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2013-01-07cpuset: schedule hotplug propagation from cpuset_attach() if the cpuset is emptyTejun Heo
cpuset is scheduled to be decoupled from cgroup_lock which will make hotplug handling race with task migration. cpus or mems will be allowed to go offline between ->can_attach() and ->attach(). If hotplug takes down all cpus or mems of a cpuset while attach is in progress, ->attach() may end up putting tasks into an empty cpuset. This patchset makes ->attach() schedule hotplug propagation if the cpuset is empty after attaching is complete. This will move the tasks to the nearest ancestor which can execute and the end result would be as if hotplug handling happened after the tasks finished attaching. cpuset_write_resmask() now also flushes cpuset_propagate_hotplug_wq to wait for propagations scheduled directly by cpuset_attach(). This currently doesn't make any functional difference as everything is protected by cgroup_mutex but enables decoupling the locking. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: pin down cpus and mems while a task is being attachedTejun Heo
cpuset is scheduled to be decoupled from cgroup_lock which will make configuration updates race with task migration. Any config update will be allowed to happen between ->can_attach() and ->attach(). If such config update removes either all cpus or mems, by the time ->attach() is called, the condition verified by ->can_attach(), that the cpuset is capable of hosting the tasks, is no longer true. This patch adds cpuset->attach_in_progress which is incremented from ->can_attach() and decremented when the attach operation finishes either successfully or not. validate_change() treats cpusets w/ non-zero ->attach_in_progress like cpusets w/ tasks and refuses to remove all cpus or mems from it. This currently doesn't make any functional difference as everything is protected by cgroup_mutex but enables decoupling the locking. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: make CPU / memory hotplug propagation asynchronousTejun Heo
cpuset_hotplug_workfn() has been invoking cpuset_propagate_hotplug() directly to propagate hotplug updates to !root cpusets; however, this has the following problems. * cpuset locking is scheduled to be decoupled from cgroup_mutex, cgroup_mutex will be unexported, and cgroup_attach_task() will do cgroup locking internally, so propagation can't synchronously move tasks to a parent cgroup while walking the hierarchy. * We can't use cgroup generic tree iterator because propagation to each cpuset may sleep. With propagation done asynchronously, we can lose the rather ugly cpuset specific iteration. Convert cpuset_propagate_hotplug() to cpuset_propagate_hotplug_workfn() and execute it from newly added cpuset->hotplug_work. The work items are run on an ordered workqueue, so the propagation order is preserved. cpuset_hotplug_workfn() schedules all propagations while holding cgroup_mutex and waits for completion without cgroup_mutex. Each in-flight propagation holds a reference to the cpuset->css. This patch doesn't cause any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: drop async_rebuild_sched_domains()Tejun Heo
In general, we want to make cgroup_mutex one of the outermost locks and be able to use get_online_cpus() and friends from cgroup methods. With cpuset hotplug made async, get_online_cpus() can now be nested inside cgroup_mutex. Currently, cpuset avoids nesting get_online_cpus() inside cgroup_mutex by bouncing sched_domain rebuilding to a work item. As such nesting is allowed now, remove the workqueue bouncing code and always rebuild sched_domains synchronously. This also nests sched_domains_mutex inside cgroup_mutex, which is intended and should be okay. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: don't nest cgroup_mutex inside get_online_cpus()Tejun Heo
CPU / memory hotplug path currently grabs cgroup_mutex from hotplug event notifications. We want to separate cpuset locking from cgroup core and make cgroup_mutex outer to hotplug synchronization so that, among other things, mechanisms which depend on get_online_cpus() can be used from cgroup callbacks. In general, we want to keep cgroup_mutex the outermost lock to minimize locking interactions among different controllers. Convert cpuset_handle_hotplug() to cpuset_hotplug_workfn() and schedule it from the hotplug notifications. As the function can already handle multiple mixed events without any input, converting it to a work function is mostly trivial; however, one complication is that cpuset_update_active_cpus() needs to update sched domains synchronously to reflect an offlined cpu to avoid confusing the scheduler. This is worked around by falling back to the the default single sched domain synchronously before scheduling the actual hotplug