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* Merge branch 'rcu/doc' of ↵Ingo Molnar2013-04-3016-518/+842
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent Pull RCU documentation update for reducing OS jitter due to per-CPU kthreads, from Paul McKenney. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * kthread: Document ways of reducing OS jitter due to per-CPU kthreadsPaul E. McKenney2013-04-271-0/+202
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Linux kernel uses a number of per-CPU kthreads, any of which might contribute to OS jitter at any time. The usual approach to normal kthreads, namely to bind them to a "housekeeping" CPU, does not work with these kthreads because they cannot operate correctly if moved to some other CPU. This commit therefore lists ways of controlling OS jitter from the Linux kernel's per-CPU kthreads. It also lists some ways of diagnosing excessive jitter. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Christoph Lameter <cl@linux.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Olivier Baetz <olivier.baetz@novasparks.com> Cc: Pradeep Satyanarayana <pradeeps@linux.vnet.ibm.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Borislav Petkov <bp@suse.de>
| *-. Merge branches 'doc.2013.03.12a', 'fixes.2013.03.13a' and ↵Paul E. McKenney2013-03-2611-505/+603
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'idlenocb.2013.03.26b' into HEAD doc.2013.03.12a: Documentation changes. fixes.2013.03.13a: Miscellaneous fixes. idlenocb.2013.03.26b: Remove restrictions on no-CBs CPUs, make RCU_FAST_NO_HZ take advantage of numbered callbacks, add callback acceleration based on numbered callbacks.
| | | * rcu: Make rcu_accelerate_cbs() note need for future grace periodsPaul E. McKenney2013-03-261-18/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that rcu_start_future_gp() has been abstracted from rcu_nocb_wait_gp(), rcu_accelerate_cbs() can invoke rcu_start_future_gp() so as to register the need for any future grace periods needed by a CPU about to enter dyntick-idle mode. This commit makes this change. Note that some refactoring of rcu_start_gp() is carried out to avoid recursion and subsequent self-deadlocks. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Abstract rcu_start_future_gp() from rcu_nocb_wait_gp()Paul E. McKenney2013-03-263-99/+130
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUs going idle will need to record the need for a future grace period, but won't actually need to block waiting on it. This commit therefore splits rcu_start_future_gp(), which does the recording, from rcu_nocb_wait_gp(), which now invokes rcu_start_future_gp() to do the recording, after which rcu_nocb_wait_gp() does the waiting. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Rename n_nocb_gp_requests to need_future_gpPaul E. McKenney2013-03-262-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUs going idle need to be able to indicate their need for future grace periods. A mechanism for doing this already exists for no-callbacks CPUs, so the idea is to re-use that mechanism. This commit therefore moves the ->n_nocb_gp_requests field of the rcu_node structure out from under the CONFIG_RCU_NOCB_CPU #ifdef and renames it to ->need_future_gp. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Push lock release to rcu_start_gp()'s callersPaul E. McKenney2013-03-262-17/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If CPUs are to give prior notice of needed grace periods, it will be necessary to invoke rcu_start_gp() without dropping the root rcu_node structure's ->lock. This commit takes a second step in this direction by moving the release of this lock to rcu_start_gp()'s callers. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Repurpose no-CBs event tracing to future-GP eventsPaul E. McKenney2013-03-262-38/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dyntick-idle CPUs need to be able to pre-announce their need for grace periods. This can be done using something similar to the mechanism used by no-CB CPUs to announce their need for grace periods. This commit moves in this direction by renaming the no-CBs grace-period event tracing to suit the new future-grace-period needs. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Rearrange locking in rcu_start_gp()Paul E. McKenney2013-03-261-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If CPUs are to give prior notice of needed grace periods, it will be necessary to invoke rcu_start_gp() without dropping the root rcu_node structure's ->lock. This commit takes a first step in this direction by moving the release of this lock to the end of rcu_start_gp(). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacksPaul E. McKenney2013-03-267-313/+149
