Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.
Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: James Morris <jmorris@namei.org>
Impact: cleanup
We can remove MMIOTRACE_HOOKS and replace it with just MMIOTRACE.
MMIOTRACE_HOOKS is a remnant from the time when I thought that
something else could also use the kmmio facilities.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change oops_end such that signr=0 signals that do_exit
is not to be called.
Currently, each use of __die is soon followed by a call
to oops_end and 'regs' is set to NULL if oops_end is expected
not to call do_exit. Change all such pairs to set signr=0
instead. On x86_64 oops_end is used 'bare' in die_nmi; use
signr=0 instead of regs=NULL there, too.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus noticed that the "again:" versus "survive:" OOM logic for
the init task was arbitrarily different.
The 64-bit codepath is the better one, because it correctly re-lookups
the vma after having dropped the ->mmap_sem.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan reported a spike in the following bug pattern in v2.6.27:
http://www.kerneloops.org/searchweek.php?search=lock_page
which happens because hwclock started triggering warnings due to
a (correct) might_sleep() check in the MM code.
The warning occurs because hwclock uses this dubious sequence of
code to run "atomic" code:
static unsigned long
atomic(const char *name, unsigned long (*op)(unsigned long),
unsigned long arg)
{
unsigned long v;
__asm__ volatile ("cli");
v = (*op)(arg);
__asm__ volatile ("sti");
return v;
}
Then it pagefaults in that "atomic" section, triggering the warning.
There is no way the kernel could provide "atomicity" in this path,
a page fault is a cannot-continue machine event so the kernel has to
wait for the page to be filled in.
Even if it was just a minor fault we'd have to take locks and might have
to spend quite a bit of time with interrupts disabled - not nice to irq
latencies in general.
So instead just enable interrupts in the pagefault path unconditionally
if we come from user-space, and handle the fault.
Also, while touching this code, unify some trivial parts of the x86
VM paths at the same time.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The last use of trace_hardirqs_fixup is unnecessary, because the
trap is taken with interrupt off on i386 as well as x86_64, and
the irq-tracer is notified of this from the assembly code.
trace_hardirqs_fixup and trace_hardirqs_fixup_flags are removed
from include/asm-x86/irqflags.h as they are no longer used.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Perodically check for corruption in low phusical memory. Don't bother
checking at fault time, since it won't show anything useful.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some BIOSes have been observed to corrupt memory in the low 64k. This
change:
- Reserves all memory which does not have to be in that area, to
prevent it from being used as general memory by the kernel. Things
like the SMP trampoline are still in the memory, however.
- Clears the reserved memory so we can observe changes to it.
- Adds a function check_for_bios_corruption() which checks and reports on
memory becoming unexpectedly non-zero. Currently it's called in the
x86 fault handler, and the powermanagement debug output.
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since the fourth PDPT entry cannot be shared under Xen,
vmalloc_sync_all() must iterate over pmd-s rather than pgd-s here.
Luckily, the code isn't used for native PAE (SHARED_KERNEL_PMD is 1)
and the change is benign to non-PAE.
Also do a little more cleanup in that function.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
declared do_page_fault() in asm-x86/trap.h for both X86_32 and X86_64
removed do_invalid_op declaration from mm/fault.c as it is already declared in asm-x86/trap.h
Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
vmalloc_sync_all() is only called from register_die_notifier and
alloc_vm_area. Neither is on any performance-critical paths, so
vmalloc_sync_all() itself is not on any hot paths.
Given that the optimisations in vmalloc_sync_all add a fair amount of
code and complexity, and are fairly hard to evaluate for correctness,
it's better to just remove them to simplify the code rather than worry
about its absolute performance.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove the #ifdef conditional because this comparison is already done in
user_mode_vm().
Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Cc: akpm@osdl.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
'man 3 printf' tells me that %p should be printed as if by %#x, but
this is not true for the kernel, which does not use the '0x' prefix
for the %p conversion specifier.
A small cast to (void *) is also prettier than #ifdef/#else/#endif.
