02 Nov, 2017
1 commit
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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
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
15 Sep, 2017
1 commit
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Pull ipc compat cleanup and 64-bit time_t from Al Viro:
"IPC copyin/copyout sanitizing, including 64bit time_t work from Deepa
Dinamani"* 'work.ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
utimes: Make utimes y2038 safe
ipc: shm: Make shmid_kernel timestamps y2038 safe
ipc: sem: Make sem_array timestamps y2038 safe
ipc: msg: Make msg_queue timestamps y2038 safe
ipc: mqueue: Replace timespec with timespec64
ipc: Make sys_semtimedop() y2038 safe
get rid of SYSVIPC_COMPAT on ia64
semtimedop(): move compat to native
shmat(2): move compat to native
msgrcv(2), msgsnd(2): move compat to native
ipc(2): move compat to native
ipc: make use of compat ipc_perm helpers
semctl(): move compat to native
semctl(): separate all layout-dependent copyin/copyout
msgctl(): move compat to native
msgctl(): split the actual work from copyin/copyout
ipc: move compat shmctl to native
shmctl: split the work from copyin/copyout
09 Sep, 2017
1 commit
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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 with1 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 with1 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 with1 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 µslookup-only:
total total
KEYS without with1 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
Reviewed-by: Marc Pardo
Cc: Davidlohr Bueso
Cc: Kees Cook
Cc: Manfred Spraul
Cc: Alexey Dobriyan
Cc: "Eric W. Biederman"
Cc: "Peter Zijlstra (Intel)"
Cc: Ingo Molnar
Cc: Sebastian Andrzej Siewior
Cc: Serge Hallyn
Cc: Andrey Vagin
Cc: Guillaume Knispel
Cc: Marc Pardo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Jul, 2017
2 commits
-
Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
13 Jul, 2017
5 commits
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Now that ipc_rcu_alloc() and ipc_rcu_free() are removed, document when
it is valid to use ipc_getref() and ipc_putref().Link: http://lkml.kernel.org/r/20170525185107.12869-21-manfred@colorfullife.com
Signed-off-by: Manfred Spraul
Cc: Davidlohr Bueso
Cc: Kees Cook
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
No callers remain for ipc_rcu_alloc(). Drop the function.
[manfred@colorfullife.com: Rediff because the memset was temporarily inside ipc_rcu_free()]
Link: http://lkml.kernel.org/r/20170525185107.12869-13-manfred@colorfullife.com
Signed-off-by: Kees Cook
Signed-off-by: Manfred Spraul
Cc: Kees Cook
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There are no more callers of ipc_rcu_free(), so remove it.
Link: http://lkml.kernel.org/r/20170525185107.12869-9-manfred@colorfullife.com
Signed-off-by: Kees Cook
Signed-off-by: Manfred Spraul
Cc: Davidlohr Bueso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The only users of ipc_alloc() were ipc_rcu_alloc() and the on-heap
sem_io fall-back memory. Better to just open-code these to make things
easier to read.[manfred@colorfullife.com: Rediff due to inclusion of memset() into ipc_rcu_alloc()]
Link: http://lkml.kernel.org/r/20170525185107.12869-5-manfred@colorfullife.com
Signed-off-by: Kees Cook
Signed-off-by: Manfred Spraul
Cc: Davidlohr Bueso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
ipc has two management structures that exist for every id:
- struct kern_ipc_perm, it contains e.g. the permissions.
- struct ipc_rcu, it contains the rcu head for rcu handling and the
refcount.The patch merges both structures.
As a bonus, we may save one cacheline, because both structures are
cacheline aligned. In addition, it reduces the number of casts, instead
most codepaths can use container_of.To simplify code, the ipc_rcu_alloc initializes the allocation to 0.
