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2013-04-19nohz: Ensure full dynticks CPUs are RCU nocbsFrederic Weisbecker
We need full dynticks CPU to also be RCU nocb so that we don't have to keep the tick to handle RCU callbacks. Make sure the range passed to nohz_full= boot parameter is a subset of rcu_nocbs= The CPUs that fail to meet this requirement will be excluded from the nohz_full range. This is checked early in boot time, before any CPU has the opportunity to stop its tick. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19nohz: Force boot CPU outside full dynticks rangeFrederic Weisbecker
The timekeeping job must be able to run early on boot because there may be some pre-SMP (and thus pre-initcalls ) components that rely on it. The IO-APIC is one such users as it tests the timer health by watching jiffies progression. Given that it happens before we know the initial online set, we can't rely on it to select a timekeeper. We need one before SMP time otherwise we simply crash on boot. To fix this and keep things simple for now, force the boot CPU outside of the full dynticks range in any case and do this early on kernel parameter parsing time. We might want a trickier solution later, expecially for aSMP architectures that need to assign housekeeping tasks to arbitrary low power CPUs. But it's still first pass KISS time for now. Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-19mutex: Back out architecture specific check for negative mutex countWaiman Long
Linus suggested that probably all the supported architectures can allow a negative mutex count without incorrect behavior, so we can then back out the architecture specific change and allow the mutex count to go to any negative number. That should further reduce contention for non-x86 architecture. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chandramouleeswaran Aswin <aswin@hp.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Norton Scott J <scott.norton@hp.com> Cc: Rik van Riel <riel@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366226594-5506-5-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-19mutex: Queue mutex spinners with MCS lock to reduce cacheline contentionWaiman Long
The current mutex spinning code (with MUTEX_SPIN_ON_OWNER option turned on) allow multiple tasks to spin on a single mutex concurrently. A potential problem with the current approach is that when the mutex becomes available, all the spinning tasks will try to acquire the mutex more or less simultaneously. As a result, there will be a lot of cacheline bouncing especially on systems with a large number of CPUs. This patch tries to reduce this kind of contention by putting the mutex spinners into a queue so that only the first one in the queue will try to acquire the mutex. This will reduce contention and allow all the tasks to move forward faster. The queuing of mutex spinners is done using an MCS lock based implementation which will further reduce contention on the mutex cacheline than a similar ticket spinlock based implementation. This patch will add a new field into the mutex data structure for holding the MCS lock. This expands the mutex size by 8 bytes for 64-bit system and 4 bytes for 32-bit system. This overhead will be avoid if the MUTEX_SPIN_ON_OWNER option is turned off. The following table shows the jobs per minute (JPM) scalability data on an 8-node 80-core Westmere box with a 3.7.10 kernel. The numactl command is used to restrict the running of the fserver workloads to 1/2/4/8 nodes with hyperthreading off. +-----------------+-----------+-----------+-------------+----------+ | Configuration | Mean JPM | Mean JPM | Mean JPM | % Change | | | w/o patch | patch 1 | patches 1&2 | 1->1&2 | +-----------------+------------------------------------------------+ | | User Range 1100 - 2000 | +-----------------+------------------------------------------------+ | 8 nodes, HT off | 227972 | 227237 | 305043 | +34.2% | | 4 nodes, HT off | 393503 | 381558 | 394650 | +3.4% | | 2 nodes, HT off | 334957 | 325240 | 338853 | +4.2% | | 1 node , HT off | 198141 | 197972 | 198075 | +0.1% | +-----------------+------------------------------------------------+ | | User Range 200 - 1000 | +-----------------+------------------------------------------------+ | 8 nodes, HT off | 282325 | 312870 | 332185 | +6.2% | | 4 nodes, HT off | 390698 | 378279 | 393419 | +4.0% | | 2 nodes, HT off | 336986 | 326543 | 340260 | +4.2% | | 1 node , HT off | 197588 | 197622 | 197582 | 0.0% | +-----------------+-----------+-----------+-------------+----------+ At low user range 10-100, the JPM differences were within +/-1%. So they are not that interesting. The fserver workload uses mutex spinning extensively. With just the mutex change in the first patch, there is no noticeable change in performance. Rather, there is a slight drop in performance. This mutex spinning patch more than recovers the lost performance and show a significant increase of +30% at high user load with the full 8 nodes. Similar improvements