Especially when !CONFIG_HOTPLUG_CPU, avoid needlessy allocating resources for
CPUs that can never become available.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It should improve performance in some scenarii where a lot of
these nsproxy objects are created by unsharing namespaces. This is
a typical use of virtual servers that are being created or entered.

This is also a good tool to find leaks and gather statistics on
namespace usage.
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dup_mnt_ns() and clone_uts_ns() return NULL on failure.  This is wrong,
create_new_namespaces() uses ERR_PTR() to catch an error.  This means that the
subsequent create_new_namespaces() will hit BUG_ON() in copy_mnt_ns() or
copy_utsname().

Modify create_new_namespaces() to also use the errors returned by the
copy_*_ns routines and not to systematically return ENOMEM.

[oleg@tv-sign.ru: better changelog]
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Repair indenting bustage.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It's useful sometimes to disable the softlockup checker at boottime.
Especially if it triggers during a distro install.
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove not only the references to Cobalt NVRAM, but the header file as
well.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Acked-by: NTim Hockin <thockin@hockin.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add an item to the RCU documentation checklist noting that RCU callbacks
can run in parallel.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c: In function 'load_elf_binary':
fs/binfmt_elf.c:1002: warning: 'interp_map_addr' may be used uninitialized in this function

The compiler (gcc-4.1.0) is correct, but it failed to notice that we didn't
use the resulting value.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert my do_ioctl() debugging patch: Paul fixed the bug.

Cc: Paul Fulghum <paulkf@microgate.com>
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>

This patch enables the unshare of user namespaces.

It adds a new clone flag CLONE_NEWUSER and implements copy_user_ns() which
resets the current user_struct and adds a new root user (uid == 0)

For now, unsharing the user namespace allows a process to reset its
user_struct accounting and uid 0 in the new user namespace should be contained
using appropriate means, for instance selinux

The plan, when the full support is complete (all uid checks covered), is to
keep the original user's rights in the original namespace, and let a process
become uid 0 in the new namespace, with full capabilities to the new
namespace.
Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Acked-by: NPavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Basically, it will allow a process to unshare its user_struct table,
resetting at the same time its own user_struct and all the associated
accounting.

A new root user (uid == 0) is added to the user namespace upon creation.
Such root users have full privileges and it seems that theses privileges
should be controlled through some means (process capabilities ?)

The unshare is not included in this patch.

Changes since [try #4]:
	- Updated get_user_ns and put_user_ns to accept NULL, and
	  get_user_ns to return the namespace.

Changes since [try #3]:
	- moved struct user_namespace to files user_namespace.{c,h}

Changes since [try #2]:
	- removed struct user_namespace* argument from find_user()

Changes since [try #1]:
	- removed struct user_namespace* argument from find_user()
	- added a root_user per user namespace
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
Acked-by: NPavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_UTS_NS and CONFIG_IPC_NS have very little value as they only
deactivate the unshare of the uts and ipc namespaces and do not improve
performance.
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Acked-by: N"Serge E. Hallyn" <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add TTY input auditing, used to audit system administrator's actions.  This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons.  These requirements do not make it
necessary to audit TTY output as well.

Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g.  the console ioctls still
work).

TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.

Add an "audit_tty" attribute, inherited across fork ().  Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).

Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g.  for sshd restarted within an audited session.  To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g.  after daemon startup) opens a TTY.

See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.

[akpm@linux-foundation.org: build fix]
Signed-off-by: NMiloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently we handle spurious IRQ activity based upon seeing a lot of
invalid interrupts, and we clear things back on the base of lots of valid
interrupts.