[manfred@colorfullife.com: really include the memset() into ipc_alloc_rcu()]
Link: http://lkml.kernel.org/r/564f8612-0601-b267-514f-a9f650ec9b32@colorfullife.com
Link: http://lkml.kernel.org/r/20170525185107.12869-3-manfred@colorfullife.com
Signed-off-by: Manfred Spraul
Cc: Davidlohr Bueso
Cc: Kees Cook
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Apr, 2017
1 commit
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The function recompute_msgmni was removed a while ago
but it is still declared in a header file remove it.Signed-off-by: "Eric W. Biederman"
23 Jan, 2016
1 commit
-
There are many locations that do
if (memory_was_allocated_by_vmalloc)
vfree(ptr);
else
kfree(ptr);but kvfree() can handle both kmalloc()ed memory and vmalloc()ed memory
using is_vmalloc_addr(). Unless callers have special reasons, we can
replace this branch with kvfree(). Please check and reply if you found
problems.Signed-off-by: Tetsuo Handa
Acked-by: Michal Hocko
Acked-by: Jan Kara
Acked-by: Russell King
Reviewed-by: Andreas Dilger
Acked-by: "Rafael J. Wysocki"
Acked-by: David Rientjes
Cc: "Luck, Tony"
Cc: Oleg Drokin
Cc: Boris Petkov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Jul, 2015
1 commit
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... to ipc_obtain_object_idr, which is more meaningful and makes the code
slightly easier to follow.Signed-off-by: Davidlohr Bueso
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Jun, 2014
2 commits
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trailing whitespace
Signed-off-by: Paul McQuade
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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: Mathias Krause
Cc: PaX Team
Cc: Davidlohr Bueso
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Jan, 2014
4 commits
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This field is only used to reset the ids seq number if it exceeds the
smaller of INT_MAX/SEQ_MULTIPLIER and USHRT_MAX, and can therefore be
moved out of the structure and into its own macro. Since each
ipc_namespace contains a table of 3 pointers to struct ipc_ids we can
save space in instruction text:text data bss dec hex filename
56232 2348 24 58604 e4ec ipc/built-in.o
56216 2348 24 58588 e4dc ipc/built-in.o-afterSigned-off-by: Davidlohr Bueso
Reviewed-by: Jonathan Gonzalez
Cc: Aswin Chandramouleeswaran
Cc: Rik van Riel
Acked-by: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The ipc code does not adhere the typical linux coding style.
This patch fixes lots of simple whitespace errors.- mostly autogenerated by
scripts/checkpatch.pl -f --fix \
--types=pointer_location,spacing,space_before_tab
- one manual fixup (keep structure members tab-aligned)
- removal of additional space_before_tab that were not found by --fixTested with some of my msg and sem test apps.
Andrew: Could you include it in -mm and move it towards Linus' tree?
Signed-off-by: Manfred Spraul
Suggested-by: Li Bin
Cc: Joe Perches
Acked-by: Rafael Aquini
Cc: Davidlohr Bueso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
struct kern_ipc_perm.deleted is meant to be used as a boolean toggle, and
the changes introduced by this patch are just to make the case explicit.Signed-off-by: Rafael Aquini
Reviewed-by: Rik van Riel
Cc: Greg Thelen
Acked-by: Davidlohr Bueso
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
After the locking semantics for the SysV IPC API got improved, a couple
of IPC_RMID race windows were opened because we ended up dropping the
'kern_ipc_perm.deleted' check performed way down in ipc_lock(). The
spotted races got sorted out by re-introducing the old test within the
racy critical sections.This patch introduces ipc_valid_object() to consolidate the way we cope
with IPC_RMID races by using the same abstraction across the API
implementation.Signed-off-by: Rafael Aquini
Acked-by: Rik van Riel
Acked-by: Greg Thelen
Reviewed-by: Davidlohr Bueso
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Nov, 2013
1 commit
-
On 64 bit systems the test for negative message sizes is bogus as the
size, which may be positive when evaluated as a long, will get truncated
to an int when passed to load_msg(). So a long might very well contain a
positive value but when truncated to an int it would become negative.That in combination with a small negative value of msg_ctlmax (which will
be promoted to an unsigned type for the comparison against msgsz, making
it a big positive value and therefore make it pass the check) will lead to
two problems: 1/ The kmalloc() call in alloc_msg() will allocate a too
small buffer as the addition of alen is effectively a subtraction. 2/ The
copy_from_user() call in load_msg() will first overflow the buffer with
userland data and then, when the userland access generates an access
violation, the fixup handler copy_user_handle_tail() will try to fill the
remainder with zeros -- roughly 4GB. That almost instantly results in a
system crash or reset.,-[ Reproducer (needs to be run as root) ]--
| #include
| #include
| #include
| #include
|
| int main(void) {
| long msg = 1;
| int fd;
|
| fd = open("/proc/sys/kernel/msgmax", O_WRONLY);
| write(fd, "-1", 2);
| close(fd);
|
| msgsnd(0, &msg, 0xfffffff0, IPC_NOWAIT);
|
| return 0;
| }
'---Fix the issue by preventing msgsz from getting truncated by consistently
using size_t for the message length. This way the size checks in
do_msgsnd() could still be passed with a negative value for msg_ctlmax but
we would fail on the buffer allocation in that case and error out.Also change the type of m_ts from int to size_t to avoid similar nastiness
in other code paths -- it is used in similar constructs, i.e. signed vs.