were also seen in a 3.8 kernel. The table below shows the %time spent by different kernel functions as reported by perf when running the fserver workload at 1500 users with all 8 nodes. +-----------------------+-----------+---------+-------------+ | Function | % time | % time | % time | | | w/o patch | patch 1 | patches 1&2 | +-----------------------+-----------+---------+-------------+ | __read_lock_failed | 34.96% | 34.91% | 29.14% | | __write_lock_failed | 10.14% | 10.68% | 7.51% | | mutex_spin_on_owner | 3.62% | 3.42% | 2.33% | | mspin_lock | N/A | N/A | 9.90% | | __mutex_lock_slowpath | 1.46% | 0.81% | 0.14% | | _raw_spin_lock | 2.25% | 2.50% | 1.10% | +-----------------------+-----------+---------+-------------+ The fserver workload for an 8-node system is dominated by the contention in the read/write lock. Mutex contention also plays a role. With the first patch only, mutex contention is down (as shown by the __mutex_lock_slowpath figure) which help a little bit. We saw only a few percents improvement with that. By applying patch 2 as well, the single mutex_spin_on_owner figure is now split out into an additional mspin_lock figure. The time increases from 3.42% to 11.23%. It shows a great reduction in contention among the spinners leading to a 30% improvement. The time ratio 9.9/2.33=4.3 indicates that there are on average 4+ spinners waiting in the spin_lock loop for each spinner in the mutex_spin_on_owner loop. Contention in other locking functions also go down by quite a lot. The table below shows the performance change of both patches 1 & 2 over patch 1 alone in other AIM7 workloads (at 8 nodes, hyperthreading off). +--------------+---------------+----------------+-----------------+ | Workload | mean % change | mean % change | mean % change | | | 10-100 users | 200-1000 users | 1100-2000 users | +--------------+---------------+----------------+-----------------+ | alltests | 0.0% | -0.8% | +0.6% | | five_sec | -0.3% | +0.8% | +0.8% | | high_systime | +0.4% | +2.4% | +2.1% | | new_fserver | +0.1% | +14.1% | +34.2% | | shared | -0.5% | -0.3% | -0.4% | | short | -1.7% | -9.8% | -8.3% | +--------------+---------------+----------------+-----------------+ The short workload is the only one that shows a decline in performance probably due to the spinner locking and queuing overhead. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Reviewed-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chandramouleeswaran Aswin <aswin@hp.com> Cc: Norton Scott J <scott.norton@hp.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366226594-5506-4-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-19mutex: Make more scalable by doing less atomic operationsWaiman Long
In the __mutex_lock_common() function, an initial entry into the lock slow path will cause two atomic_xchg instructions to be issued. Together with the atomic decrement in the fast path, a total of three atomic read-modify-write instructions will be issued in rapid succession. This can cause a lot of cache bouncing when many tasks are trying to acquire the mutex at the same time. This patch will reduce the number of atomic_xchg instructions used by checking the counter value first before issuing the instruction. The atomic_read() function is just a simple memory read. The atomic_xchg() function, on the other hand, can be up to 2 order of magnitude or even more in cost when compared with atomic_read(). By using atomic_read() to check the value first before calling atomic_xchg(), we can avoid a lot of unnecessary cache coherency traffic. The only downside with this change is that a task on the slow path will have a tiny bit less chance of getting the mutex when competing with another task in the fast path. The same is true for the atomic_cmpxchg() function in the mutex-spin-on-owner loop. So an atomic_read() is also performed before calling atomic_cmpxchg(). The mutex locking and unlocking code for the x86 architecture can allow any negative number to be used in the mutex count to indicate that some tasks are waiting for the mutex. I am not so sure if that is the case for the other architectures. So the default is to avoid atomic_xchg() if the count has already been set to -1. For x86, the check is modified to include all negative numbers to cover a larger case. The following table shows the jobs per minutes (JPM) scalability data on an 8-node 80-core Westmere box with a 3.7.10 kernel. The numactl command is used to restrict the running of the high_systime workloads to 1/2/4/8 nodes with hyperthreading on and off. +-----------------+-----------+------------+----------+ | Configuration | Mean JPM | Mean JPM | % Change | | | w/o patch | with patch | | +-----------------+-----------------------------------+ | | User Range 1100 - 2000 | +-----------------+-----------------------------------+ | 8 nodes, HT on | 36980 | 148590 | +301.8% | | 8 nodes, HT off | 42799 | 145011 | +238.8% | | 4 nodes, HT on | 61318 | 118445 | +51.1% | | 4 nodes, HT off | 158481 | 158592 | +0.1% | | 2 nodes, HT