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From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	 Steven Rostedt <rostedt@goodmis.org>,
	Mark Rutland <mark.rutland@arm.com>
Cc: Torsten Duwe <duwe@suse.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/3] ftrace: introdue ftrace_call_init
Date: Mon, 19 Aug 2019 11:30:38 +0000	[thread overview]
Message-ID: <20190819191935.406afa82@xhacker.debian> (raw)
In-Reply-To: <20190819191622.57050fdf@xhacker.debian>

On Mon, 19 Aug 2019 19:16:22 +0800 Jisheng Zhang wrote:

> On some arch, the FTRACE_WITH_REGS is implemented with gcc's
>  -fpatchable-function-entry (=2), gcc adds 2 NOPs at the beginning
> of each function, so this makes the MCOUNT_ADDR useless. In ftrace
> common framework, MCOUNT_ADDR is mostly used to "init" the nop, so
> let's introcude ftrace_call_init().
> 
> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> ---
>  include/linux/ftrace.h | 1 +
>  kernel/trace/ftrace.c  | 4 ++++
>  2 files changed, 5 insertions(+)
> 
> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
> index 8a8cb3c401b2..8175ffb671f0 100644
> --- a/include/linux/ftrace.h
> +++ b/include/linux/ftrace.h
> @@ -458,6 +458,7 @@ extern void ftrace_regs_caller(void);
>  extern void ftrace_call(void);
>  extern void ftrace_regs_call(void);
>  extern void mcount_call(void);
> +extern int ftrace_call_init(struct module *mod, struct dyn_ftrace *rec);
>  
>  void ftrace_modify_all_code(int command);
>  
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index eca34503f178..9df5a66a6811 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -2500,7 +2500,11 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
>  	if (unlikely(ftrace_disabled))
>  		return 0;
>  
> +#ifdef MCOUNT_ADDR
>  	ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
> +#else
> +	ret = ftrace_call_init(mod, rec);
> +#endif

If we want to remove MCOUNT_ADDR from all arch, I could cook patches for
this.

_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mark Rutland <mark.rutland@arm.com>
Cc: "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Torsten Duwe <duwe@suse.de>
Subject: Re: [PATCH 1/3] ftrace: introdue ftrace_call_init
Date: Mon, 19 Aug 2019 11:30:38 +0000	[thread overview]
Message-ID: <20190819191935.406afa82@xhacker.debian> (raw)
In-Reply-To: <20190819191622.57050fdf@xhacker.debian>

On Mon, 19 Aug 2019 19:16:22 +0800 Jisheng Zhang wrote:

> On some arch, the FTRACE_WITH_REGS is implemented with gcc's
>  -fpatchable-function-entry (=2), gcc adds 2 NOPs at the beginning
> of each function, so this makes the MCOUNT_ADDR useless. In ftrace
> common framework, MCOUNT_ADDR is mostly used to "init" the nop, so
> let's introcude ftrace_call_init().
> 
> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> ---
>  include/linux/ftrace.h | 1 +
>  kernel/trace/ftrace.c  | 4 ++++
>  2 files changed, 5 insertions(+)
> 
> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
> index 8a8cb3c401b2..8175ffb671f0 100644
> --- a/include/linux/ftrace.h
> +++ b/include/linux/ftrace.h
> @@ -458,6 +458,7 @@ extern void ftrace_regs_caller(void);
>  extern void ftrace_call(void);
>  extern void ftrace_regs_call(void);
>  extern void mcount_call(void);
> +extern int ftrace_call_init(struct module *mod, struct dyn_ftrace *rec);
>  
>  void ftrace_modify_all_code(int command);
>  
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index eca34503f178..9df5a66a6811 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -2500,7 +2500,11 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
>  	if (unlikely(ftrace_disabled))
>  		return 0;
>  
> +#ifdef MCOUNT_ADDR
>  	ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
> +#else
> +	ret = ftrace_call_init(mod, rec);
> +#endif

If we want to remove MCOUNT_ADDR from all arch, I could cook patches for
this.

  reply	other threads:[~2019-08-19 11:30 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-19 11:26 [PATCH 0/3] arm64: ftrace with regs Jisheng Zhang
2019-08-19 11:26 ` Jisheng Zhang
2019-08-19 11:27 ` [PATCH 1/3] ftrace: introdue ftrace_call_init Jisheng Zhang
2019-08-19 11:27   ` Jisheng Zhang
2019-08-19 11:30   ` Jisheng Zhang [this message]
2019-08-19 11:30     ` Jisheng Zhang
2019-08-20  9:27   ` Miroslav Benes
2019-08-20  9:27     ` Miroslav Benes
2019-08-21  2:12     ` Jisheng Zhang
2019-08-21  2:12       ` Jisheng Zhang
2019-08-26 10:14     ` Jisheng Zhang
2019-08-26 10:14       ` Jisheng Zhang
2019-08-19 11:28 ` [PATCH 2/3] arm64: implement ftrace with regs Jisheng Zhang
2019-08-19 11:28   ` Jisheng Zhang
2019-08-19 11:29 ` [PATCH 3/3] arm64: use -fpatchable-function-entry if available Jisheng Zhang
2019-08-19 11:29   ` Jisheng Zhang

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