[PATCH 2/4] kprobes: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning

From: Stephen Boyd
Date: Tue May 31 2011 - 14:14:52 EST


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@xxxxxxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
---
kernel/kprobes.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 7798181..1938187 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2185,7 +2185,7 @@ 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))
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

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