on | 180602 | 173967 | -3.7% | | 2 nodes, HT off | 198409 | 198073 | -0.2% | | 1 node , HT on | 149042 | 147671 | -0.9% | | 1 node , HT off | 126036 | 126533 | +0.4% | +-----------------+-----------------------------------+ | | User Range 200 - 1000 | +-----------------+-----------------------------------+ | 8 nodes, HT on | 41525 | 122349 | +194.6% | | 8 nodes, HT off | 49866 | 124032 | +148.7% | | 4 nodes, HT on | 66409 | 106984 | +61.1% | | 4 nodes, HT off | 119880 | 130508 | +8.9% | | 2 nodes, HT on | 138003 | 133948 | -2.9% | | 2 nodes, HT off | 132792 | 131997 | -0.6% | | 1 node , HT on | 116593 | 115859 | -0.6% | | 1 node , HT off | 104499 | 104597 | +0.1% | +-----------------+------------+-----------+----------+ At low user range 10-100, the JPM differences were within +/-1%. So they are not that interesting. AIM7 benchmark run has a pretty large run-to-run variance due to random nature of the subtests executed. So a difference of less than +-5% may not be really significant. This patch improves high_systime workload performance at 4 nodes and up by maintaining transaction rates without significant drop-off at high node count. The patch has practically no impact on 1 and 2 nodes system. The table below shows the percentage time (as reported by perf record -a -s -g) spent on the __mutex_lock_slowpath() function by the high_systime workload at 1500 users for 2/4/8-node configurations with hyperthreading off. +---------------+-----------------+------------------+---------+ | Configuration | %Time w/o patch | %Time with patch | %Change | +---------------+-----------------+------------------+---------+ | 8 nodes | 65.34% | 0.69% | -99% | | 4 nodes | 8.70% | 1.02% | -88% | | 2 nodes | 0.41% | 0.32% | -22% | +---------------+-----------------+------------------+---------+ It is obvious that the dramatic performance improvement at 8 nodes was due to the drastic cut in the time spent within the __mutex_lock_slowpath() function. The table below show the improvements in other AIM7 workloads (at 8 nodes, hyperthreading off). +--------------+---------------+----------------+-----------------+ | Workload | mean % change | mean % change | mean % change | | | 10-100 users | 200-1000 users | 1100-2000 users | +--------------+---------------+----------------+-----------------+ | alltests | +0.6% | +104.2% | +185.9% | | five_sec | +1.9% | +0.9% | +0.9% | | fserver | +1.4% | -7.7% | +5.1% | | new_fserver | -0.5% | +3.2% | +3.1% | | shared | +13.1% | +146.1% | +181.5% | | short | +7.4% | +5.0% | +4.2% | +--------------+---------------+----------------+-----------------+ Signed-off-by: Waiman Long <Waiman.Long@hp.com> Reviewed-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chandramouleeswaran Aswin <aswin@hp.com> Cc: Norton: Scott J <scott.norton@hp.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366226594-5506-3-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-19mutex: Move mutex spinning code from sched/core.c back to mutex.cWaiman Long
As mentioned by Ingo, the SCHED_FEAT_OWNER_SPIN scheduler feature bit was really just an early hack to make with/without mutex-spinning testable. So it is no longer necessary. This patch removes the SCHED_FEAT_OWNER_SPIN feature bit and move the mutex spinning code from kernel/sched/core.c back to kernel/mutex.c which is where they should belong. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chandramouleeswaran Aswin <aswin@hp.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Norton Scott J <scott.norton@hp.com> Cc: Rik van Riel <riel@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1366226594-5506-2-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-18cgroup: fix broken file xattrsLi Zefan
We should store file xattrs in struct cfent instead of struct cftype, because cftype is a type while cfent is object instance of cftype. For example each cgroup has a tasks file, and each tasks file is associated with a uniq cfent, but all those files share the same struct cftype. Alexey Kodanev reported a crash, which can be reproduced: # mount -t cgroup -o xattr /sys/fs/cgroup # mkdir /sys/fs/cgroup/test # setfattr -n trusted.value -v test_value /sys/fs/cgroup/tasks # rmdir /sys/fs/cgroup/test # umount /sys/fs/cgroup oops! In this case, simple_xattrs_free() will free the same struct simple_xattrs twice. tj: Dropped unused local variable @cft from cgroup_diput(). Cc: <stable@vger.kernel.org> # 3.8.x Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-18Merge branch 'userns-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux Pull user-namespace fixes from Andy Lutomirski. * 'userns-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux: userns: Changing any namespace id mappings should require privileges userns: Check uid_map's opener's fsuid, not the current fsuid userns: Don't let unprivileged users trick privileged users into setting the id_map
2013-04-18nohz: New APIs to re-evaluate the tick on full dynticks CPUsFrederic Weisbecker
