ftrace: allow archs to preform pre and post process for code modification (000ab691) · Commits · 戴 / test

include/linux/ftrace.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -99,6 +99,9 @@ stack_trace_sysctl(struct ctl_table *table, int write,
		/* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
		#include <asm/ftrace.h>

		int ftrace_arch_code_modify_prepare(void);
		int ftrace_arch_code_modify_post_process(void);

		enum {
		FTRACE_FL_FREE = (1 << 0),
		FTRACE_FL_FAILED = (1 << 1),

+28 −0

Original line number	Diff line number	Diff line
		@@ -585,6 +585,24 @@ ftrace_code_disable(struct module mod, struct dyn_ftrace rec)
		return 1;
		}

		/*
		* archs can override this function if they must do something
		* before the modifying code is performed.
		*/
		int __weak ftrace_arch_code_modify_prepare(void)
		{
		return 0;
		}

		/*
		* archs can override this function if they must do something
		* after the modifying code is performed.
		*/
		int __weak ftrace_arch_code_modify_post_process(void)
		{
		return 0;
		}

		static int __ftrace_modify_code(void *data)
		{
		int *command = data;
		@@ -607,7 +625,17 @@ static int __ftrace_modify_code(void *data)

		static void ftrace_run_update_code(int command)
		{
		int ret;

		ret = ftrace_arch_code_modify_prepare();
		FTRACE_WARN_ON(ret);
		if (ret)
		return;

		stop_machine(__ftrace_modify_code, &command, NULL);

		ret = ftrace_arch_code_modify_post_process();
		FTRACE_WARN_ON(ret);
		}

		static ftrace_func_t saved_ftrace_func;