minix/lib/libc/sys-minix/shmat.c

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#define _SYSTEM 1
#define _MINIX_SYSTEM 1
#include <sys/cdefs.h>
#include <lib.h>
#include "namespace.h"
#include <minix/rs.h>
#include <lib.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
static int get_ipc_endpt(endpoint_t *pt)
{
return minix_rs_lookup("ipc", pt);
}
/* Attach shared memory segment. */
void *shmat(int shmid, const void *shmaddr, int shmflg)
{
message m;
endpoint_t ipc_pt;
int r;
if (get_ipc_endpt(&ipc_pt) != OK) {
errno = ENOSYS;
return NULL;
}
memset(&m, 0, sizeof(m));
m.SHMAT_ID = shmid;
m.SHMAT_ADDR = (long) shmaddr;
m.SHMAT_FLAG = shmflg;
r = _syscall(ipc_pt, IPC_SHMAT, &m);
if (r != OK)
return (void *) -1;
return (void *) m.SHMAT_RETADDR;
}
/* Deattach shared memory segment. */
int shmdt(const void *shmaddr)
{
message m;
endpoint_t ipc_pt;
if (get_ipc_endpt(&ipc_pt) != OK) {
errno = ENOSYS;
return -1;
}
memset(&m, 0, sizeof(m));
m.SHMDT_ADDR = (long) shmaddr;
return _syscall(ipc_pt, IPC_SHMDT, &m);
}