Add a comment to ep_poll(), rename labels a bit clearly, fix a warning of
unused variable from gcc and optimize the non-blocking path a little.
Hinted-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavide Libenzi <davidel@xmailserver.org>

hannes@cmpxchg.org:

: The non-blocking ep_poll path optimization introduced skipping over the
: return value setup.
:
: Initialize it properly, my userspace gets upset by epoll_wait() returning
: random things.
:
: In addition, remove the reinitialization at the fetch_events label, the
: return value is garuanteed to be zero when execution reaches there.

[hannes@cmpxchg.org: fix initialization]
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Shawn Bohrer <shawn.bohrer@gmail.com>
Acked-by: NDavide Libenzi <davidel@xmailserver.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the event readiness check into a proper inline, and use it uniformly
inside ep_poll() code.  Events in the ->ovflist are no less ready than the
ones in ->rdllist.
Signed-off-by: NDavide Libenzi <davidel@xmailserver.org>
Cc: Shawn Bohrer <shawn.bohrer@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add brackets around typecasted argument in crc32() macro.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Because the second and third arguments of memset have the same type, it
turns out to be really easy to mix them up.

This bug comes up time after time, so checkpatch should really be checking
for it at patch submission time.
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If you run checkpatch against multiple patches, and one of them has a
whitespace issue which can be helped via a script (rpt_cleaners), you will
see the same NOTE over and over for all subsequent patches.  It makes it
seem like those patches also have whitespace problems when in reality,
there's only one or two bad apples.

So reset rpt_cleaners back to 0 after we've issued the note so that it
only shows up near the patch with the actual problems.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use resource_size().
Signed-off-by: NChris Ball <cjb@laptop.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NChris Ball <cjb@laptop.org>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Analog Devices' SigmaStudio can produce firmware blobs for devices with
these DSPs embedded (like some audio codecs).  Allow these device drivers
to easily parse and load them.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1. simple_strto*() do not contain overflow checks and crufty,
   libc way to indicate failure.
2. strict_strto*() also do not have overflow checks but the name and
   comments pretend they do.
3. Both families have only "long long" and "long" variants,
   but users want strtou8()
4. Both "simple" and "strict" prefixes are wrong:
   Simple doesn't exactly say what's so simple, strict should not exist
   because conversion should be strict by default.

The solution is to use "k" prefix and add convertors for more types.
Enter
	kstrtoull()
	kstrtoll()
	kstrtoul()
	kstrtol()
	kstrtouint()
	kstrtoint()

	kstrtou64()
	kstrtos64()
	kstrtou32()
	kstrtos32()
	kstrtou16()
	kstrtos16()
	kstrtou8()
	kstrtos8()

Include runtime testsuite (somewhat incomplete) as well.

strict_strto*() become deprecated, stubbed to kstrto*() and
eventually will be removed altogether.

Use kstrto*() in code today!

Note: on some archs _kstrtoul() and _kstrtol() are left in tree, even if
      they'll be unused at runtime. This is temporarily solution,
      because I don't want to hardcode list of archs where these
      functions aren't needed. Current solution with sizeof() and
      __alignof__ at least always works.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NKenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 5b2e303f ("[media] rc-core: convert winbond-cir") moved the
files, update the pattern.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NDavid Härdeman <david@hardeman.nu>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

And set the status to Orphan.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Jeroen Vreeken <pe1rxq@amsat.org>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 937f961a ("x86: Move sfi to platform") moved the files, update
the pattern.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 82e6923e ("ARM: lh7a40x: remove unmaintained platform support")
removed support, remove it from MAINTAINERS.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 3b3da9d2 ("x86: Move scx200 to platform") moved it, convert the
pattern too.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 88606e80 ("MAINTAINERS: Update timer related entries") added a
file pattern that didn't actually exist.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 66fa12c5 ("ieee1394: remove the old IEEE 1394 driver stack")

removed the code, remove the MAINTAINERS entry.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 52b66144 ("[media] rc: Rename remote controller type to rc_type
instead of ir_type") moved it around.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Acked-by: NHarry Wei <harryxiyou@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 6d803ba7 ("ARM: 6483/1: arm & sh: factorised duplicated
clkdev.c") moved it to a separate directory.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CC'ing lkml is the default and doesn't need separate entries.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NHarry Wei <harryxiyou@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NHarry Wei <harryxiyou@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove these patterns until such files are actually in the tree.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

wiki-analog doesn't seem to work, but wiki.analog does.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Typo in path.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add quotes around email address with periods and commas.  So they don't
explode when pasted into certain email clients.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NHarry Wei <harryxiyou@gmail.com>
Cc: "Mark F. Brown" <mark.brown314@gmail.com>
Cc: "Gustavo F. Padovan" <padovan@profusion.mobi>
Cc: "Stephen M. Cameron" <scameron@beardog.cce.hp.com>
Cc: "Lee, Chun-Yi" <jlee@novell.com>
Acked-by: NHarry Wei <harryxiyou@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

At least one tree:

