user/sven/linux.git/include/linux/ipc_namespace.h, branch v3.10.34

ipc,mqueue: remove limits for the amount of system-wide queues

2014-03-07T05:30:12Z

commit f3713fd9cff733d9df83116422d8e4af6e86b2bb upstream. Commit 93e6f119c0ce ("ipc/mqueue: cleanup definition names and locations") added global hardcoded limits to the amount of message queues that can be created. While these limits are per-namespace, reality is that it ends up breaking userspace applications. Historically users have, at least in theory, been able to create up to INT_MAX queues, and limiting it to just 1024 is way too low and dramatic for some workloads and use cases. For instance, Madars reports: "This update imposes bad limits on our multi-process application. As our app uses approaches that each process opens its own set of queues (usually something about 3-5 queues per process). In some scenarios we might run up to 3000 processes or more (which of-course for linux is not a problem). Thus we might need up to 9000 queues or more. All processes run under one user." Other affected users can be found in launchpad bug #1155695: https://bugs.launchpad.net/ubuntu/+source/manpages/+bug/1155695 Instead of increasing this limit, revert it entirely and fallback to the original way of dealing queue limits -- where once a user's resource limit is reached, and all memory is used, new queues cannot be created. Signed-off-by: Davidlohr Bueso Reported-by: Madars Vitolins Acked-by: Doug Ledford Cc: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ipc, msg: forbid negative values for "msg{max,mnb,mni}"

2013-12-04T18:56:11Z

commit 9bf76ca325d5e9208eb343f7bd4cc666f703ed30 upstream. Negative message lengths make no sense -- so don't do negative queue lenghts or identifier counts. Prevent them from getting negative. Also change the underlying data types to be unsigned to avoid hairy surprises with sign extensions in cases where those variables get evaluated in unsigned expressions with bigger data types, e.g size_t. In case a user still wants to have "unlimited" sizes she could just use INT_MAX instead. Signed-off-by: Mathias Krause Cc: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ipc: rename ids->rw_mutex

2013-10-18T14:45:47Z

commit d9a605e40b1376eb02b067d7690580255a0df68f upstream. 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 Cc: Mike Galbraith Signed-off-by: Greg Kroah-Hartman

ipc: sysv shared memory limited to 8TiB

2013-05-01T15:12:58Z

Trying to run an application which was trying to put data into half of memory using shmget(), we found that having a shmall value below 8EiB-8TiB would prevent us from using anything more than 8TiB. By setting kernel.shmall greater than 8EiB-8TiB would make the job work. In the newseg() function, ns->shm_tot which, at 8TiB is INT_MAX. ipc/shm.c: 458 static int newseg(struct ipc_namespace *ns, struct ipc_params *params) 459 { ... 465 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; ... 474 if (ns->shm_tot + numpages > ns->shm_ctlall) 475 return -ENOSPC; [akpm@linux-foundation.org: make ipc/shm.c:newseg()'s numpages size_t, not int] Signed-off-by: Robin Holt Reported-by: Alex Thorlton Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: add sysctl to specify desired next object id

2013-01-05T00:11:45Z

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

proc: Usable inode numbers for the namespace file descriptors.

2012-11-20T12:19:49Z

Assign a unique proc inode to each namespace, and use that inode number to ensure we only allocate at most one proc inode for every namespace in proc. A single proc inode per namespace allows userspace to test to see if two processes are in the same namespace. This has been a long requested feature and only blocked because a naive implementation would put the id in a global space and would ultimately require having a namespace for the names of namespaces, making migration and certain virtualization tricks impossible. We still don't have per superblock inode numbers for proc, which appears necessary for application unaware checkpoint/restart and migrations (if the application is using namespace file descriptors) but that is now allowd by the design if it becomes important. I have preallocated the ipc and uts initial proc inode numbers so their structures can be statically initialized. Signed-off-by: Eric W. Biederman

userns: Make create_new_namespaces take a user_ns parameter

2012-11-20T12:17:43Z

Modify create_new_namespaces to explicitly take a user namespace parameter, instead of implicitly through the task_struct. This allows an implementation of unshare(CLONE_NEWUSER) where the new user namespace is not stored onto the current task_struct until after all of the namespaces are created. Acked-by: Serge Hallyn Signed-off-by: "Eric W. Biederman"

mqueue: separate mqueue default value from maximum value

2012-06-01T00:49:31Z

Commit b231cca4381e ("message queues: increase range limits") changed mqueue default value when attr parameter is specified NULL from hard coded value to fs.mqueue.{msg,msgsize}_max sysctl value. This made large side effect. When user need to use two mqueue applications 1) using !NULL attr parameter and it require big message size and 2) using NULL attr parameter and only need small size message, app (1) require to raise fs.mqueue.msgsize_max and app (2) consume large memory size even though it doesn't need. Doug Ledford propsed to switch back it to static hard coded value. However it also has a compatibility problem. Some applications might started depend on the default value is tunable. The solution is to separate default value from maximum value. Signed-off-by: KOSAKI Motohiro Signed-off-by: Doug Ledford Acked-by: Doug Ledford Acked-by: Joe Korty Cc: Amerigo Wang Acked-by: Serge E. Hallyn Cc: Jiri Slaby Cc: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mqueue: revert bump up DFLT_*MAX

2012-06-01T00:49:31Z

Mqueue limitation is slightly naieve parameter likes other ipcs because unprivileged user can consume kernel memory by using ipcs. Thus, too aggressive raise bring us security issue. Example, current setting allow evil unprivileged user use 256GB (= 256 * 1024 * 1024*1024) and it's enough large to system will belome unresponsive. Don't do that. Instead, every admin should adjust the knobs for their own systems. Signed-off-by: KOSAKI Motohiro Acked-by: Doug Ledford Acked-by: Joe Korty Cc: Amerigo Wang Acked-by: Serge E. Hallyn Cc: Jiri Slaby Cc: Manfred Spraul Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc/mqueue: update maximums for the mqueue subsystem

2012-06-01T00:49:30Z

Commit b231cca4381e ("message queues: increase range limits") changed the maximum size of a message in a message queue from INT_MAX to 8192*128. Unfortunately, we had customers that relied on a size much larger than 8192*128 on their production systems. After reviewing POSIX, we found that it is silent on the maximum message size. We did find a couple other areas in which it was not silent. Fix up the mqueue maximums so that the customer's system can continue to work, and document both the POSIX and real world requirements in ipc_namespace.h so that we don't have this issue crop back up. Also, commit 9cf18e1dd74cd0 ("ipc: HARD_MSGMAX should be higher not lower on 64bit") fiddled with HARD_MSGMAX without realizing that the number was intentionally in place to limit the msg queue depth to one that was small enough to kmalloc an array of pointers (hence why we divided 128k by sizeof(long)). If we wish to meet POSIX requirements, we have no choice but to change our allocation to a vmalloc instead (at least for the large queue size case). With that, it's possible to increase our allowed maximum to the POSIX requirements (or more if we choose). [sfr@canb.auug.org.au: using vmalloc requires including vmalloc.h] Signed-off-by: Doug Ledford Cc: Serge E. Hallyn Cc: Amerigo Wang Cc: Joe Korty Cc: Jiri Slaby Acked-by: KOSAKI Motohiro Cc: Manfred Spraul Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds