[PATCH 1/1] kernel: futex: fixed to else and initcall

[PATCH 1/1] kernel: futex: fixed to else and initcall

[Ozgur Karatas]

The include/linux/init.h file have to content; to not used __initcall functions.
I think, needs to be replaced to device_initcall.

device_initcall() or more appropriate function instead of __initcall.

else doesn't need to be used, if should be enclosed in parentheses.
Also, I used checkpatch scripts and fixed to errors.

ERROR: "(foo*)" should be "(foo *)"
ERROR: "foo * bar" should be "foo *bar"
ERROR: "foo * bar" should be "foo *bar"

Signed-off-by: Ozgur Karatas <okaratas@member.fsf.org>
---
 kernel/futex.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 2c4be46..fd8a451 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -390,7 +390,7 @@ static inline int hb_waiters_pending(struct futex_hash_bucket *hb)
  */
 static struct futex_hash_bucket *hash_futex(union futex_key *key)
 {
-	u32 hash = jhash2((u32*)&key->both.word,
+	u32 hash = jhash2((u32 *)&key->both.word,
 			  (sizeof(key->both.word)+sizeof(key->both.ptr))/4,
 			  key->both.offset);
 	return &futex_queues[hash & (futex_hashsize - 1)];
@@ -545,10 +545,10 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
 		err = get_user_pages_fast(address, 1, 0, &page);
 		ro = 1;
 	}
-	if (err < 0)
+	if (err < 0) {
 		return err;
-	else
 		err = 0;
+	}
 
 	/*
 	 * The treatment of mapping from this point on is critical. The page
@@ -800,7 +800,7 @@ static int refill_pi_state_cache(void)
 	return 0;
 }
 
-static struct futex_pi_state * alloc_pi_state(void)
+static struct futex_pi_state *alloc_pi_state(void)
 {
 	struct futex_pi_state *pi_state = current->pi_state_cache;
 
@@ -854,7 +854,7 @@ static void put_pi_state(struct futex_pi_state *pi_state)
  * Look up the task based on what TID userspace gave us.
  * We dont trust it.
  */
-static struct task_struct * futex_find_get_task(pid_t pid)
+static struct task_struct *futex_find_get_task(pid_t pid)
 {
 	struct task_struct *p;
 
@@ -3323,4 +3323,4 @@ static int __init futex_init(void)
 
 	return 0;
 }
-__initcall(futex_init);
+device_initcall(futex_init);
-- 
2.1.4

Re: [PATCH 1/1] kernel: futex: fixed to else and initcall

[Thomas Gleixner]

On Mon, 19 Dec 2016, Ozgur Karatas wrote:

> else doesn't need to be used, if should be enclosed in parentheses.

Really?

> -	if (err < 0)
> +	if (err < 0) {
>  		return err;
> -	else
>  		err = 0;
> +	}

So you change the code from

	if (err < 0)
		return err;
    	else
		err = 0;

to

	if (err < 0) {
		return err;
		err = 0;
	}

How on earth is that equivivalent and how would that 'err = 0;' statement
be ever executed?

You clearly ran checkpatch.pl on this file and the output for this
construct is:

WARNING: else is not generally useful after a break or return
#550: FILE: kernel/futex.c:550:
+		return err;
+	else

So the proper change would have been:

	if (err < 0)
		return err;

	err = 0;

and not the trainwreck you created.

checkpatch.pl does not substitute basic knowlegde of C.

Thanks,

	tglx

Re: [PATCH 1/1] kernel: futex: fixed to else and initcall

[Ozgur Karatas]

20.12.2016, 11:21, "Thomas Gleixner" <tglx@linutronix.de>:
> On Mon, 19 Dec 2016, Ozgur Karatas wrote:
>
>>  else doesn't need to be used, if should be enclosed in parentheses.
>
> Really?
>
>
> So you change the code from
>
>         if (err < 0)
>                 return err;
>             else
>                 err = 0;
>
> to
>
>         if (err < 0) {
>                 return err;
>                 err = 0;
>         }
>
> How on earth is that equivivalent and how would that 'err = 0;' statement
> be ever executed?

Oh my god, I missed this point, sorry! 
Thank you so much for correct me.

This "return err;" will give to "err" and err defined to err = "0".
Then removed to "else" and return = err;  and should it be like this?

#define err = 0;

         if (err < 0) {
                 return err;
         }

Regards,

Ozgur

> You clearly ran checkpatch.pl on this file and the output for this
> construct is:
>
> WARNING: else is not generally useful after a break or return
> #550: FILE: kernel/futex.c:550:
> + return err;
> + else
>
> So the proper change would have been:
>
>         if (err < 0)
>                 return err;
>
>         err = 0;
>
> and not the trainwreck you created.
>
> checkpatch.pl does not substitute basic knowlegde of C.
>
> Thanks,
>
>         tglx

Re: [PATCH 1/1] kernel: futex: fixed to else and initcall

[Thomas Gleixner]

[-- Attachment #1: Type: text/plain, Size: 1184 bytes --]

On Tue, 20 Dec 2016, Ozgur Karatas wrote:
> 20.12.2016, 11:21, "Thomas Gleixner" <tglx@linutronix.de>:
> > On Mon, 19 Dec 2016, Ozgur Karatas wrote:
> >
> >>  else doesn't need to be used, if should be enclosed in parentheses.
> >
> > Really?
> >
> >
> > So you change the code from
> >
> >         if (err < 0)
> >                 return err;
> >             else
> >                 err = 0;
> >
> > to
> >
> >         if (err < 0) {
> >                 return err;
> >                 err = 0;
> >         }
> >
> > How on earth is that equivivalent and how would that 'err = 0;' statement
> > be ever executed?
> 
> Oh my god, I missed this point, sorry! 
> Thank you so much for correct me.
> 
> This "return err;" will give to "err" and err defined to err = "0".
> Then removed to "else" and return = err;  and should it be like this?
> 
> #define err = 0;
> 
>          if (err < 0) {
>                  return err;
>          }

I seriously recommend to take a basic C course first before trying to
change code in the kernel.

Thanks,

	tglx