proc_subdir_lock protects only modifying and walking through PDE lists, so
after we've found PDE to remove and actually removed it from lists, there is
no need to hold proc_subdir_lock for the rest of operation.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This cleans up the permission checks done for /proc/PID/mem i/o calls. It
puts all the logic in a new function, check_mem_permission().
The old code repeated the (!MAY_PTRACE(task) || !ptrace_may_attach(task))
magical expression multiple times. The new function does all that work in one
place, with clear comments.
The old code called security_ptrace() twice on successful checks, once in
MAY_PTRACE() and once in __ptrace_may_attach(). Now it's only called once,
and only if all other checks have succeeded.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel implements readlink of /proc/pid/exe by getting the file from
the first executable VMA. Then the path to the file is reconstructed and
reported as the result.
Because of the VMA walk the code is slightly different on nommu systems.
This patch avoids separate /proc/pid/exe code on nommu systems. Instead of
walking the VMAs to find the first executable file-backed VMA we store a
reference to the exec'd file in the mm_struct.
That reference would prevent the filesystem holding the executable file
from being unmounted even after unmapping the VMAs. So we track the number
of VM_EXECUTABLE VMAs and drop the new reference when the last one is
unmapped. This avoids pinning the mounted filesystem.
[akpm@linux-foundation.org: improve comments]
[yamamoto@valinux.co.jp: fix dup_mmap]
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Cc:"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make key_serial() an inline function rather than a macro if CONFIG_KEYS=y.
This prevents double evaluation of the key pointer and also provides better
type checking.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since these two source files invoke kmalloc(), they should explicitly
include <linux/slab.h>.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the keyring quotas controllable through /proc/sys files:
(*) /proc/sys/kernel/keys/root_maxkeys
/proc/sys/kernel/keys/root_maxbytes
Maximum number of keys that root may have and the maximum total number of
bytes of data that root may have stored in those keys.
(*) /proc/sys/kernel/keys/maxkeys
/proc/sys/kernel/keys/maxbytes
Maximum number of keys that each non-root user may have and the maximum
total number of bytes of data that each of those users may have stored in
their keys.
Also increase the quotas as a number of people have been complaining that it's
not big enough. I'm not sure that it's big enough now either, but on the
other hand, it can now be set in /etc/sysctl.conf.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't generate the per-UID user and user session keyrings unless they're
explicitly accessed. This solves a problem during a login process whereby
set*uid() is called before the SELinux PAM module, resulting in the per-UID
keyrings having the wrong security labels.
This also cures the problem of multiple per-UID keyrings sometimes appearing
due to PAM modules (including pam_keyinit) setuiding and causing user_structs
to come into and go out of existence whilst the session keyring pins the user
keyring. This is achieved by first searching for extant per-UID keyrings
before inventing new ones.
The serial bound argument is also dropped from find_keyring_by_name() as it's
not currently made use of (setting it to 0 disables the feature).
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The key_create_or_update() function provided by the keyring code has a default
set of permissions that are always applied to the key when created. This
might not be desirable to all clients.
Here's a patch that adds a "perm" parameter to the function to address this,
which can be set to KEY_PERM_UNDEF to revert to the current behaviour.
Signed-off-by: Arun Raghavan <arunsr@cse.iitk.ac.in>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a keyctl() function to get the security label of a key.
The following is added to Documentation/keys.txt:
(*) Get the LSM security context attached to a key.
long keyctl(KEYCTL_GET_SECURITY, key_serial_t key, char *buffer,
size_t buflen)
This function returns a string that represents the LSM security context
attached to a key in the buffer provided.
Unless there's an error, it always returns the amount of data it could
produce, even if that's too big for the buffer, but it won't copy more
than requested to userspace. If the buffer pointer is NULL then no copy
will take place.
A NUL character is included at the end of the string if the buffer is
sufficiently big. This is included in the returned count. If no LSM is
in force then an empty string will be returned.
A process must have view permission on the key for this function to be
successful.
[akpm@linux-foundation.org: declare keyctl_get_security()]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Paul Moore <paul.moore@hp.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: James Morris <jmorris@namei.org>
Cc: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow the callout data to be passed as a blob rather than a string for
internal kernel services that call any request_key_*() interface other than
request_key(). request_key() itself still takes a NUL-terminated string.
The functions that change are:
request_key_with_auxdata()
request_key_async()
request_key_async_with_auxdata()
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Paul Moore <paul.moore@hp.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check the starting keyring as part of the search to (a) see if that is what
we're searching for, and (b) to check it is still valid for searching.
