@@ -1205,6 +1205,19 @@ Here are the available options:
default instance. The only way the top level instance has this flag
cleared, is by it being set in another instance.
+ copy_trace_marker
+ If there are applications that hard code writing into the top level
+ trace_marker file (/sys/kernel/tracing/trace_marker or trace_marker_raw),
+ and the tooling would like it to go into an instance, this option can
+ be used. Create an instance and set this option, and then all writes
+ into the top level trace_marker file will also be redirected into this
+ instance.
+
+ Note, by default this option is set for the top level instance. If it
+ is disabled, then writes to the trace_marker or trace_marker_raw files
+ will not be written into the top level file. If no instance has this
+ option set, then a write will error with the errno of ENODEV.
+
annotate
It is sometimes confusing when the CPU buffers are full
and one CPU buffer had a lot of events recently, thus
@@ -493,7 +493,8 @@ EXPORT_SYMBOL_GPL(unregister_ftrace_export);
TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | \
TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | \
TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | \
- TRACE_ITER_HASH_PTR | TRACE_ITER_TRACE_PRINTK)
+ TRACE_ITER_HASH_PTR | TRACE_ITER_TRACE_PRINTK | \
+ TRACE_ITER_COPY_MARKER)
/* trace_options that are only supported by global_trace */
#define TOP_LEVEL_TRACE_FLAGS (TRACE_ITER_PRINTK | \
@@ -501,7 +502,8 @@ EXPORT_SYMBOL_GPL(unregister_ftrace_export);
/* trace_flags that are default zero for instances */
#define ZEROED_TRACE_FLAGS \
- (TRACE_ITER_EVENT_FORK | TRACE_ITER_FUNC_FORK | TRACE_ITER_TRACE_PRINTK)
+ (TRACE_ITER_EVENT_FORK | TRACE_ITER_FUNC_FORK | TRACE_ITER_TRACE_PRINTK | \
+ TRACE_ITER_COPY_MARKER)
/*
* The global_trace is the descriptor that holds the top-level tracing
@@ -513,6 +515,9 @@ static struct trace_array global_trace = {
static struct trace_array *printk_trace = &global_trace;
+/* List of trace_arrays interested in the top level trace_marker */
+static LIST_HEAD(marker_copies);
+
static __always_inline bool printk_binsafe(struct trace_array *tr)
{
/*
@@ -534,6 +539,28 @@ static void update_printk_trace(struct trace_array *tr)
tr->trace_flags |= TRACE_ITER_TRACE_PRINTK;
}
+/* Returns true if the status of tr changed */
+static bool update_marker_trace(struct trace_array *tr, int enabled)
+{
+ lockdep_assert_held(&event_mutex);
+
+ if (enabled) {
+ if (!list_empty(&tr->marker_list))
+ return false;
+
+ list_add_rcu(&tr->marker_list, &marker_copies);
+ tr->trace_flags |= TRACE_ITER_COPY_MARKER;
+ return true;
+ }
+
+ if (list_empty(&tr->marker_list))
+ return false;
+
+ list_del_init(&tr->marker_list);
+ tr->trace_flags &= ~TRACE_ITER_COPY_MARKER;
+ return true;
+}
+
void trace_set_ring_buffer_expanded(struct trace_array *tr)
{
if (!tr)
@@ -5189,7 +5216,8 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
{
if ((mask == TRACE_ITER_RECORD_TGID) ||
(mask == TRACE_ITER_RECORD_CMD) ||
- (mask == TRACE_ITER_TRACE_PRINTK))
+ (mask == TRACE_ITER_TRACE_PRINTK) ||
+ (mask == TRACE_ITER_COPY_MARKER))
lockdep_assert_held(&event_mutex);
/* do nothing if flag is already set */
@@ -5220,6 +5248,9 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
}
}
+ if (mask == TRACE_ITER_COPY_MARKER)
+ update_marker_trace(tr, enabled);
+
if (enabled)
tr->trace_flags |= mask;
else
@@ -7097,11 +7128,9 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp)
#define TRACE_MARKER_MAX_SIZE 4096
-static ssize_t
-tracing_mark_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *fpos)
+static ssize_t write_marker_to_buffer(struct trace_array *tr, const char __user *ubuf,
+ size_t cnt)
{
- struct trace_array *tr = filp->private_data;
struct ring_buffer_event *event;
enum event_trigger_type tt = ETT_NONE;
struct trace_buffer *buffer;
@@ -7115,18 +7144,6 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
#define FAULTED_STR "<faulted>"
#define FAULTED_SIZE (sizeof(FAULTED_STR) - 1) /* '\0' is already accounted for */
