From: takahiro.akashi@linaro•org (AKASHI Takahiro)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 1/6] arm64: Add ftrace support
Date: Wed, 19 Feb 2014 19:46:53 +0900 [thread overview]
Message-ID: <53048B9D.2050606@linaro.org> (raw)
In-Reply-To: <20140217181209.GF26590@mudshark.cambridge.arm.com>
On 02/18/2014 03:12 AM, Will Deacon wrote:
> On Fri, Feb 07, 2014 at 10:18:51AM +0000, AKASHI Takahiro wrote:
>> This patch implements arm64 specific part to support function tracers,
>> such as function (CONFIG_FUNCTION_TRACER), function_graph
>> (CONFIG_FUNCTION_GRAPH_TRACER) and function profiler
>> (CONFIG_FUNCTION_PROFILER).
>>
>> With 'function' tracer, all the functions in the kernel are traced with
>> timestamps in ${sysfs}/tracing/trace. If function_graph tracer is
>> specified, call graph is generated.
>>
>> The kernel must be compiled with -pg option so that _mcount() is inserted
>> at the beginning of functions. This function is called on every function's
>> entry as long as tracing is enabled.
>> In addition, function_graph tracer also needs to be able to probe function's
>> exit. ftrace_graph_caller() & return_to_handler do this by faking link
>> register's value to intercept function's return path.
>>
>> More details on architecture specific requirements are described in
>> Documentation/trace/ftrace-design.txt.
>
> [...]
>
>> diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
>> new file mode 100644
>> index 0000000..0d5dfdb
>> --- /dev/null
>> +++ b/arch/arm64/include/asm/ftrace.h
>> @@ -0,0 +1,23 @@
>> +/*
>> + * arch/arm64/include/asm/ftrace.h
>> + *
>> + * Copyright (C) 2013 Linaro Limited
>> + * Author: AKASHI Takahiro <takahiro.akashi@linaro•org>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +#ifndef __ASM_FTRACE_H
>> +#define __ASM_FTRACE_H
>> +
>> +#ifdef CONFIG_FUNCTION_TRACER
>> +#define MCOUNT_ADDR ((unsigned long)_mcount)
>> +#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
>
> You can use AARCH64_INSN_SIZE here.
OK, but MCOUNT_INSN_SIZE can't be removed here because it is also used in
kernel/trace/ftrace.c. So I will redefine it as
#define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
In this case, I need to add __ASSEMBLY__ in asm/insn.h because
asm/ftrace.h (and so asm/insn.h) is included in entry-ftrace.S.
Is it OK?
>> +#include <linux/linkage.h>
>> +#include <asm/ftrace.h>
>> +
>> +/*
>> + * Gcc with -pg will put the following code in the beginning of each function:
>> + * mov x0, x30
>> + * bl _mcount
>> + * [function's body ...]
>> + * "bl _mcount" may be replaced to "bl ftrace_caller" or NOP if dynamic
>> + * ftrace is enabled.
>> + *
>> + * Please note that x0 as an argument will not be used here because we can
>> + * get lr(x30) of insturmented function at any time by winding up call stack
>
> instrumented
I will fix two occurences of "insturmented" :-)
Just a question: Is there any better word than "instrument"?
>> + * as long as the kernel is compiled without -fomit-frame-pointer.
>> + * (or CONFIG_FRAME_POINTER, this is forced on arm64)
>> + *
>> + * stack layout after mcount_enter:
>> + *
>> + * 0 ---------------------------------------- sp of _mcount()
>> + * x29: fp of instrumented function fp is not winded
>> + * --------------------
>> + * x30: lr of _mcount() (= instrumented function's pc)
>> + * +16 ---------------------------------------- sp of instrumented function
>> + *
>> + * ....
>> + *
>> + * +xx ---------------------------------------- fp of instrumented function
>> + * x29: fp of parent
>> + * --------------------
>> + * x30: lr of insturmented function (= parent's pc)
>> + * --------------------
>> + * xxx
>> + */
>> +
>> + .macro mcount_enter
>> + stp x29, x30, [sp, #-48]!
>> + .endm
>
> Can you elaborate in your comment about where this 48 comes from please? I
> can't join it up with your ascii art.
Right. It should be -16 as shown in the stack layout.
When I removed an operation of saving/restoring x0-x3 at v3 patch, this value
should also have been changed.