Unfortunately in some cases you get legitimate invalid interrupts caused by
timing asynchronicity between the PCI bus and the APIC bus when disabling
interrupts and pulling other tricks.  In this case although the spurious
IRQs are not a problem our unhandled counters didn't clear and they act as
a slow running timebomb.  (This is effectively what the serial port/tty
problem that was fixed by clearing counters when registering a handler
showed up)

It's easy enough to add a second parameter - time.  This means that if we
see a regular stream of harmless spurious interrupts which are not harming
processing we don't go off and do something stupid like disable the IRQ
after a month of running.  OTOH lockups and performance killers show up a
lot more than 10/second

[akpm@linux-foundation.org: cleanup]
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The intel-rng printed a nice well formatted message when the port was
disabled.  Someone then came along and blindly trashed it by screwing up a
trim down to 80 columns.

Put it back into the right format and keep the overlong lines as the result
is also MUCH easier to read in this specific case.
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Michael Buesch <mb@bu3sch.de>
Acked-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I was seeing a null pointer deref in fs/super.c:vfs_kern_mount().
Some file system get_sb() handler was returning NULL mnt_sb with
a non-negative return value.  I also noticed a "hugetlbfs: Bad
mount option:" message in the log.

Turns out that hugetlbfs_parse_options() was not checking for an
empty option string after call to strsep().  On failure,
hugetlbfs_parse_options() returns 1.  hugetlbfs_fill_super() just
passed this return code back up the call stack where
vfs_kern_mount() missed the error and proceeded with a NULL mnt_sb.

Apparently introduced by patch:
	hugetlbfs-use-lib-parser-fix-docs.patch

The problem was exposed by this line in my fstab:

none        /huge       hugetlbfs   defaults    0 0

It can also be demonstrated by invoking mount of hugetlbfs
directly with no options or a bogus option.

This patch:

1) adds the check for empty option to hugetlbfs_parse_options(),
2) enhances the error message to bracket any unrecognized
   option with quotes ,
3) modifies hugetlbfs_parse_options() to return -EINVAL on any
   unrecognized option,
4) adds a BUG_ON() to vfs_kern_mount() to catch any get_sb()
   handler that returns a NULL mnt->mnt_sb with a return value
   >= 0.
Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use lib/parser.c to parse hugetlbfs mount options.  Correct docs in
hugetlbpage.txt.

old size of hugetlbfs_fill_super:  675 bytes
new size of hugetlbfs_fill_super:  686 bytes
(hugetlbfs_parse_options() is inlined)
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Adam Litke <agl@us.ibm.com>
Acked-by: NWilliam Lee Irwin III <wli@holomorphy.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Removed kmalloc and memset in favor of kzalloc.

To explain the HFSPLUS_SB() macro in the removed memset call:

hfsplus_fs.h:#define HFSPLUS_SB(super)  (*(struct hfsplus_sb_info *)(super)->s_fs_info)
Signed-off-by: NWyatt Banks <wyatt@banksresearch.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Despite repeated attempts over the last two and half years, this driver
seems somewhat persistant.  Remove its deprecated status as it has existing
users who may not be in a position to migrate their apps to O_DIRECT.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use NULL instead of 0 for pointer:
drivers/misc/sony-laptop.c:1920:6: warning: Using plain integer as NULL pointer
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: NMattia Dongili <malattia@linux.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make available to the user the following task and process performance
statistics:

	* Involuntary Context Switches (task_struct->nivcsw)
	* Voluntary Context Switches (task_struct->nvcsw)

Statistics information is available from:
	1. taskstats interface (Documentation/accounting/)
	2. /proc/PID/status (task only).

This data is useful for detecting hyperactivity patterns between processes.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: NMaxim Uvarov <muvarov@ru.mvista.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Jonathan Lim <jlim@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After ext3 orphan list check has been added into ext3_destroy_inode()
(please see my previous patch) the following situation has been detected:

 EXT3-fs warning (device sda6): ext3_unlink: Deleting nonexistent file (37901290), 0
 Inode 00000101a15b7840: orphan list check failed!
 00000773 6f665f00 74616d72 00000573 65725f00 06737270 66000000 616d726f
...
 Call Trace: [<ffffffff80211ea9>] ext3_destroy_inode+0x79/0x90
  [<ffffffff801a2b16>] sys_unlink+0x126/0x1a0
  [<ffffffff80111479>] error_exit+0x0/0x81
  [<ffffffff80110aba>] system_call+0x7e/0x83

First messages said that unlinked inode has i_nlink=0, then ext3_unlink()
adds this inode into orphan list.

