It is a one-liner for checking microcode header revisions. On top of
that, it can be used wrong as it was the case in _save_mc(). Get rid of
it.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit:
f893959b08 ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()")
removed drop_init_fpu() usage from flush_thread(). This seems to break
things for me - the Go 1.4 test suite fails all over the place with
floating point comparision errors (offending commit found through
bisection).
The functional change was that flush_thread() after this commit
only calls restore_init_xstate() when both use_eager_fpu() and
!used_math() are true. drop_init_fpu() (now fpu_reset_state()) calls
restore_init_xstate() regardless of whether current used_math() - apply
the same logic here.
Switch used_math() -> tsk_used_math(tsk) to consistently use the grabbed
tsk instead of current, like in the rest of flush_thread().
Tested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Bobby Powers <bobbypowers@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pekka Riikonen <priikone@iki.fi>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f893959b ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()")
Link: http://lkml.kernel.org/r/1430147441-9820-1-git-send-email-bobbypowers@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
GART registers are not present in newer AMD processors (Fam15h, Model
10h and later). So, avoid accessing those in PCI config space by
returning early in early_gart_iommu_check() and gart_iommu_hole_init()
if GART is not available.
Current code doesn't break on existing processors but there are some
side effects:
We get bogus AGP aperture messages which are simply noise on
GART-less processors:
AGP: Node 0: aperture [bus addr 0x00000000-0x01ffffff] (32MB)
AGP: Your BIOS doesn't leave aperture memory hole
AGP: Please enable the IOMMU option in the BIOS setup
AGP: This costs you 64MB of RAM
AGP: Mapping aperture over RAM [mem 0xd4000000-0xd7ffffff]
We can avoid calling allocate_aperture() and would not have to
wastefully reserve 64MB of RAM with memblock_reserve(). Also, we can
avoid having to loop through all PCI buses and devices twice, searching
for a non-existent AGP bridge if we bail out early.
Refactor the family check used in amd_nb.c into an inline function so we
can use it here as well as in amd_nb.c
Fix some typos while at it.
Tested the patch on Fam10h and Fam15h Model 00h-fh and this code runs
fine. On Fam15h Model 60h-6fh and on Fam16h, we bail early as they don't
have GART.
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Joerg Rodel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1428443197-3834-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
GCC 5 added a compiler option, -mskip-rax-setup, for x86-64. It skips
setting up the RAX register when SSE is disabled and there are no
variable arguments passed in vector registers. (According to the x86_64
ABI, %al is used as a hidden register containing the number of vector
registers used).
Since the kernel doesn't pass vector registers to functions with
variable arguments, this option can be used to optimize the x86-64
kernel.
This GCC feature was suggested by Rasmus Villemoes <linux@rasmusvillemoes.dk>.
This is the corresponding kernel change using it.
For kernel v3.17:
text data bss dec filename
11455921 2204048 5853184 19513153 vmlinux #with -mskip-rax-setup
11480079 2204048 5853184 19537311 vmlinux
For Kernel v4.0+ - custom config:
text data bss dec filename
10231778 3479800 16617472 30329050 vmlinux-gcc5+-mskip-rax-setup
10268797 3547448 16621568 30437813 vmlinux
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remove the per-CPU delays during SMP initialization, which seems
to be possible on newer architectures with an x2APIC.
Xen does this since 2011. In fact, this commit is basically a
combination of the following Xen commits. The first removes the
delays, the second fixes an issue with the removal:
commit 68fce206f6dba9981e8322269db49692c95ce250
Author: Tim Deegan <Tim.Deegan@citrix.com>
Date: Tue Jul 19 14:13:01 2011 +0100
x86: Remove timeouts from INIT-SIPI-SIPI sequence when using x2apic.
Some of the timeouts are pointless since they're waiting for the ICR
to ack the IPI delivery and that doesn't happen on x2apic.
The others should be benign (and are suggested in the SDM) but
removing them makes AP bringup much more reliable on some test boxes.
Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>
commit f12ee533150761df5a7099c83f2a5fa6c07d1187
Author: Gang Wei <gang.wei@intel.com>
Date: Thu Dec 29 10:07:54 2011 +0000
X86: Add a delay between INIT & SIPIs for tboot AP bring-up in X2APIC case
Without this delay, Xen could not bring APs up while working with
TXT/tboot, because tboot needs some time in APs to handle INIT before
becoming ready for receiving SIPIs (this delay was removed as part of
c/s 23724 by Tim Deegan).