work. This makes sched domain rebuilt twice per CPU hotplug event but the operation isn't that heavy and a lot of the second operation would be noop for systems w/ single sched domain, which is the common case. This decouples cpuset hotplug handling from the notification callbacks and there can be an arbitrary delay between the actual event and updates to cpusets. Scheduler and mm can handle it fine but moving tasks out of an empty cpuset may race against writes to the cpuset restoring execution resources which can lead to confusing behavior. Flush hotplug work item from cpuset_write_resmask() to avoid such confusions. v2: Synchronous sched domain rebuilding using the fallback sched domain added. This fixes various issues caused by confused scheduler putting tasks on a dead CPU, including the one reported by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: reorganize CPU / memory hotplug handlingTejun Heo
Reorganize hotplug path to prepare for async hotplug handling. * Both CPU and memory hotplug handlings are collected into a single function - cpuset_handle_hotplug(). It doesn't take any argument but compares the current setttings of top_cpuset against what's actually available to determine what happened. This function directly updates top_cpuset. If there are CPUs or memory nodes which are taken down, cpuset_propagate_hotplug() in invoked on all !root cpusets. * cpuset_propagate_hotplug() is responsible for updating the specified cpuset so that it doesn't include any resource which isn't available to top_cpuset. If no CPU or memory is left after update, all tasks are moved to the nearest ancestor with both resources. * update_tasks_cpumask() and update_tasks_nodemask() are now always called after cpus or mems masks are updated even if the cpuset doesn't have any task. This is for brevity and not expected to have any measureable effect. * cpu_active_mask and N_HIGH_MEMORY are read exactly once per cpuset_handle_hotplug() invocation, all cpusets share the same view of what resources are available, and cpuset_handle_hotplug() can handle multiple resources going up and down. These properties will allow async operation. The reorganization, while drastic, is equivalent and shouldn't cause any behavior difference. This will enable making hotplug handling async and remove get_online_cpus() -> cgroup_mutex nesting. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: cleanup cpuset[_can]_attach()Tejun Heo
cpuset_can_attach() prepare global variables cpus_attach and cpuset_attach_nodemask_{to|from} which are used by cpuset_attach(). There is no reason to prepare in cpuset_can_attach(). The same information can be accessed from cpuset_attach(). Move the prepartion logic from cpuset_can_attach() to cpuset_attach() and make the global variables static ones inside cpuset_attach(). With this change, there's no reason to keep cpuset_attach_nodemask_{from|to} global. Move them inside cpuset_attach(). Unfortunately, we need to keep cpus_attach global as it can't be allocated from cpuset_attach(). v2: cpus_attach not converted to cpumask_t as per Li Zefan and Rusty Russell. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Rusty Russell <rusty@rustcorp.com.au>
2013-01-07cpuset: introduce cpuset_for_each_child()Tejun Heo
Instead of iterating cgroup->children directly, introduce and use cpuset_for_each_child() which wraps cgroup_for_each_child() and performs online check. As it uses the generic iterator, it requires RCU read locking too. As cpuset is currently protected by cgroup_mutex, non-online cpusets aren't visible to all the iterations and this patch currently doesn't make any functional difference. This will be used to de-couple cpuset locking from cgroup core. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: introduce CS_ONLINETejun Heo
Add CS_ONLINE which is set from css_online() and cleared from css_offline(). This will enable using generic cgroup iterator while allowing decoupling cpuset from cgroup internal locking. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: introduce ->css_on/offline()Tejun Heo
Add cpuset_css_on/offline() and rearrange css init/exit such that, * Allocation and clearing to the default values happen in css_alloc(). Allocation now uses kzalloc(). * Config inheritance and registration happen in css_online(). * css_offline() undoes what css_online() did. * css_free() frees. This doesn't introduce any visible behavior changes. This will help cleaning up locking. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: remove fast exit path from remove_tasks_in_empty_cpuset()Tejun Heo
The function isn't that hot, the overhead of missing the fast exit is low, the test itself depends heavily on cgroup internals, and it's gonna be a hindrance when trying to decouple cpuset locking from cgroup core. Remove the fast exit path. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: remove unused cpuset_unlock()Tejun Heo