unsigned checks. It should never become negative under normal
circumstances, though.Setting msg_ctlmax to a negative value is an odd configuration and should
be prevented. As that might break existing userland, it will be handled
in a separate commit so it could easily be reverted and reworked without
reintroducing the above described bug.Hardening mechanisms for user copy operations would have catched that bug
early -- e.g. checking slab object sizes on user copy operations as the
usercopy feature of the PaX patch does. Or, for that matter, detect the
long vs. int sign change due to truncation, as the size overflow plugin
of the very same patch does.[akpm@linux-foundation.org: fix i386 min() warnings]
Signed-off-by: Mathias Krause
Cc: Pax Team
Cc: Davidlohr Bueso
Cc: Brad Spengler
Cc: Manfred Spraul
Cc: [ v2.3.27+ -- yes, that old ;) ]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Sep, 2013
1 commit
-
Currently, IPC mechanisms do security and auditing related checks under
RCU. However, since security modules can free the security structure,
for example, through selinux_[sem,msg_queue,shm]_free_security(), we can
race if the structure is freed before other tasks are done with it,
creating a use-after-free condition. Manfred illustrates this nicely,
for instance with shared mem and selinux:-> do_shmat calls rcu_read_lock()
-> do_shmat calls shm_object_check().
Checks that the object is still valid - but doesn't acquire any locks.
Then it returns.
-> do_shmat calls security_shm_shmat (e.g. selinux_shm_shmat)
-> selinux_shm_shmat calls ipc_has_perm()
-> ipc_has_perm accesses ipc_perms->securityshm_close()
-> shm_close acquires rw_mutex & shm_lock
-> shm_close calls shm_destroy
-> shm_destroy calls security_shm_free (e.g. selinux_shm_free_security)
-> selinux_shm_free_security calls ipc_free_security(&shp->shm_perm)
-> ipc_free_security calls kfree(ipc_perms->security)This patch delays the freeing of the security structures after all RCU
readers are done. Furthermore it aligns the security life cycle with
that of the rest of IPC - freeing them based on the reference counter.
For situations where we need not free security, the current behavior is
kept. Linus states:"... the old behavior was suspect for another reason too: having the
security blob go away from under a user sounds like it could cause
various other problems anyway, so I think the old code was at least
_prone_ to bugs even if it didn't have catastrophic behavior."I have tested this patch with IPC testcases from LTP on both my
quad-core laptop and on a 64 core NUMA server. In both cases selinux is
enabled, and tests pass for both voluntary and forced preemption models.
While the mentioned races are theoretical (at least no one as reported
them), I wanted to make sure that this new logic doesn't break anything
we weren't aware of.Suggested-by: Linus Torvalds
Signed-off-by: Davidlohr Bueso
Acked-by: Manfred Spraul
Signed-off-by: Linus Torvalds
12 Sep, 2013
4 commits
-
No remaining users, we now use ipc_obtain_object_check().