Signed-off-by: Gang Wei <gang.wei@intel.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Tim Deegan <tim@xen.org>
Committed-by: Tim Deegan <tim@xen.org>
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Cc: Anthony Liguori <aliguori@amazon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Gang Wei <gang.wei@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Deegan <tim@xen.org>
Link: http://lkml.kernel.org/r/1430732554-7294-1-git-send-email-jschoenh@amazon.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull EFI fixes from Matt Fleming:
* Avoid garbage names in efivarfs due to buggy firmware by zeroing
EFI variable name. (Ross Lagerwall)
* Stop erroneously dropping upper 32 bits of boot command line pointer
in EFI boot stub and stash them in ext_cmd_line_ptr. (Roy Franz)
* Fix double-free bug in error handling code path of EFI runtime map
code. (Dan Carpenter)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Recent PCI changes stopped exporting PCI constants if !CONFIG_PCI,
which made the UV build fail:
arch/x86/kernel/apic/x2apic_uv_x.c:843:16: error: ‘PCI_VGA_STATE_CHANGE_BRIDGE’ undeclared (first use in this function)
arch/x86/kernel/apic/x2apic_uv_x.c:1023:2: error: implicit declaration of function ‘pci_register_set_vga_state’ [-Werror=implicit-function-declaration]
As it's unlikely that an UV bootup will get far without PCI
enumeration, make the platform Kconfig switch (CONFIG_X86_UV)
depend on CONFIG_PCI=y.
Cc: Robin Holt <holt@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We don't have any arch specific scatterlist now that parisc switched over
to the generic one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit 75182b1632 ("x86/asm/entry: Switch all C consumers of
kernel_stack to this_cpu_sp0()") changed current_thread_info
to use this_cpu_sp0, and indirectly made it rely on init_tss
which was exported with EXPORT_PER_CPU_SYMBOL_GPL.
As a result some macros and inline functions such as set/get_fs,
test_thread_flag and variants have been made unusable for
external modules.
Make cpu_tss exported with EXPORT_PER_CPU_SYMBOL so that these
functions are accessible again, as they were previously.
Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/1430763404-21221-1-git-send-email-marc.dionne@your-file-system.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit 61f01dd941 ("x86_64, asm: Work around AMD SYSRET SS descriptor
attribute issue") makes AMD processors set SS to __KERNEL_DS in
__switch_to() to deal with cases when SS is NULL.
This breaks Xen PV guests who do not want to load SS with__KERNEL_DS.
Since the problem that the commit is trying to address would have to be
fixed in the hypervisor (if it in fact exists under Xen) there is no
reason to set X86_BUG_SYSRET_SS_ATTRS flag for PV VPCUs here.
This can be easily achieved by adding x86_hyper_xen_hvm.set_cpu_features
op which will clear this flag. (And since this structure is no longer
HVM-specific we should do some renaming).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Nothing changes those ops. Make the initializers readable while at it.
Reported-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add sysfs files for the EFI System Resource Table (ESRT) under
/sys/firmware/efi/esrt and for each EFI System Resource Entry under
entries/ as a subdir.
The EFI System Resource Table (ESRT) provides a read-only catalog of
system components for which the system accepts firmware upgrades via
UEFI's "Capsule Update" feature. This module allows userland utilities
to evaluate what firmware updates can be applied to this system, and
potentially arrange for those updates to occur.
The ESRT is described as part of the UEFI specification, in version 2.5
which should be available from http://uefi.org/specifications in early
2015. If you're a member of the UEFI Forum, information about its
addition to the standard is available as UEFI Mantis 1090.
For some hardware platforms, additional restrictions may be found at
http://msdn.microsoft.com/en-us/library/windows/hardware/jj128256.aspx ,
and additional documentation may be found at
http://download.microsoft.com/download/5/F/5/5F5D16CD-2530-4289-8019-94C6A20BED3C/windows-uefi-firmware-update-platform.docx
.
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
An IO port or MMIO resource assigned to a PCI host bridge may be
consumed by the host bridge itself or available to its child
bus/devices. The ACPI specification defines a bit (Producer/Consumer)
to tell whether the resource is consumed by the host bridge itself,
but firmware hasn't used that bit consistently, so we can't rely on it.
Before commit 593669c2ac ("x86/PCI/ACPI: Use common ACPI resource
interfaces to simplify implementation"), arch/x86/pci/acpi.c ignored
all IO port resources defined by acpi_resource_io and
acpi_resource_fixed_io to filter out IO ports consumed by the host
bridge itself.
