[PATCH] x86, dumpstack: Fix unused variable warning.

[PATCH] x86, dumpstack: Fix unused variable warning.

[Rakib Mullick]

With allnoconfig, bp becomes unused. So put bp into defination of
CONFIG_FRAME_POINTER.

arch/x86/kernel/dumpstack.c: In function ‘dump_stack’:
arch/x86/kernel/dumpstack.c:200: warning: unused variable ‘bp’

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
---

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 8474c99..fc5a253 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -197,10 +197,10 @@ void show_stack(struct task_struct *task,
unsigned long *sp)
  */
 void dump_stack(void)
 {
-	unsigned long bp = 0;
 	unsigned long stack;

 #ifdef CONFIG_FRAME_POINTER
+	unsigned long bp = 0;
 	if (!bp)
 		get_bp(bp);
 #endif

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Jesper Juhl]

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On Wed, 24 Nov 2010, Rakib Mullick wrote:

> With allnoconfig, bp becomes unused. So put bp into defination of
> CONFIG_FRAME_POINTER.
> 
> arch/x86/kernel/dumpstack.c: In function ‘dump_stack’:
> arch/x86/kernel/dumpstack.c:200: warning: unused variable ‘bp’
> 
> Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
> ---
> 
> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> index 8474c99..fc5a253 100644
> --- a/arch/x86/kernel/dumpstack.c
> +++ b/arch/x86/kernel/dumpstack.c
> @@ -197,10 +197,10 @@ void show_stack(struct task_struct *task,
> unsigned long *sp)
>   */
>  void dump_stack(void)
>  {
> -	unsigned long bp = 0;
>  	unsigned long stack;
> 
>  #ifdef CONFIG_FRAME_POINTER
> +	unsigned long bp = 0;
>  	if (!bp)
>  		get_bp(bp);
>  #endif

So, now the bp variable does not exist at all if CONFIG_FRAME_POINTER is 
not defined.
That's going to make this line :

          show_trace(NULL, NULL, &stack, bp);

found further down in the dump_stack() function, quite unhappy.


-- 
Jesper Juhl <jj@chaosbits.net>            http://www.chaosbits.net/
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please.

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Rakib Mullick]

On Wed, Nov 24, 2010 at 3:57 PM, Jesper Juhl <jj@chaosbits.net> wrote:
> On Wed, 24 Nov 2010, Rakib Mullick wrote:
>
>
> So, now the bp variable does not exist at all if CONFIG_FRAME_POINTER is
> not defined.

Yes - right. And its not used outside CONFIG_FRAME_POINTER.

> That's going to make this line :
>
>          show_trace(NULL, NULL, &stack, bp);
>
Not clear what are you trying to say. Would you please, clear it up a bit?

> found further down in the dump_stack() function, quite unhappy.
>
>
> --
> Jesper Juhl <jj@chaosbits.net>            http://www.chaosbits.net/
> Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
> Plain text mails only, please.
>

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Frederic Weisbecker]

On Wed, Nov 24, 2010 at 04:26:01PM +0600, Rakib Mullick wrote:
> On Wed, Nov 24, 2010 at 3:57 PM, Jesper Juhl <jj@chaosbits.net> wrote:
> > On Wed, 24 Nov 2010, Rakib Mullick wrote:
> >
> >
> > So, now the bp variable does not exist at all if CONFIG_FRAME_POINTER is
> > not defined.
>
> Yes - right. And its not used outside CONFIG_FRAME_POINTER.
>
> > That's going to make this line :
> >
> >          show_trace(NULL, NULL, &stack, bp);
> >
> Not clear what are you trying to say. Would you please, clear it up a bit?


I think Jesper is confused because your patch applies on -tip (tip/master or
tip/perf/core) where we have zapped the bp argument from show_trace() lately.

But in the mainline, show_trace() still has the bp argument.

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Jesper Juhl]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1086 bytes --]

On Wed, 24 Nov 2010, Frederic Weisbecker wrote:

> On Wed, Nov 24, 2010 at 04:26:01PM +0600, Rakib Mullick wrote:
> > On Wed, Nov 24, 2010 at 3:57 PM, Jesper Juhl <jj@chaosbits.net> wrote:
> > > On Wed, 24 Nov 2010, Rakib Mullick wrote:
> > >
> > >
> > > So, now the bp variable does not exist at all if CONFIG_FRAME_POINTER is
> > > not defined.
> >
> > Yes - right. And its not used outside CONFIG_FRAME_POINTER.
> >
> > > That's going to make this line :
> > >
> > >          show_trace(NULL, NULL, &stack, bp);
> > >
> > Not clear what are you trying to say. Would you please, clear it up a bit?
> 
> 
> I think Jesper is confused because your patch applies on -tip (tip/master or
> tip/perf/core) where we have zapped the bp argument from show_trace() lately.
> 
> But in the mainline, show_trace() still has the bp argument.


