[PATCH]initialize the array of fs/ncpfs/inode.c

[PATCH]initialize the array of fs/ncpfs/inode.c

[Harry Wei]

Hi us,
	When i compile the linux-2.6.38.2, some warnings happened
to me. One of them is like following.

fs/ncpfs/inode.c: In function 'ncp_fill_super':
fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used 
uninitialized in this function
...
See details by the URL: 
http://s1202.photobucket.com/albums/bb364/harrywei/Kernel/?action=view&current=patched.png

So i patch for it below.

Thanks.
Harry Wei.

From: Harry Wei <harryxiyou@gmail.com>
Signed-off-by: Harry Wei <harryxiyou@gmail.com>
---
 fs/ncpfs/inode.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 00a1d1c..15f0ebb 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -30,6 +30,7 @@
 #include <linux/mount.h>
 #include <linux/seq_file.h>
 #include <linux/namei.h>
+#include <linux/ncp.h>
 
 #include <net/sock.h>
 
@@ -461,6 +462,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 #endif
 	struct ncp_entry_info finfo;
 
+	data.mounted_vol[NCP_VOLNAME_LEN + 1] = {0};
 	data.wdog_pid = NULL;
 	server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL);
 	if (!server)
-- 
1.7.0.4

Re: [PATCH]initialize the array of fs/ncpfs/inode.c

[Andrew Morton]

On Sun, 10 Apr 2011 18:08:18 +0800
Harry Wei <jiaweiwei.xiyou@gmail.com> wrote:

> Hi us,
> 	When i compile the linux-2.6.38.2, some warnings happened
> to me. One of them is like following.
> 
> fs/ncpfs/inode.c: In function 'ncp_fill_super':
> fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used 
> uninitialized in this function
> ...
> See details by the URL: 
> http://s1202.photobucket.com/albums/bb364/harrywei/Kernel/?action=view&current=patched.png

Yup.  The compiler is "wrong" because it doesn't know that the
uninitialised bytes will never be read, because they fall after the
'\0' in a null-terminated string.

> @@ -461,6 +462,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
>  #endif
>  	struct ncp_entry_info finfo;
>  
> +	data.mounted_vol[NCP_VOLNAME_LEN + 1] = {0};
>  	data.wdog_pid = NULL;
>  	server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL);
>  	if (!server)

hm.  I'm not sure that this fixed data.mounted_vol[2u],
data.mounted_vol[3u], etc.

How about we use the big hammer?



From: Andrew Morton <akpm@linux-foundation.org>

fs/ncpfs/inode.c: In function 'ncp_fill_super':
fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used uninitialized in this function
fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[2u]' may be used uninitialized in this function
fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[3u]' may be used uninitialized in this function
...

It's notabug, but we can easily fix it with a memset().

Reported-by: Harry Wei <jiaweiwei.xiyou@gmail.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ncpfs/inode.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff -puN fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning fs/ncpfs/inode.c
--- a/fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning
+++ a/fs/ncpfs/inode.c
@@ -461,7 +461,7 @@ static int ncp_fill_super(struct super_b
 #endif
 	struct ncp_entry_info finfo;
 
-	data.wdog_pid = NULL;
+	memset(data, 0, sizeof(data));
 	server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL);
 	if (!server)
 		return -ENOMEM;
@@ -496,7 +496,6 @@ static int ncp_fill_super(struct super_b
 				struct ncp_mount_data_v4* md = (struct ncp_mount_data_v4*)raw_data;
 
 				data.flags = md->flags;
-				data.int_flags = 0;
 				data.mounted_uid = md->mounted_uid;
 				data.wdog_pid = find_get_pid(md->wdog_pid);
 				data.ncp_fd = md->ncp_fd;
@@ -507,7 +506,6 @@ static int ncp_fill_super(struct super_b
 				data.file_mode = md->file_mode;
 				data.dir_mode = md->dir_mode;
 				data.info_fd = -1;
-				data.mounted_vol[0] = 0;
 			}
 			break;
 		default:
_

Re: [PATCH]initialize the array of fs/ncpfs/inode.c

[Tim Gardner]