Second message means that this inode has not been removed from orphan list.
 Inode dump has showed that i_fop = &bad_file_ops and it can be set in
make_bad_inode() only.  Then I've found that ext3_read_inode() can call
make_bad_inode() without any error/warning messages, for example in the
following case:

...
        if (inode->i_nlink == 0) {
                if (inode->i_mode == 0 ||
                    !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
                        /* this inode is deleted */
                        brelse (bh);
                        goto bad_inode;
...

Bad inode can live some time, ext3_unlink can add it to orphan list, but
ext3_delete_inode() do not deleted this inode from orphan list.  As result
we can have orphan list corruption detected in ext3_destroy_inode().

However it is not clear for me how to fix this issue correctly.

As far as i see is_bad_inode() is called after iget() in all places
excluding ext3_lookup() and ext3_get_parent().  I believe it makes sense to
add bad inode check to these functions too and call iput if bad inode
detected.
Signed-off-by: NVasily Averin <vvs@sw.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Customers claims to ext3-related errors, investigation showed that ext3
orphan list has been corrupted and have the reference to non-ext3 inode.
The following debug helps to understand the reasons of this issue.

[akpm@linux-foundation.org: update for print_hex_dump() changes]
Signed-off-by: NVasily Averin <vvs@sw.ru>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Drop <linux/isicom.h> from being exported to user space since it would
be only an empty file.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Acked-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the no longer used sonypi_camera_command().
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NMattia Dongili <malattia@linux.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes dead keys and copy/paste of non-ASCII characters in UTF-8
mode on Linux console.  See more details about the original patch at:
http://chris.heathens.co.nz/linux/utf8.html

Already posted on
	(Oldest) http://lkml.org/lkml/2003/5/31/148
	         http://lkml.org/lkml/2005/12/24/69
	(Recent) http://lkml.org/lkml/2006/8/7/75

[bunk@stusta.de: make drivers/char/selection.c:store_utf8() static]
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Cc: Alexander E. Patrakov <patrakov@ums.usu.ru>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I forgot to remove capability.h from mm.h while removing sched.h!  This
patch remedies that, because the only inline function which was using
CAP_something was made out of line.

Cross-compile tested without regressions on:

	all powerpc defconfigs
	all mips defconfigs
	all m68k defconfigs
	all arm defconfigs
	all ia64 defconfigs

	alpha alpha-allnoconfig alpha-defconfig alpha-up
	arm
	i386 i386-allnoconfig i386-defconfig i386-up
	ia64 ia64-allnoconfig ia64-defconfig ia64-up
	m68k
	mips
	parisc parisc-allnoconfig parisc-defconfig parisc-up
	powerpc powerpc-up
	s390 s390-allnoconfig s390-defconfig s390-up
	sparc sparc-allnoconfig sparc-defconfig sparc-up
	sparc64 sparc64-allnoconfig sparc64-defconfig sparc64-up
	um-x86_64
	x86_64 x86_64-allnoconfig x86_64-defconfig x86_64-up

as well as my two usual configs.
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>

Original problem: in some circumstances seq_file interface can present
infinite proc file to the following script when normally said proc file is
finite:

	while read line; do
		[do something with $line]
	done </proc/$FILE

bash, to implement such loop does essentially

	read(0, buf, 128);
	[find \n]
	lseek(0, -difference, SEEK_CUR);

Consider, proc file prints list of objects each of them consists of many
lines, each line is shorter than 128 bytes.

Two objects in list, with ->index'es being 0 and 1.  Current one is 1, as
bash prints second object line by line.

Imagine first object being removed right before lseek().
traverse() will be called, because there is negative offset.
traverse() will reset ->index to 0 (!).
traverse() will call ->next() and get NULL in any usual iterate-over-list
code using list_for_each_entry_continue() and such. There is one object in
list now after all...
traverse() will return 0, lseek() will update file position and pretend
everything is OK.

