Re: [PATCH 2/5] um: port: Delete three error messages for a failed memory allocation

[SF Markus Elfring]

>> +++ b/arch/um/drivers/port_kern.c
>> @@ -87,11 +87,8 @@ static int port_accept(struct port_list *port)
>>  }
>>  
>>  conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
>> -if (conn == NULL) {
>> -printk(KERN_ERR "port_accept : failed to allocate "
>> -   "connection\n");
>> +if (!conn)
>>  goto out_close;
>> -}
>>  *conn = ((struct connection)
>>  { .list = LIST_HEAD_INIT(conn->list),
>>.fd   = fd,
> 
> I don't see how this eliminates a possible error.

The suggested change affects three coding style issues at this place.

* Repetition of an out-of-memory message

  See also:
  
http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf

* Unwanted splitting of a message string

* Usage of a specific preprocessor symbol


> !x is something you use with something that is conceptually a Boolean.

Pointers can be also treated in this way, can't they?

Regards,
Markus

Re: [PATCH 2/5] um: port: Delete three error messages for a failed memory allocation

[SF Markus Elfring]

>> +++ b/arch/um/drivers/port_kern.c
>> @@ -87,11 +87,8 @@ static int port_accept(struct port_list *port)
>>  }
>>  
>>  conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
>> -if (conn == NULL) {
>> -printk(KERN_ERR "port_accept : failed to allocate "
>> -   "connection\n");
>> +if (!conn)
>>  goto out_close;
>> -}
>>  *conn = ((struct connection)
>>  { .list = LIST_HEAD_INIT(conn->list),
>>.fd   = fd,
> 
> I don't see how this eliminates a possible error.

The suggested change affects three coding style issues at this place.

* Repetition of an out-of-memory message

  See also:
  
http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf

* Unwanted splitting of a message string

* Usage of a specific preprocessor symbol


> !x is something you use with something that is conceptually a Boolean.

Pointers can be also treated in this way, can't they?

Regards,
Markus

Re: [PATCH 2/5] um: port: Delete three error messages for a failed memory allocation

[Jeff Dike]

> --- a/arch/um/drivers/port_kern.c
> +++ b/arch/um/drivers/port_kern.c
> @@ -87,11 +87,8 @@ static int port_accept(struct port_list *port)
>   }
>  
>   conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
> - if (conn == NULL) {
> - printk(KERN_ERR "port_accept : failed to allocate "
> -"connection\n");
> + if (!conn)
>   goto out_close;
> - }
>   *conn = ((struct connection)
>   { .list = LIST_HEAD_INIT(conn->list),
> .fd   = fd,

I don't see how this eliminates a possible error.  It should behave
exactly the same.  To me, this is an expressiveness issue.

!x is something you use with something that is conceptually a Boolean.

x == NULL is a question about a pointer, which is the case here.

Jeff
-- 
Jeff Dike
AddToIt
978-254-0789 (o)
978-394-8986 (c)

Re: [PATCH 2/5] um: port: Delete three error messages for a failed memory allocation

[Jeff Dike]

> --- a/arch/um/drivers/port_kern.c
> +++ b/arch/um/drivers/port_kern.c
> @@ -87,11 +87,8 @@ static int port_accept(struct port_list *port)
>   }
>  
>   conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
> - if (conn == NULL) {
> - printk(KERN_ERR "port_accept : failed to allocate "
> -"connection\n");
> + if (!conn)
>   goto out_close;
> - }
>   *conn = ((struct connection)
>   { .list = LIST_HEAD_INIT(conn->list),
> .fd   = fd,

I don't see how this eliminates a possible error.  It should behave
exactly the same.  To me, this is an expressiveness issue.

!x is something you use with something that is conceptually a Boolean.

x == NULL is a question about a pointer, which is the case here.

Jeff
-- 
Jeff Dike
AddToIt
978-254-0789 (o)
978-394-8986 (c)

[PATCH 2/5] um: port: Delete three error messages for a failed memory allocation

[SF Markus Elfring]

From: Markus Elfring 
Date: Wed, 18 Jan 2017 22:00:14 +0100

The script "checkpatch.pl" pointed information out like the following.

WARNING: Possible unnecessary 'out of memory' message

Thus fix the affected source code places.

Signed-off-by: Markus Elfring 
---
 arch/um/drivers/port_kern.c | 13 +++--
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
index b2bbda21c5f3..c96741e920f5 100644
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -87,11 +87,8 @@ static int port_accept(struct port_list *port)
}
 
conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
-   if (conn == NULL) {
-   printk(KERN_ERR "port_accept : failed to allocate "
-  "connection\n");
+   if (!conn)
goto out_close;
-   }
*conn = ((struct connection)
{ .list = LIST_HEAD_INIT(conn->list),
  .fd   = fd,
@@ -170,10 +167,8 @@ void *port_data(int port_num)
goto found;
}
port = kmalloc(sizeof(struct port_list), GFP_KERNEL);
-   if (port == NULL) {
-   printk(KERN_ERR "Allocation of port list failed\n");
+   if (!port)
goto out;
-   }
 
fd = port_listen_fd(port_num);
if (fd < 0) {
@@ -202,10 +197,8 @@ void *port_data(int port_num)
 
  found:
dev = kmalloc(sizeof(struct port_dev), GFP_KERNEL);
-   if (dev == NULL) {
-   printk(KERN_ERR "Allocation of port device entry failed\n");
+   if (!dev)
goto out;
-   }
 
*dev = ((struct port_dev) { .port   = port,
.helper_pid = -1,
-- 
2.11.0

[PATCH 2/5] um: port: Delete three error messages for a failed memory allocation

[SF Markus Elfring]

From: Markus Elfring 
Date: Wed, 18 Jan 2017 22:00:14 +0100

The script "checkpatch.pl" pointed information out like the following.

WARNING: Possible unnecessary 'out of memory' message

Thus fix the affected source code places.

Signed-off-by: Markus Elfring 
---
 arch/um/drivers/port_kern.c | 13 +++--
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
index b2bbda21c5f3..c96741e920f5 100644
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -87,11 +87,8 @@ static int port_accept(struct port_list *port)
}
 
conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
-   if (conn == NULL) {
-   printk(KERN_ERR "port_accept : failed to allocate "
-  "connection\n");
+   if (!conn)
goto out_close;
-   }
*conn = ((struct connection)
{ .list = LIST_HEAD_INIT(conn->list),
  .fd   = fd,
@@ -170,10 +167,8 @@ void *port_data(int port_num)
goto found;
}
port = kmalloc(sizeof(struct port_list), GFP_KERNEL);
-   if (port == NULL) {
-   printk(KERN_ERR "Allocation of port list failed\n");
+   if (!port)
goto out;
-   }
 
fd = port_listen_fd(port_num);
if (fd < 0) {
@@ -202,10 +197,8 @@ void *port_data(int port_num)
 
  found:
dev = kmalloc(sizeof(struct port_dev), GFP_KERNEL);
-   if (dev == NULL) {
-   printk(KERN_ERR "Allocation of port device entry failed\n");
+   if (!dev)
goto out;
-   }
 
*dev = ((struct port_dev) { .port   = port,
.helper_pid = -1,
-- 
2.11.0