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minix3/servers/pm/main.c

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/* This file contains the main program of the process manager and some related
* procedures. When MINIX starts up, the kernel runs for a little while,
* initializing itself and its tasks, and then it runs PM and VFS. Both PM
* and VFS initialize themselves as far as they can. PM asks the kernel for
* all free memory and starts serving requests.
*
* The entry points into this file are:
* main: starts PM running
* reply: send a reply to a process making a PM system call
*/
#include "pm.h"
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/ds.h>
#include <minix/type.h>
#include <minix/endpoint.h>
#include <minix/minlib.h>
#include <minix/type.h>
#include <minix/vm.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/resource.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <machine/archtypes.h>
#include <env.h>
#include <assert.h>
#include "mproc.h"
#include "kernel/const.h"
#include "kernel/config.h"
#include "kernel/proc.h"
#if ENABLE_SYSCALL_STATS
EXTERN unsigned long calls_stats[NR_PM_CALLS];
#endif
static int get_nice_value(int queue);
static void handle_vfs_reply(void);
/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init_fresh(int type, sef_init_info_t *info);
/*===========================================================================*
* main *
*===========================================================================*/
int main()
{
/* Main routine of the process manager. */
unsigned int call_index;
int ipc_status, result;
/* SEF local startup. */
sef_local_startup();
/* This is PM's main loop- get work and do it, forever and forever. */
while (TRUE) {
/* Wait for the next message. */
if (sef_receive_status(ANY, &m_in, &ipc_status) != OK)
panic("PM sef_receive_status error");
/* Check for system notifications first. Special cases. */
if (is_ipc_notify(ipc_status)) {
if (_ENDPOINT_P(m_in.m_source) == CLOCK)
expire_timers(m_in.m_notify.timestamp);
/* done, continue */
continue;
}
/* Extract useful information from the message. */
who_e = m_in.m_source; /* who sent the message */
if (pm_isokendpt(who_e, &who_p) != OK)
panic("PM got message from invalid endpoint: %d", who_e);
mp = &mproc[who_p]; /* process slot of caller */
call_nr = m_in.m_type; /* system call number */
/* Drop delayed calls from exiting processes. */
if (mp->mp_flags & EXITING)
continue;
if (IS_VFS_PM_RS(call_nr) && who_e == VFS_PROC_NR) {
handle_vfs_reply();
result = SUSPEND; /* don't reply */
} else if (IS_PM_CALL(call_nr)) {
/* If the system call number is valid, perform the call. */
call_index = (unsigned int) (call_nr - PM_BASE);
if (call_index < NR_PM_CALLS && call_vec[call_index] != NULL) {
#if ENABLE_SYSCALL_STATS
calls_stats[call_index]++;
#endif
result = (*call_vec[call_index])();
} else
result = ENOSYS;
} else
result = ENOSYS;
/* Send reply. */
if (result != SUSPEND) reply(who_p, result);
}
return(OK);
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
static void sef_local_startup()
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_fail);
/* No live update support for now. */
/* Register signal callbacks. */
sef_setcb_signal_manager(process_ksig);
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
static int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *UNUSED(info))
{
/* Initialize the process manager. */
int s;
static struct boot_image image[NR_BOOT_PROCS];
register struct boot_image *ip;
static char core_sigs[] = { SIGQUIT, SIGILL, SIGTRAP, SIGABRT,
SIGEMT, SIGFPE, SIGBUS, SIGSEGV };
static char ign_sigs[] = { SIGCHLD, SIGWINCH, SIGCONT, SIGINFO };
static char noign_sigs[] = { SIGILL, SIGTRAP, SIGEMT, SIGFPE,
SIGBUS, SIGSEGV };
register struct mproc *rmp;
register char *sig_ptr;
message mess;
/* Initialize process table, including timers. */
for (rmp=&mproc[0]; rmp<&mproc[NR_PROCS]; rmp++) {
init_timer(&rmp->mp_timer);
rmp->mp_magic = MP_MAGIC;
}
/* Build the set of signals which cause core dumps, and the set of signals
* that are by default ignored.
*/
sigemptyset(&core_sset);
for (sig_ptr = core_sigs; sig_ptr < core_sigs+sizeof(core_sigs); sig_ptr++)
sigaddset(&core_sset, *sig_ptr);
sigemptyset(&ign_sset);
for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++)
sigaddset(&ign_sset, *sig_ptr);
sigemptyset(&noign_sset);
for (sig_ptr = noign_sigs; sig_ptr < noign_sigs+sizeof(noign_sigs); sig_ptr++)
sigaddset(&noign_sset, *sig_ptr);
/* Obtain a copy of the boot monitor parameters.
