diff options
| -rw-r--r-- | kernel/trace/fprobe.c | 82 |
1 files changed, 65 insertions, 17 deletions
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 9b913facfd36..d0a68a2c5eaf 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -92,11 +92,8 @@ static int insert_fprobe_node(struct fprobe_hlist_node *node, struct fprobe *fp) return ret; } -/* Return true if there are synonims */ -static bool delete_fprobe_node(struct fprobe_hlist_node *node) +static void delete_fprobe_node(struct fprobe_hlist_node *node) { - bool ret; - lockdep_assert_held(&fprobe_mutex); /* Avoid double deleting and non-inserted nodes */ @@ -105,13 +102,6 @@ static bool delete_fprobe_node(struct fprobe_hlist_node *node) rhltable_remove(&fprobe_ip_table, &node->hlist, fprobe_rht_params); } - - rcu_read_lock(); - ret = !!rhltable_lookup(&fprobe_ip_table, &node->addr, - fprobe_rht_params); - rcu_read_unlock(); - - return ret; } /* Check existence of the fprobe */ @@ -343,6 +333,32 @@ static bool fprobe_is_ftrace(struct fprobe *fp) return !fp->exit_handler; } +static bool fprobe_exists_on_hash(unsigned long ip, bool ftrace) +{ + struct rhlist_head *head, *pos; + struct fprobe_hlist_node *node; + struct fprobe *fp; + + guard(rcu)(); + head = rhltable_lookup(&fprobe_ip_table, &ip, + fprobe_rht_params); + if (!head) + return false; + /* We have to check the same type on the list. */ + rhl_for_each_entry_rcu(node, pos, head, hlist) { + if (node->addr != ip) + break; + fp = READ_ONCE(node->fp); + if (likely(fp)) { + if ((!ftrace && fp->exit_handler) || + (ftrace && !fp->exit_handler)) + return true; + } + } + + return false; +} + #ifdef CONFIG_MODULES static void fprobe_remove_ips(unsigned long *ips, unsigned int cnt) { @@ -365,6 +381,29 @@ static bool fprobe_is_ftrace(struct fprobe *fp) return false; } +static bool fprobe_exists_on_hash(unsigned long ip, bool ftrace __maybe_unused) +{ + struct rhlist_head *head, *pos; + struct fprobe_hlist_node *node; + struct fprobe *fp; + + guard(rcu)(); + head = rhltable_lookup(&fprobe_ip_table, &ip, + fprobe_rht_params); + if (!head) + return false; + /* We only need to check fp is there. */ + rhl_for_each_entry_rcu(node, pos, head, hlist) { + if (node->addr != ip) + break; + fp = READ_ONCE(node->fp); + if (likely(fp)) + return true; + } + + return false; +} + #ifdef CONFIG_MODULES static void fprobe_remove_ips(unsigned long *ips, unsigned int cnt) { @@ -551,18 +590,25 @@ struct fprobe_addr_list { static int fprobe_remove_node_in_module(struct module *mod, struct fprobe_hlist_node *node, struct fprobe_addr_list *alist) { + lockdep_assert_in_rcu_read_lock(); + if (!within_module(node->addr, mod)) return 0; - if (delete_fprobe_node(node)) - return 0; + delete_fprobe_node(node); /* If no address list is available, we can't track this address. */ if (!alist->addrs) return 0; + /* + * Don't care the type here, because all fprobes on the same + * address must be removed eventually. + */ + if (!rhltable_lookup(&fprobe_ip_table, &node->addr, fprobe_rht_params)) { + alist->addrs[alist->index++] = node->addr; + if (alist->index == alist->size) + return -ENOSPC; + } - alist->addrs[alist->index++] = node->addr; - if (alist->index == alist->size) - return -ENOSPC; return 0; } @@ -933,7 +979,9 @@ static int unregister_fprobe_nolock(struct fprobe *fp) /* Remove non-synonim ips from table and hash */ count = 0; for (i = 0; i < hlist_array->size; i++) { - if (!delete_fprobe_node(&hlist_array->array[i]) && addrs) + delete_fprobe_node(&hlist_array->array[i]); + if (addrs && !fprobe_exists_on_hash(hlist_array->array[i].addr, + fprobe_is_ftrace(fp))) addrs[count++] = hlist_array->array[i].addr; } del_fprobe_hash(fp); |