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authorFrederic Weisbecker <fweisbec@gmail.com>2010-02-27 16:18:46 +0100
committerFrederic Weisbecker <fweisbec@gmail.com>2010-02-27 16:18:46 +0100
commit018cbffe6819f6f8db20a0a3acd9bab9bfd667e4 (patch)
treefadde2521591998dc653fa094c636e8a547e620d /kernel
parent1dd2980d990068e20045b90c424518cc7f3657ff (diff)
parent60b341b778cc2929df16c0a504c91621b3c6a4ad (diff)
downloadop-kernel-dev-018cbffe6819f6f8db20a0a3acd9bab9bfd667e4.zip
op-kernel-dev-018cbffe6819f6f8db20a0a3acd9bab9bfd667e4.tar.gz
Merge commit 'v2.6.33' into perf/core
Merge reason: __percpu annotations need the corresponding sparse address space definition upstream. Conflicts: tools/perf/util/probe-event.c (trivial)
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c7
-rw-r--r--kernel/cpu.c10
-rw-r--r--kernel/cred.c2
-rw-r--r--kernel/fork.c15
-rw-r--r--kernel/futex.c30
-rw-r--r--kernel/hw_breakpoint.c54
-rw-r--r--kernel/kfifo.c6
-rw-r--r--kernel/kgdb.c9
-rw-r--r--kernel/lockdep.c2
-rw-r--r--kernel/perf_event.c13
-rw-r--r--kernel/sched.c39
-rw-r--r--kernel/softirq.c15
-rw-r--r--kernel/softlockup.c15
-rw-r--r--kernel/sys.c2
-rw-r--r--kernel/time/clocksource.c18
-rw-r--r--kernel/time/timekeeping.c2
-rw-r--r--kernel/trace/Kconfig4
-rw-r--r--kernel/trace/ring_buffer.c24
-rw-r--r--kernel/trace/trace.c5
-rw-r--r--kernel/trace/trace_kprobe.c2
-rw-r--r--kernel/trace/trace_stack.c24
21 files changed, 216 insertions, 82 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1fbcc74..aa3bee5 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2936,14 +2936,17 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
for_each_subsys(root, ss) {
struct cgroup_subsys_state *css = ss->create(ss, cgrp);
+
if (IS_ERR(css)) {
err = PTR_ERR(css);
goto err_destroy;
}
init_cgroup_css(css, ss, cgrp);
- if (ss->use_id)
- if (alloc_css_id(ss, parent, cgrp))
+ if (ss->use_id) {
+ err = alloc_css_id(ss, parent, cgrp);
+ if (err)
goto err_destroy;
+ }
/* At error, ->destroy() callback has to free assigned ID. */
}
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 1c8ddd6..677f253 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -151,13 +151,13 @@ static inline void check_for_tasks(int cpu)
write_lock_irq(&tasklist_lock);
for_each_process(p) {
- if (task_cpu(p) == cpu &&
+ if (task_cpu(p) == cpu && p->state == TASK_RUNNING &&
(!cputime_eq(p->utime, cputime_zero) ||
!cputime_eq(p->stime, cputime_zero)))
- printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d\
- (state = %ld, flags = %x) \n",
- p->comm, task_pid_nr(p), cpu,
- p->state, p->flags);
+ printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d "
+ "(state = %ld, flags = %x)\n",
+ p->comm, task_pid_nr(p), cpu,
+ p->state, p->flags);
}
write_unlock_irq(&tasklist_lock);
}
diff --git a/kernel/cred.c b/kernel/cred.c
index dd76cfe..1ed8ca1 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -224,7 +224,7 @@ struct cred *cred_alloc_blank(void)
#ifdef CONFIG_KEYS
new->tgcred = kzalloc(sizeof(*new->tgcred), GFP_KERNEL);
if (!new->tgcred) {
- kfree(new);
+ kmem_cache_free(cred_jar, new);
return NULL;
}
atomic_set(&new->tgcred->usage, 1);
diff --git a/kernel/fork.c b/kernel/fork.c
index 5b2959b..f88bd98 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1241,21 +1241,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
/* Need tasklist lock for parent etc handling! */
write_lock_irq(&tasklist_lock);
- /*
- * The task hasn't been attached yet, so its cpus_allowed mask will
- * not be changed, nor will its assigned CPU.
- *
- * The cpus_allowed mask of the parent may have changed after it was
- * copied first time - so re-copy it here, then check the child's CPU
- * to ensure it is on a valid CPU (and if not, just force it back to
- * parent's CPU). This avoids alot of nasty races.
