minix/lib/nbsd_libc/sys-minix/brk.c
Gianluca Guida 4f294c247f Add NBSDLibc Minix specific files.
This patch mainly copies and modifies files existing in
the current libc implementing minix specific functions.

To keep consisten with the NetBSD libc, we remove 
namespace stubs and we use "namespace.h" and weak
links.
2011-02-17 17:11:09 +00:00

34 lines
939 B
C

#include <sys/cdefs.h>
#include "namespace.h"
#include <lib.h>
#include <unistd.h>
#ifdef __weak_alias
__weak_alias(brk, _brk)
#endif
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)
void *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);
}