- if (tracing_disabled)
- return -EINVAL;
-
- if (!(tr->trace_flags & TRACE_ITER_MARKERS))
- return -EINVAL;
-
- if ((ssize_t)cnt < 0)
- return -EINVAL;
-
- if (cnt > TRACE_MARKER_MAX_SIZE)
- cnt = TRACE_MARKER_MAX_SIZE;
-
meta_size = sizeof(*entry) + 2; /* add '\0' and possible '\n' */
again:
size = cnt + meta_size;
@@ -7192,18 +7209,11 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
}
static ssize_t
-tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
+tracing_mark_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 trace_buffer *buffer;
- struct raw_data_entry *entry;
- ssize_t written;
- int size;
- int len;
-
-#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int))
+ ssize_t written = -ENODEV;
if (tracing_disabled)
return -EINVAL;
@@ -7211,10 +7221,39 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
if (!(tr->trace_flags & TRACE_ITER_MARKERS))
return -EINVAL;
- /* The marker must at least have a tag id */
- if (cnt < sizeof(unsigned int))
+ if ((ssize_t)cnt < 0)
return -EINVAL;
+ if (cnt > TRACE_MARKER_MAX_SIZE)
+ cnt = TRACE_MARKER_MAX_SIZE;
+
+ /* The global trace_marker can go to multiple instances */
+ if (tr == &global_trace) {
+ guard(rcu)();
+ list_for_each_entry_rcu(tr, &marker_copies, marker_list) {
+ written = write_marker_to_buffer(tr, ubuf, cnt);
+ if (written < 0)
+ break;
+ }
+ } else {
+ written = write_marker_to_buffer(tr, ubuf, cnt);
+ }
+
+ return written;
+}
+
+static ssize_t write_raw_marker_to_buffer(struct trace_array *tr,
+ const char __user *ubuf, size_t cnt)
+{
+ struct ring_buffer_event *event;
+ struct trace_buffer *buffer;
+ struct raw_data_entry *entry;
+ ssize_t written;
+ int size;
+ int len;
+
+#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int))
+
size = sizeof(*entry) + cnt;
if (cnt < FAULT_SIZE_ID)
size += FAULT_SIZE_ID - cnt;
@@ -7245,6 +7284,40 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
return written;
}
+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;
+ ssize_t written = -ENODEV;
+
+#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))
+ return -EINVAL;
+
+ /* The global trace_marker_raw can go to multiple instances */
+ if (tr == &global_trace) {
+ guard(rcu)();
+ list_for_each_entry_rcu(tr, &marker_copies, marker_list) {
+ written = write_raw_marker_to_buffer(tr, ubuf, cnt);
+ if (written < 0)
+ break;
+ }
+ } else {
+ written = write_raw_marker_to_buffer(tr, ubuf, cnt);
+ }
+
+ return written;
+}
+
static int tracing_clock_show(struct seq_file *m, void *v)
{
struct trace_array *tr = m->private;
@@ -9738,6 +9811,7 @@ trace_array_create_systems(const char *name, const char *systems,
INIT_LIST_HEAD(&tr->events);
INIT_LIST_HEAD(&tr->hist_vars);
INIT_LIST_HEAD(&tr->err_log);
+ INIT_LIST_HEAD(&tr->marker_list);
#ifdef CONFIG_MODULES
INIT_LIST_HEAD(&tr->mod_events);
@@ -9897,6 +9971,9 @@ static int __remove_instance(struct trace_array *tr)
if (printk_trace == tr)
update_printk_trace(&global_trace);
+ if (update_marker_trace(tr, 0))
+ synchronize_rcu();
+
tracing_set_nop(tr);
clear_ftrace_function_probes(tr);
event_trace_del_tracer(tr);
@@ -10965,6 +11042,7 @@ __init static int tracer_alloc_buffers(void)
INIT_LIST_HEAD(&global_trace.events);
INIT_LIST_HEAD(&global_trace.hist_vars);
INIT_LIST_HEAD(&global_trace.err_log);
+ list_add(&global_trace.marker_list, &marker_copies);
list_add(&global_trace.list, &ftrace_trace_arrays);
apply_trace_boot_options();
@@ -404,6 +404,7 @@ struct trace_array {
struct trace_options *topts;
struct list_head systems;
struct list_head events;
+ struct list_head marker_list;
struct trace_event_file *trace_marker_file;
cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
/* one per_cpu trace_pipe can be opened by only one user */
@@ -1368,6 +1369,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
C(MARKERS, "markers"), \
C(EVENT_FORK, "event-fork"), \
C(TRACE_PRINTK, "trace_printk_dest"), \
+ C(COPY_MARKER, "copy_trace_marker"),\
C(PAUSE_ON_TRACE, "pause-on-trace"), \
C(HASH_PTR, "hash-ptr"), /* Print hashed pointer */ \
FUNCTION_FLAGS \