diff options
| -rw-r--r-- | kernel/trace/ftrace.c | 48 |
1 files changed, 46 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index e6effd0c40a9..dab031fec85b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2988,18 +2988,20 @@ static void ftrace_free_entry_rcu(struct rcu_head *rhp) kfree(entry); } - int register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, void *data) { struct ftrace_func_probe *entry; + struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; + struct ftrace_hash *hash; struct ftrace_page *pg; struct dyn_ftrace *rec; int type, len, not; unsigned long key; int count = 0; char *search; + int ret; type = filter_parse_regex(glob, strlen(glob), &search, ¬); len = strlen(search); @@ -3010,8 +3012,16 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, mutex_lock(&ftrace_lock); - if (unlikely(ftrace_disabled)) + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); + if (!hash) { + count = -ENOMEM; + goto out_unlock; + } + + if (unlikely(ftrace_disabled)) { + count = -ENODEV; goto out_unlock; + } do_for_each_ftrace_rec(pg, rec) { @@ -3043,6 +3053,13 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, } } + ret = enter_record(hash, rec, 0); + if (ret < 0) { + kfree(entry); + count = ret; + goto out_unlock; + } + entry->ops = ops; entry->ip = rec->ip; @@ -3050,10 +3067,16 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 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); + if (ret < 0) + count = ret; + __enable_ftrace_function_probe(); out_unlock: mutex_unlock(&ftrace_lock); + free_ftrace_hash(hash); return count; } @@ -3067,7 +3090,10 @@ static void __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, void *data, int flags) { + struct ftrace_func_entry *rec_entry; struct ftrace_func_probe *entry; + struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; + struct ftrace_hash *hash; struct hlist_node *n, *tmp; char str[KSYM_SYMBOL_LEN]; int type = MATCH_FULL; @@ -3088,6 +3114,12 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, } mutex_lock(&ftrace_lock); + + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); + if (!hash) + /* Hmm, should report this somehow */ + goto out_unlock; + for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { struct hlist_head *hhd = &ftrace_func_hash[i]; @@ -3108,12 +3140,24 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, continue; } + rec_entry = ftrace_lookup_ip(hash, entry->ip); + /* It is possible more than one entry had this ip */ + if (rec_entry) + free_hash_entry(hash, rec_entry); + hlist_del_rcu(&entry->node); call_rcu_sched(&entry->rcu, ftrace_free_entry_rcu); } } __disable_ftrace_function_probe(); + /* + * Remove after the disable is called. Otherwise, if the last + * probe is removed, a null hash means *all enabled*. + */ + ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); + out_unlock: mutex_unlock(&ftrace_lock); + free_ftrace_hash(hash); } void |