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Page faults in kernel address space between PAGE_OFFSET up to
VMALLOC_START should not try to map as vmalloc.
Fix rarely endless page faults inside mount_block_root for root
filesystem at boot time.
All 32bit kernels up to 2.6.25 can fail into this hole.
I can not present this under native linux kernel. I see, that the 64bit
has fixed the problem. I copied the same lines into 32bit part.
Recorded debugs are from coLinux kernel 2.6.22.18 (virtualisation):
http://www.henrynestler.com/colinux/testing/pfn-check-0.7.3/20080410-antinx/bug16-recursive-page-fault-endless.txt
The physicaly memory was trimmed down to 192MB to better catch the bug.
More memory gets the bug more rarely.
Details, how every x86 32bit system can fail:
Start from "mount_block_root",
http://lxr.linux.no/linux/init/do_mounts.c#L297
There the variable "fs_names" got one memory page with 4096 bytes.
Variable "p" walks through the existing file system types. The first
string is no problem.
But, with the second loop in mount_block_root the offset of "p" is not
at beginning of page, the offset is for example +9, if "reiserfs" is the
first in list.
Than calls do_mount_root, and lands in sys_mount.
Remember: Variable "type_page" contains now "fs_type+9" and not contains
a full page.
The sys_mount copies 4096 bytes with function "exact_copy_from_user()":
http://lxr.linux.no/linux/fs/namespace.c#L1540
Mostly exist pages after the buffer "fs_names+4096+9" and the page fault
handler was not called. No problem.
In the case, if the page after "fs_names+4096" is not mapped, the page
fault handler was called from http://lxr.linux.no/linux/fs/namespace.c#L1320
The do_page_fault gots an address 0xc03b4000.
It's kernel address, address >= TASK_SIZE, but not from vmalloc! It's
from "__getname()" alias "kmem_cache_alloc".
The "error_code" is 0. "vmalloc_fault" will be call:
http://lxr.linux.no/linux/arch/i386/mm/fault.c#L332
"vmalloc_fault" tryed to find the physical page for a non existing
virtual memory area. The macro "pte_present" in vmalloc_fault()
got a next page fault for 0xc0000ed0 at:
http://lxr.linux.no/linux/arch/i386/mm/fault.c#L282
No PTE exist for such virtual address. The page fault handler was trying
to sync the physical page for the PTE lockup.
This called vmalloc_fault() again for address 0xc000000, and that also
was not existing. The endless began...
In normal case the cpu would still loop with disabled interrrupts. Under
coLinux this was catched by a stack overflow inside printk debugs.
Signed-off-by: Henry Nestler <henry.nestler@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kmmio.c handles the list of mmio probes with callbacks, list of traced
pages, and attaching into the page fault handler and die notifier. It
arms, traps and disarms the given pages, this is the core of mmiotrace.
mmio-mod.c is a user interface, hooking into ioremap functions and
registering the mmio probes. It also decodes the required information
from trapped mmio accesses via the pre and post callbacks in each probe.
Currently, hooking into ioremap functions works by redefining the symbols
of the target (binary) kernel module, so that it calls the traced
versions of the functions.
The most notable changes done since the last discussion are:
- kmmio.c is a built-in, not part of the module
- direct call from fault.c to kmmio.c, removing all dynamic hooks
- prepare for unregistering probes at any time
- make kmmio re-initializable and accessible to more than one user
- rewrite kmmio locking to remove all spinlocks from page fault path
Can I abuse call_rcu() like I do in kmmio.c:unregister_kmmio_probe()
or is there a better way?
The function called via call_rcu() itself calls call_rcu() again,
will this work or break? There I need a second grace period for RCU
after the first grace period for page faults.
Mmiotrace itself (mmio-mod.c) is still a module, I am going to attack
that next. At some point I will start looking into how to make mmiotrace
a tracer component of ftrace (thanks for the hint, Ingo). Ftrace should
make the user space part of mmiotracing as simple as
'cat /debug/trace/mmio > dump.txt'.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The custom page fault handler list is replaced with a single function
pointer. All related functions and variables are renamed for
mmiotrace.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: pq@iki.fi
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Provides kernel modules a way to register custom page fault handlers.