Commit 593669c2ac ("x86/PCI/ACPI: Use common ACPI resource interfaces
to simplify implementation") started accepting all IO port and MMIO
resources, which caused a regression that IO port resources consumed
by the host bridge itself became available to its child devices.
Then commit 63f1789ec7 ("x86/PCI/ACPI: Ignore resources consumed by
host bridge itself") ignored resources consumed by the host bridge
itself by checking the IORESOURCE_WINDOW flag, which accidently removed
MMIO resources defined by acpi_resource_memory24, acpi_resource_memory32
and acpi_resource_fixed_memory32.
On x86 and IA64 platforms, all IO port and MMIO resources are assumed
to be available to child bus/devices except one special case:
IO port [0xCF8-0xCFF] is consumed by the host bridge itself
to access PCI configuration space.
So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF]. This solution
will also ease the way to consolidate ACPI PCI host bridge common code
from x86, ia64 and ARM64.
Related ACPI table are archived at:
https://bugzilla.kernel.org/show_bug.cgi?id=94221
Related discussions at:
http://patchwork.ozlabs.org/patch/461633/https://lkml.org/lkml/2015/3/29/304
Fixes: 63f1789ec7 (Ignore resources consumed by host bridge itself)
Reported-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fengguang's bot reported that 4545c898 ("x86: introduce kaslr_offset()") broke
randconfig build
In file included from arch/x86/xen/vga.c:5:0:
arch/x86/include/asm/setup.h: In function 'kaslr_offset':
>> arch/x86/include/asm/setup.h:77:2: error: implicit declaration of function 'ALIGN' [-Werror=implicit-function-declaration]
return (unsigned long)&_text - __START_KERNEL;
^
Fix that by making setup.h self-sufficient by explicitly including
linux/kernel.h, which is needed for ALIGN() (which is what __START_KERNEL
contains in its expansion).
Reported-by: fengguang.wu@intel.com
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Commit 77e32c89a7 ("clockevents: Manage device's state separately for
the core") decouples clockevent device's modes from states. With this
change when a Xen guest tries to resume, it won't be calling its
set_mode op which needs to be done on each VCPU in order to make the
hypervisor aware that we are in oneshot mode.
This happens because clockevents_tick_resume() (which is an intermediate
step of resuming ticks on a processor) doesn't call clockevents_set_state()
anymore and because during suspend clockevent devices on all VCPUs (except
for the one doing the suspend) are left in ONESHOT state. As result, during
resume the clockevents state machine will assume that device is already
where it should be and doesn't need to be updated.
To avoid this problem we should suspend ticks on all VCPUs during
suspend.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
We give up old_addr hint from the coming patch module in cases when kernel load
base has been randomized (as in such case, the coming module has no idea about
the exact randomization offset).
We are currently too pessimistic, and give up immediately as soon as
CONFIG_RANDOMIZE_BASE is set; this doesn't however directly imply that the
load base has actually been randomized. There are config options that
disable kASLR (such as hibernation), user could have disabled kaslr on
kernel command-line, etc.
The loader propagates the information whether kernel has been randomized
through bootparams. This allows us to have the condition more accurate.
On top of that, it seems unnecessary to give up old_addr hints even if
randomization is active. The relocation offset can be computed using
kaslr_ofsset(), and therefore old_addr can be adjusted accordingly.
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Offset that has been chosen for kaslr during kernel decompression can be
easily computed as a difference between _text and __START_KERNEL. We are
already making use of this in dump_kernel_offset() notifier and in
arch_crash_save_vmcoreinfo().
Introduce kaslr_offset() that makes this computation instead of hard-coding
it, so that other kernel code (such as live patching) can make use of it.
Also convert existing users to make use of it.
This patch is equivalent transofrmation without any effects on the resulting
code:
$ diff -u vmlinux.old.asm vmlinux.new.asm
--- vmlinux.old.asm 2015-04-28 17:55:19.520983368 +0200
+++ vmlinux.new.asm 2015-04-28 17:55:24.141206072 +0200
@@ -1,5 +1,5 @@
-vmlinux.old: file format elf64-x86-64
+vmlinux.new: file format elf64-x86-64
Disassembly of section .text:
$
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This reverts commits 0a4e6be9ca
and 80f7fdb1c7.
The task migration notifier was originally introduced in order to support
the pvclock vsyscall with non-synchronized TSC, but KVM only supports it
with synchronized TSC. Hence, on KVM the race condition is only needed
due to a bad implementation on the host side, and even then it's so rare
that it's mostly theoretical.
As far as KVM is concerned it's possible to fix the host, avoiding the
additional complexity in the vDSO and the (re)introduction of the task
migration notifier.
