This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

This typedef is unnecessary and should just be removed.
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>

+ fix small typo
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The actual Linux implementation for semctl(GETNCNT) and semctl(GETZCNT)
always (since 0.99.10) reported a thread as sleeping on all semaphores
that are listed in the semop() call.

The documented behavior (both in the Linux man page and in the Single
Unix Specification) is that a task should be reported on exactly one
semaphore: The semaphore that caused the thread to got to sleep.

This patch adds a pr_info_once() that is triggered if a thread hits the
relevant case.

The code triggers slightly too often, otherwise it would be necessary to
replicate the old code.  As there are no known users of GETNCNT or
GETZCNT, this is done to prevent unnecessary bloat.

The task that triggered is reported with name (tsk->comm) and pid.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Acked-by: NDavidlohr Bueso <davidlohr@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

SUSv4 clearly defines how semncnt and semzcnt must be calculated: A task
waits on exactly one semaphore: The semaphore from the first operation
in the sop array that cannot proceed.

The Linux implementation never followed the standard, it tried to count
all semaphores that might be the reason why a task sleeps.

This patch fixes that.

Note:
a) The implementation assumes that GETNCNT and GETZCNT are rare operations,
   therefore the code counts them only on demand.
   (If they wouldn't be rare, then the non-compliance would have
   been found earlier)

b) compared to the initial version of the patch, the BUG_ONs were removed
   and it was clarified that the new behavior conforms to SUS.

Back-compatibility concerns:

Manfred:

: - there is no application in Fedora that uses GETNCNT or GETZCNT.
:
: - application that use only single-sop semop() are also safe, the
:   difference only affects complex apps.
:
: - portable application are also safe, the new behavior is standard
:   compliant.
:
: But that's it.  The old behavior existed in Linux from 0.99.something
: until now.

Michael:

: * These operations seem to be very little used.  Grepping the public
:   source that is contained Fedora 20 source DVD, there appear to be no
:   uses.  Of course, this says nothing about uses in private /
:   non-mainstream FOSS code, but it seems likely that the same pattern
:   is followed there.
:
: * The existing behavior is hard enough to understand that I suspect
:   that no one understood it well enough to rely on it anyway
:   (especially as that behavior contradicted both man page and POSIX).
:
: So, there's a chance of breakage, but I estimate that it's minute.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Preparation for the next patch:

In the slow-path of perform_atomic_semop(), store a pointer to the
operation that caused the operation to block.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Right now, perform_atomic_semop gets the content of sem_queue as
individual fields.  Changes that, instead pass a pointer to sem_queue.

This is a preparation for the next patch: it uses sem_queue to store the
reason why a task must sleep.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

count_semzcnt and count_semncnt are more of less identical.  The patch
creates a single function that either counts the number of tasks waiting
for zero or waiting due to a decrease operation.

Compared to the initial version, the BUG_ONs were removed.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

GETZCNT is supposed to return the number of threads that wait until a
semaphore value becomes 0.

The current implementation overlooks complex operations that contain
both wait-for-zero operation and operations that alter at least one
semaphore.

The patch fixes that.  It's intentionally copy&paste, this will be
cleaned up in the next patch.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The need for volatile is not obvious, document it.
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nothing big and no logical changes, just get rid of some redundant
function declarations.  Move msg_[init/exit]_ns down the end of the
file.
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Call __set_current_state() instead of assigning the new state directly.
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Signed-off-by: NManfred Spraul <manfred@colorfullif.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is useful in the future and allows users to better understand the
reasoning behind the changes.

Also use UL as we're dealing with it anyways.
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

System V shared memory

a) can be abused to trigger out-of-memory conditions and the standard
   measures against out-of-memory do not work:

    - it is not possible to use setrlimit to limit the size of shm segments.

    - segments can exist without association with any processes, thus
      the oom-killer is unable to free that memory.

b) is typically used for shared information - today often multiple GB.
   (e.g. database shared buffers)

The current default is a maximum segment size of 32 MB and a maximum
total size of 8 GB.  This is often too much for a) and not enough for
b), which means that lots of users must change the defaults.

This patch increases the default limits (nearly) to the maximum, which
is perfect for case b).  The defaults are used after boot and as the
initial value for each new namespace.

Admins/distros that need a protection against a) should reduce the
limits and/or enable shm_rmid_forced.