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because RCU callbacks are now associated with the number of the grace period that they must wait for, CPUs can now take advance callbacks corresponding to grace periods that ended while a given CPU was in dyntick-idle mode. This eliminates the need to try forcing the RCU state machine while entering idle, thus reducing the CPU intensiveness of RCU_FAST_NO_HZ, which should increase its energy efficiency. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Accelerate RCU callbacks at grace-period endPaul E. McKenney2013-03-261-8/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that callback acceleration is idempotent, it is safe to accelerate callbacks during grace-period cleanup on any CPUs that the kthread happens to be running on. This commit therefore propagates the completion of the grace period to the per-CPU data structures, and also adds an rcu_advance_cbs() just before the cpu_needs_another_gp() check in order to reduce false-positive grace periods. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Export RCU_FAST_NO_HZ parameters to sysfsPaul E. McKenney2013-03-261-11/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RCU_FAST_NO_HZ operation is controlled by four compile-time C-preprocessor macros, but some use cases benefit greatly from runtime adjustment, particularly when tuning devices. This commit therefore creates the corresponding sysfs entries. Reported-by: Robin Randhawa <robin.randhawa@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Distinguish "rcuo" kthreads by RCU flavorPaul E. McKenney2013-03-265-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the per-no-CBs-CPU kthreads are named "rcuo" followed by the CPU number, for example, "rcuo". This is problematic given that there are either two or three RCU flavors, each of which gets a per-CPU kthread with exactly the same name. This commit therefore introduces a one-letter abbreviation for each RCU flavor, namely 'b' for RCU-bh, 'p' for RCU-preempt, and 's' for RCU-sched. This abbreviation is used to distinguish the "rcuo" kthreads, for example, for CPU 0 we would have "rcuob/0", "rcuop/0", and "rcuos/0". Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
| | | * rcu: Add event tracing for no-CBs CPUs' grace periodsPaul E. McKenney2013-03-262-0/+85
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Add event tracing for no-CBs CPUs' callback registrationPaul E. McKenney2013-03-261-0/+7
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Introduce proper blocking to no-CBs kthreads GP waitsPaul E. McKenney2013-03-263-20/+127
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the no-CBs kthreads do repeated timed waits for grace periods to elapse. This is crude and energy inefficient, so this commit allows no-CBs kthreads to specify exactly which grace period they are waiting for and also allows them to block for the entire duration until the desired grace period completes. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Provide compile-time control for no-CBs CPUsPaul E. McKenney2013-03-262-0/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the only way to specify no-CBs CPUs is via the rcu_nocbs kernel command-line parameter. This is inconvenient in some cases, particularly for randconfig testing, so this commit adds a new set of kernel configuration parameters. CONFIG_RCU_NOCB_CPU_NONE (the default) retains the old behavior, CONFIG_RCU_NOCB_CPU_ZERO offloads callback processing from CPU 0 (along with any other CPUs specified by the rcu_nocbs boot-time parameter), and CONFIG_RCU_NOCB_CPU_ALL offloads callback processing from all CPUs. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * rcu: Remove restrictions on no-CBs CPUsPaul E. McKenney2013-03-124-129/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, CPU 0 is constrained to not be a no-CBs CPU, and furthermore at least one no-CBs CPU must remain online at any given time. These restrictions are problematic in some situations, such as cases where all CPUs must run a real-time workload that needs to be insulated from OS jitter and latencies due to RCU callback invocation. This commit therefore provides no-CBs CPUs a (very crude and energy-inefficient) way to start and to wait for grace periods independently of the normal RCU callback mechanisms. This approach allows any or all of the CPUs to be designated as no-CBs CPUs, and allows any proper subset of the CPUs (whether no-CBs CPUs or not) to be offlined. This commit also provides a fix for a locking bug spotted by Xie ChanglongX <changlongx.xie@intel.com>. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Tone down debugging during boot-up and shutdown.Paul E. McKenney2013-03-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some situations, randomly delaying RCU grace-period initialization can cause more trouble than help. This commit therefore restricts this type of RCU self-torture to runtime, giving it a rest during boot and shutdown. