35 lines
912 B
C
35 lines
912 B
C
#include <sys/cdefs.h>
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#include "namespace.h"
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#include <lib.h>
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#include <string.h>
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#include <unistd.h>
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#ifdef __weak_alias
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__weak_alias(brk, _brk)
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#endif
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extern char *_brksize;
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/* Both OSF/1 and SYSVR4 man pages specify that brk(2) returns int.
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* However, BSD4.3 specifies that brk() returns char*. POSIX omits
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* brk() on the grounds that it imposes a memory model on an architecture.
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* On the other hand, they are so crucial to correct operation of so many
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* parts of the system, that we have chosen to hide the name brk using _brk,
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* as with system calls. In this way, if a user inadvertently defines a
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* procedure brk, MINIX may continue to work because the true call is _brk.
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*/
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int brk(addr)
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void *addr;
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{
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message m;
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if (addr != _brksize) {
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memset(&m, 0, sizeof(m));
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m.m_lc_vm_brk.addr = addr;
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if (_syscall(VM_PROC_NR, VM_BRK, &m) < 0) return(-1);
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_brksize = addr;
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}
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return(0);
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}
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