summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c485
1 files changed, 374 insertions, 111 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 54d5270a5042..66f829c47bec 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -40,6 +40,7 @@
#include <linux/poll.h>
#include <linux/nmi.h>
#include <linux/fs.h>
+#include <linux/trace.h>
#include <linux/sched/rt.h>
#include "trace.h"
@@ -68,6 +69,7 @@ bool __read_mostly tracing_selftest_disabled;
/* Pipe tracepoints to printk */
struct trace_iterator *tracepoint_print_iter;
int tracepoint_printk;
+static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key);
/* For tracers that don't implement custom flags */
static struct tracer_opt dummy_tracer_opt[] = {
@@ -738,6 +740,31 @@ static inline void ftrace_trace_stack(struct trace_array *tr,
#endif
+static __always_inline void
+trace_event_setup(struct ring_buffer_event *event,
+ int type, unsigned long flags, int pc)
+{
+ struct trace_entry *ent = ring_buffer_event_data(event);
+
+ tracing_generic_entry_update(ent, flags, pc);
+ ent->type = type;
+}
+
+static __always_inline struct ring_buffer_event *
+__trace_buffer_lock_reserve(struct ring_buffer *buffer,
+ int type,
+ unsigned long len,
+ unsigned long flags, int pc)
+{
+ struct ring_buffer_event *event;
+
+ event = ring_buffer_lock_reserve(buffer, len);
+ if (event != NULL)
+ trace_event_setup(event, type, flags, pc);
+
+ return event;
+}
+
static void tracer_tracing_on(struct trace_array *tr)
{
if (tr->trace_buffer.buffer)
@@ -767,6 +794,22 @@ void tracing_on(void)
}
EXPORT_SYMBOL_GPL(tracing_on);
+
+static __always_inline void
+__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
+{
+ __this_cpu_write(trace_cmdline_save, true);
+
+ /* If this is the temp buffer, we need to commit fully */
+ if (this_cpu_read(trace_buffered_event) == event) {
+ /* Length is in event->array[0] */
+ ring_buffer_write(buffer, event->array[0], &event->array[1]);
+ /* Release the temp buffer */
+ this_cpu_dec(trace_buffered_event_cnt);
+ } else
+ ring_buffer_unlock_commit(buffer, event);
+}
+
/**
* __trace_puts - write a constant string into the trace buffer.
* @ip: The address of the caller
@@ -794,8 +837,8 @@ int __trace_puts(unsigned long ip, const char *str, int size)
local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
- event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
- irq_flags, pc);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
+ irq_flags, pc);
if (!event)
return 0;
@@ -842,8 +885,8 @@ int __trace_bputs(unsigned long ip, const char *str)
local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
- event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
- irq_flags, pc);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
+ irq_flags, pc);
if (!event)
return 0;
@@ -1907,35 +1950,19 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
#endif
((pc & NMI_MASK ) ? TRACE_FLAG_NMI : 0) |
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
- ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
+ ((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
}
EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
-static __always_inline void
-trace_event_setup(struct ring_buffer_event *event,
- int type, unsigned long flags, int pc)
-{
- struct trace_entry *ent = ring_buffer_event_data(event);
-
- tracing_generic_entry_update(ent, flags, pc);
- ent->type = type;
-}
-
struct ring_buffer_event *
trace_buffer_lock_reserve(struct ring_buffer *buffer,
int type,
unsigned long len,
unsigned long flags, int pc)
{
- struct ring_buffer_event *event;
-
- event = ring_buffer_lock_reserve(buffer, len);
- if (event != NULL)
- trace_event_setup(event, type, flags, pc);
-
- return event;