On 04/11/2011 04:18 PM, Andrew Morton wrote:
> On Sun, 10 Apr 2011 18:08:18 +0800
> Harry Wei<jiaweiwei.xiyou@gmail.com>  wrote:
>
>> Hi us,
>> 	When i compile the linux-2.6.38.2, some warnings happened
>> to me. One of them is like following.
>>
>> fs/ncpfs/inode.c: In function 'ncp_fill_super':
>> fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used
>> uninitialized in this function
>> ...
>> See details by the URL:
>> http://s1202.photobucket.com/albums/bb364/harrywei/Kernel/?action=view&current=patched.png
>
> Yup.  The compiler is "wrong" because it doesn't know that the
> uninitialised bytes will never be read, because they fall after the
> '\0' in a null-terminated string.
>
>> @@ -461,6 +462,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
>>   #endif
>>   	struct ncp_entry_info finfo;
>>
>> +	data.mounted_vol[NCP_VOLNAME_LEN + 1] = {0};
>>   	data.wdog_pid = NULL;
>>   	server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL);
>>   	if (!server)
>
> hm.  I'm not sure that this fixed data.mounted_vol[2u],
> data.mounted_vol[3u], etc.
>
> How about we use the big hammer?
>
>
>
> From: Andrew Morton<akpm@linux-foundation.org>
>
> fs/ncpfs/inode.c: In function 'ncp_fill_super':
> fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used uninitialized in this function
> fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[2u]' may be used uninitialized in this function
> fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[3u]' may be used uninitialized in this function
> ...
>
> It's notabug, but we can easily fix it with a memset().
>
> Reported-by: Harry Wei<jiaweiwei.xiyou@gmail.com>
> Cc: Petr Vandrovec<petr@vandrovec.name>
> Signed-off-by: Andrew Morton<akpm@linux-foundation.org>
> ---
>
>   fs/ncpfs/inode.c |    4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff -puN fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning fs/ncpfs/inode.c
> --- a/fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning
> +++ a/fs/ncpfs/inode.c
> @@ -461,7 +461,7 @@ static int ncp_fill_super(struct super_b
>   #endif
>   	struct ncp_entry_info finfo;
>
> -	data.wdog_pid = NULL;
> +	memset(data, 0, sizeof(data));

Needs '&' ?

	memset(&data, 0, sizeof(data));

>   	server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL);
>   	if (!server)
>   		return -ENOMEM;
> @@ -496,7 +496,6 @@ static int ncp_fill_super(struct super_b
>   				struct ncp_mount_data_v4* md = (struct ncp_mount_data_v4*)raw_data;
>
>   				data.flags = md->flags;
> -				data.int_flags = 0;
>   				data.mounted_uid = md->mounted_uid;
>   				data.wdog_pid = find_get_pid(md->wdog_pid);
>   				data.ncp_fd = md->ncp_fd;
> @@ -507,7 +506,6 @@ static int ncp_fill_super(struct super_b
>   				data.file_mode = md->file_mode;
>   				data.dir_mode = md->dir_mode;
>   				data.info_fd = -1;
> -				data.mounted_vol[0] = 0;
>   			}
>   			break;
>   		default:
> _
>
> --
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-- 
Tim Gardner tim.gardner@canonical.com

Re: [PATCH]initialize the array of fs/ncpfs/inode.c

[Harry Wei]

On Mon, Apr 11, 2011 at 04:18:38PM -0700, Andrew Morton wrote:
> On Sun, 10 Apr 2011 18:08:18 +0800
> Harry Wei <jiaweiwei.xiyou@gmail.com> wrote:
> 
> > fs/ncpfs/inode.c: In function 'ncp_fill_super':
> > fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used 
> 
> It's notabug, but we can easily fix it with a memset().
> 
> Reported-by: Harry Wei <jiaweiwei.xiyou@gmail.com>
> Cc: Petr Vandrovec <petr@vandrovec.name>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  fs/ncpfs/inode.c |    4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>  
> -	data.wdog_pid = NULL;
> +	memset(data, 0, sizeof(data));
Hi Morton,
	It really need a '&' for data, i think. So i have corrected
your patch like following.

Thanks.
Harry Wei.

Reported-by: Harry Wei <jiaweiwei.xiyou@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Harry Wei <jiaweiwei.xiyou@gmail.com>
---

 fs/ncpfs/inode.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff -puN fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning fs/ncpfs/inode.c
--- a/fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning
+++ a/fs/ncpfs/inode.c
@@ -461,7 +461,7 @@ static int ncp_fill_super(struct super_b
 #endif
       struct ncp_entry_info finfo;

-      data.wdog_pid = NULL;
+       memset(&data, 0, sizeof(data));
       server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL);
       if (!server)
		return -ENOMEM;
@@ -496,7 +496,6 @@ static int ncp_fill_super(struct super_b
                               struct ncp_mount_data_v4* md = (struct ncp_mount_data_v4*)raw_data;

                               data.flags = md->flags;
-                               data.int_flags = 0;
                               data.mounted_uid = md->mounted_uid;
                               data.wdog_pid = find_get_pid(md->wdog_pid);
                               data.ncp_fd = md->ncp_fd;
@@ -507,7 +506,6 @@ static int ncp_fill_super(struct super_b
                               data.file_mode = md->file_mode;
                               data.dir_mode = md->dir_mode;
                               data.info_fd = -1;
-                               data.mounted_vol[0] = 0;
                       }
                       break;
               default:
_