License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2008-02-08 12:18:22 +00:00
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#ifndef __IPC_NAMESPACE_H__
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#define __IPC_NAMESPACE_H__
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#include <linux/err.h>
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2008-02-08 12:18:57 +00:00
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#include <linux/idr.h>
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#include <linux/rwsem.h>
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2008-04-29 08:00:42 +00:00
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#include <linux/notifier.h>
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2011-03-23 23:43:24 +00:00
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#include <linux/nsproxy.h>
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2014-11-01 02:56:04 +00:00
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#include <linux/ns_common.h>
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2017-09-08 23:17:38 +00:00
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#include <linux/refcount.h>
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2018-06-18 02:52:50 +00:00
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#include <linux/rhashtable-types.h>
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2008-04-29 08:00:42 +00:00
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2011-03-23 23:43:23 +00:00
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struct user_namespace;
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2008-02-08 12:18:57 +00:00
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struct ipc_ids {
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int in_use;
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unsigned short seq;
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2013-09-11 21:26:24 +00:00
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struct rw_semaphore rwsem;
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2008-02-08 12:18:57 +00:00
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struct idr ipcs_idr;
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2018-08-22 05:02:00 +00:00
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int max_idx;
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2019-05-14 22:46:33 +00:00
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int last_idx; /* For wrap around detection */
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2017-11-17 23:31:08 +00:00
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#ifdef CONFIG_CHECKPOINT_RESTORE
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2013-01-04 23:34:50 +00:00
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int next_id;
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2017-11-17 23:31:08 +00:00
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#endif
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ipc: optimize semget/shmget/msgget for lots of keys
ipc_findkey() used to scan all objects to look for the wanted key. This
is slow when using a high number of keys. This change adds an rhashtable
of kern_ipc_perm objects in ipc_ids, so that one lookup cease to be O(n).
This change gives a 865% improvement of benchmark reaim.jobs_per_min on a
56 threads Intel(R) Xeon(R) CPU E5-2695 v3 @ 2.30GHz with 256G memory [1]
Other (more micro) benchmark results, by the author: On an i5 laptop, the
following loop executed right after a reboot took, without and with this
change:
for (int i = 0, k=0x424242; i < KEYS; ++i)
semget(k++, 1, IPC_CREAT | 0600);
total total max single max single
KEYS without with call without call with
1 3.5 4.9 µs 3.5 4.9
10 7.6 8.6 µs 3.7 4.7
32 16.2 15.9 µs 4.3 5.3
100 72.9 41.8 µs 3.7 4.7
1000 5,630.0 502.0 µs * *
10000 1,340,000.0 7,240.0 µs * *
31900 17,600,000.0 22,200.0 µs * *
*: unreliable measure: high variance
The duration for a lookup-only usage was obtained by the same loop once
the keys are present:
total total max single max single
KEYS without with call without call with
1 2.1 2.5 µs 2.1 2.5
10 4.5 4.8 µs 2.2 2.3
32 13.0 10.8 µs 2.3 2.8
100 82.9 25.1 µs * 2.3
1000 5,780.0 217.0 µs * *
10000 1,470,000.0 2,520.0 µs * *
31900 17,400,000.0 7,810.0 µs * *
Finally, executing each semget() in a new process gave, when still
summing only the durations of these syscalls:
creation:
total total
KEYS without with
1 3.7 5.0 µs
10 32.9 36.7 µs
32 125.0 109.0 µs
100 523.0 353.0 µs
1000 20,300.0 3,280.0 µs
10000 2,470,000.0 46,700.0 µs
31900 27,800,000.0 219,000.0 µs
lookup-only:
total total
KEYS without with
1 2.5 2.7 µs
10 25.4 24.4 µs
32 106.0 72.6 µs
100 591.0 352.0 µs
1000 22,400.0 2,250.0 µs
10000 2,510,000.0 25,700.0 µs
31900 28,200,000.0 115,000.0 µs
[1] http://lkml.kernel.org/r/20170814060507.GE23258@yexl-desktop
Link: http://lkml.kernel.org/r/20170815194954.ck32ta2z35yuzpwp@debix
Signed-off-by: Guillaume Knispel <guillaume.knispel@supersonicimagine.com>
Reviewed-by: Marc Pardo <marc.pardo@supersonicimagine.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Guillaume Knispel <guillaume.knispel@supersonicimagine.com>
Cc: Marc Pardo <marc.pardo@supersonicimagine.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 23:17:55 +00:00
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struct rhashtable key_ht;
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2008-02-08 12:18:57 +00:00
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};
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2008-02-08 12:18:22 +00:00
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struct ipc_namespace {
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2017-09-08 23:17:38 +00:00
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refcount_t count;
