[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] uspr2 working intermittently/segmentation fault
From: |
Marcus D. Leech |
Subject: |
Re: [Discuss-gnuradio] uspr2 working intermittently/segmentation fault |
Date: |
Wed, 01 Apr 2009 19:28:22 -0400 |
User-agent: |
Thunderbird 2.0.0.19 (X11/20090105) |
Jeff Brower wrote:
>
> Not everything the FPGA does -- register format/contents, FIFO widths, etc --
> can be
> error checked. There has to be some reasonable expectation on the software
> side.
> The typical method is a "revision id" register, the software checks this and
> adjusts
> capabilities. If the revision is too far behind or doesn't match expectation
> then
> the software gives an error message.
>
> -Jeff
>
>
An error in the (expected) format of an external input should never
result in a Seg Fault. Nothing wrong with doing
"Gee, this parameter seems rather odd, I'm leaving".
Two decades of writing network protocol implementations has taught me
that making dangerous assumptions about external
inputs leads to various not-nice things happening, and notorious in
the press in the context of network protocols, those
assumptions often lead to ugly security problems (note the SNMPV3
parser issues of a few years ago!). No security issues
here, to be sure, but being insufficiently paranoid about external
inputs of *any* kind has leads to spectacular downfall...
Provoking a Segmentation Fault is just impolite, if nothing else.
--
Marcus Leech
Principal Investigator, Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org