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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c123
1 files changed, 63 insertions, 60 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 948f7d821c62..1cd2e8143bb4 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -652,12 +652,10 @@ void tracing_record_cmdline(struct task_struct *tsk)
}
void
-tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
+tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
+ int pc)
{
struct task_struct *tsk = current;
- unsigned long pc;
-
- pc = preempt_count();
entry->preempt_count = pc & 0xff;
entry->pid = (tsk) ? tsk->pid : 0;
@@ -670,7 +668,8 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
void
trace_function(struct trace_array *tr, struct trace_array_cpu *data,
- unsigned long ip, unsigned long parent_ip, unsigned long flags)
+ unsigned long ip, unsigned long parent_ip, unsigned long flags,
+ int pc)
{
struct ring_buffer_event *event;
struct ftrace_entry *entry;
@@ -685,7 +684,7 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
if (!event)
return;
entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, flags);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
entry->ent.type = TRACE_FN;
entry->ip = ip;
entry->parent_ip = parent_ip;
@@ -694,16 +693,17 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
void
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
- unsigned long ip, unsigned long parent_ip, unsigned long flags)
+ unsigned long ip, unsigned long parent_ip, unsigned long flags,
+ int pc)
{
if (likely(!atomic_read(&data->disabled)))
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, pc);
}
-void __trace_stack(struct trace_array *tr,
- struct trace_array_cpu *data,
- unsigned long flags,
- int skip)
+static void ftrace_trace_stack(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long flags,
+ int skip, int pc)
{
struct ring_buffer_event *event;
struct stack_entry *entry;
@@ -718,7 +718,7 @@ void __trace_stack(struct trace_array *tr,
if (!event)
return;
entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, flags);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
entry->ent.type = TRACE_STACK;
memset(&entry->caller, 0, sizeof(entry->caller));
@@ -732,9 +732,18 @@ void __trace_stack(struct trace_array *tr,
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
}
-void
-__trace_special(void *__tr, void *__data,
- unsigned long arg1, unsigned long arg2, unsigned long arg3)
+void __trace_stack(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long flags,
+ int skip)
+{
+ ftrace_trace_stack(tr, data, flags, skip, preempt_count());
+}
+
+static void
+ftrace_trace_special(void *__tr, void *__data,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3,
+ int pc)
{
struct ring_buffer_event *event;
struct trace_array_cpu *data = __data;
@@ -747,23 +756,30 @@ __trace_special(void *__tr, void *__data,
if (!event)
return;
entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, 0);
+ tracing_generic_entry_update(&entry->ent, 0, pc);
entry->ent.type = TRACE_SPECIAL;
entry->arg1 = arg1;
entry->arg2 = arg2;
entry->arg3 = arg3;
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
- __trace_stack(tr, data, irq_flags, 4);
+ ftrace_trace_stack(tr, data, irq_flags, 4, pc);
trace_wake_up();
}
void
+__trace_special(void *__tr, void *__data,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+ ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
+}
+
+void
tracing_sched_switch_trace(struct trace_array *tr,
struct trace_array_cpu *data,
struct task_struct *prev,
struct task_struct *next,
- unsigned long flags)
+ unsigned long flags, int pc)
{
struct ring_buffer_event *event;
struct ctx_switch_entry *entry;
@@ -774,7 +790,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
if (!event)
return;
entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, flags);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
entry->ent.type = TRACE_CTX;
entry->prev_pid = prev->pid;
entry->prev_prio = prev->prio;
@@ -784,7 +800,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
entry->next_state = next->state;
entry->next_cpu = task_cpu(next);
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
- __trace_stack(tr, data, flags, 5);
+ ftrace_trace_stack(tr, data, flags, 5, pc);
}
void
@@ -792,7 +808,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
struct trace_array_cpu *data,
struct task_struct *wakee,
struct task_struct *curr,
