From b50ea74c7bc3ebe3d88a357893f0b96ae9092f13 Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
Date: Sun, 26 Mar 2006 01:38:13 -0800
Subject: [PATCH] [PATCH] kprobes: clean up resume_execute()
Clean up kprobe's resume_execute() for i386 arch.
Signed-off-by: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/i386/kernel/kprobes.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
index 7a59050242a7c..b40614f5afe29 100644
--- a/arch/i386/kernel/kprobes.c
+++ b/arch/i386/kernel/kprobes.c
@@ -362,10 +362,10 @@ static void __kprobes resume_execution(struct kprobe *p,
struct pt_regs *regs, struct kprobe_ctlblk *kcb)
{
unsigned long *tos = (unsigned long *)®s->esp;
- unsigned long next_eip = 0;
unsigned long copy_eip = (unsigned long)p->ainsn.insn;
unsigned long orig_eip = (unsigned long)p->addr;
+ regs->eflags &= ~TF_MASK;
switch (p->ainsn.insn[0]) {
case 0x9c: /* pushfl */
*tos &= ~(TF_MASK | IF_MASK);
@@ -375,9 +375,9 @@ static void __kprobes resume_execution(struct kprobe *p,
case 0xcb:
case 0xc2:
case 0xca:
- regs->eflags &= ~TF_MASK;
- /* eip is already adjusted, no more changes required*/
- return;
+ case 0xea: /* jmp absolute -- eip is correct */
+ /* eip is already adjusted, no more changes required */
+ goto no_change;
case 0xe8: /* call relative - Fix return addr */
*tos = orig_eip + (*tos - copy_eip);
break;
@@ -385,27 +385,21 @@ static void __kprobes resume_execution(struct kprobe *p,
if ((p->ainsn.insn[1] & 0x30) == 0x10) {
/* call absolute, indirect */
/* Fix return addr; eip is correct. */
- next_eip = regs->eip;
*tos = orig_eip + (*tos - copy_eip);
+ goto no_change;
} else if (((p->ainsn.insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
((p->ainsn.insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
/* eip is correct. */
- next_eip = regs->eip;
+ goto no_change;
}
- break;
- case 0xea: /* jmp absolute -- eip is correct */
- next_eip = regs->eip;
- break;
default:
break;
}
- regs->eflags &= ~TF_MASK;
- if (next_eip) {
- regs->eip = next_eip;
- } else {
- regs->eip = orig_eip + (regs->eip - copy_eip);
- }
+ regs->eip = orig_eip + (regs->eip - copy_eip);
+
+no_change:
+ return;
}
/*
--
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