*/
if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK)
panic("get monitor params failed: %d", s);
/* Initialize PM's process table. Request a copy of the system image table
* that is defined at the kernel level to see which slots to fill in.
*/
if (OK != (s=sys_getimage(image)))
panic("couldn't get image table: %d", s);
procs_in_use = 0; /* start populating table */
for (ip = &image[0]; ip < &image[NR_BOOT_PROCS]; ip++) {
if (ip->proc_nr >= 0) { /* task have negative nrs */
procs_in_use += 1; /* found user process */
/* Set process details found in the image table. */
rmp = &mproc[ip->proc_nr];
strlcpy(rmp->mp_name, ip->proc_name, PROC_NAME_LEN);
(void) sigemptyset(&rmp->mp_ignore);
(void) sigemptyset(&rmp->mp_sigmask);
(void) sigemptyset(&rmp->mp_catch);
if (ip->proc_nr == INIT_PROC_NR) { /* user process */
/* INIT is root, we make it father of itself. This is
* not really OK, INIT should have no father, i.e.
* a father with pid NO_PID. But PM currently assumes
* that mp_parent always points to a valid slot number.
*/
rmp->mp_parent = INIT_PROC_NR;
rmp->mp_procgrp = rmp->mp_pid = INIT_PID;
rmp->mp_flags |= IN_USE;
/* Set scheduling info */
rmp->mp_scheduler = KERNEL;
rmp->mp_nice = get_nice_value(USR_Q);
}
else { /* system process */
if(ip->proc_nr == RS_PROC_NR) {
rmp->mp_parent = INIT_PROC_NR;
}
else {
rmp->mp_parent = RS_PROC_NR;
}
rmp->mp_pid = get_free_pid();
rmp->mp_flags |= IN_USE | PRIV_PROC;
/* RS schedules this process */
rmp->mp_scheduler = NONE;
rmp->mp_nice = get_nice_value(SRV_Q);
}
/* Get kernel endpoint identifier. */
rmp->mp_endpoint = ip->endpoint;
/* Tell VFS about this system process. */
memset(&mess, 0, sizeof(mess));
mess.m_type = VFS_PM_INIT;
mess.VFS_PM_SLOT = ip->proc_nr;
mess.VFS_PM_PID = rmp->mp_pid;
mess.VFS_PM_ENDPT = rmp->mp_endpoint;
if (OK != (s=ipc_send(VFS_PROC_NR, &mess)))
panic("can't sync up with VFS: %d", s);
}
}
/* Tell VFS that no more system processes follow and synchronize. */
memset(&mess, 0, sizeof(mess));
mess.m_type = VFS_PM_INIT;
mess.VFS_PM_ENDPT = NONE;
if (ipc_sendrec(VFS_PROC_NR, &mess) != OK || mess.m_type != OK)
panic("can't sync up with VFS");
system_hz = sys_hz();
/* Initialize user-space scheduling. */
sched_init();
return(OK);
}
/*===========================================================================*
* reply *
*===========================================================================*/
void reply(proc_nr, result)
int proc_nr; /* process to reply to */
int result; /* result of call (usually OK or error #) */
{
/* Send a reply to a user process. System calls may occasionally fill in other
* fields, this is only for the main return value and for sending the reply.
*/
struct mproc *rmp;
int r;
if(proc_nr < 0 || proc_nr >= NR_PROCS)
panic("reply arg out of range: %d", proc_nr);
rmp = &mproc[proc_nr];
rmp->mp_reply.m_type = result;
if ((r = ipc_sendnb(rmp->mp_endpoint, &rmp->mp_reply)) != OK)
printf("PM can't reply to %d (%s): %d\n", rmp->mp_endpoint,
rmp->mp_name, r);
}
/*===========================================================================*
* get_nice_value *
*===========================================================================*/
static int get_nice_value(queue)
int queue; /* store mem chunks here */
{
/* Processes in the boot image have a priority assigned. The PM doesn't know
* about priorities, but uses 'nice' values instead. The priority is between
* MIN_USER_Q and MAX_USER_Q. We have to scale between PRIO_MIN and PRIO_MAX.
