linux-toradex.git/ipc, branch v4.14-rc7

fix a typo in put_compat_shm_info()

2017-09-26T00:41:46+00:00

"uip" misspelled as "up"; unfortunately, the latter happens to be
a function and gcc is happy to convert it to void *...

Signed-off-by: Al Viro

ipc/shm: Fix order of parameters when calling copy_compat_shmid_to_user

2017-09-21T03:27:48+00:00

Commit 553f770ef71b ("ipc: move compat shmctl to native") moved the
compat IPC syscall handling into ipc/shm.c and refactored the struct
accessors in the process. Unfortunately, the call to
copy_compat_shmid_to_user when handling a compat {IPC,SHM}_STAT command
gets the arguments the wrong way round, passing a kernel stack address
as the user buffer (destination) and the user buffer as the kernel stack
address (source).

This patch fixes the parameter ordering so the buffers are accessed
correctly.

Cc: Al Viro 
Cc: Andrew Morton 
Signed-off-by: Will Deacon 
Signed-off-by: Al Viro

Merge branch 'work.ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2017-09-15T00:37:26+00:00

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

ipc: optimize semget/shmget/msgget for lots of keys

2017-09-09T01:26:51+00:00

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   Âµs            3.5         4.9
     10            7.6         8.6   Âµs            3.7         4.7
     32           16.2        15.9   Âµs            4.3         5.3
    100           72.9        41.8   Âµs            3.7         4.7
   1000        5,630.0       502.0   Âµs             *           *
  10000    1,340,000.0     7,240.0   Âµs             *           *
  31900   17,600,000.0    22,200.0   Âµs             *           *

 *: 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   Âµs            2.1         2.5
     10            4.5         4.8   Âµs            2.2         2.3
     32           13.0        10.8   Âµs            2.3         2.8
    100           82.9        25.1   Âµs             *          2.3
   1000        5,780.0       217.0   Âµs             *           *
  10000    1,470,000.0     2,520.0   Âµs             *           *
  31900   17,400,000.0     7,810.0   Âµs             *           *

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   Âµs
     10           32.9        36.7   Âµs
     32          125.0       109.0   Âµs
    100          523.0       353.0   Âµs
   1000       20,300.0     3,280.0   Âµs
  10000    2,470,000.0    46,700.0   Âµs
  31900   27,800,000.0   219,000.0   Âµs

lookup-only:
                 total       total
   KEYS        without        with

      1            2.5         2.7   Âµs
     10           25.4        24.4   Âµs
     32          106.0        72.6   Âµs
    100          591.0       352.0   Âµs
   1000       22,400.0     2,250.0   Âµs
  10000    2,510,000.0    25,700.0   Âµs
  31900   28,200,000.0   115,000.0   Âµs

[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

ipc/sem: play nicer with large nsops allocations

2017-09-09T01:26:51+00:00

Replacing semop()'s kmalloc for kvmalloc was originally proposed by
Manfred on the premise that it can be called for large (than order-1)
sizes.  For example, while Oracle recommends setting SEMOPM to a _minimum_
of 100, some distros[1] encourage the setting to be a factor of the amount
of db tasks (PROCESSES), which can get fishy for large systems (easily
going beyond 1000).

[1] An Example of Semaphore Settings
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Tuning_and_Optimizing_Red_Hat_Enterprise_Linux_for_Oracle_9i_and_10g_Databases/sect-Oracle_9i_and_10g_Tuning_Guide-Setting_Semaphores-An_Example_of_Semaphore_Settings.html

So let's just convert this to kvmalloc, just like the rest of the
allocations we do in ipc.  While the fallback vmalloc obviously involves
more overhead, this by far the uncommon path, and it's better for the user
than just erroring out with kmalloc.

Link: http://lkml.kernel.org/r/20170803184136.13855-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso 
Cc: Manfred Spraul 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc/sem: drop sem_checkid helper

2017-09-09T01:26:51+00:00

... 'tis not used.

Link: http://lkml.kernel.org/r/20170803184136.13855-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso 
Cc: Manfred Spraul 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: convert kern_ipc_perm.refcount from atomic_t to refcount_t

2017-09-09T01:26:51+00:00

refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter.  This allows to avoid
accidental refcounter overflows that might lead to use-after-free
situations.

Link: http://lkml.kernel.org/r/1499417992-3238-4-git-send-email-elena.reshetova@intel.com
Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Cc: Peter Zijlstra 
Cc: Greg Kroah-Hartman 
Cc: "Eric W. Biederman" 
Cc: Ingo Molnar 
Cc: Alexey Dobriyan 
Cc: Serge Hallyn 
Cc: 
Cc: Davidlohr Bueso 
Cc: Manfred Spraul 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: convert sem_undo_list.refcnt from atomic_t to refcount_t

2017-09-09T01:26:51+00:00

refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter.  This allows to avoid
accidental refcounter overflows that might lead to use-after-free
situations.

Link: http://lkml.kernel.org/r/1499417992-3238-3-git-send-email-elena.reshetova@intel.com
Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Cc: Peter Zijlstra 
Cc: Greg Kroah-Hartman 
Cc: "Eric W. Biederman" 
Cc: Ingo Molnar 
Cc: Alexey Dobriyan 
Cc: Serge Hallyn 
Cc: 
Cc: Davidlohr Bueso 
Cc: Manfred Spraul 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: convert ipc_namespace.count from atomic_t to refcount_t

2017-09-09T01:26:51+00:00

refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter.  This allows to avoid
accidental refcounter overflows that might lead to use-after-free
situations.

Link: http://lkml.kernel.org/r/1499417992-3238-2-git-send-email-elena.reshetova@intel.com
Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Cc: Peter Zijlstra 
Cc: Greg Kroah-Hartman 
Cc: "Eric W. Biederman" 
Cc: Ingo Molnar 
Cc: Alexey Dobriyan 
Cc: Serge Hallyn 
Cc: 
Cc: Davidlohr Bueso 
Cc: Manfred Spraul 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: shm: Make shmid_kernel timestamps y2038 safe

2017-09-04T00:24:29+00:00

time_t is not y2038 safe. Replace all uses of
time_t by y2038 safe time64_t.

Similarly, replace the calls to get_seconds() with
y2038 safe ktime_get_real_seconds().
Note that this preserves fast access on 64 bit systems,
but 32 bit systems need sequence counters.

The syscall interfaces themselves are not changed as part of
the patch. They will be part of a different series.

Signed-off-by: Deepa Dinamani 
Reviewed-by: Arnd Bergmann 
Signed-off-by: Al Viro