Sync with cat.c from netbsd-8

[minix3.git] / minix / servers / vfs / misc.c

/* This file contains a collection of miscellaneous procedures.  Some of them
 * perform simple system calls.  Some others do a little part of system calls
 * that are mostly performed by the Memory Manager.
 *
 * The entry points into this file are
 *   do_fcntl:    perform the FCNTL system call
 *   do_sync:     perform the SYNC system call
 *   do_fsync:    perform the FSYNC system call
 *   pm_setsid:   perform VFS's side of setsid system call
 *   pm_reboot:   sync disks and prepare for shutdown
 *   pm_fork:     adjust the tables after PM has performed a FORK system call
 *   do_exec:     handle files with FD_CLOEXEC on after PM has done an EXEC
 *   do_exit:     a process has exited; note that in the tables
 *   do_set:      set uid or gid for some process
 *   do_revive:   revive a process that was waiting for something (e.g. TTY)
 *   do_svrctl:   file system control
 *   do_getsysinfo:     request copy of FS data structure
 *   pm_dumpcore: create a core dump
 */

#include "fs.h"
#include <fcntl.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <minix/callnr.h>
#include <minix/safecopies.h>
#include <minix/endpoint.h>
#include <minix/com.h>
#include <minix/sysinfo.h>
#include <minix/u64.h>
#include <sys/ptrace.h>
#include <sys/svrctl.h>
#include <sys/resource.h>
#include "file.h"
#include <minix/vfsif.h>
#include "vnode.h"
#include "vmnt.h"

#define CORE_NAME       "core"
#define CORE_MODE       0777    /* mode to use on core image files */

#if ENABLE_SYSCALL_STATS
unsigned long calls_stats[NR_VFS_CALLS];
#endif

static void free_proc(int flags);

/*===========================================================================*
 *                              do_getsysinfo                                *
 *===========================================================================*/
int do_getsysinfo(void)
{
  struct fproc *rfp;
  struct fproc_light *rfpl;
  struct smap *sp;
  vir_bytes src_addr, dst_addr;
  size_t len, buf_size;
  int what;

  what = job_m_in.m_lsys_getsysinfo.what;
  dst_addr = job_m_in.m_lsys_getsysinfo.where;
  buf_size = job_m_in.m_lsys_getsysinfo.size;

  /* Only su may call do_getsysinfo. This call may leak information (and is not
   * stable enough to be part of the API/ABI). In the future, requests from
   * non-system processes should be denied.
   */

  if (!super_user) return(EPERM);

  switch(what) {
    case SI_PROC_TAB:
        src_addr = (vir_bytes) fproc;
        len = sizeof(struct fproc) * NR_PROCS;
        break;
    case SI_DMAP_TAB:
        src_addr = (vir_bytes) dmap;
        len = sizeof(struct dmap) * NR_DEVICES;
        break;
    case SI_PROCLIGHT_TAB:
        /* Fill the light process table for the MIB service upon request. */
        rfpl = &fproc_light[0];
        for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++, rfpl++) {
                rfpl->fpl_tty = rfp->fp_tty;
                rfpl->fpl_blocked_on = rfp->fp_blocked_on;
                if (rfp->fp_blocked_on == FP_BLOCKED_ON_CDEV)
                        rfpl->fpl_task = rfp->fp_cdev.endpt;
                else if (rfp->fp_blocked_on == FP_BLOCKED_ON_SDEV &&
                    (sp = get_smap_by_dev(rfp->fp_sdev.dev, NULL)) != NULL)
                        rfpl->fpl_task = sp->smap_endpt;
                else
                        rfpl->fpl_task = NONE;
        }
        src_addr = (vir_bytes) fproc_light;
        len = sizeof(fproc_light);
        break;
#if ENABLE_SYSCALL_STATS
    case SI_CALL_STATS:
        src_addr = (vir_bytes) calls_stats;
        len = sizeof(calls_stats);
        break;
#endif
    default:
        return(EINVAL);
  }

  if (len != buf_size)
        return(EINVAL);

  return sys_datacopy_wrapper(SELF, src_addr, who_e, dst_addr, len);
}

/*===========================================================================*
 *                              do_fcntl                                     *
 *===========================================================================*/
int do_fcntl(void)
{
/* Perform the fcntl(fd, cmd, ...) system call. */
  struct filp *f;
  int fd, new_fd, fl, r = OK, fcntl_req, fcntl_argx;
  vir_bytes addr;
  tll_access_t locktype;

  fd = job_m_in.m_lc_vfs_fcntl.fd;
  fcntl_req = job_m_in.m_lc_vfs_fcntl.cmd;
  fcntl_argx = job_m_in.m_lc_vfs_fcntl.arg_int;
  addr = job_m_in.m_lc_vfs_fcntl.arg_ptr;

