示例#1
0
void tst_shm2(void)
{
  int r;
  int shmid;

  syscall_wait(10);

  shmid=shm_lookup(SHRMEMNAME);
  display_puts("shm2 lookup=");
  sint2dec(shmid,s);
  display_puts(s);

  r=shm_map(shmid,(void*)SHRMEMADDR);
  display_puts(" shm2 map=");
  sint2dec(r,s);
  display_puts(s);
//  display_puts("\n");

  syscall_wait(50);
  syscall_mtx_lock((int*)SHRMEMADDR);
  memcpy(s,(void*)(SHRMEMADDR+sizeof(int)),4);
  syscall_mtx_unlock((int*)SHRMEMADDR);
  s[4]=0;
  display_puts(" shm2 shrstr=");
  display_puts(s);
//  display_puts("\n");

  r=shm_unmap(shmid);
  display_puts(" shm2 unmap=");
  sint2dec(r,s);
  display_puts(s);
  display_puts("\n");
}
示例#2
0
/* System calls. */
int
sys_shm_open(struct thread *td, struct shm_open_args *uap)
{
	struct filedesc *fdp;
	struct shmfd *shmfd;
	struct file *fp;
	char *path;
	Fnv32_t fnv;
	mode_t cmode;
	int fd, error;

#ifdef CAPABILITY_MODE
	/*
	 * shm_open(2) is only allowed for anonymous objects.
	 */
	if (IN_CAPABILITY_MODE(td) && (uap->path != SHM_ANON))
		return (ECAPMODE);
#endif

	if ((uap->flags & O_ACCMODE) != O_RDONLY &&
	    (uap->flags & O_ACCMODE) != O_RDWR)
		return (EINVAL);

	if ((uap->flags & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC)) != 0)
		return (EINVAL);

	fdp = td->td_proc->p_fd;
	cmode = (uap->mode & ~fdp->fd_cmask) & ACCESSPERMS;

	error = falloc(td, &fp, &fd, 0);
	if (error)
		return (error);

	/* A SHM_ANON path pointer creates an anonymous object. */
	if (uap->path == SHM_ANON) {
		/* A read-only anonymous object is pointless. */
		if ((uap->flags & O_ACCMODE) == O_RDONLY) {
			fdclose(fdp, fp, fd, td);
			fdrop(fp, td);
			return (EINVAL);
		}
		shmfd = shm_alloc(td->td_ucred, cmode);
	} else {
		path = malloc(MAXPATHLEN, M_SHMFD, M_WAITOK);
		error = copyinstr(uap->path, path, MAXPATHLEN, NULL);

		/* Require paths to start with a '/' character. */
		if (error == 0 && path[0] != '/')
			error = EINVAL;
		if (error) {
			fdclose(fdp, fp, fd, td);
			fdrop(fp, td);
			free(path, M_SHMFD);
			return (error);
		}

		fnv = fnv_32_str(path, FNV1_32_INIT);
		sx_xlock(&shm_dict_lock);
		shmfd = shm_lookup(path, fnv);
		if (shmfd == NULL) {
			/* Object does not yet exist, create it if requested. */
			if (uap->flags & O_CREAT) {
#ifdef MAC
				error = mac_posixshm_check_create(td->td_ucred,
				    path);
				if (error == 0) {
#endif
					shmfd = shm_alloc(td->td_ucred, cmode);
					shm_insert(path, fnv, shmfd);
#ifdef MAC
				}
#endif
			} else {
				free(path, M_SHMFD);
				error = ENOENT;
			}
		} else {
			/*
			 * Object already exists, obtain a new
			 * reference if requested and permitted.
			 */
			free(path, M_SHMFD);
			if ((uap->flags & (O_CREAT | O_EXCL)) ==
			    (O_CREAT | O_EXCL))
				error = EEXIST;
			else {
#ifdef MAC
				error = mac_posixshm_check_open(td->td_ucred,
				    shmfd, FFLAGS(uap->flags & O_ACCMODE));
				if (error == 0)
#endif
				error = shm_access(shmfd, td->td_ucred,
				    FFLAGS(uap->flags & O_ACCMODE));
			}

			/*
			 * Truncate the file back to zero length if
			 * O_TRUNC was specified and the object was
			 * opened with read/write.
			 */
			if (error == 0 &&
			    (uap->flags & (O_ACCMODE | O_TRUNC)) ==
			    (O_RDWR | O_TRUNC)) {
#ifdef MAC
				error = mac_posixshm_check_truncate(
					td->td_ucred, fp->f_cred, shmfd);
				if (error == 0)
#endif
					shm_dotruncate(shmfd, 0);
			}
			if (error == 0)
				shm_hold(shmfd);
		}
		sx_xunlock(&shm_dict_lock);

		if (error) {
			fdclose(fdp, fp, fd, td);
			fdrop(fp, td);
			return (error);
		}
	}

	finit(fp, FFLAGS(uap->flags & O_ACCMODE), DTYPE_SHM, shmfd, &shm_ops);

	FILEDESC_XLOCK(fdp);
	if (fdp->fd_ofiles[fd] == fp)
		fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
	FILEDESC_XUNLOCK(fdp);
	td->td_retval[0] = fd;
	fdrop(fp, td);

	return (0);
}
示例#3
0
int syscall_shm_lookup(unsigned int shmname)
{
  return shm_lookup(shmname);
}