On Fri, 29 May 2009, wuzhangjin@xxxxxxxxx wrote: > diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S > index ce8a0ba..bd58f16 100644 > --- a/arch/mips/kernel/mcount.S > +++ b/arch/mips/kernel/mcount.S > @@ -28,6 +28,10 @@ > PTR_SUBU sp, PT_SIZE > PTR_S ra, PT_R31(sp) > PTR_S $1, PT_R1(sp) > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER > + PTR_S v0, PT_R2(sp) > + PTR_S v1, PT_R3(sp) > +#endif > PTR_S a0, PT_R4(sp) > PTR_S a1, PT_R5(sp) > PTR_S a2, PT_R6(sp) > @@ -43,6 +47,10 @@ > .macro MCOUNT_RESTORE_REGS > PTR_L ra, PT_R31(sp) > PTR_L $1, PT_R1(sp) > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER > + PTR_L v0, PT_R2(sp) > + PTR_L v1, PT_R3(sp) > +#endif > PTR_L a0, PT_R4(sp) > PTR_L a1, PT_R5(sp) > PTR_L a2, PT_R6(sp) > @@ -89,6 +97,14 @@ ftrace_call: > nop > > MCOUNT_RESTORE_REGS > + > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER > + .globl ftrace_graph_call > +ftrace_graph_call: > + j ftrace_stub > + nop > +#endif > + > .globl ftrace_stub > ftrace_stub: > RETURN_BACK > @@ -106,7 +122,15 @@ NESTED(_mcount, PT_SIZE, ra) > PTR_L t1, ftrace_trace_function /* please don't use t1 later, safe? */ > bne t0, t1, static_trace > nop > - > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER > + PTR_L t2, ftrace_graph_return > + bne t0, t2, ftrace_graph_caller > + nop > + PTR_LA t0, ftrace_graph_entry_stub > + PTR_L t2, ftrace_graph_entry > + bne t0, t2, ftrace_graph_caller > + nop > +#endif > j ftrace_stub > nop > > @@ -125,5 +149,37 @@ ftrace_stub: > > #endif /* ! CONFIG_DYNAMIC_FTRACE */ > > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER > + > +NESTED(ftrace_graph_caller, PT_SIZE, ra) > + MCOUNT_SAVE_REGS > + > + MCOUNT_SET_ARGS > + jal prepare_ftrace_return > + nop > + > + /* overwrite the parent as &return_to_handler: v0 -> $1(at) */ > + PTR_S v0, PT_R1(sp) > + > + MCOUNT_RESTORE_REGS > + RETURN_BACK > + END(ftrace_graph_caller) > + > + .align 2 > + .globl return_to_handler > +return_to_handler: > + MCOUNT_SAVE_REGS I'm not sure which version of function_graph tracer you looked at, but I'm pretty sure you can just save the return code registers of the function. return_to_handler is called on the return of a function. Thus, any callee saved registers have already been restored and would also be restored by ftrace_return_to_handler. Any callee registers would have been saved by the function you are about to return to. Thus the only things you need to save are the return code registers. -- Steve > + > + jal ftrace_return_to_handler > + nop > + > + /* restore the real parent address: v0 -> ra */ > + PTR_S v0, PT_R31(sp) > + > + MCOUNT_RESTORE_REGS > + RETURN_BACK > + > +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > + > .set at > .set reorder > diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S > index 58738c8..67435e5 100644 > --- a/arch/mips/kernel/vmlinux.lds.S > +++ b/arch/mips/kernel/vmlinux.lds.S > @@ -36,6 +36,7 @@ SECTIONS > SCHED_TEXT > LOCK_TEXT > KPROBES_TEXT > + IRQENTRY_TEXT > *(.text.*) > *(.fixup) > *(.gnu.warning) > -- > 1.6.0.4 > >