	ARM/EZX SMARTPHONES (A780, A910, A1200, E680, ROKR E2 and ROKR E6)

is available via topgit.  Add mention of topgit in the MAINTAINERS
description section.
Signed-off-by: NHarry Wei <harryxiyou@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Extend the usage of the K section in the MAINTAINERS file to support
matching regular expressions to any arbitrary text that may precede the
patch itself.  For example, the commit message or mail headers generated
by git-format-patch.
Signed-off-by: NJoe Perches <joe@perches.com>
Original-patch-by: NL. Alberto Giménez <agimenez@sysvalve.es>
Acked-by: NL. Alberto Giménez <agimenez@sysvalve.es>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We've been burned by regressions/bugs which we later realized could have
been triaged quicker if only we'd paid closer attention to dmesg.  To make
it easier to audit dmesg, we'd like to make DEFAULT_MESSAGE_LEVEL
Kconfig-settable.  That way we can set it to KERN_NOTICE and audit any
messages <= KERN_WARNING.
Signed-off-by: NMandeep Singh Baines <msb@chromium.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Cc: Olof Johansson <olofj@chromium.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In an effort to reduce kernel address leaks that might be used to help
target kernel privilege escalation exploits, this patch uses %pK when
displaying addresses in /proc/kallsyms, /proc/modules, and
/sys/module/*/sections/*.

Note that this changes %x to %p, so some legitimately 0 values in
/proc/kallsyms would have changed from 00000000 to "(null)".  To avoid
this, "(null)" is not used when using the "K" format.  Anything that was
already successfully parsing "(null)" in addition to full hex digits
should have no problem with this change.  (Thanks to Joe Perches for the
suggestion.) Due to the %x to %p, "void *" casts are needed since these
addresses are already "unsigned long" everywhere internally, due to their
starting life as ELF section offsets.
Signed-off-by: NKees Cook <kees.cook@canonical.com>
Cc: Eugene Teo <eugene@redhat.com>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For a platform with many consoles like:
 "console=tty1 console=ttyMFD2 console=ttyS0 earlyprintk=mrst"

Each time when the non "selected_console" (tty1 and ttyMFD2 here) get
registered, the existing kernel message will be printed out on registered
consoles again, the "mrst" early console will get some same message for 3
times, and "tty1" will get some for twice.

As suggested by Andrew Morton, every time a new console is registered, it
will be set as the "exclusive" console which will dump the already
existing kernel messages.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On some architectures, the boot process involves de-registering the boot
console (early boot), initialize drivers and then re-register the console.

This mechanism introduces a window in which no printk can happen on the
console and messages are buffered and then printed once the new console is
available.

If a kernel crashes during this window, all it's left on the boot console
is "console [foo] enabled, bootconsole disabled" making debug of the crash
rather 'interesting'.

By adding "keep_bootcon" option, do not unregister the boot console, that
will allow to printk everything that is happening up to the crash.

The option is clearly meant only for debugging purposes as it introduces
lots of duplicated info printed on console, but will make bug report from
users easier as it doesn't require a kernel build just to figure out where
we crash.
Signed-off-by: NFabio M. Di Nitto <fabbione@fabbione.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If kptr restrictions are on, just set the passed pointer to NULL.

$ size lib/vsprintf.o.*
   text	   data	    bss	    dec	    hex	filename
   8247	      4	      2	   8253	   203d	lib/vsprintf.o.new
   8282	      4	      2	   8288	   2060	lib/vsprintf.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NKirill A. Shutemov <kirill@shutemov.name>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch addresses a couple of problems.  One was the case when the
hardlockup failed to start, it also failed to start the softlockup.  There
were valid cases when the hardlockup shouldn't start and that shouldn't
block the softlockup (no lapic, bios controls perf counters).

The second problem was when the hardlockup failed to start on boxes (from
a no lapic or bios controlled perf counter case), it reported failure to
the cpu notifier chain.  This blocked the notifier from continuing to
start other more critical pieces of cpu bring-up (in our case based on a
2.6.32 fork, it was the mce).  As a result, during soft cpu online/offline
testing, the system would panic when a cpu was offlined because the cpu
notifier would succeed in processing a watchdog disable cpu event and
would panic in the mce case as a result of un-initialized variables from a
never executed cpu up event.

I realized the hardlockup/softlockup cases are really just debugging aids
and should never impede the progress of a cpu up/down event.  Therefore I
modified the code to always return NOTIFY_OK and instead rely on printks
to inform the user of problems.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a cpu is considered stuck, instead of limping along and just printing
a warning, it is sometimes preferred to just panic, let kdump capture the
vmcore and reboot.  This gets the machine back into a stable state quickly
while saving the info that got it into a stuck state to begin with.

Add a Kconfig option to allow users to set the hardlockup to panic
by default.  Also add in a 'nmi_watchdog=nopanic' to override this.

[akpm@linux-foundation.org: fix strncmp length]
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Systems with unmaskable interrupts such as SMIs may massively
underestimate loops_per_jiffy, and fail to converge anywhere near the real
value.  A case seen on x86_64 was an initial estimate of 256<<12, which
converged to 511<<12 where the real value should have been over 630<<12.
This admitedly requires bypassing the TSC calibration (lpj_fine), and a
failure to settle in the direct calibration too, but is physically
possible.  This failure does not depend on my previous calibration
optimisation, but by luck is easy to fix with the optimisation in place
with a trivial retry loop.

