diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2009-02-12 01:10:57 +0100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-02-23 00:48:55 +0100 |
| commit | fad4f47cc8b2b8f7e7d062c40c66188cdf783137 (patch) | |
| tree | e0c978d7b4ffdf1ae8d7d0795c774c6fad87fdf7 /arch/powerpc/kernel/entry_32.S | |
| parent | powerpc32, ftrace: save and restore mcount regs with macro (diff) | |
| download | linux-fad4f47cc8b2b8f7e7d062c40c66188cdf783137.tar.xz linux-fad4f47cc8b2b8f7e7d062c40c66188cdf783137.zip | |
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 <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 43 |
1 files changed, 42 insertions, 1 deletions
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 */ |