From: Satoshi Oshima <soshima@redhat.com>

I found a bug of kprobes in i386.

Kprobe-booster doesn't work if CONFIG_PREEMPT is not set.  Because
pre_preempt_count is always 0.

Boostability have been disabled when removing '#ifdef CONFIG_PREEMPT' I
think.

This bug doesn't cause a kernel panic.

Signed-off-by: Satoshi Oshima <soshima@redhat.com>
Cc: bibo, mao <bibo.mao@intel.com>
Cc: 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>
---

 arch/i386/kernel/kprobes.c |    4 ++++
 1 files changed, 4 insertions(+)

diff -puN arch/i386/kernel/kprobes.c~kprobemulti-kprobe-posthandler-for-booster-kprobes-bugfix-of-kprobe-booster-reenable-kprobe-booster arch/i386/kernel/kprobes.c
--- 25/arch/i386/kernel/kprobes.c~kprobemulti-kprobe-posthandler-for-booster-kprobes-bugfix-of-kprobe-booster-reenable-kprobe-booster	Fri May 19 13:24:26 2006
+++ 25-akpm/arch/i386/kernel/kprobes.c	Fri May 19 13:24:26 2006
@@ -257,7 +257,11 @@ static int __kprobes kprobe_handler(stru
 	int ret = 0;
 	kprobe_opcode_t *addr;
 	struct kprobe_ctlblk *kcb;
+#ifdef CONFIG_PREEMPT
 	unsigned pre_preempt_count = preempt_count();
+#else
+	unsigned pre_preempt_count = 1;
+#endif
 
 	addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t));
 
_