Provide two new helpers in order to notify the full dynticks CPUs about some internal system changes against which they may reconsider the state of their tick. Some practical examples include: posix cpu timers, perf tick and sched clock tick. For now the notifying handler, implemented through IPIs, is a stub that will be implemented when we get the tick stop/restart infrastructure in. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-18Revert "block: add missing block_bio_complete() tracepoint"Linus Torvalds
This reverts commit 3a366e614d0837d9fc23f78cdb1a1186ebc3387f. Wanlong Gao reports that it causes a kernel panic on his machine several minutes after boot. Reverting it removes the panic. Jens says: "It's not quite clear why that is yet, so I think we should just revert the commit for 3.9 final (which I'm assuming is pretty close). The wifi is crap at the LSF hotel, so sending this email instead of queueing up a revert and pull request." Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Requested-by: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-18kprobes: Fix a double lock bug of kprobe_mutexMasami Hiramatsu
Fix a double locking bug caused when debug.kprobe-optimization=0. While the proc_kprobes_optimization_handler locks kprobe_mutex, wait_for_kprobe_optimizer locks it again and that causes a double lock. To fix the bug, this introduces different mutex for protecting sysctl parameter and locks it in proc_kprobes_optimization_handler. Of course, since we need to lock kprobe_mutex when touching kprobes resources, that is done in *optimize_all_kprobes(). This bug was introduced by commit ad72b3bea744 ("kprobes: fix wait_for_kprobe_optimizer()") Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-18posix-timers: Remove unused variableThomas Gleixner
Remove the unused variable *node introduced by commit 5ed67f05 (posix timers: Allocate timer id per process) Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Pavel Emelyanov <xemul@parallels.com>
2013-04-17kernel/signal.c: stop info leak via the tkill and the tgkill syscallsEmese Revfy
This fixes a kernel memory contents leak via the tkill and tgkill syscalls for compat processes. This is visible in the siginfo_t->_sifields._rt.si_sigval.sival_ptr field when handling signals delivered from tkill. The place of the infoleak: int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) { ... put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr); ... } Signed-off-by: Emese Revfy <re.emese@gmail.com> Reviewed-by: PaX Team <pageexec@freemail.hu> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-17kexec: use Crash kernel for Crash kernel lowYinghai Lu
We can extend kexec-tools to support multiple "Crash kernel" in /proc/iomem instead. So we can use "Crash kernel" instead of "Crash kernel low" in /proc/iomem. Suggested-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1366089828-19692-3-git-send-email-yinghai@kernel.org Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-04-17x86, kdump: Change crashkernel_high/low= to crashkernel=,high/lowYinghai Lu
Per hpa, use crashkernel=X,high crashkernel=Y,low instead of crashkernel_hign=X crashkernel_low=Y. As that could be extensible. -v2: according to Vivek, change delimiter to ; -v3: let hign and low only handle simple form and it conforms to description in kernel-parameters.txt still keep crashkernel=X override any crashkernel=X,high crashkernel=Y,low -v4: update get_last_crashkernel returning and add more strict checking in parse_crashkernel_simple() found by HATAYAMA. -v5: Change delimiter back to , according to HPA. also separate parse_suffix from parse_simper according to vivek. so we can avoid @pos in that path. -v6: Tight the checking about crashkernel=X,highblahblah,high found by HTYAYAMA. Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1366089828-19692-5-git-send-email-yinghai@kernel.org Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-04-17x86, kdump: Retore crashkernel= to allocate under 896MYinghai Lu
Vivek found old kexec-tools does not work new kernel anymore. So change back crashkernel= back to old behavoir, and add crashkernel_high= to let user decide if buffer could be above 4G, and also new kexec-tools will be needed. -v2: let crashkernel=X override crashkernel_high= update description about _high will be ignored by crashkernel=X -v3: update description about kernel-parameters.txt according to Vivek. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1366089828-19692-4-git-send-email-yinghai@kernel.org Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-04-17clockevents: Switch into oneshot mode even if broadcast registered lateStephen Boyd