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cgroup: implement cgroup_rightmost_descendant()Tejun Heo
Implement cgroup_rightmost_descendant() which returns the right most descendant of the specified cgroup. This can be used to skip the cgroup's subtree while iterating with cgroup_for_each_descendant_pre(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com>
2012-12-25pidns: Stop pid allocation when init diesEric W. Biederman
Oleg pointed out that in a pid namespace the sequence. - pid 1 becomes a zombie - setns(thepidns), fork,... - reaping pid 1. - The injected processes exiting. Can lead to processes attempting access their child reaper and instead following a stale pointer. That waitpid for init can return before all of the processes in the pid namespace have exited is also unfortunate. Avoid these problems by disabling the allocation of new pids in a pid namespace when init dies, instead of when the last process in a pid namespace is reaped. Pointed-out-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-12-24pidns: Outlaw thread creation after unshare(CLONE_NEWPID)Eric W. Biederman
The sequence: unshare(CLONE_NEWPID) clone(CLONE_THREAD|CLONE_SIGHAND|CLONE_VM) Creates a new process in the new pid namespace without setting pid_ns->child_reaper. After forking this results in a NULL pointer dereference. Avoid this and other nonsense scenarios that can show up after creating a new pid namespace with unshare by adding a new check in copy_prodcess. Pointed-out-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-12-20Merge branch 'for-next' of git://git.infradead.org/users/eparis/notifyLinus Torvalds
Pull filesystem notification updates from Eric Paris: "This pull mostly is about locking changes in the fsnotify system. By switching the group lock from a spin_lock() to a mutex() we can now hold the lock across things like iput(). This fixes a problem involving unmounting a fs and having inodes be busy, first pointed out by FAT, but reproducible with tmpfs. This also restores signal driven I/O for inotify, which has been broken since about 2.6.32." Ugh. I *hate* the timing of this. It was rebased after the merge window opened, and then left to sit with the pull request coming the day before the merge window closes. That's just crap. But apparently the patches themselves have been around for over a year, just gathering dust, so now it's suddenly critical. Fixed up semantic conflict in fs/notify/fdinfo.c as per Stephen Rothwell's fixes from -next. * 'for-next' of git://git.infradead.org/users/eparis/notify: inotify: automatically restart syscalls inotify: dont skip removal of watch descriptor if creation of ignored event failed fanotify: dont merge permission events fsnotify: make fasync generic for both inotify and fanotify fsnotify: change locking order fsnotify: dont put marks on temporary list when clearing marks by group fsnotify: introduce locked versions of fsnotify_add_mark() and fsnotify_remove_mark() fsnotify: pass group to fsnotify_destroy_mark() fsnotify: use a mutex instead of a spinlock to protect a groups mark list fanotify: add an extra flag to mark_remove_from_mask that indicates wheather a mark should be destroyed fsnotify: take groups mark_lock before mark lock fsnotify: use reference counting for groups fsnotify: introduce fsnotify_get_group() inotify, fanotify: replace fsnotify_put_group() with fsnotify_destroy_group()
2012-12-20Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
Merge the rest of Andrew's patches for -rc1: "A bunch of fixes and misc missed-out-on things. That'll do for -rc1. I still have a batch of IPC patches which still have a possible bug report which I'm chasing down." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (25 commits) keys: use keyring_alloc() to create module signing keyring keys: fix unreachable code sendfile: allows bypassing of notifier events SGI-XP: handle non-fatal traps fat: fix incorrect function comment Documentation: ABI: remove testing/sysfs-devices-node proc: fix inconsistent lock state linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors memcg: don't register hotcpu notifier from ->css_alloc() checkpatch: warn on uapi #includes that #include <uapi/... revert "rtc: recycle id when unloading a rtc driver" mm: clean up transparent hugepage sysfs error messages hfsplus: add error message for the case of failure of sync fs in delayed_sync_fs() method hfsplus: rework processing of hfs_btree_write() returned error hfsplus: rework processing errors in hfsplus_free_extents() hfsplus: avoid crash on failed block map free kcmp: include linux/ptrace.h drivers/rtc/rtc-imxdi.c: must include <linux/spinlock.h> mm: cma: WARN if freed memory is still in use exec: do not leave bprm->interp on stack ...
