Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.
By default are files without license information under the default
license of the kernel, which is GPLV2. Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
otherwise syscall usage would not be possible.
Update the files which contain no license information with an SPDX
license identifier. The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception. SPDX license identifiers are 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. See the previous patch in this series for the
methodology of how this patch was researched.
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>
sem_ctime is initialized to the semget() time and then updated at every
semctl() that changes the array.
Thus it does not represent the time of the last change.
Especially, semop() calls are only stored in sem_otime, not in
sem_ctime.
This is already described in ipc/sem.c, I just overlooked that there is
a comment in include/linux/sem.h and man semctl(2) as well.
So: Correct wrong comments.
Link: http://lkml.kernel.org/r/20170515171912.6298-4-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: <1vier1@web.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
a)
SysV can be abused to allocate locked kernel memory. For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.
Therefore: Increase the sysv sem limits so that all known applications
will work with these defaults.
b)
With regards to the maximum supported:
Some of the specified hard limits are not correct anymore, therefore the
patch updates the documentation.
- SEMMNI must stay below IPCMNI, which is 32768.
As for SHMMAX: Stay a bit below this limit.
- SEMMSL was limited to 8k, to ensure that the kmalloc for the kernel array
was limited to 16 kB (order=2)
This doesn't apply anymore:
- the allocation size isn't sizeof(short)*nsems anymore.
- ipc_alloc falls back to vmalloc
- SEMOPM should stay below 1000, to limit the kmalloc in semtimedop() to an
order=1 allocation.
Therefore: Leave it at 500 (order=0 allocation).
Note:
If an administrator must limit the memory allocations, then he can set the
values as necessary.
Or he can disable sysv entirely (as e.g. done by Android).
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