tick_oneshot_notify() is used to notify a particular CPU to try to switch into oneshot mode after a oneshot capable tick device is registered and tick_clock_notify() is used to notify all CPUs to try to switch into oneshot mode after a high res clocksource is registered. There is one caveat; if the tick devices suffer from FEAT_C3_STOP we don't try to switch into oneshot mode unless we have a oneshot capable broadcast device already registered. If the broadcast device is registered after the tick devices that have FEAT_C3_STOP we'll never try to switch into oneshot mode again, causing us to be stuck in periodic mode forever. Avoid this scenario by calling tick_clock_notify() after we register the broadcast device so that we try to switch into oneshot mode on all CPUs one more time. [ tglx: Adopted to timers/core and added a comment ] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Link: http://lkml.kernel.org/r/1366219566-29783-1-git-send-email-sboyd@codeaurora.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17timer_list: Convert timer list to be a proper seq_fileNathan Zimmer
When running with 4096 cores attemping to read /proc/timer_list will fail with an ENOMEM condition. On a sufficantly large systems the total amount of data is more then 4mb, so it won't fit into a single buffer. The failure can also occur on smaller systems when memory fragmentation is high as reported by Dave Jones. Convert /proc/timer_list to a proper seq_file with its own iterator. This is a little more complex given that we have to make two passes with two separate headers. sysrq_timer_list_show also needed to be updated to reflect the fact that now timer_list_show only does one cpu at at time. Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Reported-by: Dave Jones <davej@redhat.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Link: http://lkml.kernel.org/r/1364345790-14577-3-git-send-email-nzimmer@sgi.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17timer_list: Split timer_list_show_tickdevicesNathan Zimmer
Split timer_list_show_tickdevices() into the header printout and pull the rest up to timer_list_show. This is a preparatory patch for converting timer_list to a proper seqfile with its own iterator Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Reported-by: Dave Jones <davej@redhat.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Link: http://lkml.kernel.org/r/1364345790-14577-2-git-send-email-nzimmer@sgi.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17posix timers: Allocate timer id per process (v2)Pavel Emelyanov
Currently kernel generates IDs for posix timers in a global manner -- there's a kernel-wide IDR tree from which IDs are created. This makes it impossible to recreate a timer with a desired ID (in particular this is done by the CRIU checkpoint-restore project) -- since these IDs are global it may happen, that at the time we recreate a timer, the ID we want for it is already busy by some other timer. In order to address this, replace the IDR tree with a global hash table for timers and makes timer IDs unique per signal_struct (to which timers are linked anyway). With this, two timers belonging to different processes may have equal IDs and we can recreate either of them with the ID we want. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Matthew Helsley <matt.helsley@gmail.com> Link: http://lkml.kernel.org/r/513D9FF5.9010004@parallels.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17idle: Remove GENERIC_IDLE_LOOP config switchThomas Gleixner
All archs are converted over. Remove the config switch and the fallback code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17module: don't unlink the module until we've removed all exposure.Rusty Russell
Otherwise we get a race between unload and reload of the same module: the new module doesn't see the old one in the list, but then fails because it can't register over the still-extant entries in sysfs: [ 103.981925] ------------[ cut here ]------------ [ 103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0() [ 103.993606] Hardware name: CrownBay Platform [ 103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe' [ 104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe] [ 104.011362] Pid: 3021, comm: modprobe Tainted: G W 3.9.0-rc5+ #5 [ 104.018662] Call Trace: [ 104.021286] [<c103599d>] warn_slowpath_common+0x6d/0xa0 [ 104.026933] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.031986] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.037000] [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30 [ 104.042188] [<c1168c8b>] sysfs_add_one+0xab/0xd0 [ 104.046982] [<c1168dbe>] create_dir+0x5e/0xa0 [ 104.051633] [<c1168e78>] sysfs_create_dir+0x78/0xd0 [ 104.056774] [<c1262bc3>] kobject_add_internal+0x83/0x1f0 [ 104.062351] [<c126daf6>] ? kvasprintf+0x46/0x60 [ 104.067231] [<c1262ebd>] kobject_add_varg+0x2d/0x50 [ 104.072450] [<c1262f07>] kobject_init_and_add+0x27/0x30 [ 104.078075] [<c1089240>] mod_sysfs_setup+0x80/0x540 [ 104.083207] [<c1260851>] ? module_bug_finalize+0x51/0xc0 [ 104.088720] [<c108ab29>] load_module+0x1429/0x18b0 We can teardown sysfs first, then to be sure, put the state in MODULE_STATE_UNFORMED so it's ignored while we deconstruct it. Reported-by: Veaceslav Falico <vfalico@redhat.com> Tested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-16audit: allow checking the type of audit message in the user filterEric Paris