2012-12-20Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "sigaltstack infrastructure + conversion for x86, alpha and um, COMPAT_SYSCALL_DEFINE infrastructure. Note that there are several conflicts between "unify SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline; resolution is trivial - just remove definitions of SS_ONSTACK and SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and include/uapi/linux/signal.h contains the unified variant." Fixed up conflicts as per Al. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to generic sigaltstack new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those generic compat_sys_sigaltstack() introduce generic sys_sigaltstack(), switch x86 and um to it new helper: compat_user_stack_pointer() new helper: restore_altstack() unify SS_ONSTACK/SS_DISABLE definitions new helper: current_user_stack_pointer() missing user_stack_pointer() instances Bury the conditionals from kernel_thread/kernel_execve series COMPAT_SYSCALL_DEFINE: infrastructure
2012-12-20keys: use keyring_alloc() to create module signing keyringDavid Howells
Use keyring_alloc() to create special keyrings now that it has a permissions parameter rather than using key_alloc() + key_instantiate_and_link(). Signed-off-by: David Howells <dhowells@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20kcmp: include linux/ptrace.hCyrill Gorcunov
This makes it compile on s390. After all the ptrace_may_access (which we use this file) is declared exactly in linux/ptrace.h. This is preparatory work to wire this syscall up on all archs. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20sched: numa: ksm: fix oops in task_numa_placment()Hugh Dickins
task_numa_placement() oopsed on NULL p->mm when task_numa_fault() got called in the handling of break_ksm() for ksmd. That might be a peculiar case, which perhaps KSM could takes steps to avoid? but it's more robust if task_numa_placement() allows for such a possibility. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-19Merge tag 'random_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull random updates from Ted Ts'o: "A few /dev/random improvements for the v3.8 merge window." * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: random: Mix cputime from each thread that exits to the pool random: prime last_data value per fips requirements random: fix debug format strings random: make it possible to enable debugging without rebuild
2012-12-19new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to thoseAl Viro
note that they are relying on access_ok() already checked by caller. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19generic compat_sys_sigaltstack()Al Viro
Again, conditional on CONFIG_GENERIC_SIGALTSTACK Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19introduce generic sys_sigaltstack(), switch x86 and um to itAl Viro
Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not select it are completely unaffected Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19new helper: restore_altstack()Al Viro
to be used by rt_sigreturn instances Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19Bury the conditionals from kernel_thread/kernel_execve seriesAl Viro
All architectures have CONFIG_GENERIC_KERNEL_THREAD CONFIG_GENERIC_KERNEL_EXECVE __ARCH_WANT_SYS_EXECVE None of them have __ARCH_WANT_KERNEL_EXECVE and there are only two callers of kernel_execve() (which is a trivial wrapper for do_execve() now) left. Kill the conditionals and make both callers use do_execve(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19watchdog: Fix disable/enable regressionBjørn Mork
Commit 8d4516904b39 ("watchdog: Fix CPU hotplug regression") causes an oops or hard lockup when doing echo 0 > /proc/sys/kernel/nmi_watchdog echo 1 > /proc/sys/kernel/nmi_watchdog and the kernel is booted with nmi_watchdog=1 (default) Running laptop-mode-tools and disconnecting/connecting AC power will cause this to trigger, making it a common failure scenario on laptops. Instead of bailing out of watchdog_disable() when !watchdog_enabled we can initialize the hrtimer regardless of watchdog_enabled status. This makes it safe to call watchdog_disable() in the nmi_watchdog=0 case, without the negative effect on the enabled => disabled => enabled case. All these tests pass with this patch: - nmi_watchdog=1 echo 0 > /proc/sys/kernel/nmi_watchdog echo 1 > /proc/sys/kernel/nmi_watchdog - nmi_watchdog=0 echo 0 > /sys/devices/system/cpu/cpu1/online - nmi_watchdog=0 echo mem > /sys/power/state Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=51661 Cc: <stable@vger.kernel.org> # v3.7 Cc: Norbert Warmuth <nwarmuth@t-online.de> Cc: Joseph Salisbury <joseph.salisbury@canonical.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-19Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module update from Rusty Russell: "Nothing all that exciting; a new module-from-fd syscall for those who want to verify the source of the module (ChromeOS) and/or use standard IMA on it or other security hooks." * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: MODSIGN: Fix kbuild output when using default extra_certificates MODSIGN: Avoid using .incbin in C source modules: don't hand 0 to vmalloc. module: Remove a extra null character at the top of module->strtab. ASN.1: Use the ASN1_LONG_TAG and ASN1_INDEFINITE_LENGTH constants ASN.1: Define indefinite length marker constant moduleparam: use __UNIQUE_ID() __UNIQUE_ID() MODSIGN: Add modules_sign make target powerpc: add finit_module syscall. ima: support new kernel module syscall add finit_module syscall to asm-generic ARM: add finit_module syscall to ARM security: introduce kernel_module_from_file hook module: add flags arg to sys_finit_module() module: add syscall to load module from fd
