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2013-01-08tracing: Export trace_clock_local()Paul E. McKenney
The rcutorture tests need to be able to trace the time of the beginning of an RCU read-side critical section, and thus need access to trace_clock_local(). This commit therefore adds a the needed EXPORT_SYMBOL_GPL(). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-01-08rcu: Make rcu_nocb_poll an early_param instead of module_paramPaul Gortmaker
The as-documented rcu_nocb_poll will fail to enable this feature for two reasons. (1) there is an extra "s" in the documented name which is not in the code, and (2) since it uses module_param, it really is expecting a prefix, akin to "rcutree.fanout_leaf" and the prefix isn't documented. However, there are several reasons why we might not want to simply fix the typo and add the prefix: 1) we'd end up with rcutree.rcu_nocb_poll, and rather probably make a change to rcutree.nocb_poll 2) if we did #1, then the prefix wouldn't be consistent with the rcu_nocbs=<cpumap> parameter (i.e. one with, one without prefix) 3) the use of module_param in a header file is less than desired, since it isn't immediately obvious that it will get processed via rcutree.c and get the prefix from that (although use of module_param_named() could clarify that.) 4) the implied export of /sys/module/rcutree/parameters/rcu_nocb_poll data to userspace via module_param() doesn't really buy us anything, as it is read-only and we can tell if it is enabled already without it, since there is a printk at early boot telling us so. In light of all that, just change it from a module_param() to an early_setup() call, and worry about adding it to /sys later on if we decide to allow a dynamic setting of it. Also change the variable to be tagged as read_mostly, since it will only ever be fiddled with at most, once at boot. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-01-08rcu: Prevent soft-lockup complaints about no-CBs CPUsPaul Gortmaker
The wait_event() at the head of the rcu_nocb_kthread() can result in soft-lockup complaints if the CPU in question does not register RCU callbacks for an extended period. This commit therefore changes the wait_event() to a wait_event_interruptible(). Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-01-08Merge tag 'swarren-for-3.9-arm-timer-rework' of ↵Olof Johansson
git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra into next/cleanup From Stephen Warren: ARM/...: timer and clock events cleanup, and remove struct sys_timer This branch contains a number of cleanups and unifications to various timer- clock-events- and ARM timer code. The main points are: 1) Convert arch_gettimeoffset to a pointer, so that architectures with multiple timer implementations can simply set this standard pointer rather than maintaining their own arch-specific pointers for the same purpose. Various architectures are converted to using this new feature. 2) Conversion of ARM timer implementations to use clock_event_devices's suspend/resume operations, rather than the ARM-specific sys_timer versions. Thus, the ARM code begins to use more common infra-structure rather than arch-specific code. 3) Removal of ARM's struct sys_timer completely, now that everything uses common code. 4) Introduction of drivers/clocksource/clksrc-of.c, which allows ARM clock source implementations to be moved into drivers/clocksource, with the need to add SoC-specific header files for each timer initialization function; instead, all enabled implementations are registered into a table which a single core function iterates over, and calls the relevant initialization functions based on device tree. At least the Tegra and BCM2835 clocksource implementations will use this feature in the 3.9 kernel cycle. * tag 'swarren-for-3.9-arm-timer-rework' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra: clocksource: add common of_clksrc_init() function ARM: delete struct sys_timer ARM: remove struct sys_timer suspend and resume fields ARM: samsung: register syscore_ops for timer resume directly ARM: ux500: convert timer suspend/resume to clock_event_device ARM: sa1100: convert timer suspend/resume to clock_event_device ARM: pxa: convert timer suspend/resume to clock_event_device ARM: at91: convert timer suspend/resume to clock_event_device ARM: set arch_gettimeoffset directly m68k: set arch_gettimeoffset directly time: convert arch_gettimeoffset to a pointer cris: move usec/nsec conversion to do_slow_gettimeoffset Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-07cpuset: remove cpuset->parentTejun Heo
cgroup already tracks the hierarchy. Follow cgroup->parent to find the parent and drop cpuset->parent. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: replace cpuset->stack_list with cpuset_for_each_descendant_pre()Tejun Heo
Implement cpuset_for_each_descendant_pre() and replace the cpuset-specific tree walking using cpuset->stack_list with it. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com>
2013-01-07cpuset: replace cgroup_mutex locking with cpuset internal lockingTejun Heo
