Commit ac7127e1 authored by Qing Zhang's avatar Qing Zhang Committed by Huacai Chen
Browse files

LoongArch/ftrace: Add HAVE_DYNAMIC_FTRACE_WITH_ARGS support 



Allow for arguments to be passed in to ftrace_regs by default. If this
is set, then arguments and stack can be found from the pt_regs.

1. HAVE_DYNAMIC_FTRACE_WITH_ARGS don't need special hook for graph
tracer entry point, but instead we can use graph_ops::func function to
install the return_hooker.

2. Livepatch requires this option in the future.

Signed-off-by: default avatarQing Zhang <zhangqing@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 8778ba2c

arch/loongarch/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ config LOONGARCH 
	select HAVE_DEBUG_STACKOVERFLOW

	select HAVE_DMA_CONTIGUOUS

	select HAVE_DYNAMIC_FTRACE

	select HAVE_DYNAMIC_FTRACE_WITH_ARGS

	select HAVE_DYNAMIC_FTRACE_WITH_REGS

	select HAVE_EBPF_JIT

	select HAVE_EXIT_THREAD

arch/loongarch/include/asm/ftrace.h

+17 −0
Original line number Diff line number Diff line
@@ -37,6 +37,23 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent); 


#endif /* CONFIG_DYNAMIC_FTRACE */



#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS

struct ftrace_ops;



struct ftrace_regs {

	struct pt_regs regs;

};



static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)

{

	return &fregs->regs;

}



#define ftrace_graph_func ftrace_graph_func

void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,

		       struct ftrace_ops *op, struct ftrace_regs *fregs);

#endif



#endif /* __ASSEMBLY__ */



#endif /* CONFIG_FUNCTION_TRACER */

arch/loongarch/kernel/ftrace_dyn.c

+11 −0
Original line number Diff line number Diff line
@@ -139,6 +139,16 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent) 
		*parent = return_hooker;

}



#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS

void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,

		       struct ftrace_ops *op, struct ftrace_regs *fregs)

{

	struct pt_regs *regs = &fregs->regs;

	unsigned long *parent = (unsigned long *)&regs->regs[1];



	prepare_ftrace_return(ip, (unsigned long *)parent);

}

#else

static int ftrace_modify_graph_caller(bool enable)

{

	u32 branch, nop;
@@ -166,4 +176,5 @@ int ftrace_disable_ftrace_graph_caller(void) 
{

	return ftrace_modify_graph_caller(false);

}

#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */