[PATCH] kprobe: fix resume execution on i386

Fix resume_execution() to handle iret and absolute jump opcode correctly on
i386.

Signed-off-by: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Yumiko Sugita <sugita@sdl.hitachi.co.jp>
Cc: Satoshi Oshima <soshima@redhat.com>
Cc: Hideo Aoki <haoki@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
index 6c93ddf09512..38806f427849 100644
--- a/arch/i386/kernel/kprobes.c
+++ b/arch/i386/kernel/kprobes.c
@@ -443,10 +443,11 @@ static void __kprobes resume_execution(struct kprobe *p,
                 *tos &= ~(TF_MASK | IF_MASK);
                 *tos |= kcb->kprobe_old_eflags;
                 break;
-        case 0xc3:              /* ret/lret */
-        case 0xcb:
-        case 0xc2:
+        case 0xc2:              /* iret/ret/lret */
+        case 0xc3:
         case 0xca:
+        case 0xcb:
+        case 0xcf:
         case 0xea:              /* jmp absolute -- eip is correct */
                 /* eip is already adjusted, no more changes required */
                 p->ainsn.boostable = 1;
@@ -454,10 +455,13 @@ static void __kprobes resume_execution(struct kprobe *p,
         case 0xe8:              /* call relative - Fix return addr */
                 *tos = orig_eip + (*tos - copy_eip);
                 break;
+        case 0x9a:              /* call absolute -- same as call absolute, indirect */
+                *tos = orig_eip + (*tos - copy_eip);
+                goto no_change;
         case 0xff:
                 if ((p->ainsn.insn[1] & 0x30) == 0x10) {
-                        /* call absolute, indirect */
                         /*
+                         * call absolute, indirect
                          * Fix return addr; eip is correct.
                          * But this is not boostable
                          */