- */
- p->cpus_allowed = current->cpus_allowed;
- p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed;
- if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
- !cpu_online(task_cpu(p))))
- set_task_cpu(p, smp_processor_id());
-
/* CLONE_PARENT re-uses the old parent */
if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
p->real_parent = current->real_parent;
diff --git a/kernel/futex.c b/kernel/futex.c
index d9b3a22..e7a35f10 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -530,8 +530,25 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
return -EINVAL;
WARN_ON(!atomic_read(&pi_state->refcount));
- WARN_ON(pid && pi_state->owner &&
- pi_state->owner->pid != pid);
+
+ /*
+ * When pi_state->owner is NULL then the owner died
+ * and another waiter is on the fly. pi_state->owner
+ * is fixed up by the task which acquires
+ * pi_state->rt_mutex.
+ *
+ * We do not check for pid == 0 which can happen when
+ * the owner died and robust_list_exit() cleared the
+ * TID.
+ */
+ if (pid && pi_state->owner) {
+ /*
+ * Bail out if user space manipulated the
+ * futex value.
+ */
+ if (pid != task_pid_vnr(pi_state->owner))
+ return -EINVAL;
+ }
atomic_inc(&pi_state->refcount);
*ps = pi_state;
@@ -758,6 +775,13 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
if (!pi_state)
return -EINVAL;
+ /*
+ * If current does not own the pi_state then the futex is
+ * inconsistent and user space fiddled with the futex value.
+ */
+ if (pi_state->owner != current)
+ return -EINVAL;
+
raw_spin_lock(&pi_state->pi_mutex.wait_lock);
new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
@@ -1971,7 +1995,7 @@ retry_private:
/* Unqueue and drop the lock */
unqueue_me_pi(&q);
- goto out;
+ goto out_put_key;
out_unlock_put_key:
queue_unlock(&q, hb);
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index c030ae6..967e6614 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -243,38 +243,70 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable)
* ((per_cpu(nr_bp_flexible, *) > 1) + max(per_cpu(nr_cpu_bp_pinned, *))
* + max(per_cpu(nr_task_bp_pinned, *))) < HBP_NUM
*/
-int reserve_bp_slot(struct perf_event *bp)
+static int __reserve_bp_slot(struct perf_event *bp)
{
struct bp_busy_slots slots = {0};
- int ret = 0;
-
- mutex_lock(&nr_bp_mutex);
fetch_bp_busy_slots(&slots, bp);
/* Flexible counters need to keep at least one slot */
- if (slots.pinned + (!!slots.flexible) == HBP_NUM) {
- ret = -ENOSPC;
- goto end;
- }
+ if (slots.pinned + (!!slots.flexible) == HBP_NUM)
+ return -ENOSPC;
toggle_bp_slot(bp, true);
-end:
+ return 0;
+}
+
+int reserve_bp_slot(struct perf_event *bp)
+{
+ int ret;
+
+ mutex_lock(&nr_bp_mutex);
+
+ ret = __reserve_bp_slot(bp);
+
mutex_unlock(&nr_bp_mutex);
return ret;
}
+static void __release_bp_slot(struct perf_event *bp)
+{
+ toggle_bp_slot(bp, false);
+}
+
void release_bp_slot(struct perf_event *bp)
{
mutex_lock(&nr_bp_mutex);
- toggle_bp_slot(bp, false);
+ __release_bp_slot(bp);
mutex_unlock(&nr_bp_mutex);
}
+/*
+ * Allow the kernel debugger to reserve breakpoint slots without
+ * taking a lock using the dbg_* variant of for the reserve and
+ * release breakpoint slots.