When userspace sends messages to the audit system it includes a type. We want to be able to filter messages based on that type without have to do the all or nothing option currently available on the AUDIT_FILTER_TYPE filter list. Instead we should be able to use the AUDIT_FILTER_USER filter list and just use the message type as one part of the matching decision. Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-16audit: fix build break when AUDIT_DEBUG == 2Eric Paris
Looks like this one has been around since 5195d8e21: kernel/auditsc.c: In function ‘audit_free_names’: kernel/auditsc.c:998: error: ‘i’ undeclared (first use in this function) ...and this warning: kernel/auditsc.c: In function ‘audit_putname’: kernel/auditsc.c:2045: warning: ‘i’ may be used uninitialized in this function Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-16Merge branch 'uprobes/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core Pull uprobes updates from Oleg Nesterov: - "uretprobes" - an optimization to uprobes, like kretprobes are an optimization to kprobes. "perf probe -x file sym%return" now works like kretprobes. - PowerPC fixes plus a couple of cleanups/optimizations in uprobes and trace_uprobes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-15rcu: Kick adaptive-ticks CPUs that are holding up RCU grace periodsPaul E. McKenney
Adaptive-ticks CPUs inform RCU when they enter kernel mode, but they do not necessarily turn the scheduler-clock tick back on. This state of affairs could result in RCU waiting on an adaptive-ticks CPU running for an extended period in kernel mode. Such a CPU will never run the RCU state machine, and could therefore indefinitely extend the RCU state machine, sooner or later resulting in an OOM condition. This patch, inspired by an earlier patch by Frederic Weisbecker, therefore causes RCU's force-quiescent-state processing to check for this condition and to send an IPI to CPUs that remain in that state for too long. "Too long" currently means about three jiffies by default, which is quite some time for a CPU to remain in the kernel without blocking. The rcu_tree.jiffies_till_first_fqs and rcutree.jiffies_till_next_fqs sysfs variables may be used to tune "too long" if needed. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15nohz: Improve a bit the full dynticks Kconfig documentationFrederic Weisbecker
Remove the "single task" statement from CONFIG_NO_HZ_FULL title. The constraint can be invalidated when tasks from other sched classes than SCHED_FAIR are running. Moreover it's possible that hrtick join the party in the future. Also add a line about the dependency on SMP. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15nohz: Align periodic tick Kconfig with other choices' naming conventionFrederic Weisbecker
Rename CONFIG_PERIODIC_HZ to CONFIG_HZ_PERIODIC in order to stay consistent with other tick implementation entries: CONFIG_HZ_PERIODIC CONFIG_NO_HZ_IDLE CONFIG_NO_HZ_FULL Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15nohz: Switch from "extended nohz" to "full nohz" based namingFrederic Weisbecker
"Extended nohz" was used as a naming base for the full dynticks API and Kconfig symbols. It reflects the fact the system tries to stop the tick in more places than just idle. But that "extended" name is a bit opaque and vague. Rename it to "full" makes it clearer what the system tries to do under this config: try to shutdown the tick anytime it can. The various constraints that prevent that to happen shouldn't be considered as fundamental properties of this feature but rather technical issues that may be solved in the future. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15nohz: Fix old dynticks idle Kconfig backward compatibilityFrederic Weisbecker
In order to enforce backward compatibility with older config files, we want the new dynticks-idle Kconfig entry to default its value to the one of the old CONFIG_NO_HZ symbol if present. Namely we want: config NO_HZ # old obsolete dynticks idle symbol bool config NO_HZ_IDLE # new dynticks idle symbol default NO_HZ However Kconfig prevents this to work if the old symbol is not visible. And this is currently the case because NO_HZ lacks a title in order to show it in make oldconfig and alike. To fix this, bring a minimal title and help text to the obsolete Kconfig entry that explains its purpose. This makes the "defaulting" to work. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-15uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is emptyOleg Nesterov
perf_trace_buf_prepare() + perf_trace_buf_submit() make no sense if this task/CPU has no active counters. Change uprobe_perf_print() to return if hlist_empty(call->perf_events). Note: this is not uprobe-specific, we can change other users too. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-15Merge branches 'timers-urgent-for-linus', 'irq-urgent-for-linus' and ↵Linus Torvalds
