From 2fd7c761a24c28e83d7194b4b4a099451126a503 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Mon, 16 Nov 2009 09:40:14 +0100 Subject: [PATCH] microblaze: ftrace: add static function tracer If -pg of gcc is enabled with CONFIG_FUNCTION_TRACER=y. a calling to _mcount will be inserted into each kernel function. so, there is a possibility to trace the kernel functions in _mcount. This patch add the specific _mcount support for static function tracing. by default, ftrace_trace_function is initialized as ftrace_stub(an empty function), so, the default _mcount will introduce very little overhead. after enabling ftrace in user-space, it will jump to a real tracing function and do static function tracing for us. Commit message from Wu Zhangjin Signed-off-by: Michal Simek --- arch/microblaze/Kconfig | 1 + arch/microblaze/include/asm/ftrace.h | 14 +++ arch/microblaze/kernel/Makefile | 11 +++ arch/microblaze/kernel/cpu/Makefile | 4 + arch/microblaze/kernel/mcount.S | 105 ++++++++++++++++++++++ arch/microblaze/kernel/microblaze_ksyms.c | 5 ++ 6 files changed, 140 insertions(+) create mode 100644 arch/microblaze/kernel/mcount.S diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index 57eeaa60ca6..18003ca0819 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -6,6 +6,7 @@ mainmenu "Linux/Microblaze Kernel Configuration" config MICROBLAZE def_bool y select HAVE_LMB + select HAVE_FUNCTION_TRACER select USB_ARCH_HAS_EHCI select ARCH_WANT_OPTIONAL_GPIOLIB diff --git a/arch/microblaze/include/asm/ftrace.h b/arch/microblaze/include/asm/ftrace.h index 8b137891791..22beec58c02 100644 --- a/arch/microblaze/include/asm/ftrace.h +++ b/arch/microblaze/include/asm/ftrace.h @@ -1 +1,15 @@ +#ifndef _ASM_MICROBLAZE_FTRACE +#define _ASM_MICROBLAZE_FTRACE +#ifdef CONFIG_FUNCTION_TRACER + +#define MCOUNT_ADDR ((long)(_mcount)) +#define MCOUNT_INSN_SIZE 8 /* sizeof mcount call */ + +#ifndef __ASSEMBLY__ +extern void _mcount(void); +extern void ftrace_call_graph(void); +#endif + +#endif /* CONFIG_FUNCTION_TRACER */ +#endif /* _ASM_MICROBLAZE_FTRACE */ diff --git a/arch/microblaze/kernel/Makefile b/arch/microblaze/kernel/Makefile index c465a5c4669..d5ee3264cd7 100644 --- a/arch/microblaze/kernel/Makefile +++ b/arch/microblaze/kernel/Makefile @@ -2,6 +2,16 @@ # Makefile # +ifdef CONFIG_FUNCTION_TRACER +# Do not trace early boot code and low level code +CFLAGS_REMOVE_timer.o = -pg +CFLAGS_REMOVE_intc.o = -pg +CFLAGS_REMOVE_early_printk.o = -pg +CFLAGS_REMOVE_selfmod.o = -pg +CFLAGS_REMOVE_heartbeat.o = -pg +CFLAGS_REMOVE_ftrace.o = -pg +endif + extra-y := head.o vmlinux.lds obj-y += exceptions.o \ @@ -17,5 +27,6 @@ obj-$(CONFIG_HEART_BEAT) += heartbeat.o obj-$(CONFIG_MODULES) += microblaze_ksyms.o module.o obj-$(CONFIG_MMU) += misc.o obj-$(CONFIG_STACKTRACE) += stacktrace.o +obj-$(CONFIG_FUNCTION_TRACER) += mcount.o obj-y += entry$(MMU).o diff --git a/arch/microblaze/kernel/cpu/Makefile b/arch/microblaze/kernel/cpu/Makefile index 20646e54927..59cc7bceaf8 100644 --- a/arch/microblaze/kernel/cpu/Makefile +++ b/arch/microblaze/kernel/cpu/Makefile @@ -2,6 +2,10 @@ # Build the appropriate CPU version support # +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_cache.o = -pg +endif + EXTRA_CFLAGS += -DCPU_MAJOR=$(CPU_MAJOR) -DCPU_MINOR=$(CPU_MINOR) \ -DCPU_REV=$(CPU_REV) diff --git a/arch/microblaze/kernel/mcount.S b/arch/microblaze/kernel/mcount.S new file mode 100644 index 00000000000..a257a1b75ed --- /dev/null +++ b/arch/microblaze/kernel/mcount.S @@ -0,0 +1,105 @@ +/* + * Low-level ftrace handling + * + * Copyright (C) 2009 Michal Simek + * Copyright (C) 2009 PetaLogix + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + */ + +#include + +#define NOALIGN_ENTRY(name) .globl name; name: + +/* FIXME MS: I think that I don't need to save all regs */ +#define SAVE_REGS \ + addik r1, r1, -120; \ + swi r2, r1, 4; \ + swi r3, r1, 8; \ + swi r4, r1, 12; \ + swi r5, r1, 116; \ + swi r6, r1, 16; \ + swi r7, r1, 20; \ + swi r8, r1, 24; \ + swi r9, r1, 28; \ + swi r10, r1, 32; \ + swi r11, r1, 36; \ + swi r12, r1, 40; \ + swi r13, r1, 44; \ + swi r14, r1, 48; \ + swi r16, r1, 52; \ + swi r17, r1, 56; \ + swi r18, r1, 60; \ + swi r19, r1, 64; \ + swi r20, r1, 68; \ + swi r21, r1, 72; \ + swi r22, r1, 76; \ + swi r23, r1, 80; \ + swi r24, r1, 84; \ + swi r25, r1, 88; \ + swi r26, r1, 92; \ + swi r27, r1, 96; \ + swi r28, r1, 100; \ + swi r29, r1, 104; \ + swi r30, r1, 108; \ + swi r31, r1, 112; + +#define RESTORE_REGS \ + lwi r2, r1, 4; \ + lwi r3, r1, 8; \ + lwi r4, r1, 12; \ + lwi r5, r1, 116; \ + lwi r6, r1, 16; \ + lwi r7, r1, 20; \ + lwi r8, r1, 24; \ + lwi r9, r1, 28; \ + lwi r10, r1, 32; \ + lwi r11, r1, 36; \ + lwi r12, r1, 40; \ + lwi r13, r1, 44; \ + lwi r14, r1, 48; \ + lwi r16, r1, 52; \ + lwi r17, r1, 56; \ + lwi r18, r1, 60; \ + lwi r19, r1, 64; \ + lwi r20, r1, 68; \ + lwi r21, r1, 72; \ + lwi r22, r1, 76; \ + lwi r23, r1, 80; \ + lwi r24, r1, 84; \ + lwi r25, r1, 88; \ + lwi r26, r1, 92; \ + lwi r27, r1, 96; \ + lwi r28, r1, 100; \ + lwi r29, r1, 104; \ + lwi r30, r1, 108; \ + lwi r31, r1, 112; \ + addik r1, r1, 120; + +ENTRY(ftrace_stub) + rtsd r15, 8; + nop; + +ENTRY(_mcount) + SAVE_REGS + swi r15, r1, 0; + /* MS: test function trace if is taken or not */ + lwi r20, r0, ftrace_trace_function; + addik r6, r0, ftrace_stub; + cmpu r5, r20, r6; /* ftrace_trace_function != ftrace_stub */ + beqid r5, end; /* MS: not taken -> jump over */ + nop; +/* static normal trace */ + lwi r6, r1, 120; /* MS: load parent addr */ + addik r5, r15, 0; /* MS: load current function addr */ + /* MS: here is dependency on previous code */ + brald r15, r20; /* MS: jump to ftrace handler */ + nop; +end: + lwi r15, r1, 0; + RESTORE_REGS + + rtsd r15, 8; /* MS: jump back */ + nop; diff --git a/arch/microblaze/kernel/microblaze_ksyms.c b/arch/microblaze/kernel/microblaze_ksyms.c index 59ff20e33e0..bc4dcb7d386 100644 --- a/arch/microblaze/kernel/microblaze_ksyms.c +++ b/arch/microblaze/kernel/microblaze_ksyms.c @@ -18,6 +18,7 @@ #include #include #include +#include #include /* @@ -47,3 +48,7 @@ extern void __umodsi3(void); EXPORT_SYMBOL(__umodsi3); extern char *_ebss; EXPORT_SYMBOL_GPL(_ebss); +#ifdef CONFIG_FUNCTION_TRACER +extern void _mcount(void); +EXPORT_SYMBOL(_mcount); +#endif -- 2.41.0