The scenario: User in process A does things that cause things to be created in
its process session keyring. The user then does an su to another user and
starts a new process, B. The two processes now share the same process session
keyring.
Process B does an NFS access which results in an upcall to gssd. When gssd
attempts to instantiate the context key (to be linked into the process session
keyring), it is denied access even though it has an authorization key.
The order of calls is:
keyctl_instantiate_key()
lookup_user_key() (the default: case)
search_process_keyrings(current)
search_process_keyrings(rka->context) (recursive call)
keyring_search_aux()
keyring_search_aux() verifies the keys and keyrings underneath the top-level
keyring it is given, but that top-level keyring is neither fully validated nor
checked to see if it is the thing being searched for.
This patch changes keyring_search_aux() to:
1) do more validation on the top keyring it is given and
2) check whether that top-level keyring is the thing being searched for
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Paul Moore <paul.moore@hp.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Kevin Coffman <kwc@citi.umich.edu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Increase the size of a payload that can be used to instantiate a key in
add_key() and keyctl_instantiate_key(). This permits huge CIFS SPNEGO blobs
to be passed around. The limit is raised to 1MB. If kmalloc() can't allocate
a buffer of sufficient size, vmalloc() will be tried instead.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Paul Moore <paul.moore@hp.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Kevin Coffman <kwc@citi.umich.edu>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix these sparse warings:
fs/binfmt_elf.c:1749:29: warning: symbol 'tmp' shadows an earlier one
fs/binfmt_elf.c:1734:28: originally declared here
fs/binfmt_elf.c:2009:26: warning: symbol 'vma' shadows an earlier one
fs/binfmt_elf.c:1892:24: originally declared here
[akpm@linux-foundation.org: chose better variable name]
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch does simplify fill_elf_header function by setting
to zero the whole elf header first. So we fillup the fields
we really need only.
before:
text data bss dec hex filename
11735 80 0 11815 2e27 fs/binfmt_elf.o
after:
text data bss dec hex filename
11710 80 0 11790 2e0e fs/binfmt_elf.o
viola, 25 bytes of text is freed
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A void returning function returned the return value of another void
returning function...
Spotted by sparse.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the needlessly global ipmi_alloc_recv_msg() static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lots of style fixes for the miscellaneous IPMI files. No functional
changes. Basically fixes everything reported by checkpatch and fixes the
comment style.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lots of style fixes for the IPMI system interface driver. No functional
changes. Basically fixes everything reported by checkpatch and fixes the
comment style.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Rocky Craig <rocky.craig@hp.com>
Cc: Hannes Schulz <schulz@schwaar.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lots of style fixes for the base IPMI driver. No functional changes.
Basically fixes everything reported by checkpatch and fixes the comment
style.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the #defines for statistics into an enum in the IPMI system interface
and remove the unused timeout_restart statistic. And comment what these
statistics mean.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Atomics are faster and neater than locked counters.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the #defines for statistics into an enum in the IPMI message
handler.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Atomics are a lot more efficient and neat than using a lock.
Signed-off-by: Konstantin Baydarov <kbaidarov@ru.mvista.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enough bug fixes and changes that we need a new driver version.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't print out that the event queue is full on every event, only
print something out when it becomes full or becomes not full.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch prevents deadlocks in IPMI panic handler caused by msg_lock
in smi_info structure and waiting_msgs_lock in ipmi_smi structure.
[cminyard@mvista.com: remove unnecessary memory barriers]
Signed-off-by: Konstantin Baydarov <kbaidarov@ru.mvista.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "run_to_completion" mode was somewhat broken. Locks need to be avoided in
run_to_completion mode, and it shouldn't be used by normal users, just
internally for panic situations.
This patch removes locks in run_to_completion mode and removes the user call
for setting the mode. The only user was the poweroff code, but it was easily
converted to use the polling interface.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hold handling of ATTN until the upper layer has reported that it is
ready.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Patrick Schoeller <Patrick.Schoeller@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CLONE_NEWIPC|CLONE_SYSVSEM interaction isn't handled properly. This can cause
a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo
lists.
Fix, part 3: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC).
With unshare, specifying CLONE_SYSVSEM means unshare the sysvsem. So it seems
reasonable that CLONE_NEWIPC without CLONE_SYSVSEM would just imply
CLONE_SYSVSEM.
