[PATCH -tip 1/4] [BUGFIX] ftrace/x86: Adjust x86 regs.ip as like as x86-64

Masami Hiramatsu
2012-09-05T14:32:33Z

Adjust x86 regs.ip to ip + MCOUNT_INSN_SIZE as like as
on x86-64. This helps us to consolidate codes which use
regs->ip on both of x86/x86-64.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
---

arch/x86/kernel/entry_32.S | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 061ac17..f438a44 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1148,7 +1148,6 @@ ENTRY(ftrace_regs_caller)
* ip location, and move flags into the return ip location.
*/
pushl 4(%esp) /* save return ip into ip slot */
- subl $MCOUNT_INSN_SIZE, (%esp) /* Adjust ip */

pushl $0 /* Load 0 into orig_ax */
pushl %gs
@@ -1169,6 +1168,7 @@ ENTRY(ftrace_regs_caller)
movl $__KERNEL_CS,13*4(%esp)

movl 12*4(%esp), %eax /* Load ip (1st parameter) */
+ subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */
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 */
@@ -1180,7 +1180,6 @@ GLOBAL(ftrace_regs_call)
movl 14*4(%esp), %eax /* Move flags back into cs */
movl %eax, 13*4(%esp) /* Needed to keep addl from modifying flags */
movl 12*4(%esp), %eax /* Get return ip from regs->ip */
- addl $MCOUNT_INSN_SIZE, %eax
movl %eax, 14*4(%esp) /* Put return ip back for ret */

popl %ebx