+ return __trace_buffer_lock_reserve(buffer, type, len, flags, pc);
}
DEFINE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
@@ -2049,21 +2076,6 @@ void trace_buffered_event_disable(void)
preempt_enable();
}
-void
-__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
-{
- __this_cpu_write(trace_cmdline_save, true);
-
- /* If this is the temp buffer, we need to commit fully */
- if (this_cpu_read(trace_buffered_event) == event) {
- /* Length is in event->array[0] */
- ring_buffer_write(buffer, event->array[0], &event->array[1]);
- /* Release the temp buffer */
- this_cpu_dec(trace_buffered_event_cnt);
- } else
- ring_buffer_unlock_commit(buffer, event);
-}
-
static struct ring_buffer *temp_buffer;
struct ring_buffer_event *
@@ -2090,8 +2102,8 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
this_cpu_dec(trace_buffered_event_cnt);
}
- entry = trace_buffer_lock_reserve(*current_rb,
- type, len, flags, pc);
+ entry = __trace_buffer_lock_reserve(*current_rb,
+ type, len, flags, pc);
/*
* If tracing is off, but we have triggers enabled
* we still need to look at the event data. Use the temp_buffer
@@ -2100,13 +2112,88 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
*/
if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) {
*current_rb = temp_buffer;
- entry = trace_buffer_lock_reserve(*current_rb,
- type, len, flags, pc);
+ entry = __trace_buffer_lock_reserve(*current_rb,
+ type, len, flags, pc);
}
return entry;
}
EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
+static DEFINE_SPINLOCK(tracepoint_iter_lock);
+static DEFINE_MUTEX(tracepoint_printk_mutex);
+
+static void output_printk(struct trace_event_buffer *fbuffer)
+{
+ struct trace_event_call *event_call;
+ struct trace_event *event;
+ unsigned long flags;
+ struct trace_iterator *iter = tracepoint_print_iter;
+
+ /* We should never get here if iter is NULL */
+ if (WARN_ON_ONCE(!iter))
+ return;
+
+ event_call = fbuffer->trace_file->event_call;
+ if (!event_call || !event_call->event.funcs ||
+ !event_call->event.funcs->trace)
+ return;
+
+ event = &fbuffer->trace_file->event_call->event;
+
+ spin_lock_irqsave(&tracepoint_iter_lock, flags);
+ trace_seq_init(&iter->seq);
+ iter->ent = fbuffer->entry;
+ event_call->event.funcs->trace(iter, 0, event);
+ trace_seq_putc(&iter->seq, 0);
+ printk("%s", iter->seq.buffer);
+
+ spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
+}
+
+int tracepoint_printk_sysctl(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int save_tracepoint_printk;
+ int ret;
+
+ mutex_lock(&tracepoint_printk_mutex);
+ save_tracepoint_printk = tracepoint_printk;
+
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+ /*
+ * This will force exiting early, as tracepoint_printk
+ * is always zero when tracepoint_printk_iter is not allocated
+ */
+ if (!tracepoint_print_iter)
+ tracepoint_printk = 0;
+
+ if (save_tracepoint_printk == tracepoint_printk)
+ goto out;
+
+ if (tracepoint_printk)
+ static_key_enable(&tracepoint_printk_key.key);
+ else
+ static_key_disable(&tracepoint_printk_key.key);
+
+ out:
+ mutex_unlock(&tracepoint_printk_mutex);
+
+ return ret;
+}
+
+void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
+{
+ if (static_key_false(&tracepoint_printk_key.key))
+ output_printk(fbuffer);
+
+ event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
+ fbuffer->event, fbuffer->entry,
+ fbuffer->flags, fbuffer->pc);
+}
+EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
+
void trace_buffer_unlock_commit_regs(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
@@ -2129,6 +2216,139 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr,
ftrace_trace_userstack(buffer, flags, pc);
}
+/*
+ * Similar to trace_buffer_unlock_commit_regs() but do not dump stack.
