lkml.org 
[lkml]   [2012]   [Jul]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 07/19] ftrace/x86_32: Simplify parameter setup for ftrace_regs_caller
(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




\
 
 \ /
  Last update: 2012-07-23 07:02    [W:0.187 / U:0.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site