*/
int nice_val = (queue - USER_Q) * (PRIO_MAX-PRIO_MIN+1) /
(MIN_USER_Q-MAX_USER_Q+1);
if (nice_val > PRIO_MAX) nice_val = PRIO_MAX; /* shouldn't happen */
if (nice_val < PRIO_MIN) nice_val = PRIO_MIN; /* shouldn't happen */
return nice_val;
}
/*===========================================================================*
* handle_vfs_reply *
*===========================================================================*/
static void handle_vfs_reply()
{
struct mproc *rmp;
endpoint_t proc_e;
int r, proc_n, new_parent;
/* VFS_PM_REBOOT is the only request not associated with a process.
* Handle its reply first.
*/
if (call_nr == VFS_PM_REBOOT_REPLY) {
/* Ask the kernel to abort. All system services, including
* the PM, will get a HARD_STOP notification. Await the
* notification in the main loop.
*/
sys_abort(abort_flag);
return;
}
/* Get the process associated with this call */
proc_e = m_in.VFS_PM_ENDPT;
if (pm_isokendpt(proc_e, &proc_n) != OK) {
panic("handle_vfs_reply: got bad endpoint from VFS: %d", proc_e);
}
rmp = &mproc[proc_n];
/* Now that VFS replied, mark the process as VFS-idle again */
if (!(rmp->mp_flags & VFS_CALL))
panic("handle_vfs_reply: reply without request: %d", call_nr);
new_parent = rmp->mp_flags & NEW_PARENT;
rmp->mp_flags &= ~(VFS_CALL | NEW_PARENT);
if (rmp->mp_flags & UNPAUSED)
panic("handle_vfs_reply: UNPAUSED set on entry: %d", call_nr);
/* Call-specific handler code */
switch (call_nr) {
case VFS_PM_SETUID_REPLY:
case VFS_PM_SETGID_REPLY:
case VFS_PM_SETGROUPS_REPLY:
/* Wake up the original caller */
reply(rmp-mproc, OK);
break;
case VFS_PM_SETSID_REPLY:
/* Wake up the original caller */
reply(rmp-mproc, rmp->mp_procgrp);
break;
case VFS_PM_EXEC_REPLY:
exec_restart(rmp, m_in.VFS_PM_STATUS, (vir_bytes)m_in.VFS_PM_PC,
(vir_bytes)m_in.VFS_PM_NEWSP,
(vir_bytes)m_in.VFS_PM_NEWPS_STR);
break;
case VFS_PM_EXIT_REPLY:
exit_restart(rmp, FALSE /*dump_core*/);
break;
case VFS_PM_CORE_REPLY:
if (m_in.VFS_PM_STATUS == OK)
rmp->mp_sigstatus |= WCOREFLAG;
exit_restart(rmp, TRUE /*dump_core*/);
break;
case VFS_PM_FORK_REPLY:
/* Schedule the newly created process ... */
r = OK;
if (rmp->mp_scheduler != KERNEL && rmp->mp_scheduler != NONE) {
r = sched_start_user(rmp->mp_scheduler, rmp);
}
/* If scheduling the process failed, we want to tear down the process
* and fail the fork */
if (r != OK) {
/* Tear down the newly created process */
rmp->mp_scheduler = NONE; /* don't try to stop scheduling */
exit_proc(rmp, -1, FALSE /*dump_core*/);
/* Wake up the parent with a failed fork (unless dead) */
if (!new_parent)
reply(rmp->mp_parent, -1);
}
else {
/* Wake up the child */
reply(proc_n, OK);
/* Wake up the parent, unless the parent is already dead */
if (!new_parent)
reply(rmp->mp_parent, rmp->mp_pid);
}
break;
case VFS_PM_SRV_FORK_REPLY:
/* Nothing to do */
break;
case VFS_PM_UNPAUSE_REPLY:
/* The target process must always be stopped while unpausing; otherwise
* it could just end up pausing itself on a new call afterwards.
*/
assert(rmp->mp_flags & PROC_STOPPED);
/* Process is now unpaused */
rmp->mp_flags |= UNPAUSED;
break;
default:
panic("handle_vfs_reply: unknown reply code: %d", call_nr);
}
/* Now that the process is idle again, look at pending signals */
if ((rmp->mp_flags & (IN_USE | EXITING)) == IN_USE)
restart_sigs(rmp);
}
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