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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c326
1 files changed, 207 insertions, 119 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ee9c921d7f21..e5df02c69b1d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -343,26 +343,27 @@ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
static int trace_stop_count;
static DEFINE_SPINLOCK(tracing_start_lock);
+static void wakeup_work_handler(struct work_struct *work)
+{
+ wake_up(&trace_wait);
+}
+
+static DECLARE_DELAYED_WORK(wakeup_work, wakeup_work_handler);
+
/**
* trace_wake_up - wake up tasks waiting for trace input
*
- * Simply wakes up any task that is blocked on the trace_wait
- * queue. These is used with trace_poll for tasks polling the trace.
+ * Schedules a delayed work to wake up any task that is blocked on the
+ * trace_wait queue. These is used with trace_poll for tasks polling the
+ * trace.
*/
void trace_wake_up(void)
{
- int cpu;
+ const unsigned long delay = msecs_to_jiffies(2);
if (trace_flags & TRACE_ITER_BLOCK)
return;
- /*
- * The runqueue_is_locked() can fail, but this is the best we
- * have for now:
- */
- cpu = get_cpu();
- if (!runqueue_is_locked(cpu))
- wake_up(&trace_wait);
- put_cpu();
+ schedule_delayed_work(&wakeup_work, delay);
}
static int __init set_buf_size(char *str)
@@ -424,6 +425,7 @@ static const char *trace_options[] = {
"graph-time",
"record-cmd",
"overwrite",
+ "disable_on_free",
NULL
};
@@ -1191,6 +1193,18 @@ void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
}
EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit);
+void trace_nowake_buffer_unlock_commit_regs(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags, int pc,
+ struct pt_regs *regs)
+{
+ ring_buffer_unlock_commit(buffer, event);
+
+ ftrace_trace_stack_regs(buffer, flags, 0, pc, regs);
+ ftrace_trace_userstack(buffer, flags, pc);
+}
+EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit_regs);
+
void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event)
{
@@ -1234,30 +1248,103 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
}
#ifdef CONFIG_STACKTRACE
+
+#define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long))
+struct ftrace_stack {
+ unsigned long calls[FTRACE_STACK_MAX_ENTRIES];
+};
+
+static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack);
+static DEFINE_PER_CPU(int, ftrace_stack_reserve);
+
static void __ftrace_trace_stack(struct ring_buffer *buffer,
unsigned long flags,
- int skip, int pc)
+ int skip, int pc, struct pt_regs *regs)
{
struct ftrace_event_call *call = &event_kernel_stack;
struct ring_buffer_event *event;
struct stack_entry *entry;
struct stack_trace trace;
+ int use_stack;
+ int size = FTRACE_STACK_ENTRIES;
+
+ trace.nr_entries = 0;
+ trace.skip = skip;
+
+ /*
+ * Since events can happen in NMIs there's no safe way to
+ * use the per cpu ftrace_stacks. We reserve it and if an interrupt
+ * or NMI comes in, it will just have to use the default
+ * FTRACE_STACK_SIZE.
+ */
+ preempt_disable_notrace();
+
+ use_stack = ++__get_cpu_var(ftrace_stack_reserve);
+ /*
+ * We don't need any atomic variables, just a barrier.
+ * If an interrupt comes in, we don't care, because it would
+ * have exited and put the counter back to what we want.
+ * We just need a barrier to keep gcc from moving things
+ * around.
