Subject: Re: sbrk(0) dumps a core??
To: Emmanuel Dreyfus <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-userlevel
Date: 03/03/2001 16:51:51
> Anyone can explain me why the following program dumps a core at mine?

>    void *size = (void*)0x4000;

Some flags go up here.  Casting a nonzero number to a pointer

>    end = sbrk (0);
>    printf ("end=0x%lx\n", (long)end);
>    res = brk (size);

Whoa Nelly!  You've just set the break to 0x4000; if you have any data
segment above that, it just went poof.

>    printf ("brk(0x%lx) returned %d\n", (long)size, res);

For example, when printf tries to access stdio's internal data
structures (they are quite likely above 0x4000 on the architecture
you're using - you didn't say what it was).

You probably want size to be an int, and to write res = sbrk (size);.

					der Mouse

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