30 lines
		
	
	
		
			568 B
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			30 lines
		
	
	
		
			568 B
		
	
	
	
		
			C
		
	
	
	
| #include <_ansi.h>
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| #include <sys/types.h>
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| #include <sys/stat.h>
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| #include "sys/syscall.h"
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| 
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| caddr_t
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| _sbrk (int incr)
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| {
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|   extern char   heap_start[];	/* Defined by the linker script.  */
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|   static char * heap_end = NULL;
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|   char *        prev_heap_end;
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|   char *        sp = (char *) & sp;
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| 
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|   if (heap_end == NULL)
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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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| 
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|   if (heap_end + incr > sp)
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|     {
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| #define MESSAGE "Heap and stack collision\n"
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|       _write (1, MESSAGE, sizeof MESSAGE);
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|       abort ();
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|     }
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| 
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|   heap_end += incr;
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| 
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|   return (caddr_t) prev_heap_end;
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| }
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