aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2016-01-05 20:32:47 -0500
committerSteven Rostedt <rostedt@goodmis.org>2016-01-07 12:17:39 -0500
commit049fb9bd416077b3622d317a45796be4f2431df3 (patch)
tree407e360324e0370e8a4e73e15de76959e6ea1f24
parentf36d1be2930ede0a1947686e1126ffda5d5ee1bb (diff)
downloadleg-kernel-049fb9bd416077b3622d317a45796be4f2431df3.tar.gz
ftrace/module: Call clean up function when module init fails early
If the module init code fails after calling ftrace_module_init() and before calling do_init_module(), we can suffer from a memory leak. This is because ftrace_module_init() allocates pages to store the locations that ftrace hooks are placed in the module text. If do_init_module() fails, it still calls the MODULE_GOING notifiers which will tell ftrace to do a clean up of the pages it allocated for the module. But if load_module() fails before then, the pages allocated by ftrace_module_init() will never be freed. Call ftrace_release_mod() on the module if load_module() fails before getting to do_init_module(). Link: http://lkml.kernel.org/r/567CEA31.1070507@intel.com Reported-by: "Qiu, PeiyangX" <peiyangx.qiu@intel.com> Fixes: a949ae560a511 "ftrace/module: Hardcode ftrace_module_init() call into load_module()" Cc: stable@vger.kernel.org # v2.6.38+ Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--include/linux/ftrace.h1
-rw-r--r--kernel/module.c6
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index eae6548efbf0..60048c50404e 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -586,6 +586,7 @@ extern int ftrace_arch_read_dyn_info(char *buf, int size);
extern int skip_trace(unsigned long ip);
extern void ftrace_module_init(struct module *mod);
+extern void ftrace_release_mod(struct module *mod);
extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
diff --git a/kernel/module.c b/kernel/module.c
index 8f051a106676..38c7bd5583ff 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3571,6 +3571,12 @@ 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->module_core, mod->core_size);