On Mar 11, 2021, at 7:07 AM, ori@eigenstate.org wrote:

Quoth Shiro <rt9f.3141@gmail.com>:
Hello,

I’m not sure I’m reporting to the appropriate place.  Please advise.  And apologies in advance if I’m spamming this group.


This is fine, but 9front@9front.org is probably
better for 9front specific questions.

thx.

As far as uploading information -- 9front ships
with webpaste, so it's easy to get text uploaded,
which would let people copy values.

Noted, I’ll use this next time.


Photo 3: acid is pointing to line 431.  From above, n is too large
to be a strlen.  I suspect it actually failed in memmove(), but
I’m not sure — I’ve only got 2 months on Plan9/9front and this is
the first time I do acid.

Acid just shows whole words, so you're seeing 64
bits of a 32 bit value.  If you look closely,
you'll actually notice that the top bits in 'n'
are also the bottom bits of 'dat'

It's a bit unfortunate, you either have to tell
acid how to format the type, or you have to know
that you just need to ignore the top bits.

OK, better than nothing.  Hmm, maybe enhancing Acid to correctly format the type would be a nice GSOC project?



Anyawys, the faulting address is

       addr=0x100061fa0 pc=37930

Which shows up in R4. Given that *almost* the same
addresses (0x61fa0) in the other registers.  It
looks like it could be stack corruption.

Is this easy to reproduce?  Are you using the
binary from the last release, or is it your own
build?

Yes, this is very easy to reproduce.  It happens immediately on the first “ls”.  I’m using the released bin image:
9front-8013.d9e940a768d1.pi3.img.gz

Steps to reproduce:

1: Create and export a dir on Linux.  Add the dir to /etc/exports for NFSv3:

/srv/l9p                    192.168.1.0/24(rw,insecure,sync,no_subtree_check,no_root_squash)

Then on Plan9:

2: start the NFS server:

nfs -p 775 -s i7 192.168.1.7

3: mount the NFS export:

mount -c /srv/i7 /n/i7 /srv/l9p

4: attempt to use it:

ls /n/i7

and the NFS server will crash on RPi3 and RPi4.






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