So, what we have now: ->f_pos points to place where second object will be
printed, but ->index is 0.  seq_read() instead of returning EOF, will start
printing first line of first object every time it's called, until enough
objects are added to ->f_pos return in bounds.

Fix is to update ->index only after we're sure we saw enough objects down
the road.
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation for the /proc/$pid/stat file.
Signed-off-by: NKees Cook <kees@outflux.net>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The RXBRK field in the AT91/AT32 USART status register has the
following definition according to e.g. the AT32AP7000 data sheet:

    RXBRK: Break Received/End of Break
    0: No Break received or End of Break detected since the last RSTSTA.
    1: Break Received or End of Break detected since the last RSTSTA.

Thus, for each break, the USART sets the RXBRK bit twice. This patch
modifies the driver to report the break event to the serial core only
once by keeping track of whether a break condition is currently
active. The break_active flag is reset as soon as a character is
received, so even if we miss the start-of-break interrupt this should
do the right thing.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ivan Kuten <ivan.kuten@promwad.com>
Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@rfo.atmel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some buses (e.g.  USB and MMC) do their scanning of devices in the
background, causing a race between them and prepare_namespace().  In order
to be able to use these buses without an initrd, we now wait for the device
specified in root= to actually show up.

If the device never shows up than we will hang in an infinite loop.  In
order to not mess with setups that reboot on panic, the feature must be
turned on via the command line option "rootwait".

[bunk@stusta.de: root_wait can become static]
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Part two in the O_CLOEXEC saga: adding support for file descriptors received
through Unix domain sockets.

The patch is once again pretty minimal, it introduces a new flag for recvmsg
and passes it just like the existing MSG_CMSG_COMPAT flag.  I think this bit
is not used otherwise but the networking people will know better.

This new flag is not recognized by recvfrom and recv.  These functions cannot
be used for that purpose and the asymmetry this introduces is not worse than
the already existing MSG_CMSG_COMPAT situations.

The patch must be applied on the patch which introduced O_CLOEXEC.  It has to
remove static from the new get_unused_fd_flags function but since scm.c cannot
live in a module the function still hasn't to be exported.

Here's a test program to make sure the code works.  It's so much longer than
the actual patch...

#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>

#ifndef O_CLOEXEC
# define O_CLOEXEC 02000000
#endif
#ifndef MSG_CMSG_CLOEXEC
# define MSG_CMSG_CLOEXEC 0x40000000
#endif

int
main (int argc, char *argv[])
{
  if (argc > 1)
    {
      int fd = atol (argv[1]);
      printf ("child: fd = %d\n", fd);
      if (fcntl (fd, F_GETFD) == 0 || errno != EBADF)
        {
          puts ("file descriptor valid in child");
          return 1;
        }
      return 0;

    }

  struct sockaddr_un sun;
  strcpy (sun.sun_path, "./testsocket");
  sun.sun_family = AF_UNIX;

  char databuf[] = "hello";
  struct iovec iov[1];
  iov[0].iov_base = databuf;
  iov[0].iov_len = sizeof (databuf);

  union
  {
    struct cmsghdr hdr;
    char bytes[CMSG_SPACE (sizeof (int))];
  } buf;
  struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 1,
                        .msg_control = buf.bytes,
                        .msg_controllen = sizeof (buf) };
  struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg);

  cmsg->cmsg_level = SOL_SOCKET;
  cmsg->cmsg_type = SCM_RIGHTS;
  cmsg->cmsg_len = CMSG_LEN (sizeof (int));

  msg.msg_controllen = cmsg->cmsg_len;

  pid_t child = fork ();
  if (child == -1)
    error (1, errno, "fork");
  if (child == 0)
    {
      int sock = socket (PF_UNIX, SOCK_STREAM, 0);
      if (sock < 0)
        error (1, errno, "socket");

      if (bind (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0)
        error (1, errno, "bind");
      if (listen (sock, SOMAXCONN) < 0)
        error (1, errno, "listen");

      int conn = accept (sock, NULL, NULL);
      if (conn == -1)
        error (1, errno, "accept");

