Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: NPalmer Dabbelt <palmer@sifive.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y accounts the cputime on
any context boundary: irq entry/exit, guest entry/exit, context switch,
etc...

Calling functions such as account_system_time(), account_user_time()
and such can be costly, especially if they are called on many fastpath
such as twice per IRQ. Those functions do more than just accounting to
kcpustat and task cputime. Depending on the config, some subsystems can
perform unpleasant multiplications and divisions, among other things.

So lets accumulate the cputime instead and delay the accounting on ticks
and context switches only.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1483636310-6557-9-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

If CONFIG_VMAP_STACK=y is selected, kernel stacks are allocated with
__vmalloc_node_range().

Grsecurity has had a similar feature (called GRKERNSEC_KSTACKOVERFLOW=y)
for a long time.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/14c07d4fd173a5b117f51e8b939f9f4323e39899.1470907718.git.luto@kernel.org
[ Minor edits. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

In general, there's no need for the "restore sigmask" flag to live in
ti->flags.  alpha, ia64, microblaze, powerpc, sh, sparc (64-bit only),
tile, and x86 use essentially identical alternative implementations,
placing the flag in ti->status.

Replace those optimized implementations with an equally good common
implementation that stores it in a bitfield in struct task_struct and
drop the custom implementations.

Additional architectures can opt in by removing their
TIF_RESTORE_SIGMASK defines.

Link: http://lkml.kernel.org/r/8a14321d64a28e40adfddc90e18a96c086a6d6f9.1468522723.git.luto@kernel.orgSigned-off-by: NAndy Lutomirski <luto@kernel.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We've had the thread info allocated together with the thread stack for
most architectures for a long time (since the thread_info was split off
from the task struct), but that is about to change.

But the patches that move the thread info to be off-stack (and a part of
the task struct instead) made it clear how confused the allocator and
freeing functions are.

Because the common case was that we share an allocation with the thread
stack and the thread_info, the two pointers were identical.  That
identity then meant that we would have things like

	ti = alloc_thread_info_node(tsk, node);
	...
	tsk->stack = ti;

which certainly _worked_ (since stack and thread_info have the same
value), but is rather confusing: why are we assigning a thread_info to
the stack? And if we move the thread_info away, the "confusing" code
just gets to be entirely bogus.

So remove all this confusion, and make it clear that we are doing the
stack allocation by renaming and clarifying the function names to be
about the stack.  The fact that the thread_info then shares the
allocation is an implementation detail, and not really about the
allocation itself.

This is a pure renaming and type fix: we pass in the same pointer, it's
just that we clarify what the pointer means.

The ia64 code that actually only has one single allocation (for all of
task_struct, thread_info and kernel thread stack) now looks a bit odd,
but since "tsk->stack" is actually not even used there, that oddity
doesn't matter.  It would be a separate thing to clean that up, I
intentionally left the ia64 changes as a pure brute-force renaming and
type change.
Acked-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NRichard Weinberger <richard@nod.at>

If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: NRichard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.

Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: linux-ia64@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-6633akuird5hi3si4gbegkm8@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

No point in having this bit defined by architecture.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130917183629.090698799@linutronix.de

Move it to a common place. Preparatory patch for implementing
set/clear for the idle need_resched poll implementation.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: NCc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130321215233.446034505@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

If we want to stop the tick further idle, we need to be
able to account the cputime without using the tick.

Virtual based cputime accounting solves that problem by
hooking into kernel/user boundaries.

However implementing CONFIG_VIRT_CPU_ACCOUNTING require
low level hooks and involves more overhead. But we already
have a generic context tracking subsystem that is required
for RCU needs by archs which plan to shut down the tick
outside idle.

This patch implements a generic virtual based cputime
accounting that relies on these generic kernel/user hooks.

There are some upsides of doing this:

- This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING
if context tracking is already built (already necessary for RCU in full
tickless mode).

- We can rely on the generic context tracking subsystem to dynamically
(de)activate the hooks, so that we can switch anytime between virtual
and tick based accounting. This way we don't have the overhead
of the virtual accounting when the tick is running periodically.