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Add softirq-stall indications to stall-warning messagesPaul E. McKenney2013-03-133-10/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If RCU's softirq handler is prevented from executing, an RCU CPU stall warning can result. Ways to prevent RCU's softirq handler from executing include: (1) CPU spinning with interrupts disabled, (2) infinite loop in some softirq handler, and (3) in -rt kernels, an infinite loop in a set of real-time threads running at priorities higher than that of RCU's softirq handler. Because this situation can be difficult to track down, this commit causes the count of RCU softirq handler invocations to be printed with RCU CPU stall warnings. This information does require some interpretation, as now documented in Documentation/RCU/stallwarn.txt. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
| | * | rcu: Fix hlist_bl_set_first_rcu() annotationSteven Whitehouse2013-03-122-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Abhi noticed that we were getting a complaint from the RCU subsystem about access of an RCU protected list under the write side bit lock. This commit adds additional annotation to check both the RCU read lock and the write side bit lock before printing a message. Reported by: Abhijith Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Tested-by: Abhijith Das <adas@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Delete unused rcu_node "wakemask" fieldPaul E. McKenney2013-03-121-3/+0
| | | | | | | | | | | | | | | | Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Remove comment referring to __stop_machine()Srivatsa S. Bhat2013-03-121-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although it used to be that CPU_DYING notifiers executed on the outgoing CPU with interrupts disabled and with all other CPUs spinning, this is no longer the case. This commit therefore removes this obsolete comment. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Avoid invoking RCU core on offline CPUsPaul E. McKenney2013-03-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Offline CPUs transition through the scheduler to the idle loop one last time before being shut down. This can result in RCU raising softirq on this CPU, which is at best useless given that the CPU's callbacks will be offloaded at CPU_DEAD time. This commit therefore avoids raising softirq on offline CPUs. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Fix spacing problemJiang Fang2013-03-121-1/+1
| | |/ | | | | | | | | | | | | Signed-off-by: Jiang Fang <jiang.xx.fang@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * | rcu: Documentation updatePaul E. McKenney2013-03-123-11/+35
| | | | | | | | | | | | | | | | | | | | | This commit applies a few updates based on a quick review of the RCU documentations. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * | rcu: Make bugginess of code sample more evidentPaul E. McKenney2013-03-121-2/+2
| |/ | | | | | | | | | | | | | | | | | | One of the code samples in whatisRCU.txt shows a bug, but someone scanning the document quickly might mistake it for a valid use of RCU. Add some screaming comments to help keep speed-readers on track. Reported-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | Linux 3.9v3.9Linus Torvalds2013-04-281-1/+1
| |
* | Merge tag 'fixes-for-linus' of ↵Linus Torvalds2013-04-271-7/+11
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC fix from Olof Johansson: "A late-arriving fix for musb on OMAP4, resolving an issue where the musb IP won't be clocked and thus not functional. Small in scope, most of the lines changed is a longish comment." * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: ARM: OMAP4: hwmod data: make 'ocp2scp_usb_phy_phy_48m" as the main clock
| * \ Merge tag 'omap-for-v3.9-rc6/fixes-signed' of ↵Olof Johansson2013-04-261-7/+11
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes From Tony Lindgren: One MUSB regression fix that I forgot to send earlier. Without this MUSB no longer works on omap4 based devices. * tag 'omap-for-v3.9-rc6/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: ARM: OMAP4: hwmod data: make 'ocp2scp_usb_phy_phy_48m" as the main clock Signed-off-by: Olof Johansson <olof@lixom.net>