+ */
+void
+trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
+ struct ring_buffer_event *event)
+{
+ __buffer_unlock_commit(buffer, event);
+}
+
+static void
+trace_process_export(struct trace_export *export,
+ struct ring_buffer_event *event)
+{
+ struct trace_entry *entry;
+ unsigned int size = 0;
+
+ entry = ring_buffer_event_data(event);
+ size = ring_buffer_event_length(event);
+ export->write(entry, size);
+}
+
+static DEFINE_MUTEX(ftrace_export_lock);
+
+static struct trace_export __rcu *ftrace_exports_list __read_mostly;
+
+static DEFINE_STATIC_KEY_FALSE(ftrace_exports_enabled);
+
+static inline void ftrace_exports_enable(void)
+{
+ static_branch_enable(&ftrace_exports_enabled);
+}
+
+static inline void ftrace_exports_disable(void)
+{
+ static_branch_disable(&ftrace_exports_enabled);
+}
+
+void ftrace_exports(struct ring_buffer_event *event)
+{
+ struct trace_export *export;
+
+ preempt_disable_notrace();
+
+ export = rcu_dereference_raw_notrace(ftrace_exports_list);
+ while (export) {
+ trace_process_export(export, event);
+ export = rcu_dereference_raw_notrace(export->next);
+ }
+
+ preempt_enable_notrace();
+}
+
+static inline void
+add_trace_export(struct trace_export **list, struct trace_export *export)
+{
+ rcu_assign_pointer(export->next, *list);
+ /*
+ * We are entering export into the list but another
+ * CPU might be walking that list. We need to make sure
+ * the export->next pointer is valid before another CPU sees
+ * the export pointer included into the list.
+ */
+ rcu_assign_pointer(*list, export);
+}
+
+static inline int
+rm_trace_export(struct trace_export **list, struct trace_export *export)
+{
+ struct trace_export **p;
+
+ for (p = list; *p != NULL; p = &(*p)->next)
+ if (*p == export)
+ break;
+
+ if (*p != export)
+ return -1;
+
+ rcu_assign_pointer(*p, (*p)->next);
+
+ return 0;
+}
+
+static inline void
+add_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+ if (*list == NULL)
+ ftrace_exports_enable();
+
+ add_trace_export(list, export);
+}
+
+static inline int
+rm_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+ int ret;
+
+ ret = rm_trace_export(list, export);
+ if (*list == NULL)
+ ftrace_exports_disable();
+
+ return ret;
+}
+
+int register_ftrace_export(struct trace_export *export)
+{
+ if (WARN_ON_ONCE(!export->write))
+ return -1;
+
+ mutex_lock(&ftrace_export_lock);
+
+ add_ftrace_export(&ftrace_exports_list, export);
+
+ mutex_unlock(&ftrace_export_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_export);
+
+int unregister_ftrace_export(struct trace_export *export)
+{
+ int ret;
+
+ mutex_lock(&ftrace_export_lock);
+
+ ret = rm_ftrace_export(&ftrace_exports_list, export);
+
+ mutex_unlock(&ftrace_export_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_export);
+
void
trace_function(struct trace_array *tr,
unsigned long ip, unsigned long parent_ip, unsigned long flags,
@@ -2139,16 +2359,19 @@ trace_function(struct trace_array *tr,
struct ring_buffer_event *event;
struct ftrace_entry *entry;
- event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
- flags, pc);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
+ flags, pc);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->ip = ip;
entry->parent_ip = parent_ip;
- if (!call_filter_check_discard(call, entry, buffer, event))
+ if (!call_filter_check_discard(call, entry, buffer, event)) {
+ if (static_branch_unlikely(&ftrace_exports_enabled))
+ ftrace_exports(event);
__buffer_unlock_commit(buffer, event);
+ }
}
#ifdef CONFIG_STACKTRACE
@@ -2216,8 +2439,8 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
size *= sizeof(unsigned long);
- event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
- sizeof(*entry) + size, flags, pc);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_STACK,
+ sizeof(*entry) + size, flags, pc);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