  /* Is the file descriptor valid? */
  locktype = (fcntl_req == F_FREESP) ? VNODE_WRITE : VNODE_READ;
  if ((f = get_filp(fd, locktype)) == NULL)
        return(err_code);

  switch (fcntl_req) {
    case F_DUPFD:
    case F_DUPFD_CLOEXEC:
        /* This replaces the old dup() system call. */
        if (fcntl_argx < 0 || fcntl_argx >= OPEN_MAX) r = EINVAL;
        else if ((r = get_fd(fp, fcntl_argx, 0, &new_fd, NULL)) == OK) {
                f->filp_count++;
                fp->fp_filp[new_fd] = f;
                assert(!FD_ISSET(new_fd, &fp->fp_cloexec_set));
                if (fcntl_req == F_DUPFD_CLOEXEC)
                        FD_SET(new_fd, &fp->fp_cloexec_set);
                r = new_fd;
        }
        break;

    case F_GETFD:
        /* Get close-on-exec flag (FD_CLOEXEC in POSIX Table 6-2). */
        r = 0;
        if (FD_ISSET(fd, &fp->fp_cloexec_set))
                r = FD_CLOEXEC;
        break;

    case F_SETFD:
        /* Set close-on-exec flag (FD_CLOEXEC in POSIX Table 6-2). */
        if (fcntl_argx & FD_CLOEXEC)
                FD_SET(fd, &fp->fp_cloexec_set);
        else
                FD_CLR(fd, &fp->fp_cloexec_set);
        break;

    case F_GETFL:
        /* Get file status flags (O_NONBLOCK and O_APPEND). */
        fl = f->filp_flags & (O_NONBLOCK | O_APPEND | O_ACCMODE);
        r = fl;
        break;

    case F_SETFL:
        /* Set file status flags (O_NONBLOCK and O_APPEND). */
        fl = O_NONBLOCK | O_APPEND;
        f->filp_flags = (f->filp_flags & ~fl) | (fcntl_argx & fl);
        break;

    case F_GETLK:
    case F_SETLK:
    case F_SETLKW:
        /* Set or clear a file lock. */
        r = lock_op(fd, fcntl_req, addr);
        break;

    case F_FREESP:
     {
        /* Free a section of a file */
        off_t start, end, offset;
        struct flock flock_arg;

        /* Check if it's a regular file. */
        if (!S_ISREG(f->filp_vno->v_mode)) r = EINVAL;
        else if (!(f->filp_mode & W_BIT)) r = EBADF;
        else {
                /* Copy flock data from userspace. */
                r = sys_datacopy_wrapper(who_e, addr, SELF,
                    (vir_bytes)&flock_arg, sizeof(flock_arg));
        }

        if (r != OK) break;

        /* Convert starting offset to signed. */
        offset = (off_t) flock_arg.l_start;

        /* Figure out starting position base. */
        switch(flock_arg.l_whence) {
          case SEEK_SET: start = 0; break;
          case SEEK_CUR: start = f->filp_pos; break;
          case SEEK_END: start = f->filp_vno->v_size; break;
          default: r = EINVAL;
        }
        if (r != OK) break;

        /* Check for overflow or underflow. */
        if (offset > 0 && start + offset < start) r = EINVAL;
        else if (offset < 0 && start + offset > start) r = EINVAL;
        else {
                start += offset;
                if (start < 0) r = EINVAL;
        }
        if (r != OK) break;

        if (flock_arg.l_len != 0) {
                if (start >= f->filp_vno->v_size) r = EINVAL;
                else if ((end = start + flock_arg.l_len) <= start) r = EINVAL;
                else if (end > f->filp_vno->v_size) end = f->filp_vno->v_size;
        } else {
                end = 0;
        }
        if (r != OK) break;

        r = req_ftrunc(f->filp_vno->v_fs_e, f->filp_vno->v_inode_nr,start,end);