2012-12-18Merge branch 'akpm' (more patches from Andrew)Linus Torvalds
Merge patches from Andrew Morton: "Most of the rest of MM, plus a few dribs and drabs. I still have quite a few irritating patches left around: ones with dubious testing results, lack of review, ones which should have gone via maintainer trees but the maintainers are slack, etc. I need to be more activist in getting these things wrapped up outside the merge window, but they're such a PITA." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (48 commits) mm/vmscan.c: avoid possible deadlock caused by too_many_isolated() vmscan: comment too_many_isolated() mm/kmemleak.c: remove obsolete simple_strtoul mm/memory_hotplug.c: improve comments mm/hugetlb: create hugetlb cgroup file in hugetlb_init mm/mprotect.c: coding-style cleanups Documentation: ABI: /sys/devices/system/node/ slub: drop mutex before deleting sysfs entry memcg: add comments clarifying aspects of cache attribute propagation kmem: add slab-specific documentation about the kmem controller slub: slub-specific propagation changes slab: propagate tunable values memcg: aggregate memcg cache values in slabinfo memcg/sl[au]b: shrink dead caches memcg/sl[au]b: track all the memcg children of a kmem_cache memcg: destroy memcg caches sl[au]b: allocate objects from memcg cache sl[au]b: always get the cache from its page in kmem_cache_free() memcg: skip memcg kmem allocations in specified code regions memcg: infrastructure to match an allocation to the right cache ...
2012-12-18fork: protect architectures where THREAD_SIZE >= PAGE_SIZE against fork bombsGlauber Costa
Because those architectures will draw their stacks directly from the page allocator, rather than the slab cache, we can directly pass __GFP_KMEMCG flag, and issue the corresponding free_pages. This code path is taken when the architecture doesn't define CONFIG_ARCH_THREAD_INFO_ALLOCATOR (only ia64 seems to), and has THREAD_SIZE >= PAGE_SIZE. Luckily, most - if not all - of the remaining architectures fall in this category. This will guarantee that every stack page is accounted to the memcg the process currently lives on, and will have the allocations to fail if they go over limit. For the time being, I am defining a new variant of THREADINFO_GFP, not to mess with the other path. Once the slab is also tracked by memcg, we can get rid of that flag. Tested to successfully protect against :(){ :|:& };: Signed-off-by: Glauber Costa <glommer@parallels.com> Acked-by: Frederic Weisbecker <fweisbec@redhat.com> Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: JoonSoo Kim <js1304@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Rik van Riel <riel@redhat.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18res_counter: return amount of charges after res_counter_uncharge()Glauber Costa
It is useful to know how many charges are still left after a call to res_counter_uncharge. While it is possible to issue a res_counter_read after uncharge, this can be racy. If we need, for instance, to take some action when the counters drop down to 0, only one of the callers should see it. This is the same semantics as the atomic variables in the kernel. Since the current return value is void, we don't need to worry about anything breaking due to this change: nobody relied on that, and only users appearing from now on will be checking this value. Signed-off-by: Glauber Costa <glommer@parallels.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Frederic Weisbecker <fweisbec@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: JoonSoo Kim <js1304@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18irq: tsk->comm is an arrayAlan Cox
The array check is useless so remove it. [akpm@linux-foundation.org: remove comment, per David] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18Merge branch 'tip/perf/core-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull minor tracing updates and fixes from Steven Rostedt: "It seems that one of my old pull requests have slipped through. The changes are contained to just the files that I maintain, and are changes from others that I told I would get into this merge window. They have already been in linux-next for several weeks, and should be well tested." * 'tip/perf/core-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Remove unnecessary WARN_ONCE's from tracing_buffers_splice_read tracing: Remove unneeded checks from the stack tracer tracing: Add a resize function to make one buffer equivalent to another buffer
2012-12-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull (again) user namespace infrastructure changes from Eric Biederman: "Those bugs, those darn embarrasing bugs just want don't want to get fixed. Linus I just updated my mirror of your kernel.org tree and it appears you successfully pulled everything except the last 4 commits that fix those embarrasing bugs. When you get a chance can you please repull my branch" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: userns: Fix typo in description of the limitation of userns_install userns: Add a more complete capability subset test to commit_creds userns: Require CAP_SYS_ADMIN for most uses of setns. Fix cap_capable to only allow owners in the parent user namespace to have caps.
