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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>
This commit is contained in:
Steven Rostedt (VMware) 2017-04-04 18:16:29 -04:00
parent d3d532d798
commit 1ec3a81a0c
2 changed files with 106 additions and 155 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

260
kernel/trace/ftrace.c
View File

@ -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;
mutex_lock(&ops->ops.func_hash->regex_lock);
orig_hash = &ops->ops.func_hash->filter_hash;
old_hash = *orig_hash;
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
ret = ftrace_match_records(hash, glob, strlen(glob));
/* Nothing found? */
if (!ret)
ret = -EINVAL;
if (ret < 0)
goto out;
INIT_HLIST_HEAD(&hl);
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);
count++;
}
}
mutex_lock(&ftrace_lock);
do_for_each_ftrace_rec(pg, rec) {
ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash,
hash, 1);
if (ret < 0)
goto err_free_unlock;
if (rec->flags & FTRACE_FL_DISABLED)
continue;
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]);
}
if (!ftrace_match_record(rec, &func_g, NULL, 0))
continue;
if (!(ops->ops.flags & FTRACE_OPS_FL_ENABLED))
ret = ftrace_startup(&ops->ops, 0);
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry) {
/* If we did not process any, then return error */
if (!count)
count = -ENOMEM;
goto out_unlock;
}
count++;
/*
* 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);
continue;
}
}
ret = enter_record(hash, rec, 0);
if (ret < 0) {
kfree(entry);
count = ret;
goto out_unlock;
}
entry->ops = ops;
entry->ip = rec->ip;
key = hash_long(entry->ip, FTRACE_HASH_BITS);
hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
} while_for_each_ftrace_rec();
ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
__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;
}

1
kernel/trace/trace.h
View File

@ -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,