        if (r == OK && flock_arg.l_len == 0)
                f->filp_vno->v_size = start;

        break;
     }
    case F_GETNOSIGPIPE:
        r = !!(f->filp_flags & O_NOSIGPIPE);
        break;
    case F_SETNOSIGPIPE:
        if (fcntl_argx)
                f->filp_flags |= O_NOSIGPIPE;
        else
                f->filp_flags &= ~O_NOSIGPIPE;
        break;
    case F_FLUSH_FS_CACHE:
    {
        struct vnode *vn = f->filp_vno;
        mode_t mode = f->filp_vno->v_mode;
        if (!super_user) {
                r = EPERM;
        } else if (S_ISBLK(mode)) {
                /* Block device; flush corresponding device blocks. */
                r = req_flush(vn->v_bfs_e, vn->v_sdev);
        } else if (S_ISREG(mode) || S_ISDIR(mode)) {
                /* Directory or regular file; flush hosting FS blocks. */
                r = req_flush(vn->v_fs_e, vn->v_dev);
        } else {
                /* Remaining cases.. Meaning unclear. */
                r = ENODEV;
        }
        break;
    }
    default:
        r = EINVAL;
  }

  unlock_filp(f);
  return(r);
}

/*===========================================================================*
 *                              do_sync                                      *
 *===========================================================================*/
int do_sync(void)
{
  struct vmnt *vmp;
  int r = OK;

  for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
        if ((r = lock_vmnt(vmp, VMNT_READ)) != OK)
                break;
        if (vmp->m_dev != NO_DEV && vmp->m_fs_e != NONE &&
                 vmp->m_root_node != NULL) {
                req_sync(vmp->m_fs_e);
        }
        unlock_vmnt(vmp);
  }

  return(r);
}

/*===========================================================================*
 *                              do_fsync                                     *
 *===========================================================================*/
int do_fsync(void)
{
/* Perform the fsync() system call. */
  struct filp *rfilp;
  struct vmnt *vmp;
  dev_t dev;
  int fd, r = OK;

  fd = job_m_in.m_lc_vfs_fsync.fd;

  if ((rfilp = get_filp(fd, VNODE_READ)) == NULL)
        return(err_code);

  dev = rfilp->filp_vno->v_dev;
  unlock_filp(rfilp);

  for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) {
        if (vmp->m_dev != dev) continue;
        if ((r = lock_vmnt(vmp, VMNT_READ)) != OK)
                break;
        if (vmp->m_dev != NO_DEV && vmp->m_dev == dev &&
                vmp->m_fs_e != NONE && vmp->m_root_node != NULL) {

                req_sync(vmp->m_fs_e);
        }
        unlock_vmnt(vmp);
  }

  return(r);
}

int dupvm(struct fproc *rfp, int pfd, int *vmfd, struct filp **newfilp)
{
        int result, procfd;
        struct filp *f = NULL;
        struct fproc *vmf = fproc_addr(VM_PROC_NR);

        *newfilp = NULL;

        if ((f = get_filp2(rfp, pfd, VNODE_READ)) == NULL) {
                printf("VFS dupvm: get_filp2 failed\n");
                return EBADF;
        }

        if(!(f->filp_vno->v_vmnt->m_fs_flags & RES_HASPEEK)) {
                unlock_filp(f);
#if 0   /* Noisy diagnostic for mmap() by ld.so */
                printf("VFS dupvm: no peek available\n");
#endif
                return EINVAL;
        }

        assert(f->filp_vno);
        assert(f->filp_vno->v_vmnt);

        if (!S_ISREG(f->filp_vno->v_mode) && !S_ISBLK(f->filp_vno->v_mode)) {
                printf("VFS: mmap regular/blockdev only; dev 0x%llx ino %llu has mode 0%o\n",
                        f->filp_vno->v_dev, f->filp_vno->v_inode_nr, f->filp_vno->v_mode);
                unlock_filp(f);
                return EINVAL;
        }

        /* get free FD in VM */
        if((result=get_fd(vmf, 0, 0, &procfd, NULL)) != OK) {
                unlock_filp(f);
                printf("VFS dupvm: getfd failed\n");
                return result;
        }

        *vmfd = procfd;

        f->filp_count++;
        assert(f->filp_count > 0);
        vmf->fp_filp[procfd] = f;

