ftrace: Remove return value of ftrace_arch_modify_*()

All instances of the function ftrace_arch_modify_prepare() and ftrace_arch_modify_post_process() return zero. There's no point in checking their return value. Just have them be void functions. Link: https://lkml.kernel.org/r/20220518023639.4065-1-kunyu@nfschina.com

Li kunyu committed 4 years ago

Commit 3a2bfec1 parent 2decd166 files · +13 −28Browse files

Unified · Split

6 files

arch/arm/kernel/ftrace.c +2 −4
arch/riscv/kernel/ftrace.c +2 −4
arch/s390/kernel/ftrace.c +1 −2
arch/x86/kernel/ftrace.c +2 −4
include/linux/ftrace.h +2 −2
kernel/trace/ftrace.c +4 −12

arch/arm/kernel/ftrace.c+2−4

 	return (unsigned long)&ftrace_regs_caller_from_init;
 }
-int ftrace_arch_code_modify_prepare(void)
+void ftrace_arch_code_modify_prepare(void)
 {
-	return 0;
 }
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
 {
 	/* Make sure any TLB misses during machine stop are cleared. */
 	flush_tlb_all();
-	return 0;
 }
 static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr,

arch/riscv/kernel/ftrace.c+2−4

 #include <asm/patch.h>
 #ifdef CONFIG_DYNAMIC_FTRACE
-int ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex)
+void ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex)
 {
 	mutex_lock(&text_mutex);
-	return 0;
 }
-int ftrace_arch_code_modify_post_process(void) __releases(&text_mutex)
+void ftrace_arch_code_modify_post_process(void) __releases(&text_mutex)
 {
 	mutex_unlock(&text_mutex);
-	return 0;
 }
 static int ftrace_check_current_call(unsigned long hook_pos,

arch/s390/kernel/ftrace.c+1−2

 	ftrace_modify_all_code(command);
 }
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
 {
 	/*
 	 * Flush any pre-fetched instructions on all
 	 * CPUs to make the new code visible.
 	 */
 	text_poke_sync_lock();
-	return 0;
 }
 #ifdef CONFIG_MODULES

arch/x86/kernel/ftrace.c+2−4

 static int ftrace_poke_late = 0;
-int ftrace_arch_code_modify_prepare(void)
+void ftrace_arch_code_modify_prepare(void)
     __acquires(&text_mutex)
 {
 	/*
 	 */
 	mutex_lock(&text_mutex);
 	ftrace_poke_late = 1;
-	return 0;
 }
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
     __releases(&text_mutex)
 {
 	/*
 	text_poke_finish();
 	ftrace_poke_late = 0;
 	mutex_unlock(&text_mutex);
-	return 0;
 }
 static const char *ftrace_nop_replace(void)

include/linux/ftrace.h+2−2

@@ -449,8 +449,8 @@ static inline void stack_tracer_enable(void) { } · 448 unmodified lines
449		449
450	#ifdef CONFIG_DYNAMIC_FTRACE	450	#ifdef CONFIG_DYNAMIC_FTRACE
451		451
452	int ftrace_arch_code_modify_prepare(void);	452	void ftrace_arch_code_modify_prepare(void);
453	int ftrace_arch_code_modify_post_process(void);	453	void ftrace_arch_code_modify_post_process(void);
454		454
455	enum ftrace_bug_type {	455	enum ftrace_bug_type {
456	FTRACE_BUG_UNKNOWN,	456	FTRACE_BUG_UNKNOWN,

kernel/trace/ftrace.c+4−12

  * archs can override this function if they must do something
  * before the modifying code is performed.
  */
-int __weak ftrace_arch_code_modify_prepare(void)
+void __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)
+void __weak ftrace_arch_code_modify_post_process(void)
 {
-	return 0;
 }
 void ftrace_modify_all_code(int command)
 static void ftrace_run_update_code(int command)
 {
-	int ret;
+	ftrace_arch_code_modify_prepare();
-	ret = ftrace_arch_code_modify_prepare();
-	FTRACE_WARN_ON(ret);
-	if (ret)
-		return;
 	/*
 	 * By default we use stop_machine() to modify the code.
 	 */
 	arch_ftrace_update_code(command);
-	ret = ftrace_arch_code_modify_post_process();
+	ftrace_arch_code_modify_post_process();
-	FTRACE_WARN_ON(ret);
 }
 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,