+ */
+int dbg_reserve_bp_slot(struct perf_event *bp)
+{
+ if (mutex_is_locked(&nr_bp_mutex))
+ return -1;
+
+ return __reserve_bp_slot(bp);
+}
+
+int dbg_release_bp_slot(struct perf_event *bp)
+{
+ if (mutex_is_locked(&nr_bp_mutex))
+ return -1;
+
+ __release_bp_slot(bp);
+
+ return 0;
+}
int register_perf_hw_breakpoint(struct perf_event *bp)
{
@@ -328,8 +360,8 @@ EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
{
u64 old_addr = bp->attr.bp_addr;
+ u64 old_len = bp->attr.bp_len;
int old_type = bp->attr.bp_type;
- int old_len = bp->attr.bp_len;
int err = 0;
perf_event_disable(bp);
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 32c5c15..35edbe22 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -80,7 +80,7 @@ int kfifo_alloc(struct kfifo *fifo, unsigned int size, gfp_t gfp_mask)
buffer = kmalloc(size, gfp_mask);
if (!buffer) {
- _kfifo_init(fifo, 0, 0);
+ _kfifo_init(fifo, NULL, 0);
return -ENOMEM;
}
@@ -97,6 +97,7 @@ EXPORT_SYMBOL(kfifo_alloc);
void kfifo_free(struct kfifo *fifo)
{
kfree(fifo->buffer);
+ _kfifo_init(fifo, NULL, 0);
}
EXPORT_SYMBOL(kfifo_free);
@@ -349,6 +350,7 @@ EXPORT_SYMBOL(__kfifo_from_user_n);
* @fifo: the fifo to be used.
* @from: pointer to the data to be added.
* @len: the length of the data to be added.
+ * @total: the actual returned data length.
*
* This function copies at most @len bytes from the @from into the
* FIFO depending and returns -EFAULT/0.
@@ -399,7 +401,7 @@ EXPORT_SYMBOL(__kfifo_to_user_n);
* @fifo: the fifo to be used.
* @to: where the data must be copied.
* @len: the size of the destination buffer.
- @ @lenout: pointer to output variable with copied data
+ * @lenout: pointer to output variable with copied data
*
* This function copies at most @len bytes from the FIFO into the
* @to buffer and 0 or -EFAULT.
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 2eb517e..761fdd2 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -583,6 +583,9 @@ static void kgdb_wait(struct pt_regs *regs)
smp_wmb();
atomic_set(&cpu_in_kgdb[cpu], 1);
+ /* Disable any cpu specific hw breakpoints */
+ kgdb_disable_hw_debug(regs);
+
/* Wait till primary CPU is done with debugging */
while (atomic_read(&passive_cpu_wait[cpu]))
cpu_relax();
@@ -596,7 +599,7 @@ static void kgdb_wait(struct pt_regs *regs)
/* Signal the primary CPU that we are done: */
atomic_set(&cpu_in_kgdb[cpu], 0);
- touch_softlockup_watchdog();
+ touch_softlockup_watchdog_sync();
clocksource_touch_watchdog();
local_irq_restore(flags);
}
@@ -1450,7 +1453,7 @@ acquirelock:
(kgdb_info[cpu].task &&
kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) {
atomic_set(&kgdb_active, -1);
- touch_softlockup_watchdog();
+ touch_softlockup_watchdog_sync();
clocksource_touch_watchdog();
local_irq_restore(flags);
@@ -1550,7 +1553,7 @@ kgdb_restore:
}
/* Free kgdb_active */
atomic_set(&kgdb_active, -1);
- touch_softlockup_watchdog();
+ touch_softlockup_watchdog_sync();
clocksource_touch_watchdog();
local_irq_restore(flags);
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 5feaddc..c62ec14 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2147,7 +2147,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
return ret;
return print_irq_inversion_bug(curr, &root, target_entry,
- this, 1, irqclass);
+ this, 0, irqclass);
}
void print_irqtrace_events(struct task_struct *curr)
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index aa6155b..a661e79 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -3407,8 +3407,6 @@ static void perf_event_task_output(struct perf_event *event,
task_event->event_id.tid = perf_event_tid(event, task);
task_event->event_id.ptid = perf_event_tid(event, current);
- task_event->event_id.time = perf_clock();
-
perf_output_put(&handle, task_event->event_id);
perf_output_end(&handle);
@@ -3416,7 +3414,7 @@ static void perf_event_task_output(struct perf_event *event,
static int perf_event_task_match(struct perf_event *event)
{
- if (event->state != PERF_EVENT_STATE_ACTIVE)
+ if (event->state < PERF_EVENT_STATE_INACTIVE)
return 0;
if (event->cpu != -1 && event->cpu != smp_processor_id())
@@ -3448,7 +3446,7 @@ static void perf_event_task_event(struct perf_task_event *task_event)
cpuctx = &get_cpu_var(perf_cpu_context);
perf_event_task_ctx(&cpuctx->ctx, task_event);
if (!ctx)
- ctx = rcu_dereference(task_event->task->perf_event_ctxp);