        *newfilp = f;

        return OK;
}

/*===========================================================================*
 *                              do_vm_call                                   *
 *===========================================================================*/
int do_vm_call(void)
{
/* A call that VM does to VFS.
 * We must reply with the fixed type VM_VFS_REPLY (and put our result info
 * in the rest of the message) so VM can tell the difference between a
 * request from VFS and a reply to this call.
 */
        int req = job_m_in.VFS_VMCALL_REQ;
        int req_fd = job_m_in.VFS_VMCALL_FD;
        u32_t req_id = job_m_in.VFS_VMCALL_REQID;
        endpoint_t ep = job_m_in.VFS_VMCALL_ENDPOINT;
        u64_t offset = job_m_in.VFS_VMCALL_OFFSET;
        u32_t length = job_m_in.VFS_VMCALL_LENGTH;
        int result = OK;
        int slot;
        struct fproc *rfp;
#if !defined(NDEBUG)
        struct fproc *vmf;
#endif /* !defined(NDEBUG) */
        struct filp *f = NULL;
        int r;

        if(job_m_in.m_source != VM_PROC_NR)
                return ENOSYS;

        if(isokendpt(ep, &slot) != OK) rfp = NULL;
        else rfp = &fproc[slot];

#if !defined(NDEBUG)
        vmf = fproc_addr(VM_PROC_NR);
#endif /* !defined(NDEBUG) */
        assert(fp == vmf);
        assert(rfp != vmf);

        switch(req) {
                case VMVFSREQ_FDLOOKUP:
                {
                        int procfd;

                        /* Lookup fd in referenced process. */

                        if(!rfp) {
                                printf("VFS: why isn't ep %d here?!\n", ep);
                                result = ESRCH;
                                goto reqdone;
                        }

                        if((result = dupvm(rfp, req_fd, &procfd, &f)) != OK) {
#if 0   /* Noisy diagnostic for mmap() by ld.so */
                                printf("vfs: dupvm failed\n");
#endif
                                goto reqdone;
                        }

                        if(S_ISBLK(f->filp_vno->v_mode)) {
                                assert(f->filp_vno->v_sdev != NO_DEV);
                                job_m_out.VMV_DEV = f->filp_vno->v_sdev;
                                job_m_out.VMV_INO = VMC_NO_INODE;
                                job_m_out.VMV_SIZE_PAGES = LONG_MAX;
                        } else {
                                job_m_out.VMV_DEV = f->filp_vno->v_dev;
                                job_m_out.VMV_INO = f->filp_vno->v_inode_nr;
                                job_m_out.VMV_SIZE_PAGES =
                                        roundup(f->filp_vno->v_size,
                                                PAGE_SIZE)/PAGE_SIZE;
                        }

                        job_m_out.VMV_FD = procfd;

                        result = OK;

                        break;
                }
                case VMVFSREQ_FDCLOSE:
                {
                        result = close_fd(fp, req_fd, FALSE /*may_suspend*/);
                        if(result != OK) {
                                printf("VFS: VM fd close for fd %d, %d (%d)\n",
                                        req_fd, fp->fp_endpoint, result);
                        }
                        break;
                }
                case VMVFSREQ_FDIO:
                {
                        result = actual_lseek(fp, req_fd, SEEK_SET, offset,
                                NULL);

                        if(result == OK) {
                                result = actual_read_write_peek(fp, PEEKING,
                                        req_fd, /* vir_bytes */ 0, length);
                        }

                        break;
                }
                default:
                        panic("VFS: bad request code from VM\n");
                        break;
        }

reqdone:
        if(f)
                unlock_filp(f);

        /* fp is VM still. */
        assert(fp == vmf);
        job_m_out.VMV_ENDPOINT = ep;
        job_m_out.VMV_RESULT = result;
        job_m_out.VMV_REQID = req_id;

        /* Reply asynchronously as VM may not be able to receive
         * an ipc_sendnb() message.
         */
        job_m_out.m_type = VM_VFS_REPLY;
        r = asynsend3(VM_PROC_NR, &job_m_out, 0);
        if(r != OK) printf("VFS: couldn't asynsend3() to VM\n");

        /* VFS does not reply any further */
        return SUSPEND;
}

/*===========================================================================*
 *                              pm_reboot                                    *
 *===========================================================================*/
void
pm_reboot(void)
{
/* Perform the VFS side of the reboot call. This call is performed from the PM
 * process context.
 */
  message m_out;
  int i, r;
  struct fproc *rfp, *pmfp;

  pmfp = fp;

  do_sync();

