39 lines
866 B
C
39 lines
866 B
C
/*
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* Copyright (c) 1986 Regents of the University of California.
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* All rights reserved. The Berkeley software License Agreement
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* specifies the terms and conditions for redistribution.
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*/
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#include "param.h"
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#include "user.h"
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#include "proc.h"
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#include "vm.h"
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#include "systm.h"
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void
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brk()
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{
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struct a {
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int naddr;
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};
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register int newsize, d;
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/* set newsize to new data size */
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newsize = ((struct a*)u.u_arg)->naddr - u.u_procp->p_daddr;
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if (newsize < 0)
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newsize = 0;
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if (u.u_tsize + newsize + u.u_ssize > MAXMEM) {
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u.u_error = ENOMEM;
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return;
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}
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u.u_procp->p_dsize = newsize;
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/* set d to (new - old) */
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d = newsize - u.u_dsize;
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//printf ("brk: new size %u bytes, incremented by %d\n", newsize, d);
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if (d > 0)
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bzero ((void*) (u.u_procp->p_daddr + u.u_dsize), d);
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u.u_dsize = newsize;
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u.u_rval = u.u_procp->p_daddr + u.u_dsize;
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}
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