Ahh yes, my mistake. I checked the code in mainline.
Sorry about the confusion.


-- 
Jesper Juhl <jj@chaosbits.net>            http://www.chaosbits.net/
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please.

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Rakib Mullick]

On Wed, Nov 24, 2010 at 7:01 PM, Frederic Weisbecker <fweisbec@gmail.com> wrote:
> On Wed, Nov 24, 2010 at 04:26:01PM +0600, Rakib Mullick wrote:
>> On Wed, Nov 24, 2010 at 3:57 PM, Jesper Juhl <jj@chaosbits.net> wrote:
>
> I think Jesper is confused because your patch applies on -tip (tip/master or
> tip/perf/core) where we have zapped the bp argument from show_trace() lately.
>
Yes, the patch was made against tip/master.

> But in the mainline, show_trace() still has the bp argument.
>

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Valdis.Kletnieks]

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On Wed, 24 Nov 2010 10:57:10 +0100, Jesper Juhl said:

> On Wed, 24 Nov 2010, Rakib Mullick wrote:

> > diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> > index 8474c99..fc5a253 100644
> > --- a/arch/x86/kernel/dumpstack.c
> > +++ b/arch/x86/kernel/dumpstack.c
> > @@ -197,10 +197,10 @@ void show_stack(struct task_struct *task,
> > unsigned long *sp)
> >   */
> >  void dump_stack(void)
> >  {
> > -	unsigned long bp = 0;
> >  	unsigned long stack;
> > 
> >  #ifdef CONFIG_FRAME_POINTER
> > +	unsigned long bp = 0;
> >  	if (!bp)
> >  		get_bp(bp);
> >  #endif
> 
> So, now the bp variable does not exist at all if CONFIG_FRAME_POINTER is 
> not defined.
> That's going to make this line :
> 
>           show_trace(NULL, NULL, &stack, bp);
> 
> found further down in the dump_stack() function, quite unhappy.

OK, I'll bite.  Why does the original say 'unsigned long bp = 0;' and then turns
around and has an 'if (!bp)' check?  Why is the conditional there?

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Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Frederic Weisbecker]

Le Wed, 24 Nov 2010 23:07:47 -0500,
Valdis.Kletnieks@vt.edu a écrit :

> On Wed, 24 Nov 2010 10:57:10 +0100, Jesper Juhl said:
> 
> > On Wed, 24 Nov 2010, Rakib Mullick wrote:
> 
> > > diff --git a/arch/x86/kernel/dumpstack.c
> > > b/arch/x86/kernel/dumpstack.c index 8474c99..fc5a253 100644
> > > --- a/arch/x86/kernel/dumpstack.c
> > > +++ b/arch/x86/kernel/dumpstack.c
> > > @@ -197,10 +197,10 @@ void show_stack(struct task_struct *task,
> > > unsigned long *sp)
> > >   */
> > >  void dump_stack(void)
> > >  {
> > > -	unsigned long bp = 0;
> > >  	unsigned long stack;
> > > 
> > >  #ifdef CONFIG_FRAME_POINTER
> > > +	unsigned long bp = 0;
> > >  	if (!bp)
> > >  		get_bp(bp);
> > >  #endif
> > 
> > So, now the bp variable does not exist at all if
> > CONFIG_FRAME_POINTER is not defined.
> > That's going to make this line :
> > 
> >           show_trace(NULL, NULL, &stack, bp);
> > 
> > found further down in the dump_stack() function, quite unhappy.
> 
> OK, I'll bite.  Why does the original say 'unsigned long bp = 0;' and
> then turns around and has an 'if (!bp)' check?  Why is the
> conditional there?

The original check was indeed not necessary. But now the whole block
should be removed anyway.

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Frederic Weisbecker]

2010/11/24 Rakib Mullick <rakib.mullick@gmail.com>:
> With allnoconfig, bp becomes unused. So put bp into defination of
> CONFIG_FRAME_POINTER.
>
> arch/x86/kernel/dumpstack.c: In function ‘dump_stack’:
> arch/x86/kernel/dumpstack.c:200: warning: unused variable ‘bp’
>
> Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
> ---
>
> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> index 8474c99..fc5a253 100644
> --- a/arch/x86/kernel/dumpstack.c
> +++ b/arch/x86/kernel/dumpstack.c
> @@ -197,10 +197,10 @@ void show_stack(struct task_struct *task,
> unsigned long *sp)
>  */
>  void dump_stack(void)
>  {
> -       unsigned long bp = 0;
>        unsigned long stack;
>
>  #ifdef CONFIG_FRAME_POINTER
> +       unsigned long bp = 0;
>        if (!bp)
>                get_bp(bp);
>  #endif
>

Looks like you can even remove that block. bp is not used any more in
this function.
get_bp() was only loading bp but did not make any use of it.