+ */
+ barrier();
+ if (use_stack == 1) {
+ trace.entries = &__get_cpu_var(ftrace_stack).calls[0];
+ trace.max_entries = FTRACE_STACK_MAX_ENTRIES;
+
+ if (regs)
+ save_stack_trace_regs(regs, &trace);
+ else
+ save_stack_trace(&trace);
+
+ if (trace.nr_entries > size)
+ size = trace.nr_entries;
+ } else
+ /* From now on, use_stack is a boolean */
+ use_stack = 0;
+
+ size *= sizeof(unsigned long);
event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
- sizeof(*entry), flags, pc);
+ sizeof(*entry) + size, flags, pc);
if (!event)
- return;
- entry = ring_buffer_event_data(event);
- memset(&entry->caller, 0, sizeof(entry->caller));
+ goto out;
+ entry = ring_buffer_event_data(event);
- trace.nr_entries = 0;
- trace.max_entries = FTRACE_STACK_ENTRIES;
- trace.skip = skip;
- trace.entries = entry->caller;
+ memset(&entry->caller, 0, size);
+
+ if (use_stack)
+ memcpy(&entry->caller, trace.entries,
+ trace.nr_entries * sizeof(unsigned long));
+ else {
+ trace.max_entries = FTRACE_STACK_ENTRIES;
+ trace.entries = entry->caller;
+ if (regs)
+ save_stack_trace_regs(regs, &trace);
+ else
+ save_stack_trace(&trace);
+ }
+
+ entry->size = trace.nr_entries;
- save_stack_trace(&trace);
if (!filter_check_discard(call, entry, buffer, event))
ring_buffer_unlock_commit(buffer, event);
+
+ out:
+ /* Again, don't let gcc optimize things here */
+ barrier();
+ __get_cpu_var(ftrace_stack_reserve)--;
+ preempt_enable_notrace();
+
+}
+
+void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
+ int skip, int pc, struct pt_regs *regs)
+{
+ if (!(trace_flags & TRACE_ITER_STACKTRACE))
+ return;
+
+ __ftrace_trace_stack(buffer, flags, skip, pc, regs);
}
void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
@@ -1266,13 +1353,13 @@ void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
if (!(trace_flags & TRACE_ITER_STACKTRACE))
return;
- __ftrace_trace_stack(buffer, flags, skip, pc);
+ __ftrace_trace_stack(buffer, flags, skip, pc, NULL);
}
void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
int pc)
{
- __ftrace_trace_stack(tr->buffer, flags, skip, pc);
+ __ftrace_trace_stack(tr->buffer, flags, skip, pc, NULL);
}
/**
@@ -1288,7 +1375,7 @@ void trace_dump_stack(void)
local_save_flags(flags);
/* skipping 3 traces, seems to get us at the caller of this function */
- __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count());
+ __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count(), NULL);
}
static DEFINE_PER_CPU(int, user_stack_count);
@@ -1536,7 +1623,12 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
ftrace_enable_cpu();
- return event ? ring_buffer_event_data(event) : NULL;
+ if (event) {
+ iter->ent_size = ring_buffer_event_length(event);
+ return ring_buffer_event_data(event);
+ }
+ iter->ent_size = 0;
+ return NULL;
}
static struct trace_entry *
@@ -2051,6 +2143,9 @@ void trace_default_header(struct seq_file *m)
{
struct trace_iterator *iter = m->private;
+ if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
+ return;
+
if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
/* print nothing if the buffers are empty */
if (trace_empty(iter))
@@ -2701,20 +2796,11 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
struct trace_array *tr = filp->private_data;
- char buf[64];
unsigned long val;
int ret;
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- ret = strict_strtoul(buf, 10, &val);
- if (ret < 0)
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
return ret;
val = !!val;
@@ -2767,7 +2853,7 @@ int tracer_init(struct tracer *t, struct trace_array *tr)
return t->init(tr);
}
-static int tracing_resize_ring_buffer(unsigned long size)
+static int __tracing_resize_ring_buffer(unsigned long size)
{
int ret;
@@ -2819,6 +2905,41 @@ static int tracing_resize_ring_buffer(unsigned long size)
return ret;
}
+static ssize_t tracing_resize_ring_buffer(unsigned long size)
+{
+ int cpu, ret = size;
+
+ mutex_lock(&trace_types_lock);
+
+ tracing_stop();
+
+ /* disable all cpu buffers */
+ for_each_tracing_cpu(cpu) {
+ if (global_trace.data[cpu])
+ atomic_inc(&global_trace.data[cpu]->disabled);
+ if (max_tr.data[cpu])
+ atomic_inc(&max_tr.data[cpu]->disabled);
+ }
+
+ if (size != global_trace.entries)
+ ret = __tracing_resize_ring_buffer(size);
+
+ if (ret < 0)
+ ret = -ENOMEM;
+
+ for_each_tracing_cpu(cpu) {
+ if (global_trace.data[cpu])
+ atomic_dec(&global_trace.data[cpu]->disabled);
+ if (max_tr.data[cpu])
+ atomic_dec(&max_tr.data[cpu]->disabled);
+ }
+
+ tracing_start();
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
/**
* tracing_update_buffers - used by tracing facility to expand ring buffers
@@ -2836,7 +2957,7 @@ int tracing_update_buffers(void)
mutex_lock(&trace_types_lock);
if (!ring_buffer_expanded)
- ret = tracing_resize_ring_buffer(trace_buf_size);
+ ret = __tracing_resize_ring_buffer(trace_buf_size);
