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-rw-r--r--kernel/trace/ftrace.c42
-rw-r--r--kernel/trace/trace.h1
-rw-r--r--kernel/trace/trace_events.c113
-rw-r--r--kernel/trace/trace_events_filter.c6
-rw-r--r--kernel/trace/trace_functions.c3
5 files changed, 135 insertions, 30 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index c997f7371c6..a0e246e2cee 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1732,10 +1732,36 @@ static cycle_t ftrace_update_time;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
+static int ops_traces_mod(struct ftrace_ops *ops)
+{
+ struct ftrace_hash *hash;
+
+ hash = ops->filter_hash;
+ return !!(!hash || !hash->count);
+}
+
static int ftrace_update_code(struct module *mod)
{
struct dyn_ftrace *p;
cycle_t start, stop;
+ unsigned long ref = 0;
+
+ /*
+ * When adding a module, we need to check if tracers are
+ * currently enabled and if they are set to trace all functions.
+ * If they are, we need to enable the module functions as well
+ * as update the reference counts for those function records.
+ */
+ if (mod) {
+ struct ftrace_ops *ops;
+
+ for (ops = ftrace_ops_list;
+ ops != &ftrace_list_end; ops = ops->next) {
+ if (ops->flags & FTRACE_OPS_FL_ENABLED &&
+ ops_traces_mod(ops))
+ ref++;
+ }
+ }
start = ftrace_now(raw_smp_processor_id());
ftrace_update_cnt = 0;
@@ -1748,7 +1774,7 @@ static int ftrace_update_code(struct module *mod)
p = ftrace_new_addrs;
ftrace_new_addrs = p->newlist;
- p->flags = 0L;
+ p->flags = ref;
/*
* Do the initial record conversion from mcount jump
@@ -1771,7 +1797,7 @@ static int ftrace_update_code(struct module *mod)
* conversion puts the module to the correct state, thus
* passing the ftrace_make_call check.
*/
- if (ftrace_start_up) {
+ if (ftrace_start_up && ref) {
int failed = __ftrace_replace_code(p, 1);
if (failed) {
ftrace_bug(failed, p->ip);
@@ -2395,10 +2421,9 @@ ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
*/
static int
-ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
+ftrace_mod_callback(struct ftrace_hash *hash,
+ char *func, char *cmd, char *param, int enable)
{
- struct ftrace_ops *ops = &global_ops;
- struct ftrace_hash *hash;
char *mod;
int ret = -EINVAL;
@@ -2418,11 +2443,6 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
if (!strlen(mod))
return ret;
- if (enable)
- hash = ops->filter_hash;
- else
- hash = ops->notrace_hash;
-
ret = ftrace_match_module_records(hash, func, mod);
if (!ret)
ret = -EINVAL;
@@ -2748,7 +2768,7 @@ static int ftrace_process_regex(struct ftrace_hash *hash,
mutex_lock(&ftrace_cmd_mutex);
list_for_each_entry(p, &ftrace_commands, list) {
if (strcmp(p->name, command) == 0) {
- ret = p->func(func, command, next, enable);
+ ret = p->func(hash, func, command, next, enable);
goto out_unlock;
}
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index a3e2db70807..30a94c26dcb 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -687,6 +687,7 @@ struct event_subsystem {
struct dentry *entry;
struct event_filter *filter;
int nr_events;
+ int ref_count;
};
#define FILTER_PRED_INVALID ((unsigned short)-1)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 4d7e1498ae9..581876f9f38 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -244,6 +244,35 @@ static void ftrace_clear_events(void)
mutex_unlock(&event_mutex);
}
+static void __put_system(struct event_subsystem *system)
+{
+ struct event_filter *filter = system->filter;
+
+ WARN_ON_ONCE(system->ref_count == 0);
+ if (--system->ref_count)
+ return;
+
+ if (filter) {
+ kfree(filter->filter_string);
+ kfree(filter);
+ }
+ kfree(system->name);
+ kfree(system);
+}
+
+static void __get_system(struct event_subsystem *system)
+{
+ WARN_ON_ONCE(system->ref_count == 0);
+ system->ref_count++;
+}
+
+static void put_system(struct event_subsystem *system)
+{
+ mutex_lock(&event_mutex);
+ __put_system(system);
+ mutex_unlock(&event_mutex);
+}
+
/*
* __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
*/
@@ -519,7 +548,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
{
const char set_to_char[4] = { '?', '0', '1', 'X' };
- const char *system = filp->private_data;
+ struct event_subsystem *system = filp->private_data;
struct ftrace_event_call *call;
char buf[2];
int set = 0;
@@ -530,7 +559,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
if (!call->name || !call->class || !call->class->reg)
continue;
- if (system && strcmp(call->class->system, system) != 0)
+ if (system && strcmp(call->class->system, system->name) != 0)
continue;
/*
@@ -560,7 +589,8 @@ static ssize_t
system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
loff_t *ppos)
{
- const char *system = filp->private_data;
+ struct event_subsystem *system = filp->private_data;
+ const char *name = NULL;
unsigned long val;
ssize_t ret;
@@ -575,7 +605,14 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
if (val != 0 && val != 1)
return -EINVAL;
- ret = __ftrace_set_clr_event(NULL, system, NULL, val);
+ /*
+ * Opening of "enable" adds a ref count to system,
+ * so the name is safe to use.