  /* Do exit processing for all leftover processes and servers, but don't
   * actually exit them (if they were really gone, PM will tell us about it).
   * Skip processes that handle parts of the file system; we first need to give
   * them the chance to unmount (which should be possible as all normal
   * processes have no open files anymore).
   */
  /* This is the only place where we allow special modification of "fp". The
   * reboot procedure should really be implemented as a PM message broadcasted
   * to all processes, so that each process will be shut down cleanly by a
   * thread operating on its behalf. Doing everything here is simpler, but it
   * requires an exception to the strict model of having "fp" be the process
   * that owns the current worker thread.
   */
  for (i = 0; i < NR_PROCS; i++) {
        rfp = &fproc[i];

        /* Don't just free the proc right away, but let it finish what it was
         * doing first */
        if (rfp != fp) lock_proc(rfp);
        if (rfp->fp_endpoint != NONE && find_vmnt(rfp->fp_endpoint) == NULL) {
                worker_set_proc(rfp);   /* temporarily fake process context */
                free_proc(0);
                worker_set_proc(pmfp);  /* restore original process context */
        }
        if (rfp != fp) unlock_proc(rfp);
  }

  do_sync();
  unmount_all(0 /* Don't force */);

  /* Try to exit all processes again including File Servers */
  for (i = 0; i < NR_PROCS; i++) {
        rfp = &fproc[i];

        /* Don't just free the proc right away, but let it finish what it was
         * doing first */
        if (rfp != fp) lock_proc(rfp);
        if (rfp->fp_endpoint != NONE) {
                worker_set_proc(rfp);   /* temporarily fake process context */
                free_proc(0);
                worker_set_proc(pmfp);  /* restore original process context */
        }
        if (rfp != fp) unlock_proc(rfp);
  }

  do_sync();
  unmount_all(1 /* Force */);

  /* Reply to PM for synchronization */
  memset(&m_out, 0, sizeof(m_out));

  m_out.m_type = VFS_PM_REBOOT_REPLY;

  if ((r = ipc_send(PM_PROC_NR, &m_out)) != OK)
        panic("pm_reboot: ipc_send failed: %d", r);
}

/*===========================================================================*
 *                              pm_fork                                      *
 *===========================================================================*/
void pm_fork(endpoint_t pproc, endpoint_t cproc, pid_t cpid)
{
/* Perform those aspects of the fork() system call that relate to files.
 * In particular, let the child inherit its parent's file descriptors.
 * The parent and child parameters tell who forked off whom. The file
 * system uses the same slot numbers as the kernel.  Only PM makes this call.
 */
  struct fproc *cp;
#if !defined(NDEBUG)
  struct fproc *pp;
#endif /* !defined(NDEBUG) */
  int i, parentno, childno;
  mutex_t c_fp_lock;

  /* Check up-to-dateness of fproc. */
  okendpt(pproc, &parentno);

  /* PM gives child endpoint, which implies process slot information.
   * Don't call isokendpt, because that will verify if the endpoint
   * number is correct in fproc, which it won't be.
   */
  childno = _ENDPOINT_P(cproc);
  if (childno < 0 || childno >= NR_PROCS)
        panic("VFS: bogus child for forking: %d", cproc);
  if (fproc[childno].fp_pid != PID_FREE)
        panic("VFS: forking on top of in-use child: %d", childno);

  /* Copy the parent's fproc struct to the child. */
  /* However, the mutex variables belong to a slot and must stay the same. */
  c_fp_lock = fproc[childno].fp_lock;
  fproc[childno] = fproc[parentno];
  fproc[childno].fp_lock = c_fp_lock;

  /* Increase the counters in the 'filp' table. */
  cp = &fproc[childno];
#if !defined(NDEBUG)
  pp = &fproc[parentno];
#endif /* !defined(NDEBUG) */

  for (i = 0; i < OPEN_MAX; i++)
        if (cp->fp_filp[i] != NULL) cp->fp_filp[i]->filp_count++;

  /* Fill in new process and endpoint id. */
  cp->fp_pid = cpid;
  cp->fp_endpoint = cproc;

#if !defined(NDEBUG)
  /* A forking process cannot possibly be suspended on anything. */
  assert(pp->fp_blocked_on == FP_BLOCKED_ON_NONE);
#endif /* !defined(NDEBUG) */

