ftrace: x86 mcount stub

x86 now sets up the mcount locations through the build and no longer
needs to record the ip when the function is executed. This patch changes
the initial mcount to simply return. There's no need to do any other work.
If the ftrace start up test fails, the original mcount will be what everything
will use, so having this as fast as possible is a good thing.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 14 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index b21fbfaffe39..4e4269c73bb7 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1153,20 +1153,6 @@ ENDPROC(xen_failsafe_callback)
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 ENTRY(mcount)
-        pushl %eax
-        pushl %ecx
-        pushl %edx
-        movl 0xc(%esp), %eax
-        subl $MCOUNT_INSN_SIZE, %eax
-
-.globl mcount_call
-mcount_call:
-        call ftrace_stub
-
-        popl %edx
-        popl %ecx
-        popl %eax
-
         ret
 END(mcount)