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Commit fad4f47c authored by Steven Rostedt's avatar Steven Rostedt Committed by Benjamin Herrenschmidt
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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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent bf528a3a

arch/powerpc/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/powerpc/kernel/entry_32.S

+42 −1
Original line number Diff line number Diff line
@@ -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 */

arch/powerpc/kernel/ftrace.c

+1 −1
Original line number Diff line number Diff line
@@ -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"