However with clone, specifying CLONE_SYSVSEM means *share* the sysvsem. So
calling clone(CLONE_SYSVSEM|CLONE_NEWIPC) is explicitly asking for something
we can't allow. So return -EINVAL in that case.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can
cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing
undo lists.
Fix, part 2: perform an implicit CLONE_SYSVSEM in CLONE_NEWIPC. CLONE_NEWIPC
creates a new IPC namespace, the task cannot access the existing semaphore
arrays after the unshare syscall. Thus the task can/must detach from the
existing undo list entries, too.
This fixes the kernel corruption, because it makes it impossible that
undo records from two different namespaces are in sysvsem.undo_list.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can
cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing
undo lists.
Fix, part 1: add support for sys_unshare(CLONE_SYSVSEM)
The original reason to not support it was the potential (inevitable?)
confusion due to the fact that sys_unshare(CLONE_SYSVSEM) has the
inverse meaning of clone(CLONE_SYSVSEM).
Our two most reasonable options then appear to be (1) fully support
CLONE_SYSVSEM, or (2) continue to refuse explicit CLONE_SYSVSEM,
but always do it anyway on unshare(CLONE_SYSVSEM). This patch does
(1).
Changelog:
Apr 16: SEH: switch to Manfred's alternative patch which
removes the unshare_semundo() function which
always refused CLONE_SYSVSEM.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add definitions of USHORT_MAX and others into kernel. ipc uses it and slub
implementation might also use it.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: "Pierre Peiffer" <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
semctl_down(), msgctl_down() and shmctl_down() are used to handle the same set
of commands for each kind of IPC. They all start to do the same job (they
retrieve the ipc and do some permission checks) before handling the commands
on their own.
This patch proposes to consolidate this by moving these same pieces of code
into one common function called ipcctl_pre_down().
It simplifies a little these xxxctl_down() functions and increases a little
the maintainability.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The IPC_SET command performs the same permission setting for all IPCs. This
patch introduces a common ipc_update_perm() function to update these
permissions and makes use of it for all IPCs.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All IPCs make use of an intermetiate *_setbuf structure to handle the IPC_SET
command. This is not really needed and, moreover, it complicates a little bit
the code.
This patch gets rid of the use of it and uses directly the semid64_ds/
msgid64_ds/shmid64_ds structure.
In addition of removing one struture declaration, it also simplifies and
improves a little bit the common 64-bits path.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
semctl_down() takes one unused parameter: semnum. This patch proposes to get
rid of it.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
semctl_down is called with the rwmutex (the one which protects the list of
ipcs) taken in write mode.
This patch moves this rwmutex taken in write-mode inside semctl_down.
This has the advantages of reducing a little bit the window during which this
rwmutex is taken, clarifying sys_semctl, and finally of having a coherent
behaviour with [shm|msg]ctl_down
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, sys_msgctl is not easy to read.
This patch tries to improve that by introducing the msgctl_down function to
handle all commands requiring the rwmutex to be taken in write mode (ie
IPC_SET and IPC_RMID for now). It is the equivalent function of semctl_down
for message queues.
This greatly changes the readability of sys_msgctl and also harmonizes the way
these commands are handled among all IPCs.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the way the different commands are handled in sys_shmctl introduces
some duplicated code.
This patch introduces the shmctl_down function to handle all the commands
requiring the rwmutex to be taken in write mode (ie IPC_SET and IPC_RMID for
now). It is the equivalent function of semctl_down for shared memory.
This removes some duplicated code for handling these both commands and
harmonizes the way they are handled among all IPCs.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trivial patch which adds some small locking functions and makes use of them to
factorize some part of the code and to make it cleaner.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The enhancement as asked for by Yasunori: if msgmni is set to a negative
value, register it back into the ipcns notifier chain.
A new interface has been added to the notification mechanism:
notifier_chain_cond_register() registers a notifier block only if not already
registered. With that new interface we avoid taking care of the states
changes in procfs.
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make msgmni not recomputed anymore upon ipc namespace creation / removal or
memory add/remove, as soon as it has been set from userland.
As soon as msgmni is explicitly set via procfs or sysctl(), the associated
callback routine is unregistered from the ipc namespace notifier chain.
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a notification mechanism that aims at recomputing msgmni each time
an ipc namespace is created or removed.
The ipc namespace notifier chain already defined for memory hotplug management
is used for that purpose too.
Each time a new ipc namespace is allocated or an existing ipc namespace is
removed, the ipcns notifier chain is notified. The callback routine for each
registered ipc namespace is then activated in order to recompute msgmni for
that namespace.
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