Unix has historically required setting these limits for shared memory,
and Linux inherited such behavior.  The consequence of this is added
complexity for users and administrators.  One very common example are
Database setup/installation documents and scripts, where users must
manually calculate the values for these limits.  This also requires
(some) knowledge of how the underlying memory management works, thus
causing, in many occasions, the limits to just be flat out wrong.
Disabling these limits sooner could have saved companies a lot of time,
headaches and money for support.  But it's never too late, simplify
users life now.

Further notes:
- The patch only changes default, overrides behave as before:
        # sysctl kernel.shmall=33554432
  would recreate the previous limit for SHMMAX (for the current namespace).

- Disabling sysv shm allocation is possible with:
        # sysctl kernel.shmall=0
  (not a new feature, also per-namespace)

- The limits are intentionally set to a value slightly less than ULONG_MAX,
  to avoid triggering overflows in user space apps.
  [not unreasonable, see http://marc.info/?l=linux-mm&m=139638334330127]
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Reported-by: NDavidlohr Bueso <davidlohr@hp.com>
Acked-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

SHMMAX is the upper limit for the size of a shared memory segment, counted
in bytes.  The actual allocation is that size, rounded up to the next full
page.

Add a check that prevents the creation of segments where the rounded up
size causes an integer overflow.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Acked-by: NDavidlohr Bueso <davidlohr@hp.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

shm_tot counts the total number of pages used by shm segments.

If SHMALL is ULONG_MAX (or nearly ULONG_MAX), then the number can
overflow.  Subsequent calls to shmctl(,SHM_INFO,) would return wrong
values for shm_tot.

The patch adds a detection for overflows.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Acked-by: NDavidlohr Bueso <davidlohr@hp.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The increase of SHMMAX/SHMALL is a 4 patch series.

The change itself is trivial, the only problem are interger overflows.
The overflows are not new, but if we make huge values the default, then
the code should be free from overflows.

SHMMAX:

- shmmem_file_setup places a hard limit on the segment size:
  MAX_LFS_FILESIZE.

  On 32-bit, the limit is > 1 TB, i.e. 4 GB-1 byte segments are
  possible. Rounded up to full pages the actual allocated size
  is 0. --> must be fixed, patch 3

- shmat:
  - find_vma_intersection does not handle overflows properly.
    --> must be fixed, patch 1

  - the rest is fine, do_mmap_pgoff limits mappings to TASK_SIZE
    and checks for overflows (i.e.: map 2 GB, starting from
    addr=2.5GB fails).

SHMALL:
- after creating 8192 segments size (1L<<63)-1, shm_tot overflows and
  returns 0.  --> must be fixed, patch 2.

Userspace:
- Obviously, there could be overflows in userspace. There is nothing
  we can do, only use values smaller than ULONG_MAX.
  I ended with "ULONG_MAX - 1L<<24":

  - TASK_SIZE cannot be used because it is the size of the current
    task. Could be 4G if it's a 32-bit task on a 64-bit kernel.

  - The maximum size is not standardized across archs:
    I found TASK_MAX_SIZE, TASK_SIZE_MAX and TASK_SIZE_64.

  - Just in case some arch revives a 4G/4G split, nearly
    ULONG_MAX is a valid segment size.

  - Using "0" as a magic value for infinity is even worse, because
    right now 0 means 0, i.e. fail all allocations.

This patch (of 4):

find_vma_intersection() does not work as intended if addr+size overflows.
The patch adds a manual check before the call to find_vma_intersection.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Acked-by: NDavidlohr Bueso <davidlohr@hp.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

trailing whitespace
Signed-off-by: NPaul McQuade <paulmcquad@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
Use #include <linux/types.h> instead of <asm/types.h>
Signed-off-by: NPaul McQuade <paulmcquad@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no need to recreate the very same ipc_ops structure on every
kernel entry for msgget/semget/shmget.  Just declare it static and be
done with it.  While at it, constify it as we don't modify the structure
at runtime.

Found in the PaX patch, written by the PaX Team.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 9ba4bcb6 ("initramfs: read CONFIG_RD_ variables for initramfs
compression") removed the users of the various INITRAMFS_COMPRESSION_*
Kconfig symbols.  So since v3.13 the entire "Built-in initramfs
compression mode" choice is a set of knobs connected to nothing.  The
entire choice can safely be removed.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Cc: P J P <ppandit@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Also convert spaces to tabs (checkpatch warnings) if (!dentry) KERN_NOTICE
converted to pr_err (like if (!inode) error process)

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Also add pr_fmt in internal.h
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NFabian Frederick <fabf@skynet.be>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>