[PATCH] kprobe: fix resume execution on i386

[Masami Hiramatsu]

Hi, Andrew

Here is a patch to fix resume_execution() to handle
iret and absolute jump opcode correctly on i386.
This patch can be applied against 2.6.17-rc2.

Best regards,
-- 
Masami HIRAMATSU
2nd Research Dept.
Hitachi, Ltd., Systems Development Laboratory
E-mail: hiramatu@xxxxxxxxxxxxxxxxx

Signed-off-by: Masami Hiramatsu <hiramatu@xxxxxxxxxxxxxxxxx>
 kprobes.c |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)
diff -Narup a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
--- a/arch/i386/kernel/kprobes.c	2006-04-21 12:23:45.000000000 +0900
+++ b/arch/i386/kernel/kprobes.c	2006-04-21 21:26:51.000000000 +0900
@@ -452,10 +452,11 @@ static void __kprobes resume_execution(s
 		*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;
@@ -463,10 +464,13 @@ static void __kprobes resume_execution(s
 	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
 			 */



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