Signed-off-by: Davidlohr Bueso
Cc: Sedat Dilek
Cc: Rik van Riel
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
After previous cleanups and optimizations, this function is no longer
heavily used and we don't have a good reason to keep it. Update the few
remaining callers and get rid of it.Signed-off-by: Davidlohr Bueso
Cc: Sedat Dilek
Cc: Rik van Riel
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Since in some situations the lock can be shared for readers, we shouldn't
be calling it a mutex, rename it to rwsem.Signed-off-by: Davidlohr Bueso
Tested-by: Sedat Dilek
Cc: Rik van Riel
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that sem, msgque and shm, through *_down(), all use the lockless
variant of ipcctl_pre_down(), go ahead and delete it.[akpm@linux-foundation.org: fix function name in kerneldoc, cleanups]
Signed-off-by: Davidlohr Bueso
Tested-by: Sedat Dilek
Cc: Rik van Riel
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Jul, 2013
2 commits
-
Signed-off-by: Davidlohr Bueso
Cc: Andi Kleen
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Simple helpers around the (kern_ipc_perm *)->lock spinlock.
Signed-off-by: Davidlohr Bueso
Cc: Andi Kleen
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 May, 2013
5 commits
-
Introduce finer grained locking for semtimedop, to handle the common case
of a program wanting to manipulate one semaphore from an array with
multiple semaphores.If the call is a semop manipulating just one semaphore in an array with
multiple semaphores, only take the lock for that semaphore itself.If the call needs to manipulate multiple semaphores, or another caller is
in a transaction that manipulates multiple semaphores, the sem_array lock
is taken, as well as all the locks for the individual semaphores.On a 24 CPU system, performance numbers with the semop-multi
test with N threads and N semaphores, look like this:vanilla Davidlohr's Davidlohr's + Davidlohr's +
threads patches rwlock patches v3 patches
10 610652 726325 1783589 2142206
20 341570 365699 1520453 1977878
30 288102 307037 1498167 2037995
40 290714 305955 1612665 2256484
50 288620 312890 1733453 2650292
60 289987 306043 1649360 2388008
70 291298 306347 1723167 2717486
80 290948 305662 1729545 2763582
90 290996 306680 1736021 2757524
100 292243 306700 1773700 3059159[davidlohr.bueso@hp.com: do not call sem_lock when bogus sma]
[davidlohr.bueso@hp.com: make refcounter atomic]
Signed-off-by: Rik van Riel
Suggested-by: Linus Torvalds
Acked-by: Davidlohr Bueso
Cc: Chegu Vinod
Cc: Jason Low
Reviewed-by: Michel Lespinasse
Cc: Peter Hurley
Cc: Stanislav Kinsbursky
Tested-by: Emmanuel Benisty
Tested-by: Sedat Dilek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Instead of holding the ipc lock for permissions and security checks, among
others, only acquire it when necessary.Some numbers....
1) With Rik's semop-multi.c microbenchmark we can see the following
results:Baseline (3.9-rc1):
cpus 4, threads: 256, semaphores: 128, test duration: 30 secs
total operations: 151452270, ops/sec 5048409+ 59.40% a.out [kernel.kallsyms] [k] _raw_spin_lock
+ 6.14% a.out [kernel.kallsyms] [k] sys_semtimedop
+ 3.84% a.out [kernel.kallsyms] [k] avc_has_perm_flags
+ 3.64% a.out [kernel.kallsyms] [k] __audit_syscall_exit
+ 2.06% a.out [kernel.kallsyms] [k] copy_user_enhanced_fast_string
+ 1.86% a.out [kernel.kallsyms] [k] ipc_lockWith this patchset:
cpus 4, threads: 256, semaphores: 128, test duration: 30 secs
total operations: 273156400, ops/sec 9105213+ 18.54% a.out [kernel.kallsyms] [k] _raw_spin_lock
+ 11.72% a.out [kernel.kallsyms] [k] sys_semtimedop
+ 7.70% a.out [kernel.kallsyms] [k] ipc_has_perm.isra.21
+ 6.58% a.out [kernel.kallsyms] [k] avc_has_perm_flags
+ 6.54% a.out [kernel.kallsyms] [k] __audit_syscall_exit
+ 4.71% a.out [kernel.kallsyms] [k] ipc_obtain_object_check2) While on an Oracle swingbench DSS (data mining) workload the
improvements are not as exciting as with Rik's benchmark, we can see
some positive numbers. For an 8 socket machine the following are the
percentages of %sys time incurred in the ipc lock:Baseline (3.9-rc1):
100 swingbench users: 8,74%
400 swingbench users: 21,86%
800 swingbench users: 84,35%With this patchset:
100 swingbench users: 8,11%
400 swingbench users: 19,93%
800 swingbench users: 77,69%[riel@redhat.com: fix two locking bugs]
[sasha.levin@oracle.com: prevent releasing RCU read lock twice in semctl_main]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Davidlohr Bueso
Signed-off-by: Rik van Riel
Reviewed-by: Chegu Vinod
Acked-by: Michel Lespinasse
Cc: Rik van Riel
Cc: Jason Low
Cc: Emmanuel Benisty
Cc: Peter Hurley
Cc: Stanislav Kinsbursky
Tested-by: Sedat Dilek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Various forms of ipc use ipcctl_pre_down() to retrieve an ipc object and
check permissions, mostly for IPC_RMID and IPC_SET commands.Introduce ipcctl_pre_down_nolock(), a lockless version of this function.
