[PATCH] fs: wipe off the compiler warn

[PATCH] fs: wipe off the compiler warn

[zhongjiang]

From: zhong jiang <zhongjiang@huawei.com>

when compile the kenrel code, I happens to the following warn.
fs/reiserfs/ibalance.c:1156:2: warning: a??new_insert_keya?? may be used
uninitialized in this function.
memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
^
The patch just fix it to avoid the warn.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/reiserfs/ibalance.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
index b751eea..512ce95 100644
--- a/fs/reiserfs/ibalance.c
+++ b/fs/reiserfs/ibalance.c
@@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
 	int order;
 	int insert_num, n, k;
 	struct buffer_head *S_new;
-	struct item_head new_insert_key;
+	struct item_head uninitialized_var(new_insert_key);
 	struct buffer_head *new_insert_ptr = NULL;
 	struct item_head *new_insert_key_addr = insert_key;
 
-- 
1.8.3.1

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[PATCH] fs: wipe off the compiler warn

[zhongjiang]

From: zhong jiang <zhongjiang@huawei.com>

when compile the kenrel code, I happens to the following warn.
fs/reiserfs/ibalance.c:1156:2: warning: ‘new_insert_key’ may be used
uninitialized in this function.
memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
^
The patch just fix it to avoid the warn.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/reiserfs/ibalance.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
index b751eea..512ce95 100644
--- a/fs/reiserfs/ibalance.c
+++ b/fs/reiserfs/ibalance.c
@@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
 	int order;
 	int insert_num, n, k;
 	struct buffer_head *S_new;
-	struct item_head new_insert_key;
+	struct item_head uninitialized_var(new_insert_key);
 	struct buffer_head *new_insert_ptr = NULL;
 	struct item_head *new_insert_key_addr = insert_key;
 
-- 
1.8.3.1

Re: [PATCH] fs: wipe off the compiler warn

[Andrew Morton]

On Fri, 29 Jul 2016 22:46:39 +0800 zhongjiang <zhongjiang@huawei.com> wrote:

> From: zhong jiang <zhongjiang@huawei.com>
> 
> when compile the kenrel code, I happens to the following warn.
> fs/reiserfs/ibalance.c:1156:2: warning: ___new_insert_key___ may be used
> uninitialized in this function.
> memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
> ^
> The patch just fix it to avoid the warn.
> 
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
> ---
>  fs/reiserfs/ibalance.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
> index b751eea..512ce95 100644
> --- a/fs/reiserfs/ibalance.c
> +++ b/fs/reiserfs/ibalance.c
> @@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
>  	int order;
>  	int insert_num, n, k;
>  	struct buffer_head *S_new;
> -	struct item_head new_insert_key;
> +	struct item_head uninitialized_var(new_insert_key);
>  	struct buffer_head *new_insert_ptr = NULL;
>  	struct item_head *new_insert_key_addr = insert_key;

How do we know this isn't a real bug?  It isn't obvious to me that this
warning is a false positive.

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Re: [PATCH] fs: wipe off the compiler warn

[Andrew Morton]

On Fri, 29 Jul 2016 22:46:39 +0800 zhongjiang <zhongjiang@huawei.com> wrote:

> From: zhong jiang <zhongjiang@huawei.com>
> 
> when compile the kenrel code, I happens to the following warn.
> fs/reiserfs/ibalance.c:1156:2: warning: ___new_insert_key___ may be used
> uninitialized in this function.
> memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
> ^
> The patch just fix it to avoid the warn.
> 
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
> ---
>  fs/reiserfs/ibalance.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
> index b751eea..512ce95 100644
> --- a/fs/reiserfs/ibalance.c
> +++ b/fs/reiserfs/ibalance.c
> @@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
>  	int order;
>  	int insert_num, n, k;
>  	struct buffer_head *S_new;
> -	struct item_head new_insert_key;
> +	struct item_head uninitialized_var(new_insert_key);
>  	struct buffer_head *new_insert_ptr = NULL;
>  	struct item_head *new_insert_key_addr = insert_key;

How do we know this isn't a real bug?  It isn't obvious to me that this
warning is a false positive.

