diff. Because then it becomes
pretty obvious:
* The BSP-loading path - load_ucode_bsp() is working independently from
the AP path now and it doesn't save any pointers or patches anymore -
it solely parses the builtin or initrd microcode and applies the patch.
That's it.
This fixes the CONFIG_RANDOMIZE_MEMORY offset fun more solidly.
* The AP-loading path - load_ucode_ap() then goes and scans
builtin/initrd *again* for the microcode patches but it caches them this
time so that we don't have to do that scan on each AP but only once.
This simplifies the code considerably.
Then, when we save the microcode from the initrd/builtin, we go and
add the relevant patches to our own cache. The AMD side did do that
and now the Intel side does it too. So no more pointer copying and
blabla, we save the microcode patches ourselves and are independent from
initrd/builtin.
This whole conversion gives us other benefits like unifying the
initrd parsing into a single function: find_microcode_in_initrd() is
used by both.
The diffstat speaks for itself: 456 insertions(+), 695 deletions(-)
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161025095522.11964-12-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Its functions are used in intel.c only now, so get rid of it. Make
functions static.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161025095522.11964-11-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make them all static as they're used in a single file now.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161025095522.11964-10-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Will be needed in a following patch.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161025095522.11964-7-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It will be used by both drivers so move it to core.c.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161025095522.11964-6-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move the function declaration to the other #ifdef CONFIG_MICROCODE
together with the other functions.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161025095522.11964-5-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Its all generic atomic_long_t stuff now.
Tested-by: Jason Low <jason.low2@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With frame pointers, when a task is interrupted, its stack is no longer
completely reliable because the function could have been interrupted
before it had a chance to save the previous frame pointer on the stack.
So the caller of the interrupted function could get skipped by a stack
trace.
This is problematic for live patching, which needs to know whether a
stack trace of a sleeping task can be relied upon. There's currently no
way to detect if a sleeping task was interrupted by a page fault
exception or preemption before it went to sleep.
Another issue is that when dumping the stack of an interrupted task, the
unwinder has no way of knowing where the saved pt_regs registers are, so
it can't print them.
This solves those issues by encoding the pt_regs pointer in the frame
pointer on entry from an interrupt or an exception.
This patch also updates the unwinder to be able to decode it, because
otherwise the unwinder would be broken by this change.
Note that this causes a change in the behavior of the unwinder: each
instance of a pt_regs on the stack is now considered a "frame". So
callers of unwind_get_return_address() will now get an occasional
'regs->ip' address that would have previously been skipped over.
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8b9f84a21e39d249049e0547b559ff8da0df0988.1476973742.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit:
c65eacbe290b ("sched/core: Allow putting thread_info into task_struct")
... made 'struct thread_info' a generic struct with only a
single ::flags member, if CONFIG_THREAD_INFO_IN_TASK_STRUCT=y is
selected.
This change however seems to be quite x86 centric, since at least the
generic preemption code (asm-generic/preempt.h) assumes that struct
thread_info also has a preempt_count member, which apparently was not
true for x86.
We could add a bit more #ifdefs to solve this problem too, but it seems
to be much simpler to make struct thread_info arch specific
again. This also makes the conversion to THREAD_INFO_IN_TASK_STRUCT a
bit easier for architectures that have a couple of arch specific stuff
in their thread_info definition.
The arch specific stuff _could_ be moved to thread_struct. However
keeping them in thread_info makes it easier: accessing thread_info
members is simple, since it is at the beginning of the task_struct,
while the thread_struct is at the end. At least on s390 the offsets
needed to access members of the thread_struct (with task_struct as
base) are too large for various asm instructions. This is not a
problem when keeping these members within thread_info.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: keescook@chromium.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1476901693-8492-2-git-send-email-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
AVX512_4VNNIW - Vector instructions for deep learning enhanced word
variable precision.
AVX512_4FMAPS - Vector instructions for deep learning floating-point
single precision.
These new instructions are to be used in future Intel Xeon & Xeon Phi
processors. The bits 2&3 of CPUID[level:0x07, EDX] inform that new
instructions are supported by a processor.
The spec can be found in the Intel Software Developer Manual (SDM) or in
the Instruction Set Extensions Programming Reference (ISE).
Define new feature flags to enumerate the new instructions in /proc/cpuinfo
accordingly to CPUID bits and add the required xsave extensions which are
required for proper operation.
Signed-off-by: Piotr Luc <piotr.luc@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20161018150111.29926-1-piotr.luc@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
