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>

As execution domain support is gone we can remove
signal translation from the signal code and remove
exec_domain from thread_info.
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>

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>

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>

This provides a simple interface modelled after sparc64/m32r to encode
the error code in the upper byte of thread_info for finer-grained
handling in the page fault path.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The core now has a threadinfo allocator which uses a kmemcache when
THREAD_SIZE < PAGE_SIZE.

Deal with the xstate cleanup in the new arch_release_task_struct()
function.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/20120505150142.189348931@linutronix.de

We error out when compiling with gcc4.1.[01] as it miscompiles
__weak. The workaround with magic defines is not longer
necessary. Make it __weak again.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120505150141.306358267@linutronix.de

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

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>

This follows the x86 xstate changes and implements a task_xstate slab
cache that is dynamically sized to match one of hard FP/soft FP/FPU-less.

This also tidies up and consolidates some of the SH-2A/SH-4 FPU
fragmentation. Now fpu state restorers are commonly defined, with the
init_fpu()/fpu_init() mess reworked to follow the x86 convention.
The fpu_init() register initialization has been replaced by xstate setup
followed by writing out to hardware via the standard restore path.

As init_fpu() now performs a slab allocation a secondary lighterweight
restorer is also introduced for the context switch.

In the future the DSP state will be rolled in here, too.

More work remains for math emulation and the SH-5 FPU, which presently
uses its own special (UP-only) interfaces.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently the thread_info allocators are special cased, depending on
THREAD_SHIFT < PAGE_SHIFT. This provides a sensible definition for them
regardless of configuration, in preparation for extended CPU state.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This was used by the old hw-breakpoints API, but now there is nothing
is using it anymore, so just kill it off.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds preliminary support for the SH-4A UBC to the hw-breakpoints API.
Presently only a single channel is implemented, and the ptrace interface
still needs to be converted. This is the first step to cleaning up the
long-standing UBC mess, making the UBC more generally accessible, and
finally making it SMP safe.

An additional abstraction will be layered on top of this as with the perf
events code to permit the various CPU families to wire up support for
their own specific UBCs, as many variations exist.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

A number of small optimisations to FPU handling, in particular:

 - move the task USEDFPU flag from the thread_info flags field (which
   is accessed asynchronously to the thread) to a new status field,
   which is only accessed by the thread itself. This allows locking to
   be removed in most cases, or can be reduced to a preempt_lock().
   This mimics the i386 behaviour.

 - move the modification of regs->sr and thread_info->status flags out
   of save_fpu() to __unlazy_fpu(). This gives the compiler a better
   chance to optimise things, as well as making save_fpu() symmetrical
   with restore_fpu() and init_fpu().

 - implement prepare_to_copy(), so that when creating a thread, we can
   unlazy the FPU prior to copying the thread data structures.

Also make sure that the FPU is disabled while in the kernel, in
particular while booting, and for newly created kernel threads,

In a very artificial benchmark, the execution time for 2500000
context switches was reduced from 50 to 45 seconds.
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.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.

Based on the x86 and powerpc change.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This is necessary to get ftrace syscall tracing working again.. a fairly
trivial and mechanical change. The one benefit is that this can also be
enabled on sh64, despite not having its own ftrace port.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

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>

Now that I've added TIF_SYSCALL_FTRACE the thread flags do not fit into
a single byte any more. Code testing them now needs to be aware of the
upper and lower bytes.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This follows the powerpc commit f6a61680
'[POWERPC] Fix kernel stack allocation alignment'.

SH has traditionally forced the thread order to be relative to the page
size, so there were never any situations where the same bug was
triggered by slub. Regardless, the usage of > 8kB stacks for the larger
page sizes is overkill, so we switch to using slab allocations there,
as per the powerpc change.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This follows the changes in commits:

7d6d637d
4f72c427

on powerpc. Adding in TIF_NOTIFY_RESUME, and cleaning up the syscall
tracing to be more generic. This is an incremental step to turning
on tracehook, as well as unifying more of the ptrace and signal code
across the 32/64 split.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This hooks up the seccomp thread flag and associated callback from the
syscall tracer.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This follows the sparc changes a439fe51.

Most of the moving about was done with Sam's directions at:

http://marc.info/?l=linux-sh&m=121724823706062&w=2

with subsequent hacking and fixups entirely my fault.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

16kB is a useful size on nommu, while 64kB still tends to be too big to
be useful. Newer MMUs are likely to support this as well, so plug it
in in anticipation of those, too.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

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>

Remove the deprecated __attribute_used__.

[Introduce __section in a few places to silence checkpatch /sam]
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Support syscall auditing..
Signed-off-by: NYuichi Nakamura <ynakam@hitachisoft.jp>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

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>

This takes care of tearing down the UBC so it's not inadvertently
left configured at the next context switch time. Failure to do
this results in spurious SIGTRAPs in certain debug sequences.
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

There were a few more things that needed fixing up, namely THREAD_SIZE
and the TLB miss handler where certain PTRS_PER_PGD == PTRS_PER_PTE
assumptions were being made.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

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>

There were a number of places that made evil PAGE_SIZE == 4k
assumptions that ended up breaking when trying to play with
8k and 64k page sizes, this fixes those up.

The most significant change is the way we load THREAD_SIZE,
previously this was done via:

	mov	#(THREAD_SIZE >> 8), reg
	shll8	reg

to avoid a memory access and allow the immediate load. With
a 64k PAGE_SIZE, we're out of range for the immediate load
size without resorting to special instructions available in
later ISAs (movi20s and so on). The "workaround" for this is
to bump up the shift to 10 and insert a shll2, which gives a
bit more flexibility while still being much cheaper than a
memory access.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This enables support for 4K stacks on SH.

Currently this depends on DEBUG_KERNEL, but likely all boards
will switch to this as the default in the future.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds a DEBUG_STACK_USAGE and DEBUG_STACKOVERFLOW for SH.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>