The locking version is retained, yet modified to call the nolock version
without affecting its semantics, thus transparent to all ipc callers.Signed-off-by: Davidlohr Bueso
Signed-off-by: Rik van Riel
Suggested-by: Linus Torvalds
Cc: Chegu Vinod
Cc: Emmanuel Benisty
Cc: Jason Low
Cc: Michel Lespinasse
Cc: Peter Hurley
Cc: Stanislav Kinsbursky
Tested-by: Sedat Dilek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Through ipc_lock() and therefore ipc_lock_check() we currently return the
locked ipc object. This is not necessary for all situations and can,
therefore, cause unnecessary ipc lock contention.Introduce analogous ipc_obtain_object() and ipc_obtain_object_check()
functions that only lookup and return the ipc object.Both these functions must be called within the RCU read critical section.
[akpm@linux-foundation.org: propagate the ipc_obtain_object() errno from ipc_lock()]
Signed-off-by: Davidlohr Bueso
Signed-off-by: Rik van Riel
Reviewed-by: Chegu Vinod
Acked-by: Michel Lespinasse
Cc: Emmanuel Benisty
Cc: Jason Low
Cc: Peter Hurley
Cc: Stanislav Kinsbursky
Tested-by: Sedat Dilek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This series makes the sysv semaphore code more scalable, by reducing the
time the semaphore lock is held, and making the locking more scalable for
semaphore arrays with multiple semaphores.The first four patches were written by Davidlohr Buesso, and reduce the
hold time of the semaphore lock.The last three patches change the sysv semaphore code locking to be more
fine grained, providing a performance boost when multiple semaphores in a
semaphore array are being manipulated simultaneously.On a 24 CPU system, performance numbers with the semop-multi
test with N threads and N semaphores, look like this:vanilla Davidlohr's Davidlohr's + Davidlohr's +
threads patches rwlock patches v3 patches
10 610652 726325 1783589 2142206
20 341570 365699 1520453 1977878
30 288102 307037 1498167 2037995
40 290714 305955 1612665 2256484
50 288620 312890 1733453 2650292
60 289987 306043 1649360 2388008
70 291298 306347 1723167 2717486
80 290948 305662 1729545 2763582
90 290996 306680 1736021 2757524
100 292243 306700 1773700 3059159This patch:
There is no reason to be holding the ipc lock while reading ipcp->seq,
hence remove misleading comment.Also simplify the return value for the function.
