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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2017-04-04 18:16:29 -0400
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2017-04-20 22:06:43 -0400
commit1ec3a81a0cf4236b644282794932c4eda9c1714a (patch)
tree398e8cab5a17fdf09b6923a880deb1336f40fbb3 /kernel/trace
parentd3d532d798c5720055ab02a10bf7829a33c3645a (diff)
downloadlinux-1ec3a81a0cf4236b644282794932c4eda9c1714a.tar.bz2
ftrace: Have each function probe use its own ftrace_ops
Have the function probes have their own ftrace_ops, and remove the trace_probe_ops. This simplifies some of the ftrace infrastructure code. Individual entries for each function is still allocated for the use of the output for set_ftrace_filter, but they will be removed soon too. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ftrace.c246
-rw-r--r--kernel/trace/trace.h1
2 files changed, 99 insertions, 148 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index cbae7fb1be15..cf6b7263199a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3789,63 +3789,6 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
preempt_enable_notrace();
}
-static struct ftrace_ops trace_probe_ops __read_mostly =
-{
- .func = function_trace_probe_call,
- .flags = FTRACE_OPS_FL_INITIALIZED,
- INIT_OPS_HASH(trace_probe_ops)
-};
-
-static int ftrace_probe_registered;
-
-static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash)
-{
- int ret;
- int i;
-
- if (ftrace_probe_registered) {
- /* still need to update the function call sites */
- if (ftrace_enabled)
- ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,
- old_hash);
- return;
- }
-
- for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
- struct hlist_head *hhd = &ftrace_func_hash[i];
- if (hhd->first)
- break;
- }
- /* Nothing registered? */
- if (i == FTRACE_FUNC_HASHSIZE)
- return;
-
- ret = ftrace_startup(&trace_probe_ops, 0);
-
- ftrace_probe_registered = 1;
-}
-
-static bool __disable_ftrace_function_probe(void)
-{
- int i;
-
- if (!ftrace_probe_registered)
- return false;
-
- for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
- struct hlist_head *hhd = &ftrace_func_hash[i];
- if (hhd->first)
- return false;
- }
-
- /* no more funcs left */
- ftrace_shutdown(&trace_probe_ops, 0);
-
- ftrace_probe_registered = 0;
- return true;
-}
-
-
static void ftrace_free_entry(struct ftrace_func_probe *entry)
{
if (entry->ops->free)
@@ -3996,110 +3939,110 @@ void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
int
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
- void *data)
+ void *data)
{
- struct ftrace_ops_hash old_hash_ops;
- struct ftrace_func_probe *entry;
- struct ftrace_glob func_g;
- struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
- struct ftrace_hash *old_hash = *orig_hash;
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_probe *probe;
+ struct ftrace_hash **orig_hash;
+ struct ftrace_hash *old_hash;
struct ftrace_hash *hash;
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
- int not;
+ struct hlist_head hl;
+ struct hlist_node *n;
unsigned long key;
int count = 0;
+ int size;
int ret;
+ int i;
- func_g.type = filter_parse_regex(glob, strlen(glob),
- &func_g.search, &not);
- func_g.len = strlen(func_g.search);
-
- /* we do not support '!' for function probes */
- if (WARN_ON(not))
+ /* We do not support '!' for function probes */
+ if (WARN_ON(glob[0] == '!'))
return -EINVAL;
- mutex_lock(&trace_probe_ops.func_hash->regex_lock);
-
- old_hash_ops.filter_hash = old_hash;
- /* Probes only have filters */
- old_hash_ops.notrace_hash = NULL;
-
- hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
- if (!hash) {
- count = -ENOMEM;
- goto out;
+ if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED)) {
+ ops->ops.func = function_trace_probe_call;
+ ftrace_ops_init(&ops->ops);
}
- if (unlikely(ftrace_disabled)) {
- count = -ENODEV;
- goto out;
- }
-
- mutex_lock(&ftrace_lock);
+ mutex_lock(&ops->ops.func_hash->regex_lock);
- do_for_each_ftrace_rec(pg, rec) {
+ orig_hash = &ops->ops.func_hash->filter_hash;
+ old_hash = *orig_hash;
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
- if (rec->flags & FTRACE_FL_DISABLED)
- continue;
+ ret = ftrace_match_records(hash, glob, strlen(glob));
- if (!ftrace_match_record(rec, &func_g, NULL, 0))
- continue;
+ /* Nothing found? */
+ if (!ret)
+ ret = -EINVAL;
- entry = kmalloc(sizeof(*entry), GFP_KERNEL);
- if (!entry) {
- /* If we did not process any, then return error */
- if (!count)
- count = -ENOMEM;
- goto out_unlock;
- }
+ if (ret < 0)
+ goto out;
- count++;
+ INIT_HLIST_HEAD(&hl);
- /*
- * The caller might want to do something special
- * for each function we find. We call the callback
- * to give the caller an opportunity to do so.
