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phunix/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
* setreply: set the reply to be sent to process making an PM system call
*/
#include "pm.h"
#include <minix/keymap.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 <minix/crtso.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/resource.h>
#include <sys/utsname.h>
#include <string.h>
#include <machine/archtypes.h>
#include <env.h>
#include "mproc.h"
#include "param.h"
#include "kernel/const.h"
#include "kernel/config.h"
#include "kernel/proc.h"
#if ENABLE_SYSCALL_STATS
EXTERN unsigned long calls_stats[NCALLS];
#endif
static void sendreply(void);
static int get_nice_value(int queue);
static void handle_vfs_reply(void);
#define click_to_round_k(n) \
((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init_fresh(int type, sef_init_info_t *info);
static int sef_cb_signal_manager(endpoint_t target, int signo);
/*===========================================================================*
* main *
*===========================================================================*/
int main()
{
/* Main routine of the process manager. */
int result;
/* SEF local startup. */
sef_local_startup();
/* This is PM's main loop- get work and do it, forever and forever. */
while (TRUE) {
int ipc_status;
/* Wait for the next message and extract useful information from it. */
if (sef_receive_status(ANY, &m_in, &ipc_status) != OK)
panic("PM sef_receive_status error");
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);
call_nr = m_in.m_type; /* system call number */
/* Process slot of caller. Misuse PM's own process slot if the kernel is
* calling. This can happen in case of synchronous alarms (CLOCK) or or
* event like pending kernel signals (SYSTEM).
*/
mp = &mproc[who_p < 0 ? PM_PROC_NR : who_p];
if(who_p >= 0 && mp->mp_endpoint != who_e) {
panic("PM endpoint number out of sync with source: %d",
mp->mp_endpoint);
}
/* Drop delayed calls from exiting processes. */
if (mp->mp_flags & EXITING)
continue;
/* Check for system notifications first. Special cases. */
if (is_ipc_notify(ipc_status)) {
if (who_p == CLOCK) {
expire_timers(m_in.NOTIFY_TIMESTAMP);
}
/* done, send reply and continue */
sendreply();
continue;
}
switch(call_nr)
{
case PM_SETUID_REPLY:
case PM_SETGID_REPLY:
case PM_SETSID_REPLY:
case PM_EXEC_REPLY:
case PM_EXIT_REPLY:
case PM_CORE_REPLY:
case PM_FORK_REPLY:
case PM_SRV_FORK_REPLY:
case PM_UNPAUSE_REPLY:
case PM_REBOOT_REPLY:
case PM_SETGROUPS_REPLY:
if (who_e == VFS_PROC_NR)