Xen, on the other hand, hasn't yet implemented vsyscall support at
all, so we do not care about its plans for non-synchronized TSC.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The kvmclock spec says that the host will increment a version field to
an odd number, then update stuff, then increment it to an even number.
The host is buggy and doesn't do this, and the result is observable
when one vcpu reads another vcpu's kvmclock data.
There's no good way for a guest kernel to keep its vdso from reading
a different vcpu's kvmclock data, but we don't need to care about
changing VCPUs as long as we read a consistent data from kvmclock.
(VCPU can change outside of this loop too, so it doesn't matter if we
return a value not fit for this VCPU.)
Based on a patch by Radim Krčmář.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AMD CPUs don't reinitialize the SS descriptor on SYSRET, so SYSRET with
SS == 0 results in an invalid usermode state in which SS is apparently
equal to __USER_DS but causes #SS if used.
Work around the issue by setting SS to __KERNEL_DS __switch_to, thus
ensuring that SYSRET never happens with SS set to NULL.
This was exposed by a recent vDSO cleanup.
Fixes: e7d6eefaaa x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull fourth vfs update from Al Viro:
"d_inode() annotations from David Howells (sat in for-next since before
the beginning of merge window) + four assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
RCU pathwalk breakage when running into a symlink overmounting something
fix I_DIO_WAKEUP definition
direct-io: only inc/dec inode->i_dio_count for file systems
fs/9p: fix readdir()
VFS: assorted d_backing_inode() annotations
VFS: fs/inode.c helpers: d_inode() annotations
VFS: fs/cachefiles: d_backing_inode() annotations
VFS: fs library helpers: d_inode() annotations
VFS: assorted weird filesystems: d_inode() annotations
VFS: normal filesystems (and lustre): d_inode() annotations
VFS: security/: d_inode() annotations
VFS: security/: d_backing_inode() annotations
VFS: net/: d_inode() annotations
VFS: net/unix: d_backing_inode() annotations
VFS: kernel/: d_inode() annotations
VFS: audit: d_backing_inode() annotations
VFS: Fix up some ->d_inode accesses in the chelsio driver
VFS: Cachefiles should perform fs modifications on the top layer only
VFS: AF_UNIX sockets should call mknod on the top layer only
Pull crypto fixes from Herbert Xu:
"This push fixes a build problem with img-hash under non-standard
configurations and a serious regression with sha512_ssse3 which can
lead to boot failures"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: img-hash - CRYPTO_DEV_IMGTEC_HASH should depend on HAS_DMA
crypto: x86/sha512_ssse3 - fixup for asm function prototype change
Pull second batch of KVM changes from Paolo Bonzini:
"This mostly includes the PPC changes for 4.1, which this time cover
Book3S HV only (debugging aids, minor performance improvements and
some cleanups). But there are also bug fixes and small cleanups for
ARM, x86 and s390.
The task_migration_notifier revert and real fix is still pending
review, but I'll send it as soon as possible after -rc1"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (29 commits)
KVM: arm/arm64: check IRQ number on userland injection
KVM: arm: irqfd: fix value returned by kvm_irq_map_gsi
KVM: VMX: Preserve host CR4.MCE value while in guest mode.
KVM: PPC: Book3S HV: Use msgsnd for signalling threads on POWER8
KVM: PPC: Book3S HV: Translate kvmhv_commence_exit to C
KVM: PPC: Book3S HV: Streamline guest entry and exit
KVM: PPC: Book3S HV: Use bitmap of active threads rather than count
KVM: PPC: Book3S HV: Use decrementer to wake napping threads
KVM: PPC: Book3S HV: Don't wake thread with no vcpu on guest IPI
KVM: PPC: Book3S HV: Get rid of vcore nap_count and n_woken
KVM: PPC: Book3S HV: Move vcore preemption point up into kvmppc_run_vcpu
KVM: PPC: Book3S HV: Minor cleanups
KVM: PPC: Book3S HV: Simplify handling of VCPUs that need a VPA update
KVM: PPC: Book3S HV: Accumulate timing information for real-mode code
KVM: PPC: Book3S HV: Create debugfs file for each guest's HPT
KVM: PPC: Book3S HV: Add ICP real mode counters
KVM: PPC: Book3S HV: Move virtual mode ICP functions to real-mode
KVM: PPC: Book3S HV: Convert ICS mutex lock to spin lock
KVM: PPC: Book3S HV: Add guest->host real mode completion counters
KVM: PPC: Book3S HV: Add helpers for lock/unlock hpte
...
