Commit 1323eac7 authored Jan 08, 2018 by Namit Gupta Committed by Jessica Yu Jan 15, 2018

ftrace/module: Move ftrace_release_mod() to ddebug_cleanup label

ftrace_module_init happen after dynamic_debug_setup, it is desired that
cleanup should be called after this label however in current implementation
it is called in free module label,ie:even though ftrace in not initialized,
from so many fail case ftrace_release_mod() will be called and unnecessary
traverse the whole list.
In below patch we moved ftrace_release_mod() from free_module label to
ddebug_cleanup label. that is the best possible location, other solution
is to make new label to ftrace_release_mod() but since ftrace_module_init()
is not return with minimum changes it should be in ddebug_cleanup label.

Signed-off-by: Namit Gupta <gupta.namit@samsung.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>

parent ed875ea1

kernel/module.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -3789,6 +3789,7 @@ static int load_module(struct load_info info, const char __user uargs,
		module_disable_nx(mod);

		ddebug_cleanup:
		ftrace_release_mod(mod);
		dynamic_debug_remove(mod, info->debug);
		synchronize_sched();
		kfree(mod->args);
		@@ -3808,12 +3809,6 @@ static int load_module(struct load_info info, const char __user uargs,
		synchronize_sched();
		mutex_unlock(&module_mutex);
		free_module:
		/*
		* Ftrace needs to clean up what it initialized.
		* This does nothing if ftrace_module_init() wasn't called,
		* but it must be called outside of module_mutex.
		*/
		ftrace_release_mod(mod);
		/* Free lock-classes; relies on the preceding sync_rcu() */
		lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);