diff options
| -rw-r--r-- | include/linux/ftrace.h | 2 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 47 |
2 files changed, 37 insertions, 12 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index f0b0edbf55a9..ef37286547fc 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -56,6 +56,8 @@ struct ftrace_ops; typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *regs); +ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); + /* * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are * set in the flags member. diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 17b606362ab4..dabf734f909c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -259,20 +259,12 @@ static void update_ftrace_function(void) * then have the mcount trampoline call the function directly. */ if (ftrace_ops_list == &ftrace_list_end || - (ftrace_ops_list->next == &ftrace_list_end && - !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && - !FTRACE_FORCE_LIST_FUNC)) { + (ftrace_ops_list->next == &ftrace_list_end)) { + /* Set the ftrace_ops that the arch callback uses */ set_function_trace_op = ftrace_ops_list; - /* - * If the func handles its own recursion, call it directly. - * Otherwise call the recursion protected function that - * will call the ftrace ops function. - */ - if (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) - func = ftrace_ops_list->func; - else - func = ftrace_ops_recurs_func; + + func = ftrace_ops_get_func(ftrace_ops_list); } else { /* Just use the default ftrace_ops */ set_function_trace_op = &ftrace_list_end; @@ -4856,6 +4848,37 @@ static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, trace_clear_recursion(bit); } +/** + * ftrace_ops_get_func - get the function a trampoline should call + * @ops: the ops to get the function for + * + * Normally the mcount trampoline will call the ops->func, but there + * are times that it should not. For example, if the ops does not + * have its own recursion protection, then it should call the + * ftrace_ops_recurs_func() instead. + * + * Returns the function that the trampoline should call for @ops. + */ +ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) +{ + /* + * If this is a dynamic ops or we force list func, + * then it needs to call the list anyway. + */ + if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC) + return ftrace_ops_list_func; + + /* + * If the func handles its own recursion, call it directly. + * Otherwise call the recursion protected function that + * will call the ftrace ops function. + */ + if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE)) + return ftrace_ops_recurs_func; + + return ops->func; +} + static void clear_ftrace_swapper(void) { struct task_struct *p; |