Re: linux-kernel-digest V1 #101

Rob Janssen reading Linux mailinglist (linux@pe1chl.ampr.org)
Thu, 29 Jun 1995 09:57:45 +0200 (MET DST)


According to owner-linux-kernel-digest@vger.rutgers.edu:
> From: John Michael Floyd <jmf@pwd.nsw.gov.au>
> Date: Wed, 28 Jun 1995 15:55:38 +1000 (EST)
> Subject: Repost - uugetty dies with 1.2.10/11
>
> I am having some problems with uugetty with V1.2.10 and V1.2.11 of the kernel.
> The version of uugetty is 2.0.7e.
>
> On a connecting call by modem the program gets a segment violation.
> This occurs after connection but before the login prompt.
> The same binary of the uugetty runs happily on V1.2.8.
>
> I have tried a number of compile options - optimizations, -g, different
> compilers etc. No luck. Ie for the uugetty binary!
>
> My main compile is using Elf libraries 5.0.9 and 5.1.2 but I have also tried the
> 4.7.2 aout libs.
>
> I have tried to debug this as much as possible - but I have run into problems
> doing this. However, it appears to be memory overwrite, with some variables
> locations being zeroed (pointers). This is what causes the seg. but i
> cannot find the region that actually does it.

In 'the old days' this was caused by mismatch between the #include file
<sys/utsname.h> and the actual implementation in the kernel. The uname()
function would return a "struct utsname" much larger than the one defined
in <sys/utsname.h> and would thereby overwrite other things, which happen
to be in the stack and thus this caused great damage.

However, the change in struct utsname size happened a long time ago.
Maybe you should look along these lines... did you upgrade your include
files?

Rob

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| Rob Janssen         rob@knoware.nl | AMPRnet:   rob@pe1chl.ampr.org       |
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