3.9-rc1 powerpc ptrace.c: 'brk.len' is used uninitialized

[Philippe De Muyter]

Hello Mikey,

On Thu, Mar 07, 2013 at 10:14:30AM +1100, Michael Neuling wrote:
> Philippe De Muyter <phdm at macqel.be> wrote:
> 
> > On Thu, Mar 07, 2013 at 09:09:48AM +1100, Michael Neuling wrote:
> > > > bisect tells me that since your commit 9422de3e953d0e60eb95f5430a9dd803eec1c6d7 
> > > > "powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers",
> > > > compiling linux fails with :
> > > > 
> > > >   cc1: warnings being treated as errors
> > > >   arch/powerpc/kernel/ptrace.c: In function 'arch_ptrace':
> > > >   arch/powerpc/kernel/ptrace.c:1450: warning: 'brk.len' is used uninitialized in this function
> > > >   arch/powerpc/kernel/ptrace.c:1352: note: 'brk.len' was declared here
> > > > 
> > > > could you look at that ?
> > > 
> > > Sure. 
> > 
> > I use gcc-4.2.2, and my .config follows.
> 
> I'm a bit lost.  
> 
> I don't have 4.2.2 (which is ancient BTW) and I can't hit this on
> 4.3,4.5 or 4.6 with your config.  It compiles fine.
> 
> Also:
> 
> >   arch/powerpc/kernel/ptrace.c:1450: warning: 'brk.len' is used uninitialized in this function
> >   arch/powerpc/kernel/ptrace.c:1352: note: 'brk.len' was declared here
> 
> These line numbers make no sense at all WRT v3.9-rc1.  brk.len is neither
> declared or used in those lines:

those were the line numbers just after your commit

In 3.9-rc1 they are :

cc1: warnings being treated as errors
arch/powerpc/kernel/ptrace.c: In function 'arch_ptrace':
arch/powerpc/kernel/ptrace.c:1479: warning: 'brk.len' is used uninitialized in this function
arch/powerpc/kernel/ptrace.c:1381: note: 'brk.len' was declared here

		if (child->thread.hw_brk.address)
			return -ENOSPC;

1479:		child->thread.hw_brk = brk;

		return 1;
	#endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */

Philippe