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From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>, Uros Bizjak <ubizjak@gmail.com>,
	yrl.pp-manager.tt@hitachi.com
Subject: Re: [PATCH 07/19] ftrace/x86_32: Simplify parameter setup for ftrace_regs_caller
Date: Mon, 23 Jul 2012 13:06:13 +0900	[thread overview]
Message-ID: <500CCDB5.5000706@hitachi.com> (raw)
In-Reply-To: <20120721022108.261804403@goodmis.org>

(2012/07/21 11:19), Steven Rostedt wrote:
> From: Uros Bizjak <ubizjak@gmail.com>
> 
> The final position of the stack after saving regs and setting up
> the parameters for ftrace_regs_call, is the position of the pt_regs
> needed for the 4th parameter. Instead of saving it into a temporary
> reg and pushing the reg, simply push the stack pointer.
> 
> Link: http://lkml.kernel.org/r/1342702344.12353.16.camel@gandalf.stny.rr.com
> 

Looks simple and readable :)

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Thanks!

> Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> ---
>  arch/x86/kernel/entry_32.S |    5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
> index 46caa56..4dc3017 100644
> --- a/arch/x86/kernel/entry_32.S
> +++ b/arch/x86/kernel/entry_32.S
> @@ -1169,10 +1169,9 @@ ENTRY(ftrace_regs_caller)
>  	movl $__KERNEL_CS,13*4(%esp)
>  
>  	movl 12*4(%esp), %eax	/* Load ip (1st parameter) */
> -	movl 0x4(%ebp), %edx	/* Load parent ip (2cd parameter) */
> -	lea  (%esp), %ecx
> -	pushl %ecx		/* Save pt_regs as 4th parameter */
> +	movl 0x4(%ebp), %edx	/* Load parent ip (2nd parameter) */
>  	leal function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
> +	pushl %esp		/* Save pt_regs as 4th parameter */
>  
>  GLOBAL(ftrace_regs_call)
>  	call ftrace_stub
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com



  reply	other threads:[~2012-07-23  4:06 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-21  2:19 [PATCH 00/19] [GIT PULL][v3.6] ftrace: Allow kprobes to work with ftace Steven Rostedt
2012-07-21  2:19 ` [PATCH 01/19] ftrace: Pass ftrace_ops as third parameter to function trace callback Steven Rostedt
2012-07-21  2:19 ` [PATCH 02/19] ftrace: Consolidate arch dependent functions with list function Steven Rostedt
2012-07-21  2:19 ` [PATCH 03/19] ftrace: Return pt_regs to function trace callback Steven Rostedt
2012-07-21  2:19 ` [PATCH 04/19] ftrace/x86_32: Push ftrace_ops in as 3rd parameter to function tracer Steven Rostedt
2012-07-21  2:19 ` [PATCH 05/19] ftrace/x86: Add separate function to save regs Steven Rostedt
2012-07-21  2:19 ` [PATCH 06/19] ftrace/x86: Add save_regs for i386 function calls Steven Rostedt
2012-07-21  2:19 ` [PATCH 07/19] ftrace/x86_32: Simplify parameter setup for ftrace_regs_caller Steven Rostedt
2012-07-23  4:06   ` Masami Hiramatsu [this message]
2012-07-21  2:19 ` [PATCH 08/19] ftrace/x86: Remove function_trace_stop check from graph caller Steven Rostedt
2012-07-21  2:19 ` [PATCH 09/19] ftrace: Add default recursion protection for function tracing Steven Rostedt
2012-07-21  2:19 ` [PATCH 10/19] ftrace: Only compile ftrace selftest if selftests are enabled Steven Rostedt
2012-07-21  2:19 ` [PATCH 11/19] ftrace: Add selftest to test function trace recursion protection Steven Rostedt
2012-07-21  2:19 ` [PATCH 12/19] ftrace: Add selftest to test function save-regs support Steven Rostedt
2012-07-21  2:19 ` [PATCH 13/19] ftrace: add ftrace_set_filter_ip() for address based filter Steven Rostedt
2012-07-21  2:19 ` [PATCH 14/19] kprobes: Inverse taking of module_mutex with kprobe_mutex Steven Rostedt
2012-07-21  2:19 ` [PATCH 15/19] kprobes: cleanup to separate probe-able check Steven Rostedt
2012-07-21  2:19 ` [PATCH 16/19] kprobes: Move locks into appropriate functions Steven Rostedt
2012-07-21  2:20 ` [PATCH 17/19] ftrace: Make ftrace_location() a nop on !DYNAMIC_FTRACE Steven Rostedt
2012-07-21  2:20 ` [PATCH 18/19] kprobes: introduce ftrace based optimization Steven Rostedt
2012-07-21  2:20 ` [PATCH 19/19] kprobes/x86: ftrace based optimization for x86 Steven Rostedt
2012-07-30 15:51 ` [PATCH 00/19] [GIT PULL][v3.6] ftrace: Allow kprobes to work with ftace Steven Rostedt
2012-07-31 14:37   ` [GIT PULL][v3.7] (was: Re: [PATCH 00/19] [GIT PULL][v3.6]) " Steven Rostedt
2012-07-31 15:12   ` [PATCH 00/19] [GIT PULL][v3.6] " Ingo Molnar
2012-08-07 13:23     ` Steven Rostedt
2012-08-21  9:26 ` Ingo Molnar

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