On every page fault this will call a list of registered functions. The
functions may handle the fault and force do_page_fault() to return
immediately.
This functionality is similar to the now removed page fault notifiers.
Custom page fault handlers are used by debugging and reverse engineering
tools. Mmiotrace is one such tool and a patch to add it into the tree
will follow.
The custom page fault handlers are called earlier in do_page_fault()
than the page fault notifiers were.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch renames VM_MASK to X86_VM_MASK (which
in turn defined as alias to X86_EFLAGS_VM) to better
distinguish from virtual memory flags. We can't just
use X86_EFLAGS_VM instead because it is also used
for conditional compilation
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus noticed a second bug and an uncleanliness:
- we'd return on any instruction fetch fault
- we'd use both the value of 16 and the PF_INSTR symbol which are
the same and make no sense
the cleanup nicely unifies this piece of logic.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
some early Athlon XP's and Opterons generate bogus faults on prefetch
instructions. The workaround for this regressed over .24 - reinstate it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
dump_pagetable() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
lockdep just caught this one:
=================================
[ INFO: inconsistent lock state ]
2.6.24 #38
---------------------------------
inconsistent {in-softirq-W} -> {softirq-on-W} usage.
swapper/1 [HC0[0]:SC0[0]:HE1:SE1] takes:
(pgd_lock){-+..}, at: [<ffffffff8022a9ea>] mm_init+0x1da/0x250
{in-softirq-W} state was registered at:
[<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 394559
hardirqs last enabled at (394559): [<ffffffff80267f0a>] get_page_from_freelist+0x30a/0x4c0
hardirqs last disabled at (394558): [<ffffffff80267d25>] get_page_from_freelist+0x125/0x4c0
softirqs last enabled at (393952): [<ffffffff80232f8e>] __do_softirq+0xce/0xe0
softirqs last disabled at (393945): [<ffffffff8020c57c>] call_softirq+0x1c/0x30
other info that might help us debug this:
no locks held by swapper/1.
stack backtrace:
Pid: 1, comm: swapper Not tainted 2.6.24 #38
Call Trace:
[<ffffffff8024e1fb>] print_usage_bug+0x18b/0x190
[<ffffffff8024f55d>] mark_lock+0x53d/0x560
[<ffffffff8024fffa>] __lock_acquire+0x3ca/0xed0
[<ffffffff80250ba8>] lock_acquire+0xa8/0xe0
[<ffffffff8022a9ea>] ? mm_init+0x1da/0x250
[<ffffffff809bcd10>] _spin_lock+0x30/0x70
[<ffffffff8022a9ea>] mm_init+0x1da/0x250
[<ffffffff8022aa99>] mm_alloc+0x39/0x50
[<ffffffff8028b95a>] bprm_mm_init+0x2a/0x1a0
[<ffffffff8028d12b>] do_execve+0x7b/0x220
[<ffffffff80209776>] sys_execve+0x46/0x70
[<ffffffff8020c214>] kernel_execve+0x64/0xd0
[<ffffffff8020901e>] ? _stext+0x1e/0x20
[<ffffffff802090ba>] init_post+0x9a/0xf0
[<ffffffff809bc5f6>] ? trace_hardirqs_on_thunk+0x35/0x3a
[<ffffffff8024f75a>] ? trace_hardirqs_on+0xba/0xd0
[<ffffffff8020c1a8>] ? child_rip+0xa/0x12
[<ffffffff8020bcbc>] ? restore_args+0x0/0x44
[<ffffffff8020c19e>] ? child_rip+0x0/0x12
turns out that pgd_lock has been used on 64-bit x86 in an irq-unsafe
way for almost two years, since commit 8c914cb704.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In very rare cases, on certain CPUs, we could end up in the spurious
fault handler and ignore a large pud/pmd mapping. The resulting pte
pointer points into the mapped physical space and dereferencing it
will fault recursively.
