Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: add and use INIT_WORK_ON_STACK
  rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
  relay: fix lock imbalance in relay_late_setup_files
  oprofile: fix uninitialized use of struct op_entry
  rcu: move Kconfig menu
  softlock: fix false panic which can occur if softlockup_thresh is reduced
  rcu: add __cpuinit to rcu_init_percpu_data()

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index bb2e0f0975ae67d0a903f5542b4822595bda4ded..64d5ad0b8add85190ef600bb4f4887889729ef29 100644 (file)
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -633,6 +633,7 @@ static int hpet_cpuhp_notify(struct notifier_block *n,
                /* FIXME: add schedule_work_on() */
                schedule_delayed_work_on(cpu, &work.work, 0);
                wait_for_completion(&work.complete);
+               destroy_timer_on_stack(&work.work.timer);
                break;
        case CPU_DEAD:
                if (hdev) {

diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 2e03b6d796d39aac794e6c8c52d5de979f82a7c7..e76d715e4342b70b636183be3e23bbe880a74173 100644 (file)
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -393,16 +393,21 @@ oprofile_write_reserve(struct op_entry *entry, struct pt_regs * const regs,
        return;
 
 fail:
+       entry->event = NULL;
        cpu_buf->sample_lost_overflow++;
 }
 
 int oprofile_add_data(struct op_entry *entry, unsigned long val)
 {
+       if (!entry->event)
+               return 0;
        return op_cpu_buffer_add_data(entry, val);
 }
 
 int oprofile_write_commit(struct op_entry *entry)
 {
+       if (!entry->event)
+               return -EINVAL;
        return op_cpu_buffer_write_commit(entry);
 }
 

diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h
index 63f81c44846ae28b5bf2020d8fe445e4e4377d7b..272995d20293ab10aa4d77fb44d7f4bd79d76afb 100644 (file)
--- a/drivers/oprofile/cpu_buffer.h
+++ b/drivers/oprofile/cpu_buffer.h
@@ -66,6 +66,13 @@ static inline void op_cpu_buffer_reset(int cpu)
        cpu_buf->last_task = NULL;
 }
 
+/*
+ * op_cpu_buffer_add_data() and op_cpu_buffer_write_commit() may be
+ * called only if op_cpu_buffer_write_reserve() did not return NULL or
+ * entry->event != NULL, otherwise entry->size or entry->event will be
+ * used uninitialized.
+ */
+
 struct op_sample
 *op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
 int op_cpu_buffer_write_commit(struct op_entry *entry);

diff --git a/include/linux/sched.h b/include/linux/sched.h
index c20943eabb4c94b13d3ca70de00ad8550548b39d..02e16d2073042857e8f59565e2848c9821818744 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -293,6 +293,9 @@ extern void sched_show_task(struct task_struct *p);
 extern void softlockup_tick(void);
 extern void touch_softlockup_watchdog(void);
 extern void touch_all_softlockup_watchdogs(void);
+extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
+                                   struct file *filp, void __user *buffer,
+                                   size_t *lenp, loff_t *ppos);
 extern unsigned int  softlockup_panic;
 extern unsigned long sysctl_hung_task_check_count;
 extern unsigned long sysctl_hung_task_timeout_secs;

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 47151c8495aa87af42fd32b1c5c269af62f19dd4..3cd51e579ab1c2cddd3960e1154b9c493794a85b 100644 (file)
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -130,6 +130,12 @@ struct execute_work {
                init_timer_deferrable(&(_work)->timer);         \
        } while (0)
 
+#define INIT_DELAYED_WORK_ON_STACK(_work, _func)               \
+       do {                                                    \
+               INIT_WORK(&(_work)->work, (_func));             \
+               init_timer_on_stack(&(_work)->timer);           \
+       } while (0)
+
 /**
  * work_pending - Find out whether a work item is currently pending
  * @work: The work item in question

diff --git a/init/Kconfig b/init/Kconfig
index 2af83825634e2acbde448f88655f855df226f0b7..3be35f3a001b4bfc1741139dbc0fe20e2071e3cb 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -238,6 +238,98 @@ config AUDIT_TREE
        def_bool y
        depends on AUDITSYSCALL && INOTIFY
 
