[tip:sched/urgent] sched/debug: Fix sd-> *_idx limit range avoiding overflow

[tip-bot for libin <tipbot@zytor.com>]

Commit-ID:  fd9b86d37a600488dbd80fe60cca46b822bff1cd
Gitweb:     http://git.kernel.org/tip/fd9b86d37a600488dbd80fe60cca46b822bff1cd
Author:     libin <huawei.libin@huawei.com>
AuthorDate: Mon, 8 Apr 2013 14:39:12 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 8 Apr 2013 13:23:03 +0200

sched/debug: Fix sd->*_idx limit range avoiding overflow

Commit 201c373e8e ("sched/debug: Limit sd->*_idx range on
sysctl") was an incomplete bug fix.

This patch fixes sd->*_idx limit range to [0 ~ CPU_LOAD_IDX_MAX-1]
avoiding array overflow caused by setting sd->*_idx to CPU_LOAD_IDX_MAX
on sysctl.

Signed-off-by: Libin <huawei.libin@huawei.com>
Cc: <jiang.liu@huawei.com>
Cc: <guohanjun@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51626610.2040607@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 306943f..fa07792 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4933,7 +4933,7 @@ static void sd_free_ctl_entry(struct ctl_table **tablep)
 }
 
 static int min_load_idx = 0;
-static int max_load_idx = CPU_LOAD_IDX_MAX;
+static int max_load_idx = CPU_LOAD_IDX_MAX-1;
 
 static void
 set_table_entry(struct ctl_table *entry,