+ ctx = rcu_dereference(current->perf_event_ctxp);
if (ctx)
perf_event_task_ctx(ctx, task_event);
put_cpu_var(perf_cpu_context);
@@ -3479,6 +3477,7 @@ static void perf_event_task(struct task_struct *task,
/* .ppid */
/* .tid */
/* .ptid */
+ .time = perf_clock(),
},
};
@@ -3528,7 +3527,7 @@ static void perf_event_comm_output(struct perf_event *event,
static int perf_event_comm_match(struct perf_event *event)
{
- if (event->state != PERF_EVENT_STATE_ACTIVE)
+ if (event->state < PERF_EVENT_STATE_INACTIVE)
return 0;
if (event->cpu != -1 && event->cpu != smp_processor_id())
@@ -3648,7 +3647,7 @@ static void perf_event_mmap_output(struct perf_event *event,
static int perf_event_mmap_match(struct perf_event *event,
struct perf_mmap_event *mmap_event)
{
- if (event->state != PERF_EVENT_STATE_ACTIVE)
+ if (event->state < PERF_EVENT_STATE_INACTIVE)
return 0;
if (event->cpu != -1 && event->cpu != smp_processor_id())
@@ -4728,7 +4727,7 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
if (attr->type >= PERF_TYPE_MAX)
return -EINVAL;
- if (attr->__reserved_1 || attr->__reserved_2)
+ if (attr->__reserved_1)
return -EINVAL;
if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
diff --git a/kernel/sched.c b/kernel/sched.c
index 7266b91..3e71ebb 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2320,14 +2320,12 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
}
/*
- * Called from:
+ * Gets called from 3 sites (exec, fork, wakeup), since it is called without
+ * holding rq->lock we need to ensure ->cpus_allowed is stable, this is done
+ * by:
*
- * - fork, @p is stable because it isn't on the tasklist yet
- *
- * - exec, @p is unstable, retry loop
- *
- * - wake-up, we serialize ->cpus_allowed against TASK_WAKING so
- * we should be good.
+ * exec: is unstable, retry loop
+ * fork & wake-up: serialize ->cpus_allowed against TASK_WAKING
*/
static inline
int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
@@ -2620,9 +2618,6 @@ void sched_fork(struct task_struct *p, int clone_flags)
if (p->sched_class->task_fork)
p->sched_class->task_fork(p);
-#ifdef CONFIG_SMP
- cpu = select_task_rq(p, SD_BALANCE_FORK, 0);
-#endif
set_task_cpu(p, cpu);
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
@@ -2652,6 +2647,21 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
{
unsigned long flags;
struct rq *rq;
+ int cpu = get_cpu();
+
+#ifdef CONFIG_SMP
+ /*
+ * Fork balancing, do it here and not earlier because:
+ * - cpus_allowed can change in the fork path
+ * - any previously selected cpu might disappear through hotplug
+ *
+ * We still have TASK_WAKING but PF_STARTING is gone now, meaning
+ * ->cpus_allowed is stable, we have preemption disabled, meaning
+ * cpu_online_mask is stable.
+ */
+ cpu = select_task_rq(p, SD_BALANCE_FORK, 0);
+ set_task_cpu(p, cpu);
+#endif
rq = task_rq_lock(p, &flags);
BUG_ON(p->state != TASK_WAKING);
@@ -2665,6 +2675,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
p->sched_class->task_woken(rq, p);
#endif
task_rq_unlock(rq, &flags);
+ put_cpu();
}
#ifdef CONFIG_PREEMPT_NOTIFIERS
@@ -7145,14 +7156,18 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
* the ->cpus_allowed mask from under waking tasks, which would be
* possible when we change rq->lock in ttwu(), so synchronize against
* TASK_WAKING to avoid that.
+ *
+ * Make an exception for freshly cloned tasks, since cpuset namespaces
+ * might move the task about, we have to validate the target in
+ * wake_up_new_task() anyway since the cpu might have gone away.
*/
again:
- while (p->state == TASK_WAKING)
+ while (p->state == TASK_WAKING && !(p->flags & PF_STARTING))
cpu_relax();
rq = task_rq_lock(p, &flags);
- if (p->state == TASK_WAKING) {
+ if (p->state == TASK_WAKING && !(p->flags & PF_STARTING)) {
task_rq_unlock(rq, &flags);
goto again;
}
diff --git a/kernel/softirq.c b/kernel/softirq.c
index a09502e..7c1a67e 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -500,22 +500,17 @@ EXPORT_SYMBOL(tasklet_kill);
*/
/*
- * The trampoline is called when the hrtimer expires. If this is
- * called from the hrtimer interrupt then we schedule the tasklet as
- * the timer callback function expects to run in softirq context. If
- * it's called in softirq context anyway (i.e. high resolution timers
- * disabled) then the hrtimer callback is called right away.