Thanks.

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Rakib Mullick]

On Wed, Nov 24, 2010 at 7:19 PM, Frederic Weisbecker <fweisbec@gmail.com> wrote:
> 2010/11/24 Rakib Mullick <rakib.mullick@gmail.com>:
>
> Looks like you can even remove that block. bp is not used any more in
> this function.
> get_bp() was only loading bp but did not make any use of it.

Yes, right. Here is the updated one.

 In dump_stack function, bp isn't used anymore, which is introduced by
commit 9c0729dc8062bed96189bd14ac6d4920f3958743. This patch removes bp
completely.


Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
---

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 8474c99..d6fb146 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -197,14 +197,8 @@ void show_stack(struct task_struct *task,
unsigned long *sp)
  */
 void dump_stack(void)
 {
-	unsigned long bp = 0;
 	unsigned long stack;

-#ifdef CONFIG_FRAME_POINTER
-	if (!bp)
-		get_bp(bp);
-#endif
-
 	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
 		current->pid, current->comm, print_tainted(),
 		init_utsname()->release,


>
> Thanks.
>

Re: [PATCH] x86, dumpstack: Fix unused variable warning.

[Frederic Weisbecker]

Le Thu, 25 Nov 2010 11:35:16 +0600,
Rakib Mullick <rakib.mullick@gmail.com> a écrit :

> On Wed, Nov 24, 2010 at 7:19 PM, Frederic Weisbecker
> <fweisbec@gmail.com> wrote:
> > 2010/11/24 Rakib Mullick <rakib.mullick@gmail.com>:
> >
> > Looks like you can even remove that block. bp is not used any more
> > in this function.
> > get_bp() was only loading bp but did not make any use of it.
> 
> Yes, right. Here is the updated one.
> 
>  In dump_stack function, bp isn't used anymore, which is introduced by
> commit 9c0729dc8062bed96189bd14ac6d4920f3958743. This patch removes bp
> completely.
> 
> 
> Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
> ---
> 
> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> index 8474c99..d6fb146 100644
> --- a/arch/x86/kernel/dumpstack.c
> +++ b/arch/x86/kernel/dumpstack.c
> @@ -197,14 +197,8 @@ void show_stack(struct task_struct *task,
> unsigned long *sp)
>   */
>  void dump_stack(void)
>  {
> -	unsigned long bp = 0;
>  	unsigned long stack;
> 
> -#ifdef CONFIG_FRAME_POINTER
> -	if (!bp)
> -		get_bp(bp);
> -#endif
> -
>  	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
>  		current->pid, current->comm, print_tainted(),
>  		init_utsname()->release,
> 

Queued, thanks!

[tip:perf/urgent] x86, dumpstack: Fix unused variable warning

[tip-bot for Rakib Mullick]

Commit-ID:  39a6eebda253aa34d659ca9436e3c32ef60473f1
Gitweb:     http://git.kernel.org/tip/39a6eebda253aa34d659ca9436e3c32ef60473f1
Author:     Rakib Mullick <rakib.mullick@gmail.com>
AuthorDate: Fri, 7 Jan 2011 16:59:49 +0100
Committer:  Frederic Weisbecker <fweisbec@gmail.com>
CommitDate: Fri, 7 Jan 2011 16:59:49 +0100

x86, dumpstack: Fix unused variable warning

In dump_stack function, bp isn't used anymore, which is introduced by
commit 9c0729dc8062bed96189bd14ac6d4920f3958743. This patch removes bp
completely.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Soeren Sandmann <sandmann@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <AANLkTik9U_Z0WSZ7YjrykER_pBUfPDdgUUmtYx=R74nL@mail.gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
 arch/x86/kernel/dumpstack.c |    6 ------
 1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 8474c99..d6fb146 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -197,14 +197,8 @@ void show_stack(struct task_struct *task, unsigned long *sp)
  */
 void dump_stack(void)
 {
-	unsigned long bp = 0;
 	unsigned long stack;
 
-#ifdef CONFIG_FRAME_POINTER
-	if (!bp)
-		get_bp(bp);
-#endif
-
 	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
 		current->pid, current->comm, print_tainted(),
 		init_utsname()->release,