Since kzalloc() returns a void pointer, we don't need to cast the
return value in arch/x86/crypto/sha-mb/sha1_mb.c::sha1_mb_mod_init().
Signed-off-by: Firo Yang <firogm@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull initial ACPI support for arm64 from Will Deacon:
"This series introduces preliminary ACPI 5.1 support to the arm64
kernel using the "hardware reduced" profile. We don't support any
peripherals yet, so it's fairly limited in scope:
- MEMORY init (UEFI)
- ACPI discovery (RSDP via UEFI)
- CPU init (FADT)
- GIC init (MADT)
- SMP boot (MADT + PSCI)
- ACPI Kconfig options (dependent on EXPERT)
ACPI for arm64 has been in development for a while now and hardware
has been available that can boot with either FDT or ACPI tables. This
has been made possible by both changes to the ACPI spec to cater for
ARM-based machines (known as "hardware-reduced" in ACPI parlance) but
also a Linaro-driven effort to get this supported on top of the Linux
kernel. This pull request is the result of that work.
These changes allow us to initialise the CPUs, interrupt controller,
and timers via ACPI tables, with memory information and cmdline coming
from EFI. We don't support a hybrid ACPI/FDT scheme. Of course,
there is still plenty of work to do (a serial console would be nice!)
but I expect that to happen on a per-driver basis after this core
series has been merged.
Anyway, the diff stat here is fairly horrible, but splitting this up
and merging it via all the different subsystems would have been
extremely painful. Instead, we've got all the relevant Acks in place
and I've not seen anything other than trivial (Kconfig) conflicts in
-next (for completeness, I've included my resolution below). Nearly
half of the insertions fall under Documentation/.
So, we'll see how this goes. Right now, it all depends on EXPERT and
I fully expect people to use FDT by default for the immediate future"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (31 commits)
ARM64 / ACPI: make acpi_map_gic_cpu_interface() as void function
ARM64 / ACPI: Ignore the return error value of acpi_map_gic_cpu_interface()
ARM64 / ACPI: fix usage of acpi_map_gic_cpu_interface
ARM64: kernel: acpi: honour acpi=force command line parameter
ARM64: kernel: acpi: refactor ACPI tables init and checks
ARM64: kernel: psci: let ACPI probe PSCI version
ARM64: kernel: psci: factor out probe function
ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer
ARM64 / ACPI: Don't unflatten device tree if acpi=force is passed
ARM64 / ACPI: additions of ACPI documentation for arm64
Documentation: ACPI for ARM64
ARM64 / ACPI: Enable ARM64 in Kconfig
XEN / ACPI: Make XEN ACPI depend on X86
ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64
clocksource / arch_timer: Parse GTDT to initialize arch timer
irqchip: Add GICv2 specific ACPI boot support
ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi
ACPI / processor: Make it possible to get CPU hardware ID via GICC
ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID
ARM64 / ACPI: Parse MADT for SMP initialization
...
Commit cae2a173fe ("x86: clean up/fix 'copy_in_user()' tail zeroing")
fixed the failure case tail zeroing of one special case of the x86-64
generic user-copy routine, namely when used for the user-to-user case
("copy_in_user()").
But in the process it broke an even more unusual case: using the user
copy routine for kernel-to-kernel copying.
Now, normally kernel-kernel copies are obviously done using memcpy(),
but we have a couple of special cases when we use the user-copy
functions. One is when we pass a kernel buffer to a regular user-buffer
routine, using set_fs(KERNEL_DS). That's a "normal" case, and continued
to work fine, because it never takes any faults (with the possible
exception of a silent and successful vmalloc fault).
But Jan Beulich pointed out another, very unusual, special case: when we
use the user-copy routines not because it's a path that expects a user
pointer, but for a couple of ftrace/kgdb cases that want to do a kernel
copy, but do so using "unsafe" buffers, and use the user-copy routine to
gracefully handle faults. IOW, for probe_kernel_write().
And that broke for the case of a faulting kernel destination, because we
saw the kernel destination and wanted to try to clear the tail of the
buffer. Which doesn't work, since that's what faults.
This only triggers for things like kgdb and ftrace users (eg trying
setting a breakpoint on read-only memory), but it's definitely a bug.
The fix is to not compare against the kernel address start (TASK_SIZE),
but instead use the same limits "access_ok()" uses.
Reported-and-tested-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org # 4.0
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
io_apic_ops.init() is either NULL, if IO-APIC support is disabled at
compile time or native_io_apic_init_mappings(). No point to have that
as we can achieve the same thing with an empty inline.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