+menu "RCU Subsystem"
+
+choice
+       prompt "RCU Implementation"
+       default CLASSIC_RCU
+
+config CLASSIC_RCU
+       bool "Classic RCU"
+       help
+         This option selects the classic RCU implementation that is
+         designed for best read-side performance on non-realtime
+         systems.
+
+         Select this option if you are unsure.
+
+config TREE_RCU
+       bool "Tree-based hierarchical RCU"
+       help
+         This option selects the RCU implementation that is
+         designed for very large SMP system with hundreds or
+         thousands of CPUs.
+
+config PREEMPT_RCU
+       bool "Preemptible RCU"
+       depends on PREEMPT
+       help
+         This option reduces the latency of the kernel by making certain
+         RCU sections preemptible. Normally RCU code is non-preemptible, if
+         this option is selected then read-only RCU sections become
+         preemptible. This helps latency, but may expose bugs due to
+         now-naive assumptions about each RCU read-side critical section
+         remaining on a given CPU through its execution.
+
+endchoice
+
+config RCU_TRACE
+       bool "Enable tracing for RCU"
+       depends on TREE_RCU || PREEMPT_RCU
+       help
+         This option provides tracing in RCU which presents stats
+         in debugfs for debugging RCU implementation.
+
+         Say Y here if you want to enable RCU tracing
+         Say N if you are unsure.
+
+config RCU_FANOUT
+       int "Tree-based hierarchical RCU fanout value"
+       range 2 64 if 64BIT
+       range 2 32 if !64BIT
+       depends on TREE_RCU
+       default 64 if 64BIT
+       default 32 if !64BIT
+       help
+         This option controls the fanout of hierarchical implementations
+         of RCU, allowing RCU to work efficiently on machines with
+         large numbers of CPUs.  This value must be at least the cube
+         root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
+         systems and up to 262,144 for 64-bit systems.
+
+         Select a specific number if testing RCU itself.
+         Take the default if unsure.
+
+config RCU_FANOUT_EXACT
+       bool "Disable tree-based hierarchical RCU auto-balancing"
+       depends on TREE_RCU
+       default n
+       help
+         This option forces use of the exact RCU_FANOUT value specified,
+         regardless of imbalances in the hierarchy.  This is useful for
+         testing RCU itself, and might one day be useful on systems with
+         strong NUMA behavior.
+
+         Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
+
+         Say N if unsure.
+
+config TREE_RCU_TRACE
+       def_bool RCU_TRACE && TREE_RCU
+       select DEBUG_FS
+       help
+         This option provides tracing for the TREE_RCU implementation,
+         permitting Makefile to trivially select kernel/rcutree_trace.c.
+
+config PREEMPT_RCU_TRACE
+       def_bool RCU_TRACE && PREEMPT_RCU
+       select DEBUG_FS
+       help
+         This option provides tracing for the PREEMPT_RCU implementation,
+         permitting Makefile to trivially select kernel/rcupreempt_trace.c.
+
+endmenu # "RCU Subsystem"
+
 config IKCONFIG
        tristate "Kernel .config support"
        ---help---
@@ -972,90 +1064,3 @@ source "block/Kconfig"
 config PREEMPT_NOTIFIERS
        bool
 
-choice
-       prompt "RCU Implementation"
-       default CLASSIC_RCU
-
-config CLASSIC_RCU
-       bool "Classic RCU"
-       help
-         This option selects the classic RCU implementation that is
-         designed for best read-side performance on non-realtime
-         systems.
-
-         Select this option if you are unsure.
-
-config TREE_RCU
-       bool "Tree-based hierarchical RCU"
-       help
-         This option selects the RCU implementation that is
-         designed for very large SMP system with hundreds or
-         thousands of CPUs.
-
-config PREEMPT_RCU
-       bool "Preemptible RCU"
-       depends on PREEMPT
-       help
-         This option reduces the latency of the kernel by making certain
-         RCU sections preemptible. Normally RCU code is non-preemptible, if
-         this option is selected then read-only RCU sections become
-         preemptible. This helps latency, but may expose bugs due to
-         now-naive assumptions about each RCU read-side critical section
-         remaining on a given CPU through its execution.
-
-endchoice
-
-config RCU_TRACE
-       bool "Enable tracing for RCU"
-       depends on TREE_RCU || PREEMPT_RCU
-       help
-         This option provides tracing in RCU which presents stats
-         in debugfs for debugging RCU implementation.
-
-         Say Y here if you want to enable RCU tracing
-         Say N if you are unsure.
-
-config RCU_FANOUT
-       int "Tree-based hierarchical RCU fanout value"
-       range 2 64 if 64BIT
-       range 2 32 if !64BIT
-       depends on TREE_RCU
-       default 64 if 64BIT
-       default 32 if !64BIT
-       help
-         This option controls the fanout of hierarchical implementations
-         of RCU, allowing RCU to work efficiently on machines with
-         large numbers of CPUs.  This value must be at least the cube
-         root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
-         systems and up to 262,144 for 64-bit systems.
-
-         Select a specific number if testing RCU itself.
-         Take the default if unsure.
-
-config RCU_FANOUT_EXACT
-       bool "Disable tree-based hierarchical RCU auto-balancing"
-       depends on TREE_RCU
-       default n
-       help
-         This option forces use of the exact RCU_FANOUT value specified,
-         regardless of imbalances in the hierarchy.  This is useful for
-         testing RCU itself, and might one day be useful on systems with
-         strong NUMA behavior.
-
-         Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
-
-         Say N if unsure.
-
-config TREE_RCU_TRACE
-       def_bool RCU_TRACE && TREE_RCU
-       select DEBUG_FS
-       help
-         This option provides tracing for the TREE_RCU implementation,
-         permitting Makefile to trivially select kernel/rcutree_trace.c.
-
-config PREEMPT_RCU_TRACE
-       def_bool RCU_TRACE && PREEMPT_RCU
-       select DEBUG_FS
-       help
-         This option provides tracing for the PREEMPT_RCU implementation,
-         permitting Makefile to trivially select kernel/rcupreempt_trace.c.

diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c
index 490934fc7ac3a3b1fd9b094df0de8b0a5a794249..bd5a9003497c200d7ef7a44ec252b2d96b2ac562 100644 (file)
--- a/kernel/rcuclassic.c
+++ b/kernel/rcuclassic.c
@@ -716,7 +716,7 @@ void rcu_check_callbacks(int cpu, int user)
        raise_rcu_softirq();
 }
 
-static void rcu_init_percpu_data(int cpu, struct rcu_ctrlblk *rcp,
+static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_ctrlblk *rcp,
                                                struct rcu_data *rdp)
 {
        unsigned long flags;

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index f2d8638e6c60f12c193eb701af16cad6cb64e712..b2fd602a6f6f0433553a36a79e3a24172a8a2a2f 100644 (file)
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1314,7 +1314,7 @@ int rcu_needs_cpu(int cpu)
  * access due to the fact that this CPU cannot possibly have any RCU
  * callbacks in flight yet.
  */
-static void
+static void __cpuinit
 rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
 {
        unsigned long flags;

diff --git a/kernel/relay.c b/kernel/relay.c
index 09ac2008f77b419a5c169e41f3ddcbab6aa90746..9d79b7854fa6f98ee3595615798188ccf2f482fc 100644 (file)
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -663,8 +663,10 @@ int relay_late_setup_files(struct rchan *chan,
 
        mutex_lock(&relay_channels_mutex);
        /* Is chan already set up? */
-       if (unlikely(chan->has_base_filename))
+       if (unlikely(chan->has_base_filename)) {
+               mutex_unlock(&relay_channels_mutex);
                return -EEXIST;
+       }
        chan->has_base_filename = 1;
        chan->parent = parent;
        curr_cpu = get_cpu();

diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index d9188c66278ad5ad5dcaa2b95177bcdec3130655..85d5a2455103397015973321359a45e7d6d1928d 100644 (file)
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -16,6 +16,7 @@
 #include <linux/lockdep.h>
 #include <linux/notifier.h>
 #include <linux/module.h>
+#include <linux/sysctl.h>
 
 #include <asm/irq_regs.h>
 
@@ -88,6 +89,14 @@ void touch_all_softlockup_watchdogs(void)
 }
 EXPORT_SYMBOL(touch_all_softlockup_watchdogs);
 
+int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
+                            struct file *filp, void __user *buffer,
+                            size_t *lenp, loff_t *ppos)
+{
+       touch_all_softlockup_watchdogs();
+       return proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+}
+
 /*
  * This callback runs from the timer interrupt, and checks
  * whether the watchdog thread has hung or not:

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 368d1638ee78229c87067c4d805f7145fe79c352..790f9d785663105cdd5fcc44f33d4d8792f09761 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -809,7 +809,7 @@ static struct ctl_table kern_table[] = {
                .data           = &softlockup_thresh,
                .maxlen         = sizeof(int),
                .mode           = 0644,
-               .proc_handler   = &proc_dointvec_minmax,
+               .proc_handler   = &proc_dosoftlockup_thresh,
                .strategy       = &sysctl_intvec,
                .extra1         = &neg_one,
                .extra2         = &sixty,

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d30561dda907a1015f96160398115dba120e3349..29044f500269c3b9ad9b834adc21a77557ac897b 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -640,19 +640,6 @@ config RCU_TORTURE_TEST_RUNNABLE
          Say N here if you want the RCU torture tests to start only
          after being manually enabled via /proc.
 
-config RCU_CPU_STALL_DETECTOR
-       bool "Check for stalled CPUs delaying RCU grace periods"
-       depends on CLASSIC_RCU
-       default n
-       help
-         This option causes RCU to printk information on which
-         CPUs are delaying the current grace period, but only when
-         the grace period extends for excessive time periods.
-
-         Say Y if you want RCU to perform such checks.
-
-         Say N if you are unsure.
-
 config RCU_CPU_STALL_DETECTOR
        bool "Check for stalled CPUs delaying RCU grace periods"
        depends on CLASSIC_RCU || TREE_RCU