From fad4f47cc8b2b8f7e7d062c40c66188cdf783137 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 11 Feb 2009 19:10:57 -0500 Subject: powerpc32, ftrace: port function graph tracer to ppc32, static only This patch ports the function graph tracer for PowerPC, but only for static function tracing. Acked-by: Benjamin Herrenschmidt Signed-off-by: Steven Rostedt Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/entry_32.S | 43 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/entry_32.S') diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index fd54cb59728e..12247b937d25 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1199,9 +1199,11 @@ _GLOBAL(_mcount) mtctr r5 bctrl - nop +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + b ftrace_graph_caller +#endif MCOUNT_RESTORE_FRAME bctr @@ -1210,4 +1212,43 @@ _GLOBAL(_mcount) _GLOBAL(ftrace_stub) blr +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +_GLOBAL(ftrace_graph_caller) + /* load r4 with local address */ + lwz r4, 44(r1) + subi r4, r4, MCOUNT_INSN_SIZE + + /* get the parent address */ + addi r3, r1, 52 + + bl prepare_ftrace_return + nop + + MCOUNT_RESTORE_FRAME + /* old link register ends up in ctr reg */ + bctr + +_GLOBAL(return_to_handler) + /* need to save return values */ + stwu r1, -32(r1) + stw r3, 20(r1) + stw r4, 16(r1) + stw r31, 12(r1) + mr r31, r1 + + bl ftrace_return_to_handler + nop + + /* return value has real return address */ + mtlr r3 + + lwz r3, 20(r1) + lwz r4, 16(r1) + lwz r31,12(r1) + lwz r1, 0(r1) + + /* Jump back to real return address */ + blr +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + #endif /* CONFIG_MCOUNT */ -- cgit v1.2.3