@@ -2318,8 +2541,8 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
__this_cpu_inc(user_stack_count);
- event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
- sizeof(*entry), flags, pc);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
+ sizeof(*entry), flags, pc);
if (!event)
goto out_drop_count;
entry = ring_buffer_event_data(event);
@@ -2489,8 +2712,8 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
local_save_flags(flags);
size = sizeof(*entry) + sizeof(u32) * len;
buffer = tr->trace_buffer.buffer;
- event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
- flags, pc);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
+ flags, pc);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
@@ -2545,8 +2768,8 @@ __trace_array_vprintk(struct ring_buffer *buffer,
local_save_flags(flags);
size = sizeof(*entry) + len + 1;
- event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
- flags, pc);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
+ flags, pc);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
@@ -4055,6 +4278,7 @@ static const char readme_msg[] =
" x86-tsc: TSC cycle counter\n"
#endif
"\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n"
+ "\n trace_marker_raw\t\t- Writes into this file writes binary data into the kernel buffer\n"
" tracing_cpumask\t- Limit which CPUs to trace\n"
" instances\t\t- Make sub-buffers with: mkdir instances/foo\n"
"\t\t\t Remove sub-buffer with rmdir\n"
@@ -4066,7 +4290,7 @@ static const char readme_msg[] =
"\n available_filter_functions - list of functions that can be filtered on\n"
" set_ftrace_filter\t- echo function name in here to only trace these\n"
"\t\t\t functions\n"
- "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
+ "\t accepts: func_full_name or glob-matching-pattern\n"
"\t modules: Can select a group via module\n"
"\t Format: :mod:<module-name>\n"
"\t example: echo :mod:ext3 > set_ftrace_filter\n"
@@ -5519,21 +5743,18 @@ static ssize_t
tracing_mark_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *fpos)
{
- unsigned long addr = (unsigned long)ubuf;
struct trace_array *tr = filp->private_data;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
struct print_entry *entry;
unsigned long irq_flags;
- struct page *pages[2];
- void *map_page[2];
- int nr_pages = 1;
+ const char faulted[] = "<faulted>";
ssize_t written;
- int offset;
int size;
int len;
- int ret;
- int i;
+
+/* Used in tracing_mark_raw_write() as well */
+#define FAULTED_SIZE (sizeof(faulted) - 1) /* '\0' is already accounted for */
if (tracing_disabled)
return -EINVAL;
@@ -5544,60 +5765,33 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
if (cnt > TRACE_BUF_SIZE)
cnt = TRACE_BUF_SIZE;
- /*
- * Userspace is injecting traces into the kernel trace buffer.
- * We want to be as non intrusive as possible.
- * To do so, we do not want to allocate any special buffers
- * or take any locks, but instead write the userspace data
- * straight into the ring buffer.
- *
- * First we need to pin the userspace buffer into memory,
- * which, most likely it is, because it just referenced it.
- * But there's no guarantee that it is. By using get_user_pages_fast()
- * and kmap_atomic/kunmap_atomic() we can get access to the
- * pages directly. We then write the data directly into the
- * ring buffer.
- */
BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);
- /* check if we cross pages */
- if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK))
- nr_pages = 2;
-
- offset = addr & (PAGE_SIZE - 1);
- addr &= PAGE_MASK;
-
- ret = get_user_pages_fast(addr, nr_pages, 0, pages);
- if (ret < nr_pages) {
- while (--ret >= 0)
- put_page(pages[ret]);
- written = -EFAULT;
- goto out;
- }
+ local_save_flags(irq_flags);
+ size = sizeof(*entry) + cnt + 2; /* add '\0' and possible '\n' */
- for (i = 0; i < nr_pages; i++)
- map_page[i] = kmap_atomic(pages[i]);
+ /* If less than "<faulted>", then make sure we can still add that */
