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/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 8f79a4789ed4..84694e88b428 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -9,6 +9,7 @@
  */
 
 #include <asm/unistd.h>
+#include <asm/ftrace.h>
 #include <asm/arch/entry-macro.S>
 
 #include "entry-header.S"
@@ -104,6 +105,7 @@ ENTRY(ret_from_fork)
 ENTRY(mcount)
         stmdb sp!, {r0-r3, lr}
         mov r0, lr
+        sub r0, r0, #MCOUNT_INSN_SIZE
 
         .globl mcount_call
 mcount_call:
@@ -114,6 +116,7 @@ ENTRY(ftrace_caller)
         stmdb sp!, {r0-r3, lr}
         ldr r1, [fp, #-4]
         mov r0, lr
+        sub r0, r0, #MCOUNT_INSN_SIZE
 
         .globl ftrace_call
 ftrace_call:
@@ -134,6 +137,7 @@ ENTRY(mcount)
 trace:
         ldr r1, [fp, #-4]
         mov r0, lr
+        sub r0, r0, #MCOUNT_INSN_SIZE
         mov lr, pc
         mov pc, r2
         ldmia sp!, {r0-r3, pc}