AVILA getting close!

[John-Mark Gurney]

John-Mark Gurney wrote this message on Wed, Jun 18, 2014 at 15:58 -0700:
> So, w/ the recent couple of patches that alc has provided, I no longer
> receive kernel panics on my AVILA board!
> 
> $ uname -a
> FreeBSD avila.funkthat.com 11.0-CURRENT FreeBSD 11.0-CURRENT #27 r267333:267349M: Wed Jun 11 09:57:58 PDT 2014     jmg at carbon.funkthat.com:/usr/obj/arm.armeb/usr/src.avila/sys/AVILA  arm
> $ uptime
> 12:15AM  up 1 day, 15 mins, 2 users, load averages: 0.13, 0.11, 0.08
> 
> This survived a portsnap extract...  This is all over NFS...
> 
> Though the issue that I'm now having is that some binaries (newsyslog)
> and sometimes other binaries (awk, grep) core dump...
> 
> I believe this is an issue w/ rtld, or related...  If I compile newsyslog
> -static, it works fine...  Otherwise I get a SIGILL, and that is
> because it jumps off into the weeds..  Though gdb on arm isn't very
> useful..

ok, so the SIGILL only occures under gdb, and this is because single
stepping into a RAS sequence doesn't work very well...  If you set a
break point on the return (after the RAS sequence), you can get past
this...

I got to the point in rtld.c code:
    if (obj->pltrel)
        rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
    else
        rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloffand was seeing gdb try to execute the pltrela line, but:
i;

and was seeing gdb try to execute the pltrela line, but:
(gdb) print * (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff)
Error accessing memory address 0x118: Bad address.
(gdb) print/x obj->pltrela
$4 = 0x0
(gdb) print /x reloff
$5 = 0x118
(gdb) print obj->pltrel
$6 = (const Elf_Rel *) 0x94e8

Hun? obj->pltrel is non-zero, so it should have executed the other
line...

I recompiled rtld w/ -O0, and sure enough, newsyslog runs fine... If
I compile w/o -O, or w/ -O1, it fails...

Comments or suggestions?

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."