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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>
This commit is contained in:
Steven Rostedt 2009-02-11 19:10:57 -05:00 committed by Benjamin Herrenschmidt
parent bf528a3a9b
commit fad4f47cc8
3 changed files with 44 additions and 3 deletions
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2
arch/powerpc/Kconfig
View File

@ -111,7 +111,7 @@ config PPC
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_GRAPH_TRACER if PPC64
select HAVE_FUNCTION_GRAPH_TRACER if PPC64 || !DYNAMIC_FTRACE
select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_IDE
select HAVE_IOREMAP_PROT

43
arch/powerpc/kernel/entry_32.S
View File

@ -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 */

2
arch/powerpc/kernel/ftrace.c
View File

@ -603,7 +603,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
"1: " PPC_LL "%[old], 0(%[parent])\n"
"2: " PPC_STL "%[return_hooker], 0(%[parent])\n"
" li %[faulted], 0\n"
"3:"
"3:\n"
".section .fixup, \"ax\"\n"
"4: li %[faulted], 1\n"