From: Stephen Boyd <sboyd@codeaurora.org>
Date: Wed, 24 Aug 2011 23:47:26 +0000 (+1000)
Subject: Enabling DEBUG_STRICT_USER_COPY_CHECKS causes the following warning:
X-Git-Tag: next-20110921~1^2~45
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ac382d911fec69795b5f246621ff9d1abc904298;p=karo-tx-linux.git

Enabling DEBUG_STRICT_USER_COPY_CHECKS causes the following warning:

In file included from arch/x86/include/asm/uaccess.h:573,
                 from kernel/kprobes.c:55:
In function 'copy_from_user',
    inlined from 'write_enabled_file_bool' at
    kernel/kprobes.c:2191:
arch/x86/include/asm/uaccess_64.h:65:
warning: call to 'copy_from_user_overflow' declared with
attribute warning: copy_from_user() buffer size is not provably
correct

presumably due to buf_size being signed causing GCC to fail to see that
buf_size can't become negative.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index e5d84644823b..95dd7212e610 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2198,7 +2198,7 @@ static ssize_t write_enabled_file_bool(struct file *file,
 	       const char __user *user_buf, size_t count, loff_t *ppos)
 {
 	char buf[32];
-	int buf_size;
+	size_t buf_size;
 
 	buf_size = min(count, (sizeof(buf)-1));
 	if (copy_from_user(buf, user_buf, buf_size))