-Takahiro AKASHI
> Will
>
next prev parent reply other threads:[~2014-02-19 10:46 UTC|newest]
Thread overview: 119+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-24 7:08 [PATCH v2 0/6] arm64: Add ftrace support AKASHI Takahiro
2013-10-24 7:08 ` [PATCH v2 1/6] " AKASHI Takahiro
2013-10-24 7:08 ` [PATCH v2 2/6] arm64: ftrace: Add dynamic " AKASHI Takahiro
2013-10-24 7:08 ` [PATCH v2 3/6] arm64: ftrace: Add CALLER_ADDRx macros AKASHI Takahiro
2013-10-24 7:08 ` [PATCH v2 4/6] ftrace: Add arm64 support to recordmcount AKASHI Takahiro
2013-10-24 7:08 ` [PATCH v2 5/6] arm64: ftrace: Add system call tracepoint AKASHI Takahiro
2013-10-24 7:08 ` [PATCH v2 6/6] arm64: Add 'notrace' attribute to unwind_frame() for ftrace AKASHI Takahiro
2014-02-07 10:18 ` [PATCH v3 0/6] arm64: Add ftrace support AKASHI Takahiro
2014-02-07 10:18 ` [PATCH v3 1/6] " AKASHI Takahiro
2014-02-10 15:03 ` Arnd Bergmann
2014-02-10 15:19 ` Steven Rostedt
[not found] ` <CAB5YjtCr2KL_q1FF8kO_VKe+feg7f9qFRKtwf3xj2h0ENwuB5g@mail.gmail.com>
2014-02-12 11:03 ` Arnd Bergmann
2014-02-17 18:12 ` Will Deacon
2014-02-19 10:46 ` AKASHI Takahiro [this message]
2014-02-07 10:18 ` [PATCH v3 2/6] arm64: ftrace: Add dynamic " AKASHI Takahiro
2014-02-07 10:18 ` [PATCH v3 3/6] arm64: ftrace: Add CALLER_ADDRx macros AKASHI Takahiro
2014-02-07 10:18 ` [PATCH v3 4/6] ftrace: Add arm64 support to recordmcount AKASHI Takahiro
2014-02-07 10:18 ` [PATCH v3 5/6] arm64: ftrace: Add system call tracepoint AKASHI Takahiro
2014-02-17 19:29 ` Will Deacon
2014-02-19 10:48 ` AKASHI Takahiro
2014-02-07 10:18 ` [PATCH v3 6/6] arm64: Add 'notrace' attribute to unwind_frame() for ftrace AKASHI Takahiro
2014-02-10 14:21 ` [PATCH v3 0/6] arm64: Add ftrace support Kulkarni, Ganapatrao
2014-02-25 9:23 ` [PATCH v4 0/7] " AKASHI Takahiro
2014-02-25 9:23 ` [PATCH v4 1/7] " AKASHI Takahiro
2014-02-25 15:38 ` Kulkarni, Ganapatrao
2014-02-28 5:06 ` AKASHI Takahiro
2014-02-25 9:23 ` [PATCH v4 2/7] arm64: ftrace: Add dynamic " AKASHI Takahiro
2014-02-25 9:23 ` [PATCH v4 3/7] arm64: ftrace: Add CALLER_ADDRx macros AKASHI Takahiro
2014-02-25 9:23 ` [PATCH v4 4/7] ftrace: Add arm64 support to recordmcount AKASHI Takahiro
2014-02-25 9:23 ` [PATCH v4 5/7] arm64: ftrace: Add system call tracepoint AKASHI Takahiro
2014-02-25 9:23 ` [PATCH v4 6/7] arm64: Add 'notrace' attribute to unwind_frame() for ftrace AKASHI Takahiro
2014-02-25 9:23 ` [PATCH v4 7/7] arm64: add __ASSEMBLY__ in asm/insn.h AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 0/7] arm64: Add ftrace support AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 1/7] " AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 2/7] arm64: ftrace: Add dynamic " AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 3/7] arm64: ftrace: Add CALLER_ADDRx macros AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 4/7] ftrace: Add arm64 support to recordmcount AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 5/7] arm64: ftrace: Add system call tracepoint AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 6/7] arm64: Add 'notrace' attribute to unwind_frame() for ftrace AKASHI Takahiro
2014-02-28 5:18 ` [PATCH v5 7/7] arm64: add __ASSEMBLY__ in asm/insn.h AKASHI Takahiro
2014-03-11 14:35 ` [PATCH v5 0/7] arm64: Add ftrace support Will Deacon
2014-03-12 1:47 ` AKASHI Takahiro
2014-03-12 1:58 ` Steven Rostedt
2014-03-12 2:02 ` Steven Rostedt
2014-03-13 10:13 ` [PATCH v6 " AKASHI Takahiro
2014-03-13 10:13 ` [PATCH v6 1/7] arm64: add __ASSEMBLY__ in asm/insn.h AKASHI Takahiro
2014-03-13 12:19 ` Will Deacon
2014-03-13 10:13 ` [PATCH v6 2/7] arm64: Add 'notrace' attribute to unwind_frame() for ftrace AKASHI Takahiro
2014-03-13 12:19 ` Will Deacon