  /* A child is not a process leader, not being revived, etc. */
  cp->fp_flags = FP_NOFLAGS;

  /* Record the fact that both root and working dir have another user. */
  if (cp->fp_rd) dup_vnode(cp->fp_rd);
  if (cp->fp_wd) dup_vnode(cp->fp_wd);
}

/*===========================================================================*
 *                              free_proc                                    *
 *===========================================================================*/
static void free_proc(int flags)
{
  int i;
  register struct fproc *rfp;
  register struct filp *rfilp;
  register struct vnode *vp;
  dev_t dev;

  if (fp->fp_endpoint == NONE)
        panic("free_proc: already free");

  if (fp_is_blocked(fp))
        unpause();

  /* Loop on file descriptors, closing any that are open. */
  for (i = 0; i < OPEN_MAX; i++) {
        (void) close_fd(fp, i, FALSE /*may_suspend*/);
  }

  /* Release root and working directories. */
  if (fp->fp_rd) { put_vnode(fp->fp_rd); fp->fp_rd = NULL; }
  if (fp->fp_wd) { put_vnode(fp->fp_wd); fp->fp_wd = NULL; }

  /* The rest of these actions is only done when processes actually exit. */
  if (!(flags & FP_EXITING)) return;

  fp->fp_flags |= FP_EXITING;

  /* Check if any process is SUSPENDed on this driver.
   * If a driver exits, unmap its entries in the dmap table.
   * (unmapping has to be done after the first step, because the
   * dmap/smap tables are used in the first step.)
   */
  unsuspend_by_endpt(fp->fp_endpoint);
  dmap_unmap_by_endpt(fp->fp_endpoint);
  smap_unmap_by_endpt(fp->fp_endpoint);

  worker_stop_by_endpt(fp->fp_endpoint); /* Unblock waiting threads */
  vmnt_unmap_by_endpt(fp->fp_endpoint); /* Invalidate open files if this
                                             * was an active FS */

  /* If a session leader exits and it has a controlling tty, then revoke
   * access to its controlling tty from all other processes using it.
   */
  if ((fp->fp_flags & FP_SESLDR) && fp->fp_tty != 0) {
      dev = fp->fp_tty;
      for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
          if(rfp->fp_pid == PID_FREE) continue;
          if (rfp->fp_tty == dev) rfp->fp_tty = 0;

          for (i = 0; i < OPEN_MAX; i++) {
                if ((rfilp = rfp->fp_filp[i]) == NULL) continue;
                if (rfilp->filp_mode == FILP_CLOSED) continue;
                vp = rfilp->filp_vno;
                if (!S_ISCHR(vp->v_mode)) continue;
                if (vp->v_sdev != dev) continue;
                lock_filp(rfilp, VNODE_READ);
                (void) cdev_close(dev); /* Ignore any errors. */
                /* FIXME: missing select check */
                rfilp->filp_mode = FILP_CLOSED;
                unlock_filp(rfilp);
          }
      }
  }

  /* Exit done. Mark slot as free. */
  fp->fp_endpoint = NONE;
  fp->fp_pid = PID_FREE;
  fp->fp_flags = FP_NOFLAGS;
}

/*===========================================================================*
 *                              pm_exit                                      *
 *===========================================================================*/
void pm_exit(void)
{
/* Perform the file system portion of the exit(status) system call.
 * This function is called from the context of the exiting process.
 */

  free_proc(FP_EXITING);
}

/*===========================================================================*
 *                              pm_setgid                                    *
 *===========================================================================*/
void
pm_setgid(endpoint_t proc_e, int egid, int rgid)
{
  register struct fproc *tfp;
  int slot;

  okendpt(proc_e, &slot);
  tfp = &fproc[slot];

  tfp->fp_effgid =  egid;
  tfp->fp_realgid = rgid;
}


/*===========================================================================*
 *                              pm_setgroups                                 *
 *===========================================================================*/
void
pm_setgroups(endpoint_t proc_e, int ngroups, gid_t *groups)
{
  struct fproc *rfp;
  int slot;

  okendpt(proc_e, &slot);
  rfp = &fproc[slot];
  if (ngroups * sizeof(gid_t) > sizeof(rfp->fp_sgroups))
        panic("VFS: pm_setgroups: too much data to copy");
  if (sys_datacopy_wrapper(who_e, (vir_bytes) groups, SELF, (vir_bytes) rfp->fp_sgroups,
                   ngroups * sizeof(gid_t)) == OK) {
        rfp->fp_ngroups = ngroups;
  } else
        panic("VFS: pm_setgroups: datacopy failed");
}