- unsigned long flags)
+ unsigned long flags, int pc)
{
struct ring_buffer_event *event;
struct ctx_switch_entry *entry;
@@ -803,7 +819,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
if (!event)
return;
entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, flags);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
entry->ent.type = TRACE_WAKE;
entry->prev_pid = curr->pid;
entry->prev_prio = curr->prio;
@@ -813,7 +829,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
entry->next_state = wakee->state;
entry->next_cpu = task_cpu(wakee);
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
- __trace_stack(tr, data, flags, 6);
+ ftrace_trace_stack(tr, data, flags, 6, pc);
trace_wake_up();
}
@@ -823,23 +839,24 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
{
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
- unsigned long flags;
long disabled;
int cpu;
+ int pc;
if (tracing_disabled || !tr->ctrl)
return;
- local_irq_save(flags);
+ pc = preempt_count();
+ preempt_disable_notrace();
cpu = raw_smp_processor_id();
data = tr->data[cpu];
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1))
- __trace_special(tr, data, arg1, arg2, arg3);
+ ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
atomic_dec(&data->disabled);
- local_irq_restore(flags);
+ preempt_enable_notrace();
}
#ifdef CONFIG_FTRACE
@@ -850,7 +867,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
struct trace_array_cpu *data;
unsigned long flags;
long disabled;
- int cpu;
+ int cpu, resched;
+ int pc;
if (unlikely(!ftrace_function_enabled))
return;
@@ -858,16 +876,22 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
if (skip_trace(ip))
return;
- local_irq_save(flags);
+ pc = preempt_count();
+ resched = need_resched();
+ preempt_disable_notrace();
+ local_save_flags(flags);
cpu = raw_smp_processor_id();
data = tr->data[cpu];
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1))
- trace_function(tr, data, ip, parent_ip, flags);
+ trace_function(tr, data, ip, parent_ip, flags, pc);
atomic_dec(&data->disabled);
- local_irq_restore(flags);
+ if (resched)
+ preempt_enable_no_resched_notrace();
+ else
+ preempt_enable_notrace();
}
static struct ftrace_ops trace_ops __read_mostly =
@@ -2508,9 +2532,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
struct trace_iterator *iter = filp->private_data;
-#ifdef CONFIG_FTRACE
- int ftrace_save;
-#endif
ssize_t sret;
/* return any leftover data */
@@ -2593,20 +2614,6 @@ waitagain:
offsetof(struct trace_iterator, seq));
iter->pos = -1;
- /*
- * We need to stop all tracing on all CPUS to read the
- * the next buffer. This is a bit expensive, but is
- * not done often. We fill all what we can read,
- * and then release the locks again.
- */
-
- local_irq_disable();
-#ifdef CONFIG_FTRACE
- ftrace_save = ftrace_enabled;
- ftrace_enabled = 0;
-#endif
- smp_wmb();
-
while (find_next_entry_inc(iter) != NULL) {
enum print_line_t ret;
int len = iter->seq.len;
@@ -2624,11 +2631,6 @@ waitagain:
break;
}
-#ifdef CONFIG_FTRACE
- ftrace_enabled = ftrace_save;
-#endif
- local_irq_enable();
-
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
if (iter->seq.readpos >= iter->seq.len)
@@ -2960,12 +2962,13 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
struct print_entry *entry;
unsigned long flags, irq_flags;
long disabled;
- int cpu, len = 0, size;
+ int cpu, len = 0, size, pc;
if (!tr->ctrl || tracing_disabled)
return 0;
- local_irq_save(flags);
+ pc = preempt_count();
+ preempt_disable_notrace();
cpu = raw_smp_processor_id();
data = tr->data[cpu];
disabled = atomic_inc_return(&data->disabled);
@@ -2973,7 +2976,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
if (unlikely(disabled != 1))
goto out;
- spin_lock(&trace_buf_lock);
+ spin_lock_irqsave(&trace_buf_lock, flags);
len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
len = min(len, TRACE_BUF_SIZE-1);
@@ -2984,7 +2987,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
if (!event)
goto out_unlock;
entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, flags);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
entry->ent.type = TRACE_PRINT;
entry->ip = ip;
@@ -2993,11 +2996,11 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
out_unlock:
- spin_unlock(&trace_buf_lock);
+ spin_unlock_irqrestore(&trace_buf_lock, flags);
out:
atomic_dec(&data->disabled);
- local_irq_restore(flags);
+ preempt_enable_notrace();
return len;
}