AW: [Xenomai-help] undefinedreference __xnarch_xchg_called_with_bad_pointer

AW: [Xenomai-help] undefinedreference __xnarch_xchg_called_with_bad_pointer

[Roderik_Wildenburg]

You are right, but who is somebody ?  The example definitly does not call any xchg-function directly. The only thing I did, was to activate debugging and recompile all the libraries (make clean; configure --debug-enable;  make ) and soon I get this error message when compiling the demo (I don´t get an error message when debugging is disabled) . Amazingly I don´t get this error message when compiling the native examples (ksrc/skins/native/demos) (debug enabled).
Any ideas ?

Roderik



> -----Ursprüngliche Nachricht-----
> Von: xenomai-help-bounces@domain.hid
> [mailto:xenomai-help-bounces@domain.hid] Im Auftrag von Heikki Lindholm
> Gesendet: Dienstag, 28. Februar 2006 15:48
> An: Wildenburg, Roderik RAEK3 MRA
> Cc: xenomai@xenomai.org
> Betreff: Re: [Xenomai-help] undefinedreference 
> __xnarch_xchg_called_with_bad_pointer
> 
> Roderik_Wildenburg@domain.hid kirjoitti:
> > Dear Gurus,
> > 
> > I have compiled ppc(!)-xenomai with debug information 
> (configure --enable-debug), so far so good (compiling of 
> xenomai itself and it´s libraries, testsuite etc. was successful).  
> > Buuuut ..., when compiling the vxWorks-demos 
> (ksrc/skins/vxworks/demos/*.c), I get an error message about 
> an undefined refernce __xnarch_xchg_called_with_bad_pointer. 
> I searched for this mysterious function, but could only find 
> it in asm-powerpc/atomic.h, where it is declared as external 
> (extern void __xnarch_xchg_called_with_bad_pointer(void);).
> > 
> > Does anybody know, where I can get the implementation of 
> this function, or what I have to do else to get rid of the 
> error message ?
> 
> You might also want to read the comment near the extern 
> declaration of the function in atomic.h, where it says that 
> the function is not even intended to be implemented. The 
> error means somebody called *atomic_xchg with wrong arguments 
> (or there's something else wrong like inlines not working).
> 
> -- Heikki Lindholm
> 
> _______________________________________________
> Xenomai-help mailing list
> Xenomai-help@domain.hid
> https://mail.gna.org/listinfo/xenomai-help
> 

Re: AW: [Xenomai-help] undefinedreference __xnarch_xchg_called_with_bad_pointer

[Heikki Lindholm]

Uh. I guess the compiler isn't killing the *_bad_pointer function as 
dead code when debug is enabled (although it is dead-code.) As a 
work-around, I think, you could just comment the line, where 
*_bad_pointer is called.

-- Heikki Lindholm

Roderik_Wildenburg@domain.hid kirjoitti:
> You are right, but who is somebody ?  The example definitly does not call any xchg-function directly. The only thing I did, was to activate debugging and recompile all the libraries (make clean; configure --debug-enable;  make ) and soon I get this error message when compiling the demo (I don´t get an error message when debugging is disabled) . Amazingly I don´t get this error message when compiling the native examples (ksrc/skins/native/demos) (debug enabled).
> Any ideas ?
> 
> Roderik
> 
> 
> 
> 
>>-----Ursprüngliche Nachricht-----
>>Von: xenomai-help-bounces@domain.hid 
>>[mailto:xenomai-help-bounces@domain.hid] Im Auftrag von Heikki Lindholm
>>Gesendet: Dienstag, 28. Februar 2006 15:48
>>An: Wildenburg, Roderik RAEK3 MRA
>>Cc: xenomai@xenomai.org
>>Betreff: Re: [Xenomai-help] undefinedreference 
>>__xnarch_xchg_called_with_bad_pointer
>>
>>Roderik_Wildenburg@domain.hid kirjoitti:
>>
>>>Dear Gurus,
>>>
>>>I have compiled ppc(!)-xenomai with debug information 
>>
>>(configure --enable-debug), so far so good (compiling of 
>>xenomai itself and it´s libraries, testsuite etc. was successful).  
>>
>>>Buuuut ..., when compiling the vxWorks-demos 
>>
>>(ksrc/skins/vxworks/demos/*.c), I get an error message about 
>>an undefined refernce __xnarch_xchg_called_with_bad_pointer. 
>>I searched for this mysterious function, but could only find 
>>it in asm-powerpc/atomic.h, where it is declared as external 
>>(extern void __xnarch_xchg_called_with_bad_pointer(void);).
>>
>>>Does anybody know, where I can get the implementation of 
>>
>>this function, or what I have to do else to get rid of the 
>>error message ?
>>
>>You might also want to read the comment near the extern 
>>declaration of the function in atomic.h, where it says that 
>>the function is not even intended to be implemented. The 
>>error means somebody called *atomic_xchg with wrong arguments 
>>(or there's something else wrong like inlines not working).
>>
>>-- Heikki Lindholm
>>
>>_______________________________________________
>>Xenomai-help mailing list
>>Xenomai-help@domain.hid
>>https://mail.gna.org/listinfo/xenomai-help
>>

