[PATCH 07/19] ftrace/x86_32: Simplify parameter setup for ftrace_regs_caller

From: Steven Rostedt
Date: Fri Jul 20 2012 - 22:22:01 EST

From: Uros Bizjak <ubizjak@xxxxxxxxx>

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@xxxxxxxxxxxxxxxxxxx

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
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 */

call ftrace_stub

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