Re: [PATCH] tracing: Fix undelared ENOSYS in include/linux/tracepoint.h

[Wu Zhangjin <wuzhangjin@gmail.com>]

On Mon, 2010-06-21 at 10:28 -0400, Steven Rostedt wrote:
> On Mon, 2010-06-21 at 19:09 +0800, Wu Zhangjin wrote:
> > From: Wu Zhangjin <wuzhangjin@gmail.com>
> > 
> > The header file include/linux/tracepoint.h may be included without
> > include/linux/errno.h and then the compiler will fail on building for
> > undelcared ENOSYS. This patch fixes this problem via including <linux/errno.h>
> > to include/linux/tracepoint.h.
> > 
> 
> Hi Wu,
> 
> I have not hit this. Did you hit this with mips? Does it need to get
> into 2.6.35 or can it wait till 2.6.36?
> 

I did not hit this in the mainline linux but in the windriver linux
(2.6.34). some guys (from WR) have included the <linux/kmemtrace.h> in
lib/kernel_lock.c and have introduced the building failure under some
configurations(seems when disabling the LTTng and another config, sorry,
I forget the exact name).

I have tried to find out who have used the undeclared ENOSYS and at last
got include/linux/tracepoint.h and after checking the linux-next tree
and found it also need to declare ENOSYS, then I send this patch for I'm
worrying about somebody else may also include tracepoint.h but without
errno.h ;)

Perhaps we'd better push it into 2.6.35 as you explained: "maybe there's
a configuration already in 35 that we don't know about that this bug can
break. "

Best Regards,
	Wu Zhangjin

> -- Steve
> 
> > Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
> > ---
> >  include/linux/tracepoint.h |    1 +
> >  1 files changed, 1 insertions(+), 0 deletions(-)
> > 
> > diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
> > index 9a59d1f..103d1b6 100644
> > --- a/include/linux/tracepoint.h
> > +++ b/include/linux/tracepoint.h
> > @@ -14,6 +14,7 @@
> >   * See the file COPYING for more details.
> >   */
> >  
> > +#include <linux/errno.h>
> >  #include <linux/types.h>
> >  #include <linux/rcupdate.h>
> >  
> 
>