2012-12-17Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
Merge misc patches from Andrew Morton: "Incoming: - lots of misc stuff - backlight tree updates - lib/ updates - Oleg's percpu-rwsem changes - checkpatch - rtc - aoe - more checkpoint/restart support I still have a pile of MM stuff pending - Pekka should be merging later today after which that is good to go. A number of other things are twiddling thumbs awaiting maintainer merges." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (180 commits) scatterlist: don't BUG when we can trivially return a proper error. docs: update documentation about /proc/<pid>/fdinfo/<fd> fanotify output fs, fanotify: add @mflags field to fanotify output docs: add documentation about /proc/<pid>/fdinfo/<fd> output fs, notify: add procfs fdinfo helper fs, exportfs: add exportfs_encode_inode_fh() helper fs, exportfs: escape nil dereference if no s_export_op present fs, epoll: add procfs fdinfo helper fs, eventfd: add procfs fdinfo helper procfs: add ability to plug in auxiliary fdinfo providers tools/testing/selftests/kcmp/kcmp_test.c: print reason for failure in kcmp_test breakpoint selftests: print failure status instead of cause make error kcmp selftests: print fail status instead of cause make error kcmp selftests: make run_tests fix mem-hotplug selftests: print failure status instead of cause make error cpu-hotplug selftests: print failure status instead of cause make error mqueue selftests: print failure status instead of cause make error vm selftests: print failure status instead of cause make error ubifs: use prandom_bytes mtd: nandsim: use prandom_bytes ...
2012-12-17pidns: remove unused is_container_init()Gao feng
Since commit 1cdcbec1a337 ("CRED: Neuter sys_capset()") is_container_init() has no callers. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Cc: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: James Morris <jmorris@namei.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17ptrace: introduce PTRACE_O_EXITKILLOleg Nesterov
Ptrace jailers want to be sure that the tracee can never escape from the control. However if the tracer dies unexpectedly the tracee continues to run in potentially unsafe mode. Add the new ptrace option PTRACE_O_EXITKILL. If the tracer exits it sends SIGKILL to every tracee which has this bit set. Note that the new option is not equal to the last-option << 1. Because currently all options have an event, and the new one starts the eventless group. It uses the random 20 bit, so we have the room for 12 more events, but we can also add the new eventless options below this one. Suggested by Amnon Shiloh. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Amnon Shiloh <u3557@miso.sublimeip.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Chris Evans <scarybeasts@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17compat: generic compat_sys_sched_rr_get_interval() implementationCatalin Marinas
This function is used by sparc, powerpc tile and arm64 for compat support. The patch adds a generic implementation with a wrapper for PowerPC to do the u32->int sign extension. The reason for a single patch covering powerpc, tile, sparc and arm64 is to keep it bisectable, otherwise kernel building may fail with mismatched function declarations. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile] Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17trace: use kbasename()Andy Shevchenko
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17printk: boot_delay should only affect outputAndrew Cooks
The boot_delay parameter affects all printk(), even if the log level prevents visible output from the call. It results in delays greater than the user intended without purpose. This patch changes the behaviour of boot_delay to only delay output. Signed-off-by: Andrew Cooks <acooks@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17watchdog: store the watchdog sample period as a variableChuansheng Liu
Currently getting the sample period is always thru a complex calculation: get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5). We can store the sample period as a variable, and set it as __read_mostly type. Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Cc: Don Zickus <dzickus@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17lseek: the "whence" argument is called "whence"Andrew Morton
But the kernel decided to call it "origin" instead. Fix most of the sites. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17kernel: remove reference to feature-removal-schedule.txtTao Ma