And one downside:

- There is probably more overhead than a native virtual based cputime
accounting. But this relies on hooks that are already set anyway.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

Make default just return 0.  The current default (checking
TIF_POLLING_NRFLAG) is taken to architectures that need it;
ones that don't do polling in their idle threads don't need
to defined TIF_POLLING_NRFLAG at all.

ia64 defined both TS_POLLING (used by its tsk_is_polling())
and TIF_POLLING_NRFLAG (not used at all).  Killed the latter...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

helpers parallel to set_restore_sigmask(), used in the next commits
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Replace __HAVE_ARCH_TASK_ALLOCATOR and __HAVE_ARCH_THREAD_ALLOCATOR
with proper config switches.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20120505150142.371309416@linutronix.de

Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arch@vger.kernel.org

In commit 504f52b5
    mm: NUMA aware alloc_task_struct_node()

Eric Dumazet forgot a "\".  Add it.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a node parameter to alloc_thread_info(), and change its name to
alloc_thread_info_node()

This change is needed to allow NUMA aware kthread_create_on_cpu()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All kthreads being created from a single helper task, they all use memory
from a single node for their kernel stack and task struct.

This patch suite creates kthread_create_on_cpu(), adding a 'cpu' parameter
to parameters already used by kthread_create().

This parameter serves in allocating memory for the new kthread on its
memory node if available.

Users of this new function are : ksoftirqd, kworker, migration, pktgend...

This patch:

Add a node parameter to alloc_task_struct(), and change its name to
alloc_task_struct_node()

This change is needed to allow NUMA aware kthread_create_on_cpu()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAndreas Dilger <adilger@dilger.ca>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Pull the initial preempt_count value into a single
definition site.

Maintainers for: alpha, ia64 and m68k, please have a look,
your arch code is funny.

The header magic is a bit odd, but similar to the KERNEL_DS
one, CPP waits with expanding these macros until the
INIT_THREAD_INFO macro itself is expanded, which is in
arch/*/kernel/init_task.c where we've already included
sched.h so we're good.

Cc: tony.luck@intel.com
Cc: rth@twiddle.net
Cc: geert@linux-m68k.org
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make IA64 use generic trace hook in some paths.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

After moving the the include files there were a few clean-ups:

1) Some files used #include <asm-ia64/xyz.h>, changed to <asm/xyz.h>

2) Some comments alerted maintainers to look at various header files to
make matching updates if certain code were to be changed. Updated these
comments to use the new include paths.

3) Some header files mentioned their own names in initial comments. Just
deleted these self references.
Signed-off-by: NTony Luck <tony.luck@intel.com>

We duplicate alloc/free_thread_info defines on many platforms (the
majority uses __get_free_pages/free_pages).  This patch defines common
defines and removes these duplicated defines.
__HAVE_ARCH_THREAD_INFO_ALLOCATOR is introduced for platforms that do
something different.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define
our own set_restore_sigmask() function.  This saves the costly
SMP-safe set_bit operation, which we do not need for the sigmask
flag since TIF_SIGPENDING always has to be set too.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

TIF_RESTORE_SIGMASK no longer needs to be in the _TIF_WORK_* masks.
Those low bits are scarce.  Renumber TIF_RESTORE_SIGMASK to free one up.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch implements VIRT_CPU_ACCOUNTING for ia64,
which enable us to use more accurate cpu time accounting.

The VIRT_CPU_ACCOUNTING is an item of kernel config, which s390
and powerpc arch have.  By turning this config on, these archs
change the mechanism of cpu time accounting from tick-sampling
based one to state-transition based one.

The state-transition based accounting is done by checking time
(cycle counter in processor) at every state-transition point,
such as entrance/exit of kernel, interrupt, softirq etc.
The difference between point to point is the actual time consumed
during in the state. There is no doubt about that this value is
more accurate than that of tick-sampling based accounting.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This is base kernel patch for ptrace RSE bug. It's basically a backport
from the utrace RSE patch I sent out several weeks ago. please review.

when a thread is stopped (ptraced), debugger might change thread's user
stack (change memory directly), and we must avoid the RSE stored in
kernel to override user stack (user space's RSE is newer than kernel's
in the case). To workaround the issue, we copy kernel RSE to user RSE
before the task is stopped, so user RSE has updated data.  we then copy
user RSE to kernel after the task is resummed from traced stop and
kernel will use the newer RSE to return to user.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NPetr Tesarik <ptesarik@suse.cz>
CC: Roland McGrath <roland@redhat.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Since the RSE synchronization will need a TIF_ flag, but all

work-to-be-done bits are already used, so we have to multiplex
TIF_NOTIFY_RESUME again.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NPetr Tesarik <ptesarik@suse.cz>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Remove unused TIF_NOTIFY_RESUME flag for all processor architectures.  The
flag was not used excecpt on IA-64 where the patch replaces it with
TIF_PERFMON_WORK.
Signed-off-by: Nstephane eranian <eranian@hpl.hp.com>
Cc: <linux-arch@vger.kernel.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recently a few direct accesses to the thread_info in the task structure snuck
back, so this wraps them with the appropriate wrapper.
Signed-off-by: NRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Preparation for pselect and ppoll.
ia32 compat code not tested. :-(
Signed-off-by: NAlexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: NAlexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

As is pointed out in
http://www.gelato.org/community/view_linear.php?id=1_1036&from=authors&value=Ian%20Wienand#1_1039,
if single step on break instruction, the break fault has higher
priority than the single-step trap. When the break fault handler
is entered, it advances the IP by 1 instruction so break instruction
single-stepping is skipped, actually it is next instruction which
is single stepped.