+ */
+ if (system)
+ name = system->name;
+
+ ret = __ftrace_set_clr_event(NULL, name, NULL, val);
if (ret)
goto out;
@@ -808,6 +845,52 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
return cnt;
}
+static LIST_HEAD(event_subsystems);
+
+static int subsystem_open(struct inode *inode, struct file *filp)
+{
+ struct event_subsystem *system = NULL;
+ int ret;
+
+ if (!inode->i_private)
+ goto skip_search;
+
+ /* Make sure the system still exists */
+ mutex_lock(&event_mutex);
+ list_for_each_entry(system, &event_subsystems, list) {
+ if (system == inode->i_private) {
+ /* Don't open systems with no events */
+ if (!system->nr_events) {
+ system = NULL;
+ break;
+ }
+ __get_system(system);
+ break;
+ }
+ }
+ mutex_unlock(&event_mutex);
+
+ if (system != inode->i_private)
+ return -ENODEV;
+
+ skip_search:
+ ret = tracing_open_generic(inode, filp);
+ if (ret < 0 && system)
+ put_system(system);
+
+ return ret;
+}
+
+static int subsystem_release(struct inode *inode, struct file *file)
+{
+ struct event_subsystem *system = inode->i_private;
+
+ if (system)
+ put_system(system);
+
+ return 0;
+}
+
static ssize_t
subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
@@ -945,17 +1028,19 @@ static const struct file_operations ftrace_event_filter_fops = {
};
static const struct file_operations ftrace_subsystem_filter_fops = {
- .open = tracing_open_generic,
+ .open = subsystem_open,
.read = subsystem_filter_read,
.write = subsystem_filter_write,
.llseek = default_llseek,
+ .release = subsystem_release,
};
static const struct file_operations ftrace_system_enable_fops = {
- .open = tracing_open_generic,
+ .open = subsystem_open,
.read = system_enable_read,
.write = system_enable_write,
.llseek = default_llseek,
+ .release = subsystem_release,
};
static const struct file_operations ftrace_show_header_fops = {
@@ -984,8 +1069,6 @@ static struct dentry *event_trace_events_dir(void)
return d_events;
}
-static LIST_HEAD(event_subsystems);
-
static struct dentry *
event_subsystem_dir(const char *name, struct dentry *d_events)
{
@@ -995,6 +1078,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
/* First see if we did not already create this dir */
list_for_each_entry(system, &event_subsystems, list) {
if (strcmp(system->name, name) == 0) {
+ __get_system(system);
system->nr_events++;
return system->entry;
}
@@ -1017,6 +1101,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
}
system->nr_events = 1;
+ system->ref_count = 1;
system->name = kstrdup(name, GFP_KERNEL);
if (!system->name) {
debugfs_remove(system->entry);
@@ -1044,8 +1129,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
"'%s/filter' entry\n", name);
}
- trace_create_file("enable", 0644, system->entry,
- (void *)system->name,
+ trace_create_file("enable", 0644, system->entry, system,
&ftrace_system_enable_fops);
return system->entry;
@@ -1166,16 +1250,9 @@ static void remove_subsystem_dir(const char *name)
list_for_each_entry(system, &event_subsystems, list) {
if (strcmp(system->name, name) == 0) {
if (!--system->nr_events) {
- struct event_filter *filter = system->filter;
-
debugfs_remove_recursive(system->entry);
list_del(&system->list);
- if (filter) {
- kfree(filter->filter_string);
- kfree(filter);
- }
- kfree(system->name);
- kfree(system);
+ __put_system(system);
}
break;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 8008ddcfbf2..256764ecccd 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1886,6 +1886,12 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
mutex_lock(&event_mutex);
+ /* Make sure the system still has events */
+ if (!system->nr_events) {
+ err = -ENODEV;
+ goto out_unlock;
+ }
+
if (!strcmp(strstrip(filter_string), "0")) {
filter_free_subsystem_preds(system);
remove_filter_string(system->filter);
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8d0e1cc4e97..c7b0c6a7db0 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -324,7 +324,8 @@ ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
}
static int
-ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
+ftrace_trace_onoff_callback(struct ftrace_hash *hash,
+ char *glob, char *cmd, char *param, int enable)
{
struct ftrace_probe_ops *ops;
void *count = (void *)-1;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-25 09:51:37 +0000