/*===========================================================================*
 *                              pm_setuid                                    *
 *===========================================================================*/
void
pm_setuid(endpoint_t proc_e, int euid, int ruid)
{
  struct fproc *tfp;
  int slot;

  okendpt(proc_e, &slot);
  tfp = &fproc[slot];

  tfp->fp_effuid =  euid;
  tfp->fp_realuid = ruid;
}

/*===========================================================================*
 *                              pm_setsid                                    *
 *===========================================================================*/
void pm_setsid(endpoint_t proc_e)
{
/* Perform the VFS side of the SETSID call, i.e. get rid of the controlling
 * terminal of a process, and make the process a session leader.
 */
  struct fproc *rfp;
  int slot;

  /* Make the process a session leader with no controlling tty. */
  okendpt(proc_e, &slot);
  rfp = &fproc[slot];
  rfp->fp_flags |= FP_SESLDR;
  rfp->fp_tty = 0;
}

/*===========================================================================*
 *                              do_svrctl                                    *
 *===========================================================================*/
int do_svrctl(void)
{
  unsigned long svrctl;
  vir_bytes ptr;

  svrctl = job_m_in.m_lc_svrctl.request;
  ptr = job_m_in.m_lc_svrctl.arg;

  if (IOCGROUP(svrctl) != 'F') return(EINVAL);

  switch (svrctl) {
    case VFSSETPARAM:
    case VFSGETPARAM:
        {
                struct sysgetenv sysgetenv;
                char search_key[64];
                char val[64];
                int r, s;

                /* Copy sysgetenv structure to VFS */
                if (sys_datacopy_wrapper(who_e, ptr, SELF, (vir_bytes) &sysgetenv,
                                 sizeof(sysgetenv)) != OK)
                        return(EFAULT);

                /* Basic sanity checking */
                if (svrctl == VFSSETPARAM) {
                        if (sysgetenv.keylen <= 0 ||
                            sysgetenv.keylen > (sizeof(search_key) - 1) ||
                            sysgetenv.vallen <= 0 ||
                            sysgetenv.vallen >= sizeof(val)) {
                                return(EINVAL);
                        }
                }

                /* Copy parameter "key" */
                if ((s = sys_datacopy_wrapper(who_e, (vir_bytes) sysgetenv.key,
                                      SELF, (vir_bytes) search_key,
                                      sysgetenv.keylen)) != OK)
                        return(s);
                search_key[sysgetenv.keylen] = '\0'; /* Limit string */

                /* Is it a parameter we know? */
                if (svrctl == VFSSETPARAM) {
                        if (!strcmp(search_key, "verbose")) {
                                int verbose_val;
                                if ((s = sys_datacopy_wrapper(who_e,
                                    (vir_bytes) sysgetenv.val, SELF,
                                    (vir_bytes) &val, sysgetenv.vallen)) != OK)
                                        return(s);
                                val[sysgetenv.vallen] = '\0'; /* Limit string */
                                verbose_val = atoi(val);
                                if (verbose_val < 0 || verbose_val > 4) {
                                        return(EINVAL);
                                }
                                verbose = verbose_val;
                                r = OK;
                        } else {
                                r = ESRCH;
                        }
                } else { /* VFSGETPARAM */
                        char small_buf[60];

                        r = ESRCH;
                        if (!strcmp(search_key, "print_traces")) {
                                mthread_stacktraces();
                                sysgetenv.val = 0;
                                sysgetenv.vallen = 0;
                                r = OK;
                        } else if (!strcmp(search_key, "print_select")) {
                                select_dump();
                                sysgetenv.val = 0;
                                sysgetenv.vallen = 0;
                                r = OK;
                        } else if (!strcmp(search_key, "active_threads")) {
                                int active = NR_WTHREADS - worker_available();
                                snprintf(small_buf, sizeof(small_buf) - 1,
                                         "%d", active);
                                sysgetenv.vallen = strlen(small_buf);
                                r = OK;
                        }