This patch modifies this, it adds TIF_SINGLESTEP bit for thread
flags, and generate a fake sigtrap when single stepping break
instruction. Test case in attachment can verify this. Any comments
is welcome.
Signed-off-by: Nbibo, mao <bibo.mao@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Currently, to tell a task that it should go to the refrigerator, we set the
PF_FREEZE flag for it and send a fake signal to it.  Unfortunately there
are two SMP-related problems with this approach.  First, a task running on
another CPU may be updating its flags while the freezer attempts to set
PF_FREEZE for it and this may leave the task's flags in an inconsistent
state.  Second, there is a potential race between freeze_process() and
refrigerator() in which freeze_process() running on one CPU is reading a
task's PF_FREEZE flag while refrigerator() running on another CPU has just
set PF_FROZEN for the same task and attempts to reset PF_FREEZE for it.  If
the refrigerator wins the race, freeze_process() will state that PF_FREEZE
hasn't been set for the task and will set it unnecessarily, so the task
will go to the refrigerator once again after it's been thawed.

To solve first of these problems we need to stop using PF_FREEZE to tell
tasks that they should go to the refrigerator.  Instead, we can introduce a
special TIF_*** flag and use it for this purpose, since it is allowed to
change the other tasks' TIF_*** flags and there are special calls for it.

To avoid the freeze_process()-refrigerator() race we can make
freeze_process() to always check the task's PF_FROZEN flag after it's read
its "freeze" flag.  We should also make sure that refrigerator() will
always reset the task's "freeze" flag after it's set PF_FROZEN for it.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

cleanup: remove task_t and convert all the uses to struct task_struct. I
introduced it for the scheduler anno and it was a mistake.

Conversion was mostly scripted, the result was reviewed and all
secondary whitespace and style impact (if any) was fixed up by hand.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

During some profiling I noticed that default_idle causes a lot of
memory traffic. I think that is caused by the atomic operations
to clear/set the polling flag in thread_info. There is actually
no reason to make this atomic - only the idle thread does it
to itself, other CPUs only read it. So I moved it into ti->status.

Converted i386/x86-64/ia64 for now because that was the easiest
way to fix ACPI which also manipulates these flags in its idle
function.

Cc: Nick Piggin <npiggin@novell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In SLES10 (2.6.16) crash dumping (in my experience, LKCD) is unable to
capture the second page of the 2-page task/stack allocation.
This is particularly troublesome for dump analysis, as the stack traceback
cannot be done.
  (A similar convention is probably needed throughout the kernel to make
   kernel multi-page allocations detectable for dumping)

Multi-page kernel allocations are represented by the single page structure
associated with the first page of the allocation.  The page structures
associated with the other pages are unintialized.

If the dumper is selecting only kernel pages it has no way to identify
any but the first page of the allocation.

The fix is to make the task/stack allocation a compound page.
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

On SN2, MMIO writes which are issued from separate processors are not
guaranteed to arrive in any particular order at the IO hardware.  When
performing such writes from the kernel this is not a problem, as a
kernel thread will not migrate to another CPU during execution, and
mmiowb() calls can guarantee write ordering when control of the IO
resource is allowed to move between threads.

However, when MMIO writes can be performed from user space (e.g. DRM)
there are no such guarantees and mechanisms, as the process may
context-switch at any time, and may migrate to a different CPU as part
of the switch.  For such programs/hardware to operate correctly, it is
required that the MMIO writes from the old CPU be accepted by the IO
hardware before subsequent writes from the new CPU can be issued.

The following patch implements this behavior on SN2 by waiting for a
Shub register to indicate that these writes have been accepted.  This
is placed in the context switch-in path, and only performs the wait
when the newly scheduled task changes CPUs.
Signed-off-by: NPrarit Bhargava <prarit@sgi.com>
Signed-off-by: NBrent Casavant <bcasavan@sgi.com>

The only user of the MCA/INIT sigdelayed code (SGI's I/O probing) has
moved from the kernel into SAL.  Delete the MCA/INIT sigdelayed code.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>