2014-03-13 10:13 ` [PATCH v6 3/7] ftrace: Add arm64 support to recordmcount AKASHI Takahiro
2014-03-13 12:38 ` Will Deacon
2014-03-13 14:57 ` AKASHI Takahiro
2014-03-13 16:05 ` Will Deacon
2014-03-13 10:13 ` [PATCH v6 4/7] arm64: Add ftrace support AKASHI Takahiro
2014-03-13 17:08 ` Will Deacon
2014-03-13 18:27 ` Steven Rostedt
2014-03-13 18:37 ` Will Deacon
2014-03-13 18:49 ` Steven Rostedt
2014-03-14 4:45 ` AKASHI Takahiro
2014-03-14 10:07 ` Will Deacon
2014-03-14 16:13 ` AKASHI Takahiro
2014-03-13 10:13 ` [PATCH v6 5/7] arm64: ftrace: Add dynamic " AKASHI Takahiro
2014-03-13 18:10 ` Will Deacon
2014-03-13 18:33 ` Steven Rostedt
2014-03-14 5:28 ` AKASHI Takahiro
2014-03-14 5:26 ` AKASHI Takahiro
2014-03-13 10:13 ` [PATCH v6 6/7] arm64: ftrace: Add CALLER_ADDRx macros AKASHI Takahiro
2014-03-13 15:54 ` Will Deacon
2014-03-13 18:07 ` Steven Rostedt
2014-03-14 4:55 ` AKASHI Takahiro
2014-03-14 3:00 ` AKASHI Takahiro
2014-03-14 10:09 ` Will Deacon
2014-03-14 16:15 ` AKASHI Takahiro
2014-03-13 10:13 ` [PATCH v6 7/7] arm64: ftrace: Add system call tracepoint AKASHI Takahiro
2014-03-13 16:25 ` Will Deacon
2014-03-14 3:50 ` AKASHI Takahiro
2014-03-15 5:40 ` [PATCH v7 0/7] arm64: Add ftrace support AKASHI Takahiro
2014-03-15 5:40 ` [PATCH v7 1/7] arm64: add __ASSEMBLY__ in asm/insn.h AKASHI Takahiro
2014-03-15 5:40 ` [PATCH v7 2/7] arm64: Add 'notrace' attribute to unwind_frame() for ftrace AKASHI Takahiro
2014-03-15 5:40 ` [PATCH v7 3/7] ftrace: Add arm64 support to recordmcount AKASHI Takahiro
2014-04-16 13:31 ` Will Deacon
2014-04-30 9:54 ` [PATCH v8 0/8] arm64: Add ftrace support AKASHI Takahiro
2014-04-30 9:54 ` [PATCH v8 1/8] ftrace: make CALLER_ADDRx macros more generic AKASHI Takahiro
2014-05-02 18:13 ` Will Deacon
2014-05-02 19:02 ` Steven Rostedt
2014-05-02 19:03 ` Steven Rostedt
2014-05-02 19:19 ` Steven Rostedt
2014-05-12 15:58 ` Will Deacon
2014-05-12 16:05 ` Steven Rostedt
2014-05-12 16:12 ` Will Deacon
2014-05-12 17:23 ` Steven Rostedt
2014-05-20 11:29 ` AKASHI Takahiro
2014-05-20 11:31 ` [PATCH v8_1] " AKASHI Takahiro
2014-06-11 12:34 ` [PATCH v8 1/8] " Geert Uytterhoeven
2014-06-11 13:23 ` [PATCH] arm/ftrace: Fix function_return_addr() to function_return_address() Steven Rostedt
2014-06-11 13:38 ` Geert Uytterhoeven
2014-06-11 13:44 ` Steven Rostedt
2014-04-30 9:54 ` [PATCH v8 2/8] arm64: add __ASSEMBLY__ in asm/insn.h AKASHI Takahiro
2014-04-30 9:54 ` [PATCH v8 3/8] arm64: Add 'notrace' attribute to unwind_frame() for ftrace AKASHI Takahiro
2014-04-30 9:54 ` [PATCH v8 4/8] ftrace: Add arm64 support to recordmcount AKASHI Takahiro
2014-04-30 9:54 ` [PATCH v8 5/8] arm64: Add ftrace support AKASHI Takahiro
2014-05-28 20:19 ` Mark Brown
2014-05-29 8:07 ` Will Deacon
2014-05-29 9:47 ` Mark Brown
2014-04-30 9:54 ` [PATCH v8 6/8] arm64: ftrace: Add dynamic " AKASHI Takahiro
2014-04-30 9:54 ` [PATCH v8 7/8] arm64: ftrace: Add CALLER_ADDRx macros AKASHI Takahiro
2014-04-30 9:54 ` [PATCH v8 8/8] arm64: ftrace: Add system call tracepoint AKASHI Takahiro
2014-03-15 5:45 ` [PATCH v7 4/7] arm64: Add ftrace support AKASHI Takahiro
2014-04-16 13:45 ` Will Deacon
2014-03-15 5:45 ` [PATCH v7 5/7] arm64: ftrace: Add dynamic " AKASHI Takahiro
2014-04-16 13:48 ` Will Deacon
2014-03-15 5:45 ` [PATCH v7 6/7] arm64: ftrace: Add CALLER_ADDRx macros AKASHI Takahiro
2014-04-16 13:52 ` Will Deacon
2014-04-28 10:41 ` AKASHI Takahiro
2014-05-27 13:10 ` [for-next][PATCH] ftrace: Make CALLER_ADDRx macros more generic Steven Rostedt
2014-05-27 18:49 ` Will Deacon
2014-05-29 5:27 ` AKASHI Takahiro
2014-05-29 8:10 ` Will Deacon
2014-03-15 5:45 ` [PATCH v7 7/7] arm64: ftrace: Add system call tracepoint AKASHI Takahiro
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