| | * | ARM: OMAP4: hwmod data: make 'ocp2scp_usb_phy_phy_48m" as the main clockKishon Vijay Abraham I2013-04-101-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 92702df3570e ("ARM: OMAP4: PM: fix PM regression introduced by recent clock cleanup") makes the 'ocp2scp_usb_phy_phy_48m' as optional functional clock causing regression in MUSB. But this 48MHz clock is a mandatory clock for usb phy attached to ocp2scp and hence made as the main clock for ocp2scp. Cc: Keerthy <j-keerthy@ti.com> Cc: Benoît Cousson <b-cousson@ti.com> Cc: Paul Walmsley <paul@pwsan.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> [paul@pwsan.com: add comment to the hwmod data to try to prevent any future mistakes here] Signed-off-by: Paul Walmsley <paul@pwsan.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
* | | | vm: add no-mmu vm_iomap_memory() stubLinus Torvalds2013-04-271-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I think we could just move the full vm_iomap_memory() function into util.h or similar, but I didn't get any reply from anybody actually using nommu even to this trivial patch, so I'm not going to touch it any more than required. Here's the fairly minimal stub to make the nommu case at least potentially work. It doesn't seem like anybody cares, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2013-04-271-0/+2
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fix from Ingo Molnar: "This fix adds missing RCU read protection" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: events: Protect access via task_subsys_state_check()
| * | | | events: Protect access via task_subsys_state_check()Paul E. McKenney2013-04-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following RCU splat indicates lack of RCU protection: [ 953.267649] =============================== [ 953.267652] [ INFO: suspicious RCU usage. ] [ 953.267657] 3.9.0-0.rc6.git2.4.fc19.ppc64p7 #1 Not tainted [ 953.267661] ------------------------------- [ 953.267664] include/linux/cgroup.h:534 suspicious rcu_dereference_check() usage! [ 953.267669] [ 953.267669] other info that might help us debug this: [ 953.267669] [ 953.267675] [ 953.267675] rcu_scheduler_active = 1, debug_locks = 0 [ 953.267680] 1 lock held by glxgears/1289: [ 953.267683] #0: (&sig->cred_guard_mutex){+.+.+.}, at: [<c00000000027f884>] .prepare_bprm_creds+0x34/0xa0 [ 953.267700] [ 953.267700] stack backtrace: [ 953.267704] Call Trace: [ 953.267709] [c0000001f0d1b6e0] [c000000000016e30] .show_stack+0x130/0x200 (unreliable) [ 953.267717] [c0000001f0d1b7b0] [c0000000001267f8] .lockdep_rcu_suspicious+0x138/0x180 [ 953.267724] [c0000001f0d1b840] [c0000000001d43a4] .perf_event_comm+0x4c4/0x690 [ 953.267731] [c0000001f0d1b950] [c00000000027f6e4] .set_task_comm+0x84/0x1f0 [ 953.267737] [c0000001f0d1b9f0] [c000000000280414] .setup_new_exec+0x94/0x220 [ 953.267744] [c0000001f0d1ba70] [c0000000002f665c] .load_elf_binary+0x58c/0x19b0 ... This commit therefore adds the required RCU read-side critical section to perf_event_comm(). Reported-by: Adam Jackson <ajax@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: a.p.zijlstra@chello.nl Cc: paulus@samba.org Cc: acme@ghostprotocols.net Link: http://lkml.kernel.org/r/20130419190124.GA8638@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Gustavo Luiz Duarte <gusld@br.ibm.com>
* | | | | Merge branch 'v4l_for_linus' of ↵Linus Torvalds2013-04-262-2/+2
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull media fixes from Mauro Carvalho Chehab: "Two driver fixes. One avoids reading any file at a system with a cx25821 board (fortunately, this is not a common device). The other one prevents reading after a buffer with ISDB-T devices based on mb86a20s." * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: [media] cx25821: do not expose broken video output streams [media] mb86a20s: Fix estimate_rate setting
| * | | | | [media] cx25821: do not expose broken video output streamsHans Verkuil2013-04-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cx25821 driver has support for one audio output channel and two video output channels. This is implemented in a very ugly and very evil way through a custom ioctl that passes the filename of a file containing the video data, which is then read by the driver itself using vfs. There are a number of problems with this: 1) it's very ugly and very evil (I can't say that often enough). 2) V4L2 supports video output, so why not use that? 3) it's very buggy, closing the filehandle through which you passed the ioctl will oops the kernel. 4) it's a nasty security leak since this allows you to load any file in the system as a video or audio source, so in theory you can output /etc/passwd to audio or video out and record & decode it on another device. Because of all these issues we no longer register those output video nodes. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| * | | | | [media] mb86a20s: Fix estimate_rate settingMauro Carvalho Chehab2013-04-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As reported by Dan Carpenter <dan.carpenter@oracle.com>: Smatch warnings: drivers/media/dvb-frontends/mb86a20s.c:644 mb86a20s_layer_bitrate() error: buffer overflow 'state->estimated_rate' 3 <= 3 What happens there is that estimate_rate index should be the layer number, and not the guard interval. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* | | | | | Merge branch 'fixes-3.9-late' of ↵Linus Torvalds2013-04-268-40/+67
