Random Kernel Panic on Dreamplug (FS related)

Ian Lepore ian at FreeBSD.org
Tue Sep 30 14:17:45 UTC 2014


On Tue, 2014-09-30 at 14:14 +0200, Mattia Rossi wrote:
> Am 30.09.2014 13:29, schrieb John-Mark Gurney:
> > Mattia Rossi wrote this message on Mon, Sep 29, 2014 at 10:42 +0200:
> >> Am 29.09.2014 06:01, schrieb John-Mark Gurney:
> >>> Mattia Rossi wrote this message on Fri, Sep 26, 2014 at 14:19 +0200:
> >>>> This might be part of the weird FFS issues the Dreamplug has and no-one
> >>>> knows why they're happening.
> >>> Are you running w/ FFS journaling?  If so, try turning it off, but
> >>> keeping softupdates on..
> >> No journaling, no softupdates. I'll try enabling softupdates next time.
> >> don't know if it will panic though
> >>>> data_abort_handler() at data_abort_handler+0x5c0
> >>>>           pc = 0xc0de7a28  lr = 0xc0dd711c (exception_exit)
> >>>>           sp = 0xde019898  fp = 0xde019a20
> >>>>           r4 = 0xffffffff  r5 = 0xffff1004
> >>>>           r6 = 0xc3f3f6c0  r7 = 0x00001000
> >>>>           r8 = 0xc443e880  r9 = 0x00000000
> >>>>          r10 = 0xc3d69000
> >>>> exception_exit() at exception_exit
> >>>>           pc = 0xc0dd711c  lr = 0xc0d53828 (ffs_truncate+0xaa8)
> >>>>           sp = 0xde0198e8  fp = 0xde019a20
> >>>>           r0 = 0xd0238120  r1 = 0x00000e60
> >>>>           r2 = 0x00000000  r3 = 0x00000000
> >>>>           r4 = 0x00000120  r5 = 0x00000000
> >>>>           r6 = 0xc3f3f6c0  r7 = 0x00001000
> >>>>           r8 = 0xc443e880  r9 = 0x00000000
> >>>>          r10 = 0xc3d69000 r12 = 0xd0238120
> >>>> memset() at memset+0x48
> >>>>           pc = 0xc0de521c  lr = 0xc0d53828 (ffs_truncate+0xaa8)
> >>>>           sp = 0xde0198e8  fp = 0xde019a20
> >>>> Unwind failure (no registers changed)
> >>> No more beyond this?   If you could run addr2line on 0xc0d53828 so
> >>> that we know where in ffs_truncate it's failing, that'd be very
> >>> nice...
> >> So I was trying to save the coredump in  order to reboot and run
> >> addr2line, but that failed:
> >>
> >> Physical memory: 504 MB
> >> Dumping 67 MB:(da0:umass-sim0:0:0:0): WRITE(10). CDB: 2a 00 01 d5 1f20
> >> 00 00 01 00  <sip:2000000100>
> >> (da0:umass-sim0:0:0:0): CAM status: Resource Unavailable
> >> (da0:umass-sim0:0:0:0): Error 5, Retries exhausted
> >> Aborting dump due to I/O error.
> >>
> >> ** DUMP FAILED (ERROR 5) **
> >>
> >> So I guess this error is related to the CAM errors I'm getting from time
> >> to time. I was hoping that those errors were related to the INVARIANTS
> >> option that slowed down the system and thus might have triggered CAM
> >> errors, but obviously the SD Card seems to be the real issue here.
> >> So no crashdump for further analysis.
> > That's fine.. w/ the addr2line we have some lines to explore...
> >
> >> Interestingly the CAM errors didn't show up on the terminal as other
> >> times, the kernel just panicked straight away.
> > Hmm.. that is odd.. someone who knows the SD card layer should look
> > at this part...  It could be that the SD card driver doesn't handle
> > dumping (there is this global flag that gets set) properly and the driver
> > needs to behave differently when it's set...
> 
> I also need to grab a new SD card, just to make sure it's really not the 
> card.
> 
> >
> >> But I've got the addr2line output, even though I'm not sure it makes any
> >> difference:
> >>
> >> addr2line -f -e /mnt/kernel.debug 0xc0d53828
> >>
> >> ffs_truncate
> >> /usr/devel/dreamplug/sys/ufs/ffs/ffs_inode.c:321
> > can you give me the contents of the line?  and a few lines of context
> > around it?   In HEAD's source, this is DOINGASYNC, and there is no call
> > to memset, nor a variable assignment that would result in memset being
> > called...
> 
> Same here.. The file hasn't been changed in a while (Fri, 31 May 2013):
> 
>                  ip->i_size = length;
>                  DIP_SET(ip, i_size, length);
>                  if (bp->b_bufsize == fs->fs_bsize)
>                          bp->b_flags |= B_CLUSTEROK;
>                  if (flags & IO_SYNC)
>                          bwrite(bp);
> 321:        else if (DOINGASYNC(vp))
>                          bdwrite(bp);
>                  else
>                          bawrite(bp);
>                  ip->i_flag |= IN_CHANGE | IN_UPDATE;
>                  return (ffs_update(vp, !DOINGASYNC(vp)));
> 
> No idea what's going on.
> 
> >>>> The sad thing is, that with fsck broken for the dreamplug, I have to
> >>>> re-format the disk, reinstall everything and recreate the config files
> >>>> which I didn't manage to copy to a safe place beforehand :-(
> >> Didn't get around yet on checking whether the fsck issue persists if
> >> everything is compiled with gcc. Will take a bit, as I'm going to be on
> >> holidays for the next one and a half weeks. Fact is though, fsck is
> >> broken on the Dreamplug (ARMv5TE), at least when run on EVERY device
> >> that is attached via USB and if compiled with CLANG.
> >>>> Before I do that I'll leave the system in debugging mode for a few days,
> >>>> in case someone can help and needs some more information.
> >> Currently I've run fsck on all the disks/cards that had a working world
> >> for the dreamplug on it, so they're all gone. Can't do eny debugging
> >> atm. I'll let you know hoe the gcc build goes once I'm back from
> >> holidays though.
> > Hmmm. this is also worth investigating as it could be that clang is
> > producing bad code somewhere...
> 
> I'm trying to get kernel and world compiled with gcc atm. It fails 
> though, as somehow the armv7 code is currently broken... and the 
> toolchain build is not happy.
> 
> In file included from 
> /usr/devel/dreamplug/sys/arm/arm/cpufunc_asm_armv7.S:36:
> ./machine/sysreg.h:97:5: error: "__ARM_ARCH" is not defined
> 
> (followed by a few more of those)
> 
> My build command:
> 
>   make TARGET=arm TARGET_ARCH=arm DESTDIR=/usr/devel/dreamplug-dist 
> KERNCONF=DREAMPLUG-1001 -DWITHOUT_SHAREDOCS -DWITHOUT_EXAMPLES 
> -DWITHOUT_HTML -DWITHOUT_MAN -DWITHOUT_GAMES toolchain buildworld kernel 
> installworld


The build was broken briefly yesterday, you must have grabbed it during
that window.

But... I did a gcc build and got the same results as with clang.

-- Ian




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