                        if (r == OK) {
                                if ((s = sys_datacopy_wrapper(SELF,
                                    (vir_bytes) &sysgetenv, who_e, ptr,
                                    sizeof(sysgetenv))) != OK)
                                        return(s);
                                if (sysgetenv.val != 0) {
                                        if ((s = sys_datacopy_wrapper(SELF,
                                            (vir_bytes) small_buf, who_e,
                                            (vir_bytes) sysgetenv.val,
                                            sysgetenv.vallen)) != OK)
                                                return(s);
                                }
                        }
                }

                return(r);
        }
    default:
        return(EINVAL);
  }
}

/*===========================================================================*
 *                              pm_dumpcore                                  *
 *===========================================================================*/
int pm_dumpcore(int csig, vir_bytes exe_name)
{
  int r, core_fd;
  struct filp *f;
  char core_path[PATH_MAX];
  char proc_name[PROC_NAME_LEN];

  /* In effect, the coredump is generated through the use of calls as if made
   * by the process itself.  As such, the process must not be doing anything
   * else.  Therefore, if the process was blocked on anything, unblock it
   * first.  This step is the reason we cannot use this function to generate a
   * core dump of a process while it is still running (i.e., without
   * terminating it), as it changes the state of the process.
   */
  if (fp_is_blocked(fp))
          unpause();

  /* open core file */
  snprintf(core_path, PATH_MAX, "%s.%d", CORE_NAME, fp->fp_pid);
  r = core_fd = common_open(core_path, O_WRONLY | O_CREAT | O_TRUNC,
        CORE_MODE, FALSE /*for_exec*/);
  if (r < 0) goto core_exit;

  /* get process name */
  r = sys_datacopy_wrapper(PM_PROC_NR, exe_name, VFS_PROC_NR,
        (vir_bytes) proc_name, PROC_NAME_LEN);
  if (r != OK) goto core_exit;
  proc_name[PROC_NAME_LEN - 1] = '\0';

  /* write the core dump */
  f = get_filp(core_fd, VNODE_WRITE);
  assert(f != NULL);
  write_elf_core_file(f, csig, proc_name);
  unlock_filp(f);

core_exit:
  /* The core file descriptor will be closed as part of the process exit. */
  free_proc(FP_EXITING);

  return(r);
}

/*===========================================================================*
 *                               ds_event                                    *
 *===========================================================================*/
void
ds_event(void)
{
  char key[DS_MAX_KEYLEN];
  char *blkdrv_prefix = "drv.blk.";
  char *chrdrv_prefix = "drv.chr.";
  char *sckdrv_prefix = "drv.sck.";
  u32_t value;
  int type, ftype, r;
  endpoint_t owner_endpoint;

  /* Get the event and the owner from DS. */
  while ((r = ds_check(key, &type, &owner_endpoint)) == OK) {
        /* Only check for block, character, socket driver up events. */
        if (!strncmp(key, blkdrv_prefix, strlen(blkdrv_prefix))) {
                ftype = S_IFBLK;
        } else if (!strncmp(key, chrdrv_prefix, strlen(chrdrv_prefix))) {
                ftype = S_IFCHR;
        } else if (!strncmp(key, sckdrv_prefix, strlen(sckdrv_prefix))) {
                ftype = S_IFSOCK;
        } else {
                continue;
        }

        if ((r = ds_retrieve_u32(key, &value)) != OK) {
                printf("VFS: ds_event: ds_retrieve_u32 failed\n");
                break;
        }
        if (value != DS_DRIVER_UP) continue;

        /* Perform up. */
        if (ftype == S_IFBLK || ftype == S_IFCHR)
                dmap_endpt_up(owner_endpoint, (ftype == S_IFBLK));
        else
                smap_endpt_up(owner_endpoint);
  }

  if (r != ENOENT) printf("VFS: ds_event: ds_check failed: %d\n", r);
}

/* A function to be called on panic(). */
void panic_hook(void)
{
  printf("VFS mthread stacktraces:\n");
  mthread_stacktraces();
}

/*===========================================================================*
 *                              do_getrusage                                 *
 *===========================================================================*/
int do_getrusage(void)
{
        /* Obsolete vfs_getrusage(2) call from userland. The getrusage call is
         * now fully handled by PM, and for any future fields that should be
         * supplied by VFS, VFS should be queried by PM rather than by the user
         * program directly.  TODO: remove this call after the next release.
         */
        return OK;
}