On Wed, 2009-10-21 at 11:24 -0400, Steven Rostedt wrote: > On Wed, 2009-10-21 at 22:34 +0800, Wu Zhangjin wrote: > > > +++ b/arch/mips/kernel/mcount.S > > @@ -0,0 +1,94 @@ > > +/* > > + * the mips-specific _mcount implementation > > + * > > + * This file is subject to the terms and conditions of the GNU General Public > > + * License. See the file "COPYING" in the main directory of this archive for > > + * more details. > > + * > > + * Copyright (C) 2009 DSLab, Lanzhou University, China > > + * Author: Wu Zhangjin <wuzj@xxxxxxxxxx> > > + */ > > + > > +#include <asm/regdef.h> > > +#include <asm/stackframe.h> > > +#include <asm/ftrace.h> > > + > > + .text > > + .set noreorder > > + .set noat > > + > > + /* since there is a "addiu sp,sp,-8" before "jal _mcount" in 32bit */ > > + .macro RESTORE_SP_FOR_32BIT > > +#ifdef CONFIG_32BIT > > + PTR_ADDIU sp, 8 > > +#endif > > + .endm > > + > > + .macro MCOUNT_SAVE_REGS > > + PTR_SUBU sp, PT_SIZE > > + PTR_S ra, PT_R31(sp) > > + PTR_S AT, PT_R1(sp) > > + PTR_S a0, PT_R4(sp) > > + PTR_S a1, PT_R5(sp) > > + PTR_S a2, PT_R6(sp) > > + PTR_S a3, PT_R7(sp) > > +#ifdef CONFIG_64BIT > > + PTR_S a4, PT_R8(sp) > > + PTR_S a5, PT_R9(sp) > > + PTR_S a6, PT_R10(sp) > > + PTR_S a7, PT_R11(sp) > > +#endif > > + .endm > > + > > + .macro MCOUNT_RESTORE_REGS > > + PTR_L ra, PT_R31(sp) > > + PTR_L AT, PT_R1(sp) > > + PTR_L a0, PT_R4(sp) > > + PTR_L a1, PT_R5(sp) > > + PTR_L a2, PT_R6(sp) > > + PTR_L a3, PT_R7(sp) > > +#ifdef CONFIG_64BIT > > + PTR_L a4, PT_R8(sp) > > + PTR_L a5, PT_R9(sp) > > + PTR_L a6, PT_R10(sp) > > + PTR_L a7, PT_R11(sp) > > +#endif > > + PTR_ADDIU sp, PT_SIZE > > +.endm > > + > > + .macro MCOUNT_SET_ARGS > > + move a0, ra /* arg1: next ip, selfaddr */ > > + move a1, AT /* arg2: the caller's next ip, parent */ > > + PTR_SUBU a0, MCOUNT_INSN_SIZE > > + .endm > > + > > + .macro RETURN_BACK > > + jr ra > > + move ra, AT > > + .endm > > + > > +NESTED(_mcount, PT_SIZE, ra) > > + RESTORE_SP_FOR_32BIT > > + PTR_LA t0, ftrace_stub > > + PTR_L t1, ftrace_trace_function /* please don't use t1 later, safe? */ > > Is t0 and t1 safe for mcount to use? Remember, mcount does not follow > the dynamics of C function ABI. So, perhaps we can use the saved registers(a0,a1...) instead. Regards!
