ftrace: store mcount address in rec->ip

Record the address of the mcount call-site. Currently all archs except sparc64
record the address of the instruction following the mcount call-site. Some
general cleanups are entailed. Storing mcount addresses in rec->ip enables
looking them up in the kprobe hash table later on to check if they're kprobe'd.

Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: davem@davemloft.net
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 04ea83ccb979..95e6bbe3665e 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -51,6 +51,7 @@
 #include <asm/percpu.h>
 #include <asm/dwarf2.h>
 #include <asm/processor-flags.h>
+#include <asm/ftrace.h>
 #include "irq_vectors.h"
 
 /*
@@ -1118,6 +1119,7 @@ ENTRY(mcount)
         pushl %ecx
         pushl %edx
         movl 0xc(%esp), %eax
+        subl $MCOUNT_INSN_SIZE, %eax
 
 .globl mcount_call
 mcount_call:
@@ -1136,6 +1138,7 @@ ENTRY(ftrace_caller)
         pushl %edx
         movl 0xc(%esp), %eax
         movl 0x4(%ebp), %edx
+        subl $MCOUNT_INSN_SIZE, %eax
 
 .globl ftrace_call
 ftrace_call:
@@ -1166,6 +1169,7 @@ trace:
         pushl %edx
         movl 0xc(%esp), %eax
         movl 0x4(%ebp), %edx
+        subl $MCOUNT_INSN_SIZE, %eax
 
         call *ftrace_trace_function