From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mikael Pettersson <mikpe@it.uu.se>
Subject: Re: aranym bug, manifests as "ida_remove called for id=13" on recent
 kernels
Date: Mon, 11 Oct 2010 13:50:42 +0200
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To: Mikael Pettersson <mikpe@it.uu.se>
Cc: Al Viro <viro@ZenIV.linux.org.uk>, Geert Uytterhoeven <geert@linux-m68k.org>, linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org

Mikael Pettersson writes:
 > Al Viro writes:
 >  > On Mon, Oct 11, 2010 at 12:52:56AM +0100, Al Viro wrote:
 >  > > On Sun, Oct 10, 2010 at 10:18:03PM +0200, Geert Uytterhoeven wrote:
 >  > > > >> This is on aranym-0.9.9-1 from Ubuntu/amd64.
 >  > > > >
 >  > > > > stat -L /proc/2/exec, otherwise you'll hit lstat() instead of stat().
 >  > > > > And FWIW 0.9.10-1 squeeze/amd64 also triggers here...
 >  > > > 
 >  > > > Still, just "stat: cannot stat `proc/2/exe': No such file or directory" here...
 >  > > 
 >  > > Interesting...  Which gcc version is used?
 >  > 
 >  > Argh...  OK, going through aranym with debugger has exhonorated it.  My
 >  > apologies ;-/  It *is* gcc in sid.  Testcase:
 >  > 
 >  > extern int foo(int);
 >  > void *bar(int n)
 >  > {
 >  >         return (void *)foo(n);
 >  > }
 >  > 
 >  > and gcc -S -O2 turns that into
 >  > bar:
 >  >         link.w %fp,#0
 >  >         unlk %fp
 >  >         jra foo
 >  > 
 >  > Spot the obvious bug...  BTW, why on the Earth does debian-ports m68k tree
 >  > use gcc-4.3 with Cthulhu-scaring 700Kb gzipped patch and does *not* have
 >  > gcc-4.4?
 > 
 > I can confirm that the bug exists in gcc-4.3.4 and gcc-4.4.5,
 > but it has been fixed in gcc-4.5.1 which generates:
 > 
 > bar:
 >         link.w %fp,#0
 >         move.l 8(%fp),-(%sp)
 >         jsr foo
 >         move.l %d0,%a0
 >         unlk %fp
 >         rts
 > 
 > I don't yet know the gcc PR number or svn commit # for the fix
 > (in case people want a backport).

It's gcc PR41302 which was fixed for gcc trunk on November 4 2009
in r153890.  The patch backports easily to gcc-4.4 and solves the
test case there (manual inspection using a cross).  It also backports
easily to gcc-4.3 but I haven't tested it there.