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull late parisc fixes from Helge Deller: "I know it's *very* late in the 3.9 release cycle, but since there aren't that many people testing the parisc linux kernel, a few (for our port) critical issues just showed up a few days back for the first time. What's in it? - add missing __ucmpdi2 symbol, which is required for btrfs on 32bit kernel. - change kunmap() macro to static inline function. This fixes a debian/gcc-4.4 build error. - add locking when doing PTE updates. This fixes random userspace crashes. - disable (optional) -mlong-calls compiler option for modules, else modules can't be loaded at runtime. - a smart patch by Will Deacon which fixes 64bit put_user() warnings on 32bit kernel." * 'fixes-3.9-late' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: use spin_lock_irqsave/spin_unlock_irqrestore for PTE updates parisc: disable -mlong-calls compiler option for kernel modules parisc: uaccess: fix compiler warnings caused by __put_user casting parisc: Change kunmap macro to static inline function parisc: Provide __ucmpdi2 to resolve undefined references in 32 bit builds.
| * | | | | | parisc: use spin_lock_irqsave/spin_unlock_irqrestore for PTE updatesJohn David Anglin2013-04-252-26/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | User applications running on SMP kernels have long suffered from instability and random segmentation faults. This patch improves the situation although there is more work to be done. One of the problems is the various routines in pgtable.h that update page table entries use different locking mechanisms, or no lock at all (set_pte_at). This change modifies the routines to all use the same lock pa_dbit_lock. This lock is used for dirty bit updates in the interruption code. The patch also purges the TLB entries associated with the PTE to ensure that inconsistent values are not used after the page table entry is updated. The UP and SMP code are now identical. The change also includes a minor update to the purge_tlb_entries function in cache.c to improve its efficiency. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Helge Deller <deller@gmx.de>
| * | | | | | parisc: disable -mlong-calls compiler option for kernel modulesHelge Deller2013-04-251-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_MLONGCALLS was introduced in commit ec758f98328da3eb933a25dc7a2eed01ef44d849 to overcome linker issues when linking huge linux kernels, e.g. with many modules linked in. But in the kernel module loader there is no support yet for the new relocation types, which is why modules built with -mlong-calls can't be loaded. Furthermore, for modules long calls are not really necessary, since we already use stub sections which resolve long distance calls. So, let's just disable this compiler option when compiling kernel modules. Signed-off-by: Helge Deller <deller@gmx.de>
| * | | | | | parisc: uaccess: fix compiler warnings caused by __put_user castingWill Deacon2013-04-251-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When targetting 32-bit processors, __put_user emits a pair of stw instructions for the 8-byte case. If the type of __val is a pointer, the marshalling code casts it to the wider integer type of u64, resulting in the following compiler warnings: kernel/signal.c: In function 'copy_siginfo_to_user': kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] [...] This patch fixes the warnings by removing the marshalling code and using the correct output modifiers in the __put_{user,kernel}_asm64 macros so that GCC will allocate the right registers without the need to extract the two words explicitly. Cc: Helge Deller <deller@gmx.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Helge Deller <deller@gmx.de>
| * | | | | | parisc: Change kunmap macro to static inline functionJohn David Anglin2013-04-251-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change kunmap macro to static inline function to fix build error compiling drivers/base/dma-buf.c. Without the change, the following error can occur: CC drivers/base/dma-buf.o drivers/base/dma-buf.c: In function 'dma_buf_kunmap': drivers/base/dma-buf.c:427:46: error: macro "kunmap" passed 3 arguments, but takes just 1 I believe parisc is the only arch to implement kunmap using a macro. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Helge Deller <deller@gmx.de>
