[GIT PULL] tracing: Fixes for 6.1

From: Steven Rostedt
Date: Mon Nov 28 2022 - 14:52:10 EST



Linus,

tracing fixes for 6.1:

- Fix osnoise duration type to 64bit not 32bit.

- Have histogram triggers be able to handle an unexpected NULL pointer
for the record event, that can happen when the histogram first starts up.

- Clear out ring buffers when dynamic events are removed, as the type
that is saved in the ring buffer is used to read the event, and a
stale type that is reused by another event could cause use after free
issues.

- Trivial comment fix.

- Fix memory leak in user_event_create().


Please pull the latest trace-v6.1-rc6 tree, which can be found at:


git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace-v6.1-rc6

Tag SHA1: ace7e8ba9a89438bc7438ef42453fa8abf6fdb94
Head SHA1: 4313e5a613049dfc1819a6dfb5f94cf2caff9452


Colin Ian King (1):
tracing/hist: add in missing * in comment blocks

Daniel Bristot de Oliveira (1):
tracing/osnoise: Fix duration type

Steven Rostedt (Google) (3):
tracing: Fix race where histograms can be called before the event
tracing: Add tracing_reset_all_online_cpus_unlocked() function
tracing: Free buffers when a used dynamic event is removed

Xiu Jianfeng (1):
tracing/user_events: Fix memory leak in user_event_create()

----
kernel/trace/trace.c | 11 ++++++++++-
kernel/trace/trace.h | 1 +
kernel/trace/trace_dynevent.c | 2 ++
kernel/trace/trace_events.c | 13 +++++++++++--
kernel/trace/trace_events_hist.c | 7 +++++--
kernel/trace/trace_events_synth.c | 2 --
kernel/trace/trace_events_user.c | 4 +++-
kernel/trace/trace_osnoise.c | 6 +++---
8 files changed, 35 insertions(+), 11 deletions(-)
---------------------------
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a7fe0e115272..5cfc95a52bc3 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2180,10 +2180,12 @@ void tracing_reset_online_cpus(struct array_buffer *buf)
}

/* Must have trace_types_lock held */
-void tracing_reset_all_online_cpus(void)
+void tracing_reset_all_online_cpus_unlocked(void)
{
struct trace_array *tr;

+ lockdep_assert_held(&trace_types_lock);
+
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
if (!tr->clear_trace)
continue;
@@ -2195,6 +2197,13 @@ void tracing_reset_all_online_cpus(void)
}
}

+void tracing_reset_all_online_cpus(void)
+{
+ mutex_lock(&trace_types_lock);
+ tracing_reset_all_online_cpus_unlocked();
+ mutex_unlock(&trace_types_lock);
+}
+
/*
* The tgid_map array maps from pid to tgid; i.e. the value stored at index i
* is the tgid last observed corresponding to pid=i.
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 54ee5711c729..d42e24507152 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -580,6 +580,7 @@ int tracing_is_enabled(void);
void tracing_reset_online_cpus(struct array_buffer *buf);
void tracing_reset_current(int cpu);
void tracing_reset_all_online_cpus(void);
+void tracing_reset_all_online_cpus_unlocked(void);
int tracing_open_generic(struct inode *inode, struct file *filp);
int tracing_open_generic_tr(struct inode *inode, struct file *filp);
bool tracing_is_disabled(void);
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 154996684fb5..4376887e0d8a 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -118,6 +118,7 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type
if (ret)
break;
}
+ tracing_reset_all_online_cpus();
mutex_unlock(&event_mutex);
out:
argv_free(argv);
@@ -214,6 +215,7 @@ int dyn_events_release_all(struct dyn_event_operations *type)
break;
}
out:
+ tracing_reset_all_online_cpus();
mutex_unlock(&event_mutex);

return ret;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 0356cae0cf74..f71ea6e79b3c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2880,7 +2880,10 @@ static int probe_remove_event_call(struct trace_event_call *call)
* TRACE_REG_UNREGISTER.
*/
if (file->flags & EVENT_FILE_FL_ENABLED)
- return -EBUSY;
+ goto busy;
+
+ if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
+ tr->clear_trace = true;
/*
* The do_for_each_event_file_safe() is
* a double loop. After finding the call for this
@@ -2893,6 +2896,12 @@ static int probe_remove_event_call(struct trace_event_call *call)
__trace_remove_event_call(call);

return 0;
+ busy:
+ /* No need to clear the trace now */
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ tr->clear_trace = false;
+ }
+ return -EBUSY;
}

/* Remove an event_call */
@@ -2972,7 +2981,7 @@ static void trace_module_remove_events(struct module *mod)
* over from this module may be passed to the new module events and
* unexpected results may occur.
*/
- tracing_reset_all_online_cpus();
+ tracing_reset_all_online_cpus_unlocked();
}

static int trace_module_notify(struct notifier_block *self,
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 48465f7e97b4..1c82478e8dff 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -983,7 +983,7 @@ static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,
* A trigger can define one or more variables. If any one of them is
* currently referenced by any other trigger, this function will
* determine that.
-
+ *
* Typically used to determine whether or not a trigger can be removed
* - if there are any references to a trigger's variables, it cannot.
*
@@ -3226,7 +3226,7 @@ static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
* events. However, for convenience, users are allowed to directly
* specify an event field in an action, which will be automatically
* converted into a variable on their behalf.
-
+ *
* This function creates a field variable with the name var_name on
* the hist trigger currently being defined on the target event. If
* subsys_name and event_name are specified, this function simply
@@ -5143,6 +5143,9 @@ static void event_hist_trigger(struct event_trigger_data *data,
void *key = NULL;
unsigned int i;

+ if (unlikely(!rbe))
+ return;
+
memset(compound_key, 0, hist_data->key_size);

for_each_hist_key_field(i, hist_data) {
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 29fbfb27c2b2..c3b582d19b62 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -1425,7 +1425,6 @@ int synth_event_delete(const char *event_name)
mutex_unlock(&event_mutex);

if (mod) {
- mutex_lock(&trace_types_lock);
/*
* It is safest to reset the ring buffer if the module
* being unloaded registered any events that were
@@ -1437,7 +1436,6 @@ int synth_event_delete(const char *event_name)
* occur.
*/
tracing_reset_all_online_cpus();
- mutex_unlock(&trace_types_lock);
}

return ret;
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index ae78c2d53c8a..539b08ae7020 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1100,8 +1100,10 @@ static int user_event_create(const char *raw_command)

group = current_user_event_group();

- if (!group)
+ if (!group) {
+ kfree(name);
return -ENOENT;
+ }

mutex_lock(&group->reg_mutex);

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 78d536d3ff3d..4300c5dc4e5d 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -917,7 +917,7 @@ void osnoise_trace_irq_entry(int id)
void osnoise_trace_irq_exit(int id, const char *desc)
{
struct osnoise_variables *osn_var = this_cpu_osn_var();
- int duration;
+ s64 duration;

if (!osn_var->sampling)
return;
@@ -1048,7 +1048,7 @@ static void trace_softirq_entry_callback(void *data, unsigned int vec_nr)
static void trace_softirq_exit_callback(void *data, unsigned int vec_nr)
{
struct osnoise_variables *osn_var = this_cpu_osn_var();
- int duration;
+ s64 duration;

if (!osn_var->sampling)
return;
@@ -1144,7 +1144,7 @@ thread_entry(struct osnoise_variables *osn_var, struct task_struct *t)
static void
thread_exit(struct osnoise_variables *osn_var, struct task_struct *t)
{
- int duration;
+ s64 duration;

if (!osn_var->sampling)
return;