Re: AW: [Xenomai-help] undefinedreference __xnarch_xchg_called_with_bad_pointer

[Philippe Gerum]

Heikki Lindholm wrote:
> Uh. I guess the compiler isn't killing the *_bad_pointer function as 
> dead code when debug is enabled (although it is dead-code.)

The optimizer is disabled by --enable-debug so that we don't get strange jumps 
while tracing with GDB, I guess that's why the dead code is not eliminated. What 
about just killing this check, since the same code is already validated when 
compiling it as a kernel module? (except asm-uvm/system.h, but that's not important).

  As a
> work-around, I think, you could just comment the line, where 
> *_bad_pointer is called.
> 
> -- Heikki Lindholm
> 
> Roderik_Wildenburg@domain.hid kirjoitti:
> 
>> You are right, but who is somebody ?  The example definitly does not 
>> call any xchg-function directly. The only thing I did, was to activate 
>> debugging and recompile all the libraries (make clean; configure 
>> --debug-enable;  make ) and soon I get this error message when 
>> compiling the demo (I don´t get an error message when debugging is 
>> disabled) . Amazingly I don´t get this error message when compiling 
>> the native examples (ksrc/skins/native/demos) (debug enabled).
>> Any ideas ?
>>
>> Roderik
>>
>>
>>
>>
>>> -----Ursprüngliche Nachricht-----
>>> Von: xenomai-help-bounces@domain.hid
>>> [mailto:xenomai-help-bounces@domain.hid] Im Auftrag von Heikki Lindholm
>>> Gesendet: Dienstag, 28. Februar 2006 15:48
>>> An: Wildenburg, Roderik RAEK3 MRA
>>> Cc: xenomai@xenomai.org
>>> Betreff: Re: [Xenomai-help] undefinedreference 
>>> __xnarch_xchg_called_with_bad_pointer
>>>
>>> Roderik_Wildenburg@domain.hid kirjoitti:
>>>
>>>> Dear Gurus,
>>>>
>>>> I have compiled ppc(!)-xenomai with debug information 
>>>
>>>
>>> (configure --enable-debug), so far so good (compiling of xenomai 
>>> itself and it´s libraries, testsuite etc. was successful). 
>>>
>>>> Buuuut ..., when compiling the vxWorks-demos 
>>>
>>>
>>> (ksrc/skins/vxworks/demos/*.c), I get an error message about an 
>>> undefined refernce __xnarch_xchg_called_with_bad_pointer. I searched 
>>> for this mysterious function, but could only find it in 
>>> asm-powerpc/atomic.h, where it is declared as external (extern void 
>>> __xnarch_xchg_called_with_bad_pointer(void);).
>>>
>>>> Does anybody know, where I can get the implementation of 
>>>
>>>
>>> this function, or what I have to do else to get rid of the error 
>>> message ?
>>>
>>> You might also want to read the comment near the extern declaration 
>>> of the function in atomic.h, where it says that the function is not 
>>> even intended to be implemented. The error means somebody called 
>>> *atomic_xchg with wrong arguments (or there's something else wrong 
>>> like inlines not working).
>>>
>>> -- Heikki Lindholm
>>>
>>> _______________________________________________
>>> Xenomai-help mailing list
>>> Xenomai-help@domain.hid
>>> https://mail.gna.org/listinfo/xenomai-help
>>>
> 
> 
> _______________________________________________
> Xenomai-help mailing list
> Xenomai-help@domain.hid
> https://mail.gna.org/listinfo/xenomai-help
> 


-- 

Philippe.

