On Sun, 2010-04-18 at 04:51 +0800, Wu Zhangjin wrote: [...] > diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S [...] > > @@ -45,8 +46,6 @@ > PTR_L a5, PT_R9(sp) > 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) > @@ -71,7 +70,7 @@ _mcount: > > 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 $12, PT_R12(sp) /* $12 saved the location of the return address(at) */ > #endif > > move a0, ra /* arg1: next ip, selfaddr */ > @@ -137,25 +136,22 @@ 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 */ > + PTR_L a0, PT_R12(sp) /* arg1: the location of the return address */ > #endif > -#else > +#else /* ! CONFIG_DYNAMIC_FTRACE */ > MCOUNT_SAVE_REGS > move a1, ra /* arg2: next ip, selfaddr */ > #endif > > #ifdef KBUILD_MCOUNT_RA_ADDRESS > - bnez t0, 1f /* non-leaf func: t0 saved the location of the return address */ > + bnez a0, 1f /* non-leaf func: get the location of the return address from saved $12 */ > 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 */ > -#else > - PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */ > #endif > - jal prepare_ftrace_return The above change has broken the static function graph tracer with -mmcount-ra-address for it did not consider the argument 1 for static function graph tracer, a new revision of this patch will be sent out as "MIPS: tracing: adds misc cleanups and fixups". Regards, Wu Zhangjin
