47 lines
1.3 KiB
C
47 lines
1.3 KiB
C
/* sbrk.c -- allocate memory dynamically.
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*
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* Copyright (c) 1995,1996,1999 Cygnus Support
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*
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* The authors hereby grant permission to use, copy, modify, distribute,
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* and license this software and its documentation for any purpose, provided
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* that existing copyright notices are retained in all copies and that this
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* notice is included verbatim in any distributions. No written agreement,
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* license, or royalty fee is required for any of the authorized uses.
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* Modifications to this software may be copyrighted by their authors
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* and need not follow the licensing terms described here, provided that
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* the new terms are clearly indicated on the first page of each file where
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* they apply.
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include "glue.h"
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extern char _heap_start[];
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extern void exit (int) __attribute ((__noreturn__));
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extern int _write (int, char *, int);
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caddr_t
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_sbrk (size_t incr)
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{
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static char *heap_end;
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char *prev_heap_end;
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char *sp = (char *)&sp;
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if (heap_end == 0)
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{
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heap_end = _heap_start;
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}
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prev_heap_end = heap_end;
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if (heap_end > sp)
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{
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_write (1, "Heap and stack collision\n", 25);
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#if 0 /* Calling abort brings in the signal handling code. */
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abort ();
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#else
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exit (1);
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#endif
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}
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heap_end += incr;
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return (caddr_t) prev_heap_end;
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}
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