diff options
Diffstat (limited to 'arch/mips/kernel/mcount.S')
| -rw-r--r-- | arch/mips/kernel/mcount.S | 69 |
1 files changed, 41 insertions, 28 deletions
diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index 6851fc97a51..539b6294b61 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -6,6 +6,7 @@ * more details. * * Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China + * Copyright (C) 2010 DSLab, Lanzhou University, China * Author: Wu Zhangjin <wuzhangjin@gmail.com> */ @@ -46,39 +47,47 @@ PTR_L a6, PT_R10(sp) PTR_L a7, PT_R11(sp) #endif -#ifdef CONFIG_64BIT PTR_ADDIU sp, PT_SIZE -#else - PTR_ADDIU sp, (PT_SIZE + 8) -#endif -.endm + .endm .macro RETURN_BACK jr ra move ra, AT .endm +/* + * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass + * the location of the parent's return address. + */ +#define MCOUNT_RA_ADDRESS_REG $12 + #ifdef CONFIG_DYNAMIC_FTRACE NESTED(ftrace_caller, PT_SIZE, ra) .globl _mcount _mcount: b ftrace_stub +#ifdef CONFIG_32BIT + addiu sp,sp,8 +#else nop +#endif + + /* When tracing is activated, it calls ftrace_caller+8 (aka here) */ lw t1, function_trace_stop bnez t1, ftrace_stub nop MCOUNT_SAVE_REGS #ifdef KBUILD_MCOUNT_RA_ADDRESS - PTR_S t0, PT_R12(sp) /* t0 saved the location of the return address(at) by -mmcount-ra-address */ + PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp) #endif - move a0, ra /* arg1: next ip, selfaddr */ + PTR_SUBU a0, ra, 8 /* arg1: self address */ .globl ftrace_call ftrace_call: nop /* a placeholder for the call to a real tracing function */ - move a1, AT /* arg2: the caller's next ip, parent */ + move a1, AT /* arg2: parent's return address */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER .globl ftrace_graph_call @@ -119,9 +128,9 @@ NESTED(_mcount, PT_SIZE, ra) static_trace: MCOUNT_SAVE_REGS - move a0, ra /* arg1: next ip, selfaddr */ + move a0, ra /* arg1: self return address */ jalr t2 /* (1) call *ftrace_trace_function */ - move a1, AT /* arg2: the caller's next ip, parent */ + move a1, AT /* arg2: parent's return address */ MCOUNT_RESTORE_REGS .globl ftrace_stub @@ -134,35 +143,39 @@ ftrace_stub: #ifdef CONFIG_FUNCTION_GRAPH_TRACER NESTED(ftrace_graph_caller, PT_SIZE, ra) -#ifdef CONFIG_DYNAMIC_FTRACE - PTR_L a1, PT_R31(sp) /* load the original ra from the stack */ -#ifdef KBUILD_MCOUNT_RA_ADDRESS - PTR_L t0, PT_R12(sp) /* load the original t0 from the stack */ -#endif -#else +#ifndef CONFIG_DYNAMIC_FTRACE MCOUNT_SAVE_REGS - move a1, ra /* arg2: next ip, selfaddr */ #endif + /* arg1: Get the location of the parent's return address */ #ifdef KBUILD_MCOUNT_RA_ADDRESS - bnez t0, 1f /* non-leaf func: t0 saved the location of the return address */ - nop - PTR_LA t0, PT_R1(sp) /* leaf func: get the location of at(old ra) from our own stack */ -1: move a0, t0 /* arg1: the location of the return address */ +#ifdef CONFIG_DYNAMIC_FTRACE + PTR_L a0, PT_R12(sp) #else - PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */ + move a0, MCOUNT_RA_ADDRESS_REG #endif - jal prepare_ftrace_return -#ifdef CONFIG_FRAME_POINTER - move a2, fp /* arg3: frame pointer */ + bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */ + nop +#endif + PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */ +1: + + /* arg2: Get self return address */ +#ifdef CONFIG_DYNAMIC_FTRACE + PTR_L a1, PT_R31(sp) #else + move a1, ra +#endif + + /* arg3: Get frame pointer of current stack */ #ifdef CONFIG_64BIT - PTR_LA a2, PT_SIZE(sp) + PTR_LA a2, PT_SIZE(sp) #else - PTR_LA a2, (PT_SIZE+8)(sp) -#endif + PTR_LA a2, (PT_SIZE+8)(sp) #endif + jal prepare_ftrace_return + nop MCOUNT_RESTORE_REGS RETURN_BACK END(ftrace_graph_caller) |