In commit 9c0ece069b32 ("Get rid of Documentation/feature-removal.txt"), Linus removed feature-removal-schedule.txt from Documentation, but there is still some reference to this file. So remove them. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace changes from Eric Biederman: "While small this set of changes is very significant with respect to containers in general and user namespaces in particular. The user space interface is now complete. This set of changes adds support for unprivileged users to create user namespaces and as a user namespace root to create other namespaces. The tyranny of supporting suid root preventing unprivileged users from using cool new kernel features is broken. This set of changes completes the work on setns, adding support for the pid, user, mount namespaces. This set of changes includes a bunch of basic pid namespace cleanups/simplifications. Of particular significance is the rework of the pid namespace cleanup so it no longer requires sending out tendrils into all kinds of unexpected cleanup paths for operation. At least one case of broken error handling is fixed by this cleanup. The files under /proc/<pid>/ns/ have been converted from regular files to magic symlinks which prevents incorrect caching by the VFS, ensuring the files always refer to the namespace the process is currently using and ensuring that the ptrace_mayaccess permission checks are always applied. The files under /proc/<pid>/ns/ have been given stable inode numbers so it is now possible to see if different processes share the same namespaces. Through the David Miller's net tree are changes to relax many of the permission checks in the networking stack to allowing the user namespace root to usefully use the networking stack. Similar changes for the mount namespace and the pid namespace are coming through my tree. Two small changes to add user namespace support were commited here adn in David Miller's -net tree so that I could complete the work on the /proc/<pid>/ns/ files in this tree. Work remains to make it safe to build user namespaces and 9p, afs, ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the Kconfig guard remains in place preventing that user namespaces from being built when any of those filesystems are enabled. Future design work remains to allow root users outside of the initial user namespace to mount more than just /proc and /sys." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits) proc: Usable inode numbers for the namespace file descriptors. proc: Fix the namespace inode permission checks. proc: Generalize proc inode allocation userns: Allow unprivilged mounts of proc and sysfs userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file procfs: Print task uids and gids in the userns that opened the proc file userns: Implement unshare of the user namespace userns: Implent proc namespace operations userns: Kill task_user_ns userns: Make create_new_namespaces take a user_ns parameter userns: Allow unprivileged use of setns. userns: Allow unprivileged users to create new namespaces userns: Allow setting a userns mapping to your current uid. userns: Allow chown and setgid preservation userns: Allow unprivileged users to create user namespaces. userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped userns: fix return value on mntns_install() failure vfs: Allow unprivileged manipulation of the mount namespace. vfs: Only support slave subtrees across different user namespaces vfs: Add a user namespace reference from struct mnt_namespace ...
2012-12-17sched: numa: Fix build error if CONFIG_NUMA_BALANCING && ↵Mel Gorman
!CONFIG_TRANSPARENT_HUGEPAGE Michal Hocko reported that the following build error occurs if CONFIG_NUMA_BALANCING is set without THP support kernel/sched/fair.c: In function ‘task_numa_work’: kernel/sched/fair.c:932:55: error: call to ‘__build_bug_failed’ declared with attribute error: BUILD_BUG failed The problem is that HPAGE_PMD_SHIFT triggers a BUILD_BUG() on !CONFIG_TRANSPARENT_HUGEPAGE. This patch addresses the problem. Reported-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-16random: Mix cputime from each thread that exits to the poolNick Kossifidis
When a thread exits mix it's cputime (userspace + kernelspace) to the entropy pool. We don't know how "random" this is, so we use add_device_randomness that doesn't mess with entropy count. Signed-off-by: Nick Kossifidis <mickflemm@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2012-12-16Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "A quiet cycle for the security subsystem with just a few maintenance updates." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: Smack: create a sysfs mount point for smackfs Smack: use select not depends in Kconfig Yama: remove locking from delete path Yama: add RCU to drop read locking drivers/char/tpm: remove tasklet and cleanup KEYS: Use keyring_alloc() to create special keyrings KEYS: Reduce initial permissions on keys KEYS: Make the session and process keyrings per-thread seccomp: Make syscall skipping and nr changes more consistent key: Fix resource leak keys: Fix unreachable code KEYS: Add payload preparsing opportunity prior to key instantiate or update
