From: Srinivasa Ds <srinivasa@in.ibm.com>
Date: Sat, 23 Feb 2008 23:24:04 +0000 (-0800)
Subject: kprobes: refuse kprobe insertion on add/sub_preempt_counter()
X-Git-Tag: v2.6.25-rc3~28
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=43627582799db317e966ecb0002c2c3c9805ec0f;p=linux-2.6

kprobes: refuse kprobe insertion on add/sub_preempt_counter()

Kprobes makes use of preempt_disable(),preempt_enable_noresched() and these
functions inturn call add/sub_preempt_count().  So we need to refuse user from
inserting probe in to these functions.

This patch disallows user from probing add/sub_preempt_count().

Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/sched.c b/kernel/sched.c
index f28f19e65b..c4bc8c2109 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3766,7 +3766,7 @@ void scheduler_tick(void)
 
 #if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
 
-void add_preempt_count(int val)
+void __kprobes add_preempt_count(int val)
 {
 	/*
 	 * Underflow?
@@ -3782,7 +3782,7 @@ void add_preempt_count(int val)
 }
 EXPORT_SYMBOL(add_preempt_count);
 
-void sub_preempt_count(int val)
+void __kprobes sub_preempt_count(int val)
 {
 	/*
 	 * Underflow?