Make the code aware of large mappings and do the permission check
on the pmd/pud entry, when a large pud/pmd mapping is detected.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use a standard list threaded through page->lru for maintaining the pgd
list on PAE. This is the same as 64-bit, and seems saner than using a
non-standard list via page->index.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The change from current to tsk in do_page_fault is safe as
this is set at the very beginning of the function.
Removes a likely() annotation from the 64-bit version, this
could have instead been added to 32-bit.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When changing a kernel page from RO->RW, it's OK to leave stale TLB
entries around, since doing a global flush is expensive and they pose
no security problem. They can, however, generate a spurious fault,
which we should catch and simply return from (which will have the
side-effect of reloading the TLB to the current PTE).
This can occur when running under Xen, because it frequently changes
kernel pages from RW->RO->RW to implement Xen's pagetable semantics.
It could also occur when using CONFIG_DEBUG_PAGEALLOC, since it avoids
doing a global TLB flush after changing page permissions.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On !PAE 32-bit, _PAGE_NX will be 0, making is_prefetch always
return early. The test is sufficient on PAE as __supported_pte_mask
is updated in the same places as nx_enabled in init_32.c which also
takes disable_nx into account.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unify includes in moved fault.c.
Modify Makefiles to pick up unified file.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Elimination of these ifdefs can be done in a unified file.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It's about time to get on with unifying these files, elimination
of the ugly ifdefs can occur in the unified file.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This changes the oops dumping format for page faults to
be similar between X86_32 and 64.
This is the first user of printk_address on X86_32.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This will help when unifying the oops dumping code on 32/64
bit. No functional changes.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Further towards unifying these files, add another helper
in same spirit as is_errata93.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Further towards unifying these files, add another helper
in same spirit as is_errata93.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use v8086_mode inline in fault_32.c, no functional change
also ifdef the section for 32-bit only and add to fault_64.c
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
They now look like:
hal-resmgr[13791]: segfault at 3c rip 2b9c8caec182 rsp 7fff1e825d30 error 4 in libacl.so.1.1.0[2b9c8caea000+6000]
This makes it easier to pinpoint bugs to specific libraries.
And printing the offset into a mapping also always allows to find the
correct fault point in a library even with randomized mappings. Previously
there was no way to actually find the correct code address inside
the randomized mapping.
Relies on earlier patch to shorten the printk formats.
They are often now longer than 80 characters, but I think that's worth it.
[includes fix from Eric Dumazet to check d_path error value]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Adding the address of the faulting library missed removing a
line ending from X86_32.
Also update the shorter printk format for X86_32 in fault_64.c
to make it easier to se the remaining differences.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add caller of is_errata93() to X86_32, ifdef'd to do
nothing.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Comments, indentation, printk format.
Uses task_pid_nr() on X86_64 now, but this is always defined
to task->pid.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Copy the prefetch of map_sem from X86_64 and move the check
notify_page_fault (soon to be kprobe_handle_fault) out of
the unlikely if() statement.
This makes the X86_32|64 pagefault handlers closer to each
other.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
is_prefetch was the last user of get_segment_eip and only on
X86_32. This function returned the faulting instruction's
address and set the upper segment limit.
Instead, use the convert_ip_to_linear helper and rely on
probe_kernel_address to do the segment checks which was
already done everywhere the segment limit was being checked
on X86_32.
Remove get_segment_eip as well.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Rename convert_rip_to_linear to convert_ip_to_linear for shared
X86_32|64 use.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
For enhancing the 32 bit EBP based backtracer, I need the capability
for the backtracer to tell it's customer that an entry is either
reliable or unreliable, and the backtrace printing code then needs to
print the unreliable ones slightly different.
This patch adds the basic capability, the next patch will add a user
of this capability.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
get_segment_eip has similarities to convert_rip_to_linear(),
and is used in a similar context. Move get_segment_eip to
step.c to allow easier consolidation.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Should be the last of the error_code tests that could use
the PF_ defines. Makes X86_32|64 a little closer.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
David Howells