Supposedly for historical reasons, cpuset depends on cgroup core for locking. It depends on cgroup_mutex in cgroup callbacks and grabs cgroup_mutex from other places where it wants to be synchronized. This is majorly messy and highly prone to introducing circular locking dependency especially because cgroup_mutex is supposed to be one of the outermost locks. As previous patches already plugged possible races which may happen by decoupling from cgroup_mutex, replacing cgroup_mutex with cpuset specific cpuset_mutex is mostly straight-forward. Introduce cpuset_mutex, replace all occurrences of cgroup_mutex with it, and add cpuset_mutex locking to places which inherited cgroup_mutex from cgroup core. The only complication is from cpuset wanting to initiate task migration when a cpuset loses all cpus or memory nodes. Task migration may go through full cgroup and all subsystem locking and should be initiated without holding any cpuset specific lock; however, a previous patch already made hotplug handled asynchronously and moving the task migration part outside other locks is easy. cpuset_propagate_hotplug_workfn() now invokes remove_tasks_in_empty_cpuset() without holding any lock. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
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>
2013-01-07Merge branch 'akpm' (fixes from Andrew)Linus Torvalds
Merge emailed fixes from Andrew Morton: "Bunch of fixes: - delayed IPC updates. I held back on this because of some possible outstanding bug reports, but they appear to have been addressed in later versions - A bunch of MAINTAINERS updates - Yet Another RTC driver. I'd held this back while a couple of little issues were being worked out. I'm expecting an intrusive-but-simple patchset from Joe Perches which splits up printk.c into kernel/printk/*. That will be a pig to maintain for two months so if it passes testing I'd like to get it upstream after a week or so." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits) printk: fix incorrect length from print_time() when seconds > 99999 drivers/rtc/rtc-vt8500.c: fix handling of data passed in struct rtc_time drivers/rtc/rtc-vt8500.c: correct handling of CR_24H bitfield rtc: add RTC driver for TPS6586x MAINTAINERS: fix drivers/staging/sm7xx/ MAINTAINERS: remove include/linux/of_pwm.h MAINTAINERS: remove arch/*/lib/perf_event*.c MAINTAINERS: remove drivers/mmc/host/imxmmc.* MAINTAINERS: fix Documentation/mei/ MAINTAINERS: remove arch/x86/platform/mrst/pmu.* MAINTAINERS: remove firmware/isci/ MAINTAINERS: fix drivers/ieee802154/ MAINTAINERS: fix .../plat-mxc/include/mach/imxfb.h MAINTAINERS: remove drivers/video/epson1355fb.c MAINTAINERS: fix drivers/media/usb/dvb-usb/cxusb* MAINTAINERS: adjust for UAPI MAINTAINERS: fix drivers/media/platform/atmel-isi.c MAINTAINERS: fix arch/arm/mach-at91/include/mach/at_hdmac.h MAINTAINERS: fix drivers/rtc/rtc-vt8500.c MAINTAINERS: remove arch/arm/plat-s5p/ ...
2013-01-05signals: set_current_blocked() can use __set_current_blocked()Oleg Nesterov
Cleanup. And I think we need more cleanups, in particular __set_current_blocked() and sigprocmask() should die. Nobody should ever block SIGKILL or SIGSTOP. - Change set_current_blocked() to use __set_current_blocked() - Change sys_sigprocmask() to use set_current_blocked(), this way it should not worry about SIGKILL/SIGSTOP. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-05signals: sys_ssetmask() uses uninitialized newmaskOleg Nesterov
Commit 77097ae503b1 ("most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set") removed the initialization of newmask by accident, causing ltp to complain like this: ssetmask01 1 TFAIL : sgetmask() failed: TEST_ERRNO=???(0): Success Restore the proper initialization. Reported-and-tested-by: CAI Qian <caiqian@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org # v3.5+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04printk: fix incorrect length from print_time() when seconds > 99999Roland Dreier
print_prefix() passes a NULL buf to print_time() to get the length of the time prefix; when printk times are enabled, the current code just returns the constant 15, which matches the format "[%5lu.%06lu] " used to print the time value. However, this is obviously incorrect when the whole seconds part of the time gets beyond 5 digits (100000 seconds is a bit more than a day of uptime). The simple fix is to use snprintf(NULL, 0, ...) to calculate the actual length of the time prefix. This could be micro-optimized but it seems better to have simpler, more readable code here. The bug leads to the syslog system call miscomputing which messages fit into the userspace buffer. If there are enough messages to fill log_buf_len and some have a timestamp >= 100000, dmesg may fail with: # dmesg klogctl: Bad address When this happens, strace shows that the failure is indeed EFAULT due to the kernel mistakenly accessing past the end of dmesg's buffer, since dmesg asks the kernel how big a buffer it needs, allocates a bit more, and then gets an error when it asks the kernel to fill it: syslog(0xa, 0, 0) = 1048576 mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fa4d25d2000 syslog(0x3, 0x7fa4d25d2010, 0x100008) = -1 EFAULT (Bad address) As far as I can see, the bug has been there as long as print_time(), which comes from commit 084681d14e42 ("printk: flush continuation lines immediately to console") in 3.5-rc5. Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Cc: Sylvain Munaut <s.munaut@whatever-company.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-03module: prevent warning when finit_module a 0 sized fileSasha Levin