+ * The trampoline is called when the hrtimer expires. It schedules a tasklet
+ * to run __tasklet_hrtimer_trampoline() which in turn will call the intended
+ * hrtimer callback, but from softirq context.
*/
static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer)
{
struct tasklet_hrtimer *ttimer =
container_of(timer, struct tasklet_hrtimer, timer);
- if (hrtimer_is_hres_active(timer)) {
- tasklet_hi_schedule(&ttimer->tasklet);
- return HRTIMER_NORESTART;
- }
- return ttimer->function(timer);
+ tasklet_hi_schedule(&ttimer->tasklet);
+ return HRTIMER_NORESTART;
}
/*
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index d225790..0d4c789 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -25,6 +25,7 @@ static DEFINE_SPINLOCK(print_lock);
static DEFINE_PER_CPU(unsigned long, softlockup_touch_ts); /* touch timestamp */
static DEFINE_PER_CPU(unsigned long, softlockup_print_ts); /* print timestamp */
static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog);
+static DEFINE_PER_CPU(bool, softlock_touch_sync);
static int __read_mostly did_panic;
int __read_mostly softlockup_thresh = 60;
@@ -79,6 +80,12 @@ void touch_softlockup_watchdog(void)
}
EXPORT_SYMBOL(touch_softlockup_watchdog);
+void touch_softlockup_watchdog_sync(void)
+{
+ __raw_get_cpu_var(softlock_touch_sync) = true;
+ __raw_get_cpu_var(softlockup_touch_ts) = 0;
+}
+
void touch_all_softlockup_watchdogs(void)
{
int cpu;
@@ -118,6 +125,14 @@ void softlockup_tick(void)
}
if (touch_ts == 0) {
+ if (unlikely(per_cpu(softlock_touch_sync, this_cpu))) {
+ /*
+ * If the time stamp was touched atomically
+ * make sure the scheduler tick is up to date.
+ */
+ per_cpu(softlock_touch_sync, this_cpu) = false;
+ sched_clock_tick();
+ }
__touch_softlockup_watchdog();
return;
}
diff --git a/kernel/sys.c b/kernel/sys.c
index 26a6b73..18bde97 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -222,6 +222,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
if (which > PRIO_USER || which < PRIO_PROCESS)
return -EINVAL;
+ rcu_read_lock();
read_lock(&tasklist_lock);
switch (which) {
case PRIO_PROCESS:
@@ -267,6 +268,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
}
out_unlock:
read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return retval;
}
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index e85c234..1370083 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -343,7 +343,19 @@ static void clocksource_resume_watchdog(void)
{
unsigned long flags;
- spin_lock_irqsave(&watchdog_lock, flags);
+ /*
+ * We use trylock here to avoid a potential dead lock when
+ * kgdb calls this code after the kernel has been stopped with
+ * watchdog_lock held. When watchdog_lock is held we just
+ * return and accept, that the watchdog might trigger and mark
+ * the monitored clock source (usually TSC) unstable.
+ *
+ * This does not affect the other caller clocksource_resume()
+ * because at this point the kernel is UP, interrupts are
+ * disabled and nothing can hold watchdog_lock.
+ */
+ if (!spin_trylock_irqsave(&watchdog_lock, flags))
+ return;
clocksource_reset_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
}
@@ -458,8 +470,8 @@ void clocksource_resume(void)
* clocksource_touch_watchdog - Update watchdog
*
* Update the watchdog after exception contexts such as kgdb so as not
- * to incorrectly trip the watchdog.
- *
+ * to incorrectly trip the watchdog. This might fail when the kernel
+ * was stopped in code which holds watchdog_lock.
*/
void clocksource_touch_watchdog(void)
{
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 7faaa32..e2ab064 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -880,6 +880,7 @@ void getboottime(struct timespec *ts)
set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
}
+EXPORT_SYMBOL_GPL(getboottime);
/**
* monotonic_to_bootbased - Convert the monotonic time to boot based.
@@ -889,6 +890,7 @@ void monotonic_to_bootbased(struct timespec *ts)
{
*ts = timespec_add_safe(*ts, total_sleep_time);
}
+EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
unsigned long get_seconds(void)
{
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 6c22d8a..60e2ce0 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -27,9 +27,7 @@ config HAVE_FUNCTION_GRAPH_TRACER
config HAVE_FUNCTION_GRAPH_FP_TEST
bool
help
- An arch may pass in a unique value (frame pointer) to both the
- entering and exiting of a function. On exit, the value is compared
- and if it does not match, then it will panic the kernel.