Signed-off-by: Davidlohr Bueso
Signed-off-by: Rik van Riel
Cc: Chegu Vinod
Cc: Emmanuel Benisty
Cc: Jason Low
Cc: Michel Lespinasse
Cc: Peter Hurley
Cc: Stanislav Kinsbursky
Tested-by: Sedat Dilek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Jan, 2013
2 commits
-
This patch is required for checkpoint/restore in userspace.
c/r requires some way to get all pending IPC messages without deleting
them from the queue (checkpoint can fail and in this case tasks will be
resumed, so queue have to be valid).To achive this, new operation flag MSG_COPY for sys_msgrcv() system call
was introduced. If this flag was specified, then mtype is interpreted as
number of the message to copy.If MSG_COPY is set, then kernel will allocate dummy message with passed
size, and then use new copy_msg() helper function to copy desired message
(instead of unlinking it from the queue).Notes:
1) Return -ENOSYS if MSG_COPY is specified, but
CONFIG_CHECKPOINT_RESTORE is not set.Signed-off-by: Stanislav Kinsbursky
Cc: Serge Hallyn
Cc: "Eric W. Biederman"
Cc: Pavel Emelyanov
Cc: Al Viro
Cc: KOSAKI Motohiro
Cc: Michael Kerrisk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add 3 new variables and sysctls to tune them (by one "next_id" variable
for messages, semaphores and shared memory respectively). This variable
can be used to set desired id for next allocated IPC object. By default
it's equal to -1 and old behaviour is preserved. If this variable is
non-negative, then desired idr will be extracted from it and used as a
start value to search for free IDR slot.Notes:
1) this patch doesn't guarantee that the new object will have desired
id. So it's up to user space how to handle new object with wrong id.2) After a sucessful id allocation attempt, "next_id" will be set back
to -1 (if it was non-negative).[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stanislav Kinsbursky
Cc: Serge Hallyn
Cc: "Eric W. Biederman"
Cc: Pavel Emelyanov
Cc: Al Viro
Cc: KOSAKI Motohiro
Cc: Michael Kerrisk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Sep, 2012
1 commit
-
- Store the ipc owner and creator with a kuid
- Store the ipc group and the crators group with a kgid.
- Add error handling to ipc_update_perms, allowing it to
fail if the uids and gids can not be converted to kuids
or kgids.
- Modify the proc files to display the ipc creator and
owner in the user namespace of the opener of the proc file.Signed-off-by: Eric W. Biederman
31 Jul, 2012
1 commit
-
Rather than #define the options manually in the architecture code, add
Kconfig options for them and select them there instead. This also allows
us to select the compat IPC version parsing automatically for platforms
using the old compat IPC interface.Reported-by: Andrew Morton
Signed-off-by: Will Deacon
Cc: Arnd Bergmann
Cc: Chris Metcalf
Cc: Catalin Marinas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Mar, 2011
1 commit
-
CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(),
because the resource comes from current's own ipc namespace.setuid/setgid are to uids in own namespace, so again checks can be against
current_user_ns().Changelog:
Jan 11: Use task_ns_capable() in place of sched_capable().
Jan 11: Use nsown_capable() as suggested by Bastian Blank.
Jan 11: Clarify (hopefully) some logic in futex and sched.c
Feb 15: use ns_capable for ipc, not nsown_capable
Feb 23: let copy_ipcs handle setting ipc_ns->user_ns
Feb 23: pass ns down rather than taking it from current[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Serge E. Hallyn
Acked-by: "Eric W. Biederman"
Acked-by: Daniel Lezcano
Acked-by: David Howells
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Jun, 2009
1 commit
-
31a985f "ipc: use __ARCH_WANT_IPC_PARSE_VERSION in ipc/util.h" would
choose the implementation of ipc_parse_version() based on a symbol
defined in .But it failed to also include this header and thus broke
IPC_64-passing 32-bit userspace because the flag wasn't masked out
properly anymore and the command not understood.Include to give the architecture a chance to ask for
the no-no-op ipc_parse_version().Signed-off-by: Johannes Weiner
Acked-by: Arnd Bergmann
Signed-off-by: Linus Torvalds
19 Jun, 2009
2 commits
-
Function is really private to ipc/ and avoid struct kern_ipc_perm
forward declaration.Signed-off-by: Alexey Dobriyan
Reviewed-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The definition of ipc_parse_version depends on
__ARCH_WANT_IPC_PARSE_VERSION, but the header file declares it
conditionally based on the architecture.Use the macro consistently to make it easier to add new architectures.
Signed-off-by: Arnd Bergmann
Acked-by: Serge Hallyn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
