On Thu, 12 May 2022 15:08:08 -0700 Song Liu song@kernel.org wrote:
--- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4465,7 +4465,7 @@ int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
- @ip: The instruction pointer address to remove the data from
- Returns the data if it is found, otherwise NULL.
- Note, if the data pointer is used as the data itself, (see
*/
- Note, if the data pointer is used as the data itself, (see
- ftrace_func_mapper_find_ip(), then the return value may be meaningless,
- if the data pointer was set to zero.
@@ -5200,8 +5200,10 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { ret = register_ftrace_function(&direct_ops);
if (ret)
if (ret) { ftrace_set_filter_ip(&direct_ops, ip, 1, 0);remove_hash_entry(direct_functions, entry);}if (ret) {
Perhaps something like this is more robust?
-- Steve
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4f1d2f5e7263..cd38ad490174 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5195,8 +5195,6 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) goto out_unlock;
ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); - if (ret) - remove_hash_entry(direct_functions, entry);
if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { ret = register_ftrace_function(&direct_ops); @@ -5205,6 +5203,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) }
if (ret) { + remove_hash_entry(direct_functions, entry); kfree(entry); if (!direct->count) { list_del_rcu(&direct->next);