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2008-02-08 12:18:57 +00:00
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struct ipc_ids ids[3];
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2008-02-08 12:18:22 +00:00
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int sem_ctls[4];
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int used_sems;
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2013-11-03 11:36:28 +00:00
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unsigned int msg_ctlmax;
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unsigned int msg_ctlmnb;
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unsigned int msg_ctlmni;
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2008-02-08 12:18:22 +00:00
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atomic_t msg_bytes;
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atomic_t msg_hdrs;
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size_t shm_ctlmax;
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size_t shm_ctlall;
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2013-05-01 02:15:54 +00:00
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unsigned long shm_tot;
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2008-02-08 12:18:22 +00:00
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int shm_ctlmni;
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2011-07-26 23:08:48 +00:00
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/*
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* Defines whether IPC_RMID is forced for _all_ shm segments regardless
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* of shmctl()
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*/
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int shm_rmid_forced;
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2008-04-29 08:00:42 +00:00
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struct notifier_block ipcns_nb;
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2009-04-07 02:01:08 +00:00
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/* The kern_mount of the mqueuefs sb. We take a ref on it */
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struct vfsmount *mq_mnt;
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/* # queues in this ns, protected by mq_lock */
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unsigned int mq_queues_count;
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/* next fields are set through sysctl */
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unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
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unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
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unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
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2012-05-31 23:26:33 +00:00
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unsigned int mq_msg_default;
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unsigned int mq_msgsize_default;
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2009-04-07 02:01:08 +00:00
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2011-03-23 23:43:23 +00:00
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/* user_ns which owns the ipc ns */
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struct user_namespace *user_ns;
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2016-08-08 19:20:23 +00:00
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struct ucounts *ucounts;
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2011-06-15 17:21:48 +00:00
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2020-06-08 04:40:10 +00:00
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struct llist_node mnt_llist;
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2014-11-01 02:56:04 +00:00
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struct ns_common ns;
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2016-10-28 08:22:25 +00:00
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} __randomize_layout;
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2008-02-08 12:18:22 +00:00
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extern struct ipc_namespace init_ipc_ns;
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namespaces: ipc namespaces: implement support for posix msqueues
Implement multiple mounts of the mqueue file system, and link it to usage
of CLONE_NEWIPC.
Each ipc ns has a corresponding mqueuefs superblock. When a user does
clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an
internal mount of a new mqueuefs sb linked to the new ipc ns.
When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the
mqueuefs superblock.
Posix message queues can be worked with both through the mq_* system calls
(see mq_overview(7)), and through the VFS through the mqueue mount. Any
usage of mq_open() and friends will work with the acting task's ipc
namespace. Any actions through the VFS will work with the mqueuefs in
which the file was created. So if a user doesn't remount mqueuefs after
unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls
/dev/mqueue".
If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns,
ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1)
ipc_ns:1 will be freed, (2) it's superblock will live on until task b
umounts the corresponding mqueuefs, and vfs actions will continue to
succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to
the deceased ipc_ns:1.
To make this happen, we must protect the ipc reference count when
a) a task exits and drops its ipcns->count, since it might be dropping
it to 0 and freeing the ipcns
b) a task accesses the ipcns through its mqueuefs interface, since it
bumps the ipcns refcount and might race with the last task in the ipcns
exiting.