In the context of the optimised converging method, as we can no longer
trust the starting estimate, enlarge the search bounds exponentially so
that the number of retries is logarithmically bounded.

[akpm@linux-foundation.org: mention x86_64 SMIs in comment]
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Binary chop with a jiffy-resync on each step to find an upper bound is
slow, so just race in a tight-ish loop to find an underestimate.

If done with lots of individual steps, sometimes several hundreds of
iterations would be required, which would impose a significant overhead,
and make the initial estimate very low.  By taking slowly increasing steps
there will be less overhead.

E.g.  an x86_64 2.67GHz could have fitted in 613 individual small delays,
but in reality should have been able to fit in a single delay 644 times
longer, so underestimated by 31 steps.  To reach the equivalent of 644
small delays with the accelerating scheme now requires about 130
iterations, so has <1/4th of the overhead, and can therefore be expected
to underestimate by only 7 steps.

As now we have a better initial estimate we can binary chop over a smaller
range.  With the loop overhead in the initial estimate kept low, and the
step sizes moderate, we won't have under-estimated by much, so chose as
tight a range as we can.
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The motivation for this patch series is that currently our OMAP calibrates
itself using the trial-and-error binary chop fallback that some other
architectures no longer need to perform.  This is a lengthy process,
taking 0.2s in an environment where boot time is of great interest.

Patch 2/4 has two optimisations.  Firstly, it replaces the initial
repeated- doubling to find the relevant power of 2 with a tight loop that
just does as much as it can in a jiffy.  Secondly, it doesn't binary chop
over an entire power of 2 range, it choses a much smaller range based on
how much it squeezed in, and failed to squeeze in, during the first stage.
 Both are significant optimisations, and bring our calibration down from
23 jiffies to 5, and, in the process, often arrive at a more accurate lpj
value.

The 'bands' and 'sub-logarithmic' growth may look over-engineered, but
they only cost a small level of inaccuracy in the initial guess (for all
architectures) in order to avoid the very large inaccuracies that appeared
during testing (on x86_64 architectures, and presumably others with less
metronomic operation).  Note that due to the existence of the TSC and
other timers, the x86_64 will not typically use this fallback routine, but
I wanted to code defensively, able to cope with all kinds of processor
behaviours and kernel command line options.

Patch 3/4 is an additional trap for the nightmare scenario where the
initial estimate is very inaccurate, possibly due to things like SMIs.
It simply retries with a larger bound.

Stephen said:

I tried this patch set out on an MSM7630.
:
: Before:
:
: Calibrating delay loop... 681.57 BogoMIPS (lpj=3407872)
:
: After:
:
: Calibrating delay loop... 680.75 BogoMIPS (lpj=3403776)
:
: But the really good news is calibration time dropped from ~247ms to ~56ms.
:  Sadly we won't be able to benefit from this should my udelay patches make
: it into ARM because we would be using calibrate_delay_direct() instead (at
: least on machines who choose to).  Can we somehow reapply the logic behind
: this to calibrate_delay_direct()?  That would be even better, but this is
: definitely a boot time improvement.
:
: Or maybe we could just replace calibrate_delay_direct() with this fallback
: calculation?  If __delay() is a thin wrapper around read_current_timer()
: it should work just as well (plus patch 3 makes it handle SMIs).  I'll try
: that out.

This patch:

... so that it can be modified more clinically.

This is almost entirely cosmetic. The only change to the operation
is that the global variable is only set once after the estimation is
completed, rather than taking on all the intermediate values. However,
there are no readers of that variable, so this change is unimportant.
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cleanup: kill the dead code which does nothing but complicates the code
and confuses the reader.

sys_unshare(CLONE_THREAD/SIGHAND/VM) is not really implemented, and I
doubt very much it will ever work.  At least, nobody even tried since the
original 99d1419d ("unshare system call -v5: system call
handler function") was applied more than 4 years ago.

And the code is not consistent.  unshare_thread() always fails
unconditionally, while unshare_sighand() and unshare_vm() pretend to work
if there is nothing to unshare.

Remove unshare_thread(), unshare_sighand(), unshare_vm() helpers and
related variables and add a simple CLONE_THREAD | CLONE_SIGHAND| CLONE_VM
check into check_unshare_flags().

Also, move the "CLONE_NEWNS needs CLONE_FS" check from
check_unshare_flags() to sys_unshare().  This looks more consistent and
matches the similar do_sysvsem check in sys_unshare().

Note: with or without this patch "atomic_read(mm->mm_users) > 1" can give
a false positive due to get_task_mm().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NRoland McGrath <roland@redhat.com>
Cc: Janak Desai <janak@us.ibm.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change the printk() calls to have the KERN_INFO/KERN_ERROR stuff, and
fixes other coding style errors.  Not _all_ of them are gone, though.

[akpm@linux-foundation.org: revert the bits I disagree with]
Signed-off-by: NMichael Rodriguez <dkingston02@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>