Re: [PATCH] fs: wipe off the compiler warn

[zhong jiang]

On 2016/7/30 7:02, Andrew Morton wrote:
> On Fri, 29 Jul 2016 22:46:39 +0800 zhongjiang <zhongjiang@huawei.com> wrote:
>
>> From: zhong jiang <zhongjiang@huawei.com>
>>
>> when compile the kenrel code, I happens to the following warn.
>> fs/reiserfs/ibalance.c:1156:2: warning: ___new_insert_key___ may be used
>> uninitialized in this function.
>> memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
>> ^
>> The patch just fix it to avoid the warn.
>>
>> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
>> ---
>>  fs/reiserfs/ibalance.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
>> index b751eea..512ce95 100644
>> --- a/fs/reiserfs/ibalance.c
>> +++ b/fs/reiserfs/ibalance.c
>> @@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
>>  	int order;
>>  	int insert_num, n, k;
>>  	struct buffer_head *S_new;
>> -	struct item_head new_insert_key;
>> +	struct item_head uninitialized_var(new_insert_key);
>>  	struct buffer_head *new_insert_ptr = NULL;
>>  	struct item_head *new_insert_key_addr = insert_key;
> How do we know this isn't a real bug?  It isn't obvious to me that this
> warning is a false positive.
>
>
> .
>
  yes ,it maybe a real bug, I will resend it in v2.

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Re: [PATCH] fs: wipe off the compiler warn

[zhong jiang]

On 2016/7/30 7:02, Andrew Morton wrote:
> On Fri, 29 Jul 2016 22:46:39 +0800 zhongjiang <zhongjiang@huawei.com> wrote:
>
>> From: zhong jiang <zhongjiang@huawei.com>
>>
>> when compile the kenrel code, I happens to the following warn.
>> fs/reiserfs/ibalance.c:1156:2: warning: ___new_insert_key___ may be used
>> uninitialized in this function.
>> memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
>> ^
>> The patch just fix it to avoid the warn.
>>
>> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
>> ---
>>  fs/reiserfs/ibalance.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
>> index b751eea..512ce95 100644
>> --- a/fs/reiserfs/ibalance.c
>> +++ b/fs/reiserfs/ibalance.c
>> @@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
>>  	int order;
>>  	int insert_num, n, k;
>>  	struct buffer_head *S_new;
>> -	struct item_head new_insert_key;
>> +	struct item_head uninitialized_var(new_insert_key);
>>  	struct buffer_head *new_insert_ptr = NULL;
>>  	struct item_head *new_insert_key_addr = insert_key;
> How do we know this isn't a real bug?  It isn't obvious to me that this
> warning is a false positive.
>
>
> .
>
  yes ,it maybe a real bug, I will resend it in v2.

[PATCH] fs: wipe off the compiler warn

[zhongjiang]

From: zhong jiang <zhongjiang@huawei.com>

when compile the kenrel code, I happens to the following warn.
fs/reiserfs/ibalance.c:1156:2: warning: a??new_insert_keya?? may be used
uninitialized in this function.
memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
^
The patch just fix it to avoid the warn.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/reiserfs/ibalance.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
index b751eea..512ce95 100644
--- a/fs/reiserfs/ibalance.c
+++ b/fs/reiserfs/ibalance.c
@@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
 	int order;
 	int insert_num, n, k;
 	struct buffer_head *S_new;
-	struct item_head new_insert_key;
+	struct item_head uninitialized_var(new_insert_key);
 	struct buffer_head *new_insert_ptr = NULL;
 	struct item_head *new_insert_key_addr = insert_key;
 
-- 
1.8.3.1

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

[PATCH] fs: wipe off the compiler warn

[zhongjiang]

From: zhong jiang <zhongjiang@huawei.com>

when compile the kenrel code, I happens to the following warn.
fs/reiserfs/ibalance.c:1156:2: warning: ‘new_insert_key’ may be used
uninitialized in this function.
memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
^
The patch just fix it to avoid the warn.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/reiserfs/ibalance.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
index b751eea..512ce95 100644
--- a/fs/reiserfs/ibalance.c
+++ b/fs/reiserfs/ibalance.c
@@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
 	int order;
 	int insert_num, n, k;
 	struct buffer_head *S_new;
-	struct item_head new_insert_key;
+	struct item_head uninitialized_var(new_insert_key);
 	struct buffer_head *new_insert_ptr = NULL;
 	struct item_head *new_insert_key_addr = insert_key;
 
-- 
1.8.3.1