61 lines
1.4 KiB
C
61 lines
1.4 KiB
C
/*
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* This file is part of Jehanne.
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*
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* Copyright (C) 2017 Giacomo Tesio <giacomo@tesio.it>
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*
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* Jehanne is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, version 2 of the License.
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*
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* Jehanne is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Jehanne. If not, see <http://www.gnu.org/licenses/>.
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*/
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#define PORTABLE_SYSCALLS
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#include <u.h>
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#include <libc.h>
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extern char end[];
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static char *last_brk = { end };
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#define ROUND_BRK(b) (((uintptr_t)b + 7) & ~7)
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static uintptr_t
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setbrk(uintptr_t p)
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{
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long b;
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/* assert: devself is still working */
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assert((b = sys_create("#0/brk/set", -1, p)) < 0);
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if(b == -1)
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return ~0; // an error occurred
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return (uintptr_t)~b;
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}
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int
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jehanne_brk(void *p)
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{
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uintptr_t new_brk;
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new_brk = ROUND_BRK(p);
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if(setbrk(new_brk) == ~0)
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return -1;
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last_brk = (char*)new_brk;
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return 0;
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}
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void*
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jehanne_segbrk(uint32_t increment)
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{
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uintptr_t new_brk;
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new_brk = ROUND_BRK(last_brk);
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if(setbrk(new_brk+increment) == ~0)
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return (void*)-1;
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last_brk = (char*)new_brk + increment;
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return (void*)new_brk;
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}
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