So the kref is changed to an atomic_t so we can use
atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns
through ns = mqueuefs_sb->s_fs_info is protected by the same lock.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 02:01:10 +00:00
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extern spinlock_t mq_lock;
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2008-04-29 08:00:42 +00:00
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2009-04-07 02:01:08 +00:00
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#ifdef CONFIG_SYSVIPC
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2011-07-26 23:08:48 +00:00
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extern void shm_destroy_orphaned(struct ipc_namespace *ns);
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2008-04-29 08:00:42 +00:00
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#else /* CONFIG_SYSVIPC */
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2011-07-26 23:08:48 +00:00
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static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
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2008-04-29 08:00:42 +00:00
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#endif /* CONFIG_SYSVIPC */
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2008-02-08 12:18:22 +00:00
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2009-04-07 02:01:08 +00:00
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#ifdef CONFIG_POSIX_MQUEUE
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namespaces: ipc namespaces: implement support for posix msqueues
Implement multiple mounts of the mqueue file system, and link it to usage
of CLONE_NEWIPC.
Each ipc ns has a corresponding mqueuefs superblock. When a user does
clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an
internal mount of a new mqueuefs sb linked to the new ipc ns.
When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the
mqueuefs superblock.
Posix message queues can be worked with both through the mq_* system calls
(see mq_overview(7)), and through the VFS through the mqueue mount. Any
usage of mq_open() and friends will work with the acting task's ipc
namespace. Any actions through the VFS will work with the mqueuefs in
which the file was created. So if a user doesn't remount mqueuefs after
unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls
/dev/mqueue".
If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns,
ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1)
ipc_ns:1 will be freed, (2) it's superblock will live on until task b
umounts the corresponding mqueuefs, and vfs actions will continue to
succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to
the deceased ipc_ns:1.
To make this happen, we must protect the ipc reference count when
a) a task exits and drops its ipcns->count, since it might be dropping
it to 0 and freeing the ipcns
b) a task accesses the ipcns through its mqueuefs interface, since it
bumps the ipcns refcount and might race with the last task in the ipcns
exiting.
So the kref is changed to an atomic_t so we can use
atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns
through ns = mqueuefs_sb->s_fs_info is protected by the same lock.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 02:01:10 +00:00
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extern int mq_init_ns(struct ipc_namespace *ns);
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2012-05-31 23:26:30 +00:00
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/*
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* POSIX Message Queue default values:
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*
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* MIN_*: Lowest value an admin can set the maximum unprivileged limit to
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* DFLT_*MAX: Default values for the maximum unprivileged limits
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* DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
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* an attribute to the open call and the queue must be created
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* HARD_*: Highest value the maximums can be set to. These are enforced
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* on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
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* suitably high)
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*
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* POSIX Requirements:
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* Per app minimum openable message queues - 8. This does not map well
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* to the fact that we limit the number of queues on a per namespace
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* basis instead of a per app basis. So, make the default high enough
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* that no given app should have a hard time opening 8 queues.
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* Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
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* Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
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* we have run into a situation where running applications in the wild
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* require this to be at least 5MB, and preferably 10MB, so I set the
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* value to 16MB in hopes that this user is the worst of the bunch and
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* the new maximum will handle anyone else. I may have to revisit this
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* in the future.
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*/
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#define DFLT_QUEUESMAX 256
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#define MIN_MSGMAX 1
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2012-05-31 23:26:31 +00:00
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#define DFLT_MSG 10U
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#define DFLT_MSGMAX 10
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2012-05-31 23:26:30 +00:00
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#define HARD_MSGMAX 65536
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#define MIN_MSGSIZEMAX 128
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#define DFLT_MSGSIZE 8192U
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2012-05-31 23:26:31 +00:00
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#define DFLT_MSGSIZEMAX 8192
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2012-05-31 23:26:30 +00:00
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#define HARD_MSGSIZEMAX (16*1024*1024)
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2009-04-07 02:01:08 +00:00
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#else
|
namespaces: ipc namespaces: implement support for posix msqueues
Implement multiple mounts of the mqueue file system, and link it to usage
of CLONE_NEWIPC.
Each ipc ns has a corresponding mqueuefs superblock. When a user does
clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an
internal mount of a new mqueuefs sb linked to the new ipc ns.
When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the
mqueuefs superblock.
Posix message queues can be worked with both through the mq_* system calls
(see mq_overview(7)), and through the VFS through the mqueue mount. Any
usage of mq_open() and friends will work with the acting task's ipc
namespace. Any actions through the VFS will work with the mqueuefs in
which the file was created. So if a user doesn't remount mqueuefs after
unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls
/dev/mqueue".