'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull {timer,irq,core} fixes from Thomas Gleixner: - timer: bug fix for a cpu hotplug race. - irq: single bugfix for a wrong return value, which prevents the calling function to invoke the software fallback. - core: bugfix which plugs two race confitions which can cause hotplug per cpu threads to end up on the wrong cpu. * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hrtimer: Don't reinitialize a cpu_base lock on CPU_UP * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip: gic: fix irq_trigger return * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kthread: Prevent unpark race which puts threads on the wrong cpu
2013-04-15extable: Flip the sorting messageBorislav Petkov
Now that we do sort the __extable at build time, we actually are interested only in the case where we still do need to sort it. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: David Daney <david.daney@cavium.com> Link: http://lkml.kernel.org/r/1366023109-12098-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-15perf: Treat attr.config as u64 in perf_swevent_init()Tommi Rantala
Trinity discovered that we fail to check all 64 bits of attr.config passed by user space, resulting to out-of-bounds access of the perf_swevent_enabled array in sw_perf_event_destroy(). Introduced in commit b0a873ebb ("perf: Register PMU implementations"). Signed-off-by: Tommi Rantala <tt.rantala@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: davej@redhat.com Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/1365882554-30259-1-git-send-email-tt.rantala@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-14cgroup: remove cgrp->top_cgroupLi Zefan
It's not used, and it can be retrieved via cgrp->root->top_cgroup. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-15kernel: kallsyms: memory override issue, need check destination buffer lengthChen Gang
We don't export any symbols > 128 characters, but if we did then kallsyms_expand_symbol() would overflow the buffer handed to it. So we need check destination buffer length when copying. the related test: if we define an EXPORT function which name more than 128. will panic when call kallsyms_lookup_name by init_kprobes on booting. after check the length (provide this patch), it is ok. Implementaion: add additional destination buffer length parameter (maxlen) if uncompressed string is too long (>= maxlen), it will be truncated. not check the parameters whether valid, since it is a static function. Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-14cgroup: introduce sane_behavior mount optionTejun Heo
It's a sad fact that at this point various cgroup controllers are carrying so many idiosyncrasies and pure insanities that it simply isn't possible to reach any sort of sane consistent behavior while maintaining staying fully compatible with what already has been exposed to userland. As we can't break exposed userland interface, transitioning to sane behaviors can only be done in steps while maintaining backwards compatibility. This patch introduces a new mount option - __DEVEL__sane_behavior - which disables crazy features and enforces consistent behaviors in cgroup core proper and various controllers. As exactly which behaviors it changes are still being determined, the mount option, at this point, is useful only for development of the new behaviors. As such, the mount option is prefixed with __DEVEL__ and generates a warning message when used. Eventually, once we get to the point where all controller's behaviors are consistent enough to implement unified hierarchy, the __DEVEL__ prefix will be dropped, and more importantly, unified-hierarchy will enforce sane_behavior by default. Maybe we'll able to completely drop the crazy stuff after a while, maybe not, but we at least have a strategy to move on to saner behaviors. This patch introduces the mount option and changes the following behaviors in cgroup core. * Mount options "noprefix" and "clone_children" are disallowed. Also, cgroupfs file cgroup.clone_children is not created. * When mounting an existing superblock, mount options should match. This is currently pretty crazy. If one mounts a cgroup, creates a subdirectory, unmounts it and then mount it again with different option, it looks like the new options are applied but they aren't. * Remount is disallowed. The behaviors changes are documented in the comment above CGRP_ROOT_SANE_BEHAVIOR enum and will be expanded as different controllers are converted and planned improvements progress. v2: Dropped unnecessary explicit file permission setting sane_behavior cftype entry as suggested by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com>
2013-04-14move cgroupfs_root to include/linux/cgroup.hTejun Heo
While controllers shouldn't be accessing cgroupfs_root directly, it being hidden inside kern/cgroup.c makes somethings pretty silly. This makes routing hierarchy-wide settings which need to be visible to controllers cumbersome. We're gonna add another hierarchy-wide setting which needs to be accessed from controllers. Move cgroupfs_root and its flags to the header file so that we can access root settings with inline helpers. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-14cgroup: convert cgroupfs_root flag bits to masks and add CGRP_ prefixTejun Heo