+ See Documentation/trace/ftrace-design.txt
config HAVE_FUNCTION_TRACE_MCOUNT_TEST
bool
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index edefe3b..8c1b2d2 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -464,6 +464,8 @@ struct ring_buffer_iter {
struct ring_buffer_per_cpu *cpu_buffer;
unsigned long head;
struct buffer_page *head_page;
+ struct buffer_page *cache_reader_page;
+ unsigned long cache_read;
u64 read_stamp;
};
@@ -2716,6 +2718,8 @@ static void rb_iter_reset(struct ring_buffer_iter *iter)
iter->read_stamp = cpu_buffer->read_stamp;
else
iter->read_stamp = iter->head_page->page->time_stamp;
+ iter->cache_reader_page = cpu_buffer->reader_page;
+ iter->cache_read = cpu_buffer->read;
}
/**
@@ -3060,13 +3064,22 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
struct ring_buffer_event *event;
int nr_loops = 0;
- if (ring_buffer_iter_empty(iter))
- return NULL;
-
cpu_buffer = iter->cpu_buffer;
buffer = cpu_buffer->buffer;
+ /*
+ * Check if someone performed a consuming read to
+ * the buffer. A consuming read invalidates the iterator
+ * and we need to reset the iterator in this case.
+ */
+ if (unlikely(iter->cache_read != cpu_buffer->read ||
+ iter->cache_reader_page != cpu_buffer->reader_page))
+ rb_iter_reset(iter);
+
again:
+ if (ring_buffer_iter_empty(iter))
+ return NULL;
+
/*
* We repeat when a timestamp is encountered.
* We can get multiple timestamps by nested interrupts or also
@@ -3081,6 +3094,11 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
if (rb_per_cpu_empty(cpu_buffer))
return NULL;
+ if (iter->head >= local_read(&iter->head_page->page->commit)) {
+ rb_inc_iter(iter);
+ goto again;
+ }
+
event = rb_iter_head_event(iter);
switch (event->type_len) {
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0df1b0f..eac6875 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -951,6 +951,11 @@ void trace_find_cmdline(int pid, char comm[])
return;
}
+ if (WARN_ON_ONCE(pid < 0)) {
+ strcpy(comm, "<XXX>");
+ return;
+ }
+
if (pid > PID_MAX_DEFAULT) {
strcpy(comm, "<...>");
return;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 6178abf..356c102 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -673,7 +673,7 @@ static int create_trace_probe(int argc, char **argv)
return -EINVAL;
}
/* an address specified */
- ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr);
+ ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
if (ret) {
pr_info("Failed to parse address.\n");
return ret;
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 678a512..f4bc9b2 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -157,6 +157,7 @@ stack_max_size_write(struct file *filp, const char __user *ubuf,
unsigned long val, flags;
char buf[64];
int ret;
+ int cpu;
if (count >= sizeof(buf))
return -EINVAL;
@@ -171,9 +172,20 @@ stack_max_size_write(struct file *filp, const char __user *ubuf,
return ret;
local_irq_save(flags);
+
+ /*
+ * In case we trace inside arch_spin_lock() or after (NMI),
+ * we will cause circular lock, so we also need to increase
+ * the percpu trace_active here.
+ */
+ cpu = smp_processor_id();
+ per_cpu(trace_active, cpu)++;
+
arch_spin_lock(&max_stack_lock);
*ptr = val;
arch_spin_unlock(&max_stack_lock);
+
+ per_cpu(trace_active, cpu)--;
local_irq_restore(flags);
return count;
@@ -206,7 +218,13 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
static void *t_start(struct seq_file *m, loff_t *pos)
{
+ int cpu;
+
local_irq_disable();
+
+ cpu = smp_processor_id();
+ per_cpu(trace_active, cpu)++;
+
arch_spin_lock(&max_stack_lock);
if (*pos == 0)
@@ -217,7 +235,13 @@ static void *t_start(struct seq_file *m, loff_t *pos)
static void t_stop(struct seq_file *m, void *p)
{
+ int cpu;
+
arch_spin_unlock(&max_stack_lock);
+
+ cpu = smp_processor_id();
+ per_cpu(trace_active, cpu)--;
+
local_irq_enable();
}
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