      *(int *) CMSG_DATA (cmsg) = sock;
      if (sendmsg (conn, &msg, MSG_NOSIGNAL) < 0)
        error (1, errno, "sendmsg");

      return 0;
    }

  /* For a test suite this should be more robust like a
     barrier in shared memory.  */
  sleep (1);

  int sock = socket (PF_UNIX, SOCK_STREAM, 0);
  if (sock < 0)
    error (1, errno, "socket");

  if (connect (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0)
    error (1, errno, "connect");
  unlink (sun.sun_path);

  *(int *) CMSG_DATA (cmsg) = -1;

  if (recvmsg (sock, &msg, MSG_CMSG_CLOEXEC) < 0)
    error (1, errno, "recvmsg");

  int fd = *(int *) CMSG_DATA (cmsg);
  if (fd == -1)
    error (1, 0, "no descriptor received");

  char fdname[20];
  snprintf (fdname, sizeof (fdname), "%d", fd);
  execl ("/proc/self/exe", argv[0], fdname, NULL);
  puts ("execl failed");
  return 1;
}

[akpm@linux-foundation.org: Fix fastcall inconsistency noted by Michael Buesch]
[akpm@linux-foundation.org: build fix]
Signed-off-by: NUlrich Drepper <drepper@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The problem is as follows: in multi-threaded code (or more correctly: all
code using clone() with CLONE_FILES) we have a race when exec'ing.

   thread #1                       thread #2

   fd=open()

                                   fork + exec

  fcntl(fd,F_SETFD,FD_CLOEXEC)

In some applications this can happen frequently.  Take a web browser.  One
thread opens a file and another thread starts, say, an external PDF viewer.
 The result can even be a security issue if that open file descriptor
refers to a sensitive file and the external program can somehow be tricked
into using that descriptor.

Just adding O_CLOEXEC support to open() doesn't solve the whole set of
problems.  There are other ways to create file descriptors (socket,
epoll_create, Unix domain socket transfer, etc).  These can and should be
addressed separately though.  open() is such an easy case that it makes not
much sense putting the fix off.

The test program:

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

#ifndef O_CLOEXEC
# define O_CLOEXEC 02000000
#endif

int
main (int argc, char *argv[])
{
  int fd;
  if (argc > 1)
    {
      fd = atol (argv[1]);
      printf ("child: fd = %d\n", fd);
      if (fcntl (fd, F_GETFD) == 0 || errno != EBADF)
        {
          puts ("file descriptor valid in child");
          return 1;
        }
      return 0;
    }

  fd = open ("/proc/self/exe", O_RDONLY | O_CLOEXEC);
  printf ("in parent: new fd = %d\n", fd);
  char buf[20];
  snprintf (buf, sizeof (buf), "%d", fd);
  execl ("/proc/self/exe", argv[0], buf, NULL);
  puts ("execl failed");
  return 1;
}

[kyle@parisc-linux.org: parisc fix]
Signed-off-by: NUlrich Drepper <drepper@redhat.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a flag in /proc/timer_stats to indicate deferrable timers.  This will
let developers/users to differentiate between types of tiemrs in
/proc/timer_stats.

Deferrable timer and normal timer will appear in /proc/timer_stats as below.
  10D,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
   10,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)

Also version of timer_stats changes from v0.1 to v0.2
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Continuing the work started in 411f0f3e ...

This enables code with a dma path, that compiles away, to build without
requiring additional code factoring.  It also prevents code that calls
dma_alloc_coherent and dma_free_coherent from linking whereas previously
the code would hit a BUG() at run time.  Finally, it allows archs that set
!HAS_DMA to delete their asm/dma-mapping.h file.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: <geert@linux-m68k.org>
Cc: <zippel@linux-m68k.org>
Cc: <spyro@f2s.com>
Cc: <ysato@users.sourceforge.jp>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>