- */
- if (ops->init) {
- if (ops->init(ops, rec->ip, data) < 0) {
- /* caller does not like this func */
- kfree(entry);
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ if (ftrace_lookup_ip(old_hash, entry->ip))
continue;
+ probe = kmalloc(sizeof(*probe), GFP_KERNEL);
+ if (!probe) {
+ count = -ENOMEM;
+ goto err_free;
}
- }
+ probe->ops = ops;
+ probe->ip = entry->ip;
+ /*
+ * The caller might want to do something special
+ * for each function we find. We call the callback
+ * to give the caller an opportunity to do so.
+ */
+ if (ops->init && ops->init(ops, entry->ip, data) < 0) {
+ kfree(probe);
+ goto err_free;
+ }
+ hlist_add_head(&probe->node, &hl);
- ret = enter_record(hash, rec, 0);
- if (ret < 0) {
- kfree(entry);
- count = ret;
- goto out_unlock;
+ count++;
}
+ }
- entry->ops = ops;
- entry->ip = rec->ip;
+ mutex_lock(&ftrace_lock);
- key = hash_long(entry->ip, FTRACE_HASH_BITS);
- hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
+ ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash,
+ hash, 1);
+ if (ret < 0)
+ goto err_free_unlock;
- } while_for_each_ftrace_rec();
+ hlist_for_each_entry_safe(probe, n, &hl, node) {
+ hlist_del(&probe->node);
+ key = hash_long(probe->ip, FTRACE_HASH_BITS);
+ hlist_add_head_rcu(&probe->node, &ftrace_func_hash[key]);
+ }
- ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
+ if (!(ops->ops.flags & FTRACE_OPS_FL_ENABLED))
+ ret = ftrace_startup(&ops->ops, 0);
- __enable_ftrace_function_probe(&old_hash_ops);
+ mutex_unlock(&ftrace_lock);
if (!ret)
- free_ftrace_hash_rcu(old_hash);
- else
- count = ret;
-
- out_unlock:
- mutex_unlock(&ftrace_lock);
+ ret = count;
out:
- mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
+ mutex_unlock(&ops->ops.func_hash->regex_lock);
free_ftrace_hash(hash);
- return count;
+ return ret;
+
+ err_free_unlock:
+ mutex_unlock(&ftrace_lock);
+ err_free:
+ hlist_for_each_entry_safe(probe, n, &hl, node) {
+ hlist_del(&probe->node);
+ if (ops->free)
+ ops->free(ops, probe->ip, NULL);
+ kfree(probe);
+ }
+ goto out;
}
int
@@ -4110,14 +4053,16 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
struct ftrace_func_probe *entry;
struct ftrace_func_probe *p;
struct ftrace_glob func_g;
- struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
- struct ftrace_hash *old_hash = *orig_hash;
+ struct ftrace_hash **orig_hash;
+ struct ftrace_hash *old_hash;
struct list_head free_list;
- struct ftrace_hash *hash;
+ struct ftrace_hash *hash = NULL;
struct hlist_node *tmp;
char str[KSYM_SYMBOL_LEN];
int i, ret;
- bool disabled;
+
+ if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED))
+ return -EINVAL;
if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
func_g.search = NULL;
@@ -4134,14 +4079,21 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
return -EINVAL;
}
- mutex_lock(&trace_probe_ops.func_hash->regex_lock);
+ mutex_lock(&ops->ops.func_hash->regex_lock);
+
+ orig_hash = &ops->ops.func_hash->filter_hash;
+ old_hash = *orig_hash;
+
+ ret = -EINVAL;
+ if (ftrace_hash_empty(old_hash))
+ goto out_unlock;
old_hash_ops.filter_hash = old_hash;
/* Probes only have filters */
old_hash_ops.notrace_hash = NULL;
ret = -ENOMEM;
- hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
if (!hash)
goto out_unlock;
@@ -4181,20 +4133,18 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
}
mutex_lock(&ftrace_lock);
- disabled = __disable_ftrace_function_probe();
- /*
- * Remove after the disable is called. Otherwise, if the last
- * probe is removed, a null hash means *all enabled*.
- */
- ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
+
+ if (ftrace_hash_empty(hash))
+ ftrace_shutdown(&ops->ops, 0);
+
+ ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash,
+ hash, 1);
/* still need to update the function call sites */
- if (ftrace_enabled && !disabled)
- ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,
+ if (ftrace_enabled && !ftrace_hash_empty(hash))
+ ftrace_run_modify_code(&ops->ops, FTRACE_UPDATE_CALLS,
&old_hash_ops);
synchronize_sched();
- if (!ret)
- free_ftrace_hash_rcu(old_hash);
list_for_each_entry_safe(entry, p, &free_list, free_list) {
list_del(&entry->free_list);
@@ -4203,7 +4153,7 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
mutex_unlock(&ftrace_lock);
out_unlock:
- mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
+ mutex_unlock(&ops->ops.func_hash->regex_lock);
free_ftrace_hash(hash);
return ret;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 31d80bff9ee6..e16c67c49de4 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -932,6 +932,7 @@ static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) {
#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
struct ftrace_probe_ops {
+ struct ftrace_ops ops;
void (*func)(unsigned long ip,
unsigned long parent_ip,
struct ftrace_probe_ops *ops,