If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns,
ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1)
ipc_ns:1 will be freed, (2) it's superblock will live on until task b
umounts the corresponding mqueuefs, and vfs actions will continue to
succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to
the deceased ipc_ns:1.
To make this happen, we must protect the ipc reference count when
a) a task exits and drops its ipcns->count, since it might be dropping
it to 0 and freeing the ipcns
b) a task accesses the ipcns through its mqueuefs interface, since it
bumps the ipcns refcount and might race with the last task in the ipcns
exiting.
So the kref is changed to an atomic_t so we can use
atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns
through ns = mqueuefs_sb->s_fs_info is protected by the same lock.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 02:01:10 +00:00
|
|
|
static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
|
2009-04-07 02:01:08 +00:00
|
|
|
#endif
|
|
|
|
|
|
|
|
#if defined(CONFIG_IPC_NS)
|
2008-02-08 12:18:22 +00:00
|
|
|
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
|
2012-07-26 11:02:49 +00:00
|
|
|
struct user_namespace *user_ns, struct ipc_namespace *ns);
|
|
|
|
|
2008-02-08 12:18:22 +00:00
|
|
|
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
|
|
|
|
{
|
|
|
|
if (ns)
|
2017-09-08 23:17:38 +00:00
|
|
|
refcount_inc(&ns->count);
|
2008-02-08 12:18:22 +00:00
|
|
|
return ns;
|
|
|
|
}
|
|
|
|
|
namespaces: ipc namespaces: implement support for posix msqueues
Implement multiple mounts of the mqueue file system, and link it to usage
of CLONE_NEWIPC.
Each ipc ns has a corresponding mqueuefs superblock. When a user does
clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an
internal mount of a new mqueuefs sb linked to the new ipc ns.
When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the
mqueuefs superblock.
Posix message queues can be worked with both through the mq_* system calls
(see mq_overview(7)), and through the VFS through the mqueue mount. Any
usage of mq_open() and friends will work with the acting task's ipc
namespace. Any actions through the VFS will work with the mqueuefs in
which the file was created. So if a user doesn't remount mqueuefs after
unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls
/dev/mqueue".
If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns,
ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1)
ipc_ns:1 will be freed, (2) it's superblock will live on until task b
umounts the corresponding mqueuefs, and vfs actions will continue to
succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to
the deceased ipc_ns:1.
To make this happen, we must protect the ipc reference count when
a) a task exits and drops its ipcns->count, since it might be dropping
it to 0 and freeing the ipcns
b) a task accesses the ipcns through its mqueuefs interface, since it
bumps the ipcns refcount and might race with the last task in the ipcns
exiting.
So the kref is changed to an atomic_t so we can use
atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns
through ns = mqueuefs_sb->s_fs_info is protected by the same lock.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 02:01:10 +00:00
|
|
|
extern void put_ipc_ns(struct ipc_namespace *ns);
|
2008-02-08 12:18:22 +00:00
|
|
|
#else
|
|
|
|
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
|
2012-07-26 11:02:49 +00:00
|
|
|
struct user_namespace *user_ns, struct ipc_namespace *ns)
|
2008-02-08 12:18:22 +00:00
|
|
|
{
|
|
|
|
if (flags & CLONE_NEWIPC)
|
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
2012-07-26 11:02:49 +00:00
|
|
|
return ns;
|
2008-02-08 12:18:22 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
|
|
|
|
{
|
|
|
|
return ns;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void put_ipc_ns(struct ipc_namespace *ns)
|
|
|
|
{
|
|
|
|
}
|
|
|
|
#endif
|
2009-04-07 02:01:11 +00:00
|
|
|
|
|
|
|
#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
|
|
|
|
|
|
|
|
struct ctl_table_header;
|
|
|
|
extern struct ctl_table_header *mq_register_sysctl_table(void);
|
|
|
|
|
|
|
|
#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
|
|
|
|
|
|
|
|
static inline struct ctl_table_header *mq_register_sysctl_table(void)
|
|
|
|
{
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
|
2008-02-08 12:18:22 +00:00
|
|
|
#endif
|