Commit e999995c authored by Chengming Zhou's avatar Chengming Zhou Committed by Catalin Marinas
Browse files

ftrace: cleanup ftrace_graph_caller enable and disable 



The ftrace_[enable,disable]_ftrace_graph_caller() are used to do
special hooks for graph tracer, which are not needed on some ARCHs
that use graph_ops:func function to install return_hooker.

So introduce the weak version in ftrace core code to cleanup
in x86.

Signed-off-by: default avatarChengming Zhou <zhouchengming@bytedance.com>
Acked-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220420160006.17880-1-zhouchengming@bytedance.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent b2d229d4

arch/x86/kernel/ftrace.c

+2 −15
Original line number Diff line number Diff line
@@ -579,9 +579,7 @@ void arch_ftrace_trampoline_free(struct ftrace_ops *ops) 


#ifdef CONFIG_FUNCTION_GRAPH_TRACER



#ifdef CONFIG_DYNAMIC_FTRACE



#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS

#if defined(CONFIG_DYNAMIC_FTRACE) && !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)

extern void ftrace_graph_call(void);

static const char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)

{
@@ -610,18 +608,7 @@ int ftrace_disable_ftrace_graph_caller(void) 


	return ftrace_mod_jmp(ip, &ftrace_stub);

}

#else /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */

int ftrace_enable_ftrace_graph_caller(void)

{

	return 0;

}



int ftrace_disable_ftrace_graph_caller(void)

{

	return 0;

}

#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */

#endif /* !CONFIG_DYNAMIC_FTRACE */

#endif /* CONFIG_DYNAMIC_FTRACE && !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */



/*

 * Hook the return address and push it in the stack of return addrs

kernel/trace/fgraph.c

+18 −0
Original line number Diff line number Diff line
@@ -30,6 +30,24 @@ int ftrace_graph_active; 
/* Both enabled by default (can be cleared by function_graph tracer flags */

static bool fgraph_sleep_time = true;



/*

 * archs can override this function if they must do something

 * to enable hook for graph tracer.

 */

int __weak ftrace_enable_ftrace_graph_caller(void)

{

	return 0;

}



/*

 * archs can override this function if they must do something

 * to disable hook for graph tracer.

 */

int __weak ftrace_disable_ftrace_graph_caller(void)

{

	return 0;

}



/**

 * ftrace_graph_stop - set to permanently disable function graph tracing

 *