+ if (cnt < FAULTED_SIZE)
+ size += FAULTED_SIZE - cnt;
- local_save_flags(irq_flags);
- size = sizeof(*entry) + cnt + 2; /* possible \n added */
buffer = tr->trace_buffer.buffer;
- event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
- irq_flags, preempt_count());
- if (!event) {
+ event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
+ irq_flags, preempt_count());
+ if (unlikely(!event))
/* Ring buffer disabled, return as if not open for write */
- written = -EBADF;
- goto out_unlock;
- }
+ return -EBADF;
entry = ring_buffer_event_data(event);
entry->ip = _THIS_IP_;
- if (nr_pages == 2) {
- len = PAGE_SIZE - offset;
- memcpy(&entry->buf, map_page[0] + offset, len);
- memcpy(&entry->buf[len], map_page[1], cnt - len);
+ len = __copy_from_user_inatomic(&entry->buf, ubuf, cnt);
+ if (len) {
+ memcpy(&entry->buf, faulted, FAULTED_SIZE);
+ cnt = FAULTED_SIZE;
+ written = -EFAULT;
} else
- memcpy(&entry->buf, map_page[0] + offset, cnt);
+ written = cnt;
+ len = cnt;
if (entry->buf[cnt - 1] != '\n') {
entry->buf[cnt] = '\n';
@@ -5607,16 +5801,73 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
__buffer_unlock_commit(buffer, event);
- written = cnt;
+ if (written > 0)
+ *fpos += written;
- *fpos += written;
+ return written;
+}
+
+/* Limit it for now to 3K (including tag) */
+#define RAW_DATA_MAX_SIZE (1024*3)
+
+static ssize_t
+tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *fpos)
+{
+ struct trace_array *tr = filp->private_data;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ struct raw_data_entry *entry;
+ const char faulted[] = "<faulted>";
+ unsigned long irq_flags;
+ ssize_t written;
+ int size;
+ int len;
+
+#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int))
+
+ if (tracing_disabled)
+ return -EINVAL;
+
+ if (!(tr->trace_flags & TRACE_ITER_MARKERS))
+ return -EINVAL;
+
+ /* The marker must at least have a tag id */
+ if (cnt < sizeof(unsigned int) || cnt > RAW_DATA_MAX_SIZE)
+ return -EINVAL;
+
+ if (cnt > TRACE_BUF_SIZE)
+ cnt = TRACE_BUF_SIZE;
+
+ BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);
+
+ local_save_flags(irq_flags);
+ size = sizeof(*entry) + cnt;
+ if (cnt < FAULT_SIZE_ID)
+ size += FAULT_SIZE_ID - cnt;
+
+ buffer = tr->trace_buffer.buffer;
+ event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size,
+ irq_flags, preempt_count());
+ if (!event)
+ /* Ring buffer disabled, return as if not open for write */
+ return -EBADF;
+
+ entry = ring_buffer_event_data(event);
+
+ len = __copy_from_user_inatomic(&entry->id, ubuf, cnt);
+ if (len) {
+ entry->id = -1;
+ memcpy(&entry->buf, faulted, FAULTED_SIZE);
+ written = -EFAULT;
+ } else
+ written = cnt;
+
+ __buffer_unlock_commit(buffer, event);
+
+ if (written > 0)
+ *fpos += written;
- out_unlock:
- for (i = nr_pages - 1; i >= 0; i--) {
- kunmap_atomic(map_page[i]);
- put_page(pages[i]);
- }
- out:
return written;
}
@@ -5946,6 +6197,13 @@ static const struct file_operations tracing_mark_fops = {
.release = tracing_release_generic_tr,
};
+static const struct file_operations tracing_mark_raw_fops = {
+ .open = tracing_open_generic_tr,
+ .write = tracing_mark_raw_write,
+ .llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
+};
+
static const struct file_operations trace_clock_fops = {
.open = tracing_clock_open,
.read = seq_read,
@@ -7215,6 +7473,9 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("trace_marker", 0220, d_tracer,
tr, &tracing_mark_fops);
+ trace_create_file("trace_marker_raw", 0220, d_tracer,
+ tr, &tracing_mark_raw_fops);
+
trace_create_file("trace_clock", 0644, d_tracer, tr,
&trace_clock_fops);
@@ -7752,6 +8013,8 @@ void __init trace_init(void)
kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
if (WARN_ON(!tracepoint_print_iter))
tracepoint_printk = 0;
+ else
+ static_key_enable(&tracepoint_printk_key.key);
}
tracer_alloc_buffers();
trace_event_init();