Commit 014c257c authored by Abhishek Sagar's avatar Abhishek Sagar Committed by Ingo Molnar
Browse files

ftrace: core support for ARM 



Core ftrace support for the ARM architecture, which includes support
for dynamic function tracing.

Signed-off-by: default avatarAbhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b1829d27

arch/arm/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ config ARM 
	select HAVE_OPROFILE

	select HAVE_KPROBES if (!XIP_KERNEL)

	select HAVE_KRETPROBES if (HAVE_KPROBES)

	select HAVE_FTRACE if (!XIP_KERNEL)

	select HAVE_DYNAMIC_FTRACE if (HAVE_FTRACE)

	help

	  The ARM series is a line of low-power-consumption RISC chip designs

	  licensed by ARM Ltd and targeted at embedded applications and

arch/arm/boot/compressed/Makefile

+6 −0
Original line number Diff line number Diff line
@@ -69,6 +69,12 @@ SEDFLAGS = s/TEXT_START/$(ZTEXTADDR)/;s/BSS_START/$(ZBSSADDR)/ 


targets       := vmlinux vmlinux.lds piggy.gz piggy.o font.o font.c \

		 head.o misc.o $(OBJS)



ifeq ($(CONFIG_FTRACE),y)

ORIG_CFLAGS := $(KBUILD_CFLAGS)

KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))

endif



EXTRA_CFLAGS  := -fpic -fno-builtin

EXTRA_AFLAGS  :=

arch/arm/kernel/Makefile

+5 −0
Original line number Diff line number Diff line
@@ -4,6 +4,10 @@ 


AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)



ifdef CONFIG_DYNAMIC_FTRACE

CFLAGS_REMOVE_ftrace.o = -pg

endif



# Object file lists.



obj-y		:= compat.o entry-armv.o entry-common.o irq.o \
@@ -18,6 +22,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o 
obj-$(CONFIG_ISA_DMA)		+= dma-isa.o

obj-$(CONFIG_PCI)		+= bios32.o isa.o

obj-$(CONFIG_SMP)		+= smp.o

obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o

obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o

obj-$(CONFIG_KPROBES)		+= kprobes.o kprobes-decode.o

obj-$(CONFIG_ATAGS_PROC)	+= atags.o

arch/arm/kernel/armksyms.c

+5 −0
Original line number Diff line number Diff line
@@ -48,6 +48,11 @@ extern void __aeabi_ulcmp(void); 
extern void fpundefinstr(void);

extern void fp_enter(void);



#ifdef CONFIG_FTRACE

extern void mcount(void);

EXPORT_SYMBOL(mcount);

#endif



/*

 * This has a special calling convention; it doesn't

 * modify any of the usual registers, except for LR.

arch/arm/kernel/entry-common.S

+47 −0
Original line number Diff line number Diff line
@@ -99,6 +99,53 @@ ENTRY(ret_from_fork) 
#undef CALL

#define CALL(x) .long x



#ifdef CONFIG_FTRACE

#ifdef CONFIG_DYNAMIC_FTRACE

ENTRY(mcount)

	stmdb sp!, {r0-r3, lr}

	mov r0, lr



	.globl mcount_call

mcount_call:

	bl ftrace_stub

	ldmia sp!, {r0-r3, pc}



ENTRY(ftrace_caller)

	stmdb sp!, {r0-r3, lr}

	ldr r1, [fp, #-4]

	mov r0, lr



	.globl ftrace_call

ftrace_call:

	bl ftrace_stub

	ldmia sp!, {r0-r3, pc}



#else



ENTRY(mcount)

	stmdb sp!, {r0-r3, lr}

	ldr r0, =ftrace_trace_function

	ldr r2, [r0]

	adr r0, ftrace_stub

	cmp r0, r2

	bne trace

	ldmia sp!, {r0-r3, pc}



trace:

	ldr r1, [fp, #-4]

	mov r0, lr

	mov lr, pc

	mov pc, r2

	ldmia sp!, {r0-r3, pc}



#endif /* CONFIG_DYNAMIC_FTRACE */



	.globl ftrace_stub

ftrace_stub:

	mov pc, lr



#endif /* CONFIG_FTRACE */



/*=============================================================================

 * SWI handler

 *-----------------------------------------------------------------------------