| * | | | | | parisc: Provide __ucmpdi2 to resolve undefined references in 32 bit builds.John David Anglin2013-04-253-1/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Debian experimental linux source package (3.8.5-1) build fails with the following errors: ... MODPOST 2016 modules ERROR: "__ucmpdi2" [fs/btrfs/btrfs.ko] undefined! ERROR: "__ucmpdi2" [drivers/md/dm-verity.ko] undefined! The attached patch resolves this problem. It is based on the s390 implementation of ucmpdi2.c. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Signed-off-by: Helge Deller <deller@gmx.de>
* | | | | | | efivars: only check for duplicates on the registered listMatt Fleming2013-04-261-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | variable_is_present() accesses '__efivars' directly, but when called via gsmi_init() Michel reports observing the following crash, BUG: unable to handle kernel NULL pointer dereference at (null) IP: variable_is_present+0x55/0x170 Call Trace: register_efivars+0x106/0x370 gsmi_init+0x2ad/0x3da do_one_initcall+0x3f/0x170 The reason for the crash is that '__efivars' hasn't been initialised nor has it been registered with register_efivars() by the time the google EFI SMI driver runs. The gsmi code uses its own struct efivars, and therefore, a different variable list. Fix the above crash by passing the registered struct efivars to variable_is_present(), so that we traverse the correct list. Reported-by: Michel Lespinasse <walken@google.com> Tested-by: Michel Lespinasse <walken@google.com> Cc: Mike Waychison <mikew@google.com> Cc: Matthew Garrett <matthew.garrett@nebula.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | TTY: fix atime/mtime regressionJiri Slaby2013-04-261-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit b0de59b5733d ("TTY: do not update atime/mtime on read/write") we removed timestamps from tty inodes to fix a security issue and waited if something breaks. Well, 'w', the utility to find out logged users and their inactivity time broke. It shows that users are inactive since the time they logged in. To revert to the old behaviour while still preventing attackers to guess the password length, we update the timestamps in one-minute intervals by this patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | aio: fix possible invalid memory access when DEBUG is enabledZhao Hongjiang2013-04-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dprintk() shouldn't access @ring after it's unmapped. Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | Merge tag 'efi-urgent' into x86/urgentH. Peter Anvin2013-04-251-2/+2
|\ \ \ \ \ \ \ | |/ / / / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * The EFI variable anti-bricking algorithm merged in -rc8 broke booting on some Apple machines because they implement EFI spec 1.10, which doesn't provide a QueryVariableInfo() runtime function and the logic used to check for the existence of that function was insufficient. Fix from Josh Boyer. * The anti-bricking algorithm also introduced a compiler warning on 32-bit. Fix from Borislav Petkov. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | | | | | efi: Check EFI revision in setup_efi_varsJosh Boyer2013-04-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to check the runtime sys_table for the EFI version the firmware specifies instead of just checking for a NULL QueryVariableInfo. Older implementations of EFI don't have QueryVariableInfo but the runtime is a smaller structure, so the pointer to it may be pointing off into garbage. This is apparently the case with several Apple firmwares that support EFI 1.10, and the current check causes them to no longer boot. Fix based on a suggestion from Matthew Garrett. Signed-off-by: Josh Boyer <jwboyer@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
| * | | | | | x86, efi: Fix a build warningBorislav Petkov2013-04-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix this: arch/x86/boot/compressed/eboot.c: In function ‘setup_efi_vars’: arch/x86/boot/compressed/eboot.c:269:2: warning: passing argument 1 of ‘efi_call_phys’ makes pointer from integer without a cast [enabled by default] In file included from arch/x86/boot/compressed/eboot.c:12:0: /w/kernel/linux/arch/x86/include/asm/efi.h:8:33: note: expected ‘void *’ but argument is of type ‘long unsigned int’ after cc5a080c5d40 ("efi: Pass boot services variable info to runtime code"). Reported-by: Paul Bolle <pebolle@tiscali.nl> Cc: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* | | | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparcLinus Torvalds2013-04-241-1/+2
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull sparc fix from David Miller: "Brown paper bag fix for sparc64" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: sparc64: Fix missing put_cpu_var() in tlb_batch_add_one() when not batching.
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