mutex_unlock(&trace_types_lock);
return ret;
@@ -2860,7 +2981,7 @@ static int tracing_set_tracer(const char *buf)
mutex_lock(&trace_types_lock);
if (!ring_buffer_expanded) {
- ret = tracing_resize_ring_buffer(trace_buf_size);
+ ret = __tracing_resize_ring_buffer(trace_buf_size);
if (ret < 0)
goto out;
ret = 0;
@@ -2966,20 +3087,11 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
unsigned long *ptr = filp->private_data;
- char buf[64];
unsigned long val;
int ret;
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- ret = strict_strtoul(buf, 10, &val);
- if (ret < 0)
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
return ret;
*ptr = val * 1000;
@@ -3434,67 +3546,54 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
unsigned long val;
- char buf[64];
- int ret, cpu;
-
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
+ int ret;
- ret = strict_strtoul(buf, 10, &val);
- if (ret < 0)
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
return ret;
/* must have at least 1 entry */
if (!val)
return -EINVAL;
- mutex_lock(&trace_types_lock);
-
- tracing_stop();
-
- /* disable all cpu buffers */
- for_each_tracing_cpu(cpu) {
- if (global_trace.data[cpu])
- atomic_inc(&global_trace.data[cpu]->disabled);
- if (max_tr.data[cpu])
- atomic_inc(&max_tr.data[cpu]->disabled);
- }
-
/* value is in KB */
val <<= 10;
- if (val != global_trace.entries) {
- ret = tracing_resize_ring_buffer(val);
- if (ret < 0) {
- cnt = ret;
- goto out;
- }
- }
+ ret = tracing_resize_ring_buffer(val);
+ if (ret < 0)
+ return ret;
*ppos += cnt;
- /* If check pages failed, return ENOMEM */
- if (tracing_disabled)
- cnt = -ENOMEM;
- out:
- for_each_tracing_cpu(cpu) {
- if (global_trace.data[cpu])
- atomic_dec(&global_trace.data[cpu]->disabled);
- if (max_tr.data[cpu])
- atomic_dec(&max_tr.data[cpu]->disabled);
- }
+ return cnt;
+}
- tracing_start();
- mutex_unlock(&trace_types_lock);
+static ssize_t
+tracing_free_buffer_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ /*
+ * There is no need to read what the user has written, this function
+ * is just to make sure that there is no error when "echo" is used
+ */
+
+ *ppos += cnt;
return cnt;
}
+static int
+tracing_free_buffer_release(struct inode *inode, struct file *filp)
+{
+ /* disable tracing ? */
+ if (trace_flags & TRACE_ITER_STOP_ON_FREE)
+ tracing_off();
+ /* resize the ring buffer to 0 */
+ tracing_resize_ring_buffer(0);
+
+ return 0;
+}
+
static int mark_printk(const char *fmt, ...)
{
int ret;
@@ -3640,6 +3739,11 @@ static const struct file_operations tracing_entries_fops = {
.llseek = generic_file_llseek,
};
+static const struct file_operations tracing_free_buffer_fops = {
+ .write = tracing_free_buffer_write,
+ .release = tracing_free_buffer_release,
+};
+
static const struct file_operations tracing_mark_fops = {
.open = tracing_open_generic,
.write = tracing_mark_write,
@@ -3696,7 +3800,7 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
return 0;
if (!info->spare)
- info->spare = ring_buffer_alloc_read_page(info->tr->buffer);
+ info->spare = ring_buffer_alloc_read_page(info->tr->buffer, info->cpu);
if (!info->spare)
return -ENOMEM;
@@ -3853,7 +3957,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
ref->ref = 1;
ref->buffer = info->tr->buffer;
- ref->page = ring_buffer_alloc_read_page(ref->buffer);
+ ref->page = ring_buffer_alloc_read_page(ref->buffer, info->cpu);
if (!ref->page) {
kfree(ref);
break;
@@ -3862,8 +3966,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
r = ring_buffer_read_page(ref->buffer, &ref->page,
len, info->cpu, 1);
if (r < 0) {
- ring_buffer_free_read_page(ref->buffer,
- ref->page);
+ ring_buffer_free_read_page(ref->buffer, ref->page);
kfree(ref);
break;
}
@@ -4099,19 +4202,10 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
{
struct trace_option_dentry *topt = filp->private_data;
unsigned long val;
- char buf[64];
int ret;
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- ret = strict_strtoul(buf, 10, &val);
- if (ret < 0)
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
return ret;
if (val != 0 && val != 1)
@@ -4159,20 +4253,11 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
loff_t *ppos)
{
long index = (long)filp->private_data;
- char buf[64];
unsigned long val;
int ret;
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- ret = strict_strtoul(buf, 10, &val);
- if (ret < 0)
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
return ret;
if (val != 0 && val != 1)
@@ -4365,6 +4450,9 @@ static __init int tracer_init_debugfs(void)
trace_create_file("buffer_size_kb", 0644, d_tracer,
&global_trace, &tracing_entries_fops);
+ trace_create_file("free_buffer", 0644, d_tracer,
+ &global_trace, &tracing_free_buffer_fops);
+
trace_create_file("trace_marker", 0220, d_tracer,
NULL, &tracing_mark_fops);