From owner-freebsd-stable  Tue Oct 16  9:46:13 2001
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Date: Tue, 16 Oct 2001 09:46:10 -0700 (PDT)
From: David Marker <marker_d@yahoo.com>
Subject: Re: SIGSEGV not blocked in gdm [was Re: setenv() cores with NULL value]
To: freebsd-stable@freebsd.org
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Well, I didn't mean to start a discussion about
NULL pointers. I believe setenv() should core
in the test program sent in by Heath Nielson.

The interesting thing about gdm is that it does
_not_ core dump. Furthermore, I can't find it
ever blocking SIGSEGV in its source. Which is why
I referenced this post (there is a whole thread):
http://www.freebsd.org/cgi/getmsg.cgi?fetch=158037+0+/usr/local/www/db/text/2001/freebsd-stable/20010114.freebsd-stable

Before reading that I was not aware you could block
a SIGSEGV. But gdm doesn't even appear to block that
signal. (grep for sigation, then SIGSEGV, didn't find
anything to suggest it blocks SIGSEGV.)

So my question is why does Mr. Nielson's program
dump core and gdm does not?

-dave

> While I don't know if gdm should be setting a NULL
> value or not, I ran this simple program:
> 
> #include <stdlib.h>
> #include <stdio.h>
> 
> int main(int argc, char* argv[])
> {
>     char* name = "TEST";
>     char* value = NULL;
>     int ret;
> 
>     printf("value: %s\n", value);
>     ret = setenv(name, value, 1);
>     printf("ret: %d\n", ret);
>     return 0;
> }
> 
> On FreeBSD I get:
> hershey:~$ ./a.out
> value: (null)
> Segmentation fault (core dumped)
> 
> On Linux:
> catskill 23: ./a.out
> value: (null)
> ret: 0


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