There's no reason to be using bitops, which tends to be more cumbersome, to handle root flags. Convert them to masks. Also, as they'll be moved to include/linux/cgroup.h and it's generally a good idea, add CGRP_ prefix. Note that flags are assigned from (1 << 1). The first bit will be used by a flag which will be added soon. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-14userns: Changing any namespace id mappings should require privilegesAndy Lutomirski
Changing uid/gid/projid mappings doesn't change your id within the namespace; it reconfigures the namespace. Unprivileged programs should *not* be able to write these files. (We're also checking the privileges on the wrong task.) Given the write-once nature of these files and the other security checks, this is likely impossible to usefully exploit. Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2013-04-14userns: Check uid_map's opener's fsuid, not the current fsuidAndy Lutomirski
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2013-04-14userns: Don't let unprivileged users trick privileged users into setting the ↵Eric W. Biederman
id_map When we require privilege for setting /proc/<pid>/uid_map or /proc/<pid>/gid_map no longer allow an unprivileged user to open the file and pass it to a privileged program to write to the file. Instead when privilege is required require both the opener and the writer to have the necessary capabilities. I have tested this code and verified that setting /proc/<pid>/uid_map fails when an unprivileged user opens the file and a privielged user attempts to set the mapping, that unprivileged users can still map their own id, and that a privileged users can still setup an arbitrary mapping. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2013-04-14Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc fixlets" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/cputime: Fix accounting on multi-threaded processes sched/debug: Fix sd->*_idx limit range avoiding overflow sched_clock: Prevent 64bit inatomicity on 32bit systems sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s
2013-04-14Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixlets" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix error return code ftrace: Fix strncpy() use, use strlcpy() instead of strncpy() perf: Fix strncpy() use, use strlcpy() instead of strncpy() perf: Fix strncpy() use, always make sure it's NUL terminated perf: Fix ring_buffer perf_output_space() boundary calculation perf/x86: Fix uninitialized pt_regs in intel_pmu_drain_bts_buffer()
2013-04-14Merge tag 'trace-fixes-v3.9-rc-v3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull ftrace fixes from Steven Rostedt: "Namhyung Kim found and fixed a bug that can crash the kernel by simply doing: echo 1234 | tee -a /sys/kernel/debug/tracing/set_ftrace_pid Luckily, this can only be done by root, but still is a nasty bug." * tag 'trace-fixes-v3.9-rc-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Move ftrace_filter_lseek out of CONFIG_DYNAMIC_FTRACE section tracing: Fix possible NULL pointer dereferences
2013-04-14cgroup: make cgroup_path() not print double slashesTejun Heo
While reimplementing cgroup_path(), 65dff759d2 ("cgroup: fix cgroup_path() vs rename() race") introduced a bug where the path of a non-root cgroup would have two slahses at the beginning, which is caused by treating the root cgroup which has the name '/' like non-root cgroups. $ grep systemd /proc/self/cgroup 1:name=systemd://user/root/1 Fix it by special casing root cgroup case and not looping over it in the normal path. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com>
2013-04-14Add file_ns_capable() helper function for open-time capability checkingLinus Torvalds
Nothing is using it yet, but this will allow us to delay the open-time checks to use time, without breaking the normal UNIX permission semantics where permissions are determined by the opener (and the file descriptor can then be passed to a different process, or the process can drop capabilities). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-13uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()Oleg Nesterov
uprobe_perf_print() passes addr=ip to perf_trace_buf_submit() for no reason. This sets perf_sample_data->addr for PERF_SAMPLE_ADDR, we already have perf_sample_data->ip initialized if PERF_SAMPLE_IP. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-13uprobes/tracing: Change create_trace_uprobe() to support uretprobesOleg Nesterov
Finally change create_trace_uprobe() to check if argv[0][0] == 'r' and pass the correct "is_ret" to alloc_trace_uprobe(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Make seq_printf() code uretprobe-friendlyOleg Nesterov
Change probes_seq_show() and print_uprobe_event() to check is_ret_probe() and print the correct data. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>