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-rw-r--r--include/linux/ftrace.h6
-rw-r--r--include/linux/trace_events.h2
-rw-r--r--kernel/trace/ftrace.c41
-rw-r--r--kernel/trace/trace.h6
4 files changed, 34 insertions, 21 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 5857390..6383115 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -145,8 +145,8 @@ enum {
#ifdef CONFIG_DYNAMIC_FTRACE
/* The hash used to know what functions callbacks trace */
struct ftrace_ops_hash {
- struct ftrace_hash *notrace_hash;
- struct ftrace_hash *filter_hash;
+ struct ftrace_hash __rcu *notrace_hash;
+ struct ftrace_hash __rcu *filter_hash;
struct mutex regex_lock;
};
@@ -168,7 +168,7 @@ static inline void ftrace_free_init_mem(void) { }
*/
struct ftrace_ops {
ftrace_func_t func;
- struct ftrace_ops *next;
+ struct ftrace_ops __rcu *next;
unsigned long flags;
void *private;
ftrace_func_t saved_func;
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index f73cedf..536c80f 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -338,7 +338,7 @@ enum {
struct trace_event_file {
struct list_head list;
struct trace_event_call *event_call;
- struct event_filter *filter;
+ struct event_filter __rcu *filter;
struct dentry *dir;
struct trace_array *tr;
struct trace_subsystem_dir *system;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 53f6b64..02004ae9 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -113,7 +113,7 @@ static int ftrace_disabled __read_mostly;
static DEFINE_MUTEX(ftrace_lock);
-static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
+static struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
static struct ftrace_ops global_ops;
@@ -169,8 +169,11 @@ int ftrace_nr_registered_ops(void)
mutex_lock(&ftrace_lock);
- for (ops = ftrace_ops_list;
- ops != &ftrace_list_end; ops = ops->next)
+ for (ops = rcu_dereference_protected(ftrace_ops_list,
+ lockdep_is_held(&ftrace_lock));
+ ops != &ftrace_list_end;
+ ops = rcu_dereference_protected(ops->next,
+ lockdep_is_held(&ftrace_lock)))
cnt++;
mutex_unlock(&ftrace_lock);
@@ -275,10 +278,11 @@ static void update_ftrace_function(void)
* If there's only one ftrace_ops registered, the ftrace_ops_list
* will point to the ops we want.
*/
- set_function_trace_op = ftrace_ops_list;
+ set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
+ lockdep_is_held(&ftrace_lock));
/* If there's no ftrace_ops registered, just call the stub function */
- if (ftrace_ops_list == &ftrace_list_end) {
+ if (set_function_trace_op == &ftrace_list_end) {
func = ftrace_stub;
/*
@@ -286,7 +290,8 @@ static void update_ftrace_function(void)
* recursion safe and not dynamic and the arch supports passing ops,
* then have the mcount trampoline call the function directly.
*/
- } else if (ftrace_ops_list->next == &ftrace_list_end) {
+ } else if (rcu_dereference_protected(ftrace_ops_list->next,
+ lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
func = ftrace_ops_get_list_func(ftrace_ops_list);
} else {
@@ -348,9 +353,11 @@ int using_ftrace_ops_list_func(void)
return ftrace_trace_function == ftrace_ops_list_func;
}
-static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
+static void add_ftrace_ops(struct ftrace_ops __rcu **list,
+ struct ftrace_ops *ops)
{
- ops->next = *list;
+ rcu_assign_pointer(ops->next, *list);
+
/*
* We are entering ops into the list but another
* CPU might be walking that list. We need to make sure
@@ -360,7 +367,8 @@ static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
rcu_assign_pointer(*list, ops);
}
-static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
+static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
+ struct ftrace_ops *ops)
{
struct ftrace_ops **p;
@@ -368,7 +376,10 @@ static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
* If we are removing the last function, then simply point
* to the ftrace_stub.
*/
- if (*list == ops && ops->next == &ftrace_list_end) {
+ if (rcu_dereference_protected(*list,
+ lockdep_is_held(&ftrace_lock)) == ops &&
+ rcu_dereference_protected(ops->next,
+ lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
*list = &ftrace_list_end;
return 0;
}
@@ -1569,8 +1580,8 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
return 0;
#endif
- hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
- hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
+ rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
+ rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
if (hash_contains_ip(ip, &hash))
ret = 1;
@@ -2840,7 +2851,8 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
* If there's no more ops registered with ftrace, run a
* sanity check to make sure all rec flags are cleared.
*/
- if (ftrace_ops_list == &ftrace_list_end) {
+ if (rcu_dereference_protected(ftrace_ops_list,
+ lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
struct ftrace_page *pg;
struct dyn_ftrace *rec;
@@ -6453,7 +6465,8 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
if (ftrace_enabled) {
/* we are starting ftrace again */
- if (ftrace_ops_list != &ftrace_list_end)
+ if (rcu_dereference_protected(ftrace_ops_list,
+ lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
update_ftrace_function();
ftrace_startup_sysctl();
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 6ade1c5..490ba22 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1210,9 +1210,9 @@ struct ftrace_event_field {
struct event_filter {
int n_preds; /* Number assigned */
int a_preds; /* allocated */
- struct filter_pred *preds;
- struct filter_pred *root;
- char *filter_string;
+ struct filter_pred __rcu *preds;
+ struct filter_pred __rcu *root;
+ char *filter_string;
};
struct event_subsystem {
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