2012-12-16Merge tag 'balancenuma-v11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux-balancenuma Pull Automatic NUMA Balancing bare-bones from Mel Gorman: "There are three implementations for NUMA balancing, this tree (balancenuma), numacore which has been developed in tip/master and autonuma which is in aa.git. In almost all respects balancenuma is the dumbest of the three because its main impact is on the VM side with no attempt to be smart about scheduling. In the interest of getting the ball rolling, it would be desirable to see this much merged for 3.8 with the view to building scheduler smarts on top and adapting the VM where required for 3.9. The most recent set of comparisons available from different people are mel: https://lkml.org/lkml/2012/12/9/108 mingo: https://lkml.org/lkml/2012/12/7/331 tglx: https://lkml.org/lkml/2012/12/10/437 srikar: https://lkml.org/lkml/2012/12/10/397 The results are a mixed bag. In my own tests, balancenuma does reasonably well. It's dumb as rocks and does not regress against mainline. On the other hand, Ingo's tests shows that balancenuma is incapable of converging for this workloads driven by perf which is bad but is potentially explained by the lack of scheduler smarts. Thomas' results show balancenuma improves on mainline but falls far short of numacore or autonuma. Srikar's results indicate we all suffer on a large machine with imbalanced node sizes. My own testing showed that recent numacore results have improved dramatically, particularly in the last week but not universally. We've butted heads heavily on system CPU usage and high levels of migration even when it shows that overall performance is better. There are also cases where it regresses. Of interest is that for specjbb in some configurations it will regress for lower numbers of warehouses and show gains for higher numbers which is not reported by the tool by default and sometimes missed in treports. Recently I reported for numacore that the JVM was crashing with NullPointerExceptions but currently it's unclear what the source of this problem is. Initially I thought it was in how numacore batch handles PTEs but I'm no longer think this is the case. It's possible numacore is just able to trigger it due to higher rates of migration. These reports were quite late in the cycle so I/we would like to start with this tree as it contains much of the code we can agree on and has not changed significantly over the last 2-3 weeks." * tag 'balancenuma-v11' of git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux-balancenuma: (50 commits) mm/rmap, migration: Make rmap_walk_anon() and try_to_unmap_anon() more scalable mm/rmap: Convert the struct anon_vma::mutex to an rwsem mm: migrate: Account a transhuge page properly when rate limiting mm: numa: Account for failed allocations and isolations as migration failures mm: numa: Add THP migration for the NUMA working set scanning fault case build fix mm: numa: Add THP migration for the NUMA working set scanning fault case. mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node mm: sched: numa: Control enabling and disabling of NUMA balancing if !SCHED_DEBUG mm: sched: numa: Control enabling and disabling of NUMA balancing mm: sched: Adapt the scanning rate if a NUMA hinting fault does not migrate mm: numa: Use a two-stage filter to restrict pages being migrated for unlikely task<->node relationships mm: numa: migrate: Set last_nid on newly allocated page mm: numa: split_huge_page: Transfer last_nid on tail page mm: numa: Introduce last_nid to the page frame sched: numa: Slowly increase the scanning period as NUMA faults are handled mm: numa: Rate limit setting of pte_numa if node is saturated mm: numa: Rate limit the amount of memory that is migrated between nodes mm: numa: Structures for Migrate On Fault per NUMA migration rate limiting mm: numa: Migrate pages handled during a pmd_numa hinting fault mm: numa: Migrate on reference policy ...
2012-12-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds
Pull crypto update from Herbert Xu: - Added aesni/avx/x86_64 implementations for camellia. - Optimised AVX code for cast5/serpent/twofish/cast6. - Fixed vmac bug with unaligned input. - Allow compression algorithms in FIPS mode. - Optimised crc32c implementation for Intel. - Misc fixes. * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (32 commits) crypto: caam - Updated SEC-4.0 device tree binding for ERA information. crypto: testmgr - remove superfluous initializers for xts(aes) crypto: testmgr - allow compression algs in fips mode crypto: testmgr - add larger crc32c test vector to test FPU path in crc32c_intel crypto: testmgr - clean alg_test_null entries in alg_test_descs[] crypto: testmgr - remove fips_allowed flag from camellia-aesni null-tests crypto: cast5/cast6 - move lookup tables to shared module padata: use __this_cpu_read per-cpu helper crypto: s5p-sss - Fix compilation error crypto: picoxcell - Add terminating entry for platform_device_id table crypto: omap-aes - select BLKCIPHER2 crypto: camellia - add AES-NI/AVX/x86_64 assembler implementation of camellia cipher crypto: camellia-x86_64 - share common functions and move structures and function definitions to header file crypto: tcrypt - add async speed test for camellia cipher crypto: tegra-aes - fix error-valued pointer dereference crypto: tegra - fix missing unlock on error case crypto: cast5/avx - avoid using temporary stack buffers crypto: serpent/avx - avoid using temporary stack buffers crypto: twofish/avx - avoid using temporary stack buffers crypto: cast6/avx - avoid using temporary stack buffers ...