30 lines
876 B
C
30 lines
876 B
C
#include <lib.h>
|
|
#define brk _brk
|
|
#define sbrk _sbrk
|
|
#include <unistd.h>
|
|
|
|
extern char *_brksize;
|
|
|
|
/* Both OSF/1 and SYSVR4 man pages specify that brk(2) returns int.
|
|
* However, BSD4.3 specifies that brk() returns char*. POSIX omits
|
|
* brk() on the grounds that it imposes a memory model on an architecture.
|
|
* For this reason, brk() and sbrk() are not in the lib/posix directory.
|
|
* On the other hand, they are so crucial to correct operation of so many
|
|
* parts of the system, that we have chosen to hide the name brk using _brk,
|
|
* as with system calls. In this way, if a user inadvertently defines a
|
|
* procedure brk, MINIX may continue to work because the true call is _brk.
|
|
*/
|
|
PUBLIC int brk(addr)
|
|
char *addr;
|
|
{
|
|
message m;
|
|
|
|
if (addr != _brksize) {
|
|
m.PMBRK_ADDR = addr;
|
|
if (_syscall(PM_PROC_NR, BRK, &m) < 0) return(-1);
|
|
_brksize = m.m2_p1;
|
|
}
|
|
return(0);
|
|
}
|
|
|