If we try to finit_module on a file sized 0 bytes vmalloc will scream and spit out a warning. Since modules have to be bigger than 0 bytes anyways we can just check that beforehand and avoid the warning. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-26userns: Allow unprivileged rebootLi Zefan
In a container with its own pid namespace and user namespace, rebooting the system won't reboot the host, but terminate all the processes in it and thus have the container shutdown, so it's safe. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-12-26x32: fix sigtimedwaitAl Viro
It needs 64bit timespec. As it is, we end up truncating the timeout to whole seconds; usually it doesn't matter, but for having all sub-second timeouts truncated to one jiffy is visibly wrong. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26x32: fix waitid()Al Viro
It needs 64bit rusage and 32bit siginfo. glibc never calls it with non-NULL rusage pointer, or we would've seen breakage already... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINEAl Viro
Strictly speaking, ppc64 needs it for C ABI compliance. Realistically I would be very surprised if e.g. passing 0xffffffff as 'options' argument to waitid() from 32bit task would cause problems, but yes, it puts us into undefined behaviour territory. ppc64 expects int argument to be passed in 64bit register with bits 31..63 containing the same value. SYSCALL_DEFINE on ppc provides a wrapper that normalizes the value passed from userland; so does COMPAT_SYSCALL_DEFINE. Plain declaration of compat_sys_something() with an int argument obviously doesn't. Again, for wait4 and waitid I would be extremely surprised if gcc started to produce code depending on that value having been properly sign-extended - the argument(s) in question end up passed blindly to sys_wait4 and sys_waitid resp. and normalization for native syscalls takes care of their use there. Still, better to use COMPAT_SYSCALL_DEFINE here than worry about nasal daemons... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINEAl Viro
Makes sigaltstack conversion easier to split into per-architecture parts. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
2012-12-24time: convert arch_gettimeoffset to a pointerStephen Warren
Currently, whenever CONFIG_ARCH_USES_GETTIMEOFFSET is enabled, each arch core provides a single implementation of arch_gettimeoffset(). In many cases, different sub-architectures, different machines, or different timer providers exist, and so the arch ends up implementing arch_gettimeoffset() as a call-through-pointer anyway. Examples are ARM, Cris, M68K, and it's arguable that the remaining architectures, M32R and Blackfin, should be doing this anyway. Modify arch_gettimeoffset so that it itself is a function pointer, which the arch initializes. This will allow later changes to move the initialization of this function into individual machine support or timer drivers. This is particularly useful for code in drivers/clocksource which should rely on an arch-independant mechanism to register their implementation of arch_gettimeoffset(). This patch also converts the Cris architecture to set arch_gettimeoffset directly to the final implementation in time_init(), because Cris already had separate time_init() functions per sub-architecture. M68K and ARM are converted to set arch_gettimeoffset to the final implementation in later patches, because they already have function pointers in place for this purpose. Cc: Russell King <linux@arm.linux.org.uk> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Stephen Warren <swarren@nvidia.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>
2012-12-19workqueue: fix find_worker_executing_work() brekage from hashtable conversionTejun Heo
42f8570f43 ("workqueue: use new hashtable implementation") incorrectly made busy workers hashed by the pointer value of worker instead of work. This broke find_worker_executing_work() which in turn broke a lot of fundamental operations of workqueue - non-reentrancy and flushing among others. The flush malfunction triggered warning in disk event code in Fengguang's automated test. write_dev_root_ (3265) used greatest stack depth: 2704 bytes left ------------[ cut here ]------------ WARNING: at /c/kernel-tests/src/stable/block/genhd.c:1574 disk_clear_events+0x\ cf/0x108() Hardware name: Bochs Modules linked in: Pid: 3328, comm: ata_id Not tainted 3.7.0-01930-gbff6343 #1167 Call Trace: [<ffffffff810997c4>] warn_slowpath_common+0x83/0x9c [<ffffffff810997f7>] warn_slowpath_null+0x1a/0x1c [<ffffffff816aea77>] disk_clear_events+0xcf/0x108 [<ffffffff811bd8be>] check_disk_change+0x27/0x59 [<ffffffff822e48e2>] cdrom_open+0x49/0x68b [<ffffffff81ab0291>] idecd_open+0x88/0xb7 [<ffffffff811be58f>] __blkdev_get+0x102/0x3ec [<ffffffff811bea08>] blkdev_get+0x18f/0x30f [<ffffffff811bebfd>] blkdev_open+0x75/0x80 [<ffffffff8118f510>] do_dentry_open+0x1ea/0x295 [<ffffffff8118f5f0>] finish_open+0x35/0x41 [<ffffffff8119c720>] do_last+0x878/0xa25 [<ffffffff8119c993>] path_openat+0xc6/0x333 [<ffffffff8119cf37>] do_filp_open+0x38/0x86 [<ffffffff81190170>] do_sys_open+0x6c/0xf9 [<ffffffff8119021e>] sys_open+0x21/0x23 [<ffffffff82c1c3d9>] system_call_fastpath+0x16/0x1b Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Sasha Levin <sasha.levin@oracle.com>
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>