Re: AW: [Xenomai-help] undefinedreference __xnarch_xchg_called_with_bad_pointer

[Heikki Lindholm]

[-- Attachment #1: Type: text/plain, Size: 760 bytes --]

Philippe Gerum kirjoitti:
> Heikki Lindholm wrote:
> 
>> Uh. I guess the compiler isn't killing the *_bad_pointer function as 
>> dead code when debug is enabled (although it is dead-code.)
> 
> 
> The optimizer is disabled by --enable-debug so that we don't get strange 
> jumps while tracing with GDB, I guess that's why the dead code is not 
> eliminated. What about just killing this check, since the same code is 
> already validated when compiling it as a kernel module? (except 
> asm-uvm/system.h, but that's not important).

Yep. That seems like the way to go. I don't see much to gain from the 
check. Of course, paranoid way would be to add the __bad_ptr() function 
with abort() or something inside. Quick patch attached for the former case.

- hl

[-- Attachment #2: xeno-atomic-badptr.patch --]
[-- Type: text/plain, Size: 550 bytes --]

--- atomic.h.orig	2006-02-28 21:01:59.000000000 +0200
+++ atomic.h	2006-02-28 21:01:34.000000000 +0200
@@ -142,12 +142,6 @@
 }
 #endif
 
-/*
- * This function doesn't exist, so you'll get a linker error
- * if something tries to do an invalid xchg().
- */
-extern void __xnarch_xchg_called_with_bad_pointer(void);
-
 static __inline__ unsigned long
     __xchg(volatile void *ptr, unsigned long x, unsigned int size)
 {
@@ -159,7 +153,6 @@
 	return __xchg_u64(ptr, x);
 #endif
     }
-    __xnarch_xchg_called_with_bad_pointer();
     return x;
 }
 

Re: AW: [Xenomai-help] undefinedreference __xnarch_xchg_called_with_bad_pointer

[Philippe Gerum]

Heikki Lindholm wrote:
> Philippe Gerum kirjoitti:
> 
>> Heikki Lindholm wrote:
>>
>>> Uh. I guess the compiler isn't killing the *_bad_pointer function as 
>>> dead code when debug is enabled (although it is dead-code.)
>>
>>
>>
>> The optimizer is disabled by --enable-debug so that we don't get 
>> strange jumps while tracing with GDB, I guess that's why the dead code 
>> is not eliminated. What about just killing this check, since the same 
>> code is already validated when compiling it as a kernel module? 
>> (except asm-uvm/system.h, but that's not important).
> 
> 
> Yep. That seems like the way to go. I don't see much to gain from the 
> check. Of course, paranoid way would be to add the __bad_ptr() function 
> with abort() or something inside. Quick patch attached for the former case.

Applied, thanks.

> 
> - hl
> 
> 
> ------------------------------------------------------------------------
> 
> --- atomic.h.orig	2006-02-28 21:01:59.000000000 +0200
> +++ atomic.h	2006-02-28 21:01:34.000000000 +0200
> @@ -142,12 +142,6 @@
>  }
>  #endif
>  
> -/*
> - * This function doesn't exist, so you'll get a linker error
> - * if something tries to do an invalid xchg().
> - */
> -extern void __xnarch_xchg_called_with_bad_pointer(void);
> -
>  static __inline__ unsigned long
>      __xchg(volatile void *ptr, unsigned long x, unsigned int size)
>  {
> @@ -159,7 +153,6 @@
>  	return __xchg_u64(ptr, x);
>  #endif
>      }
> -    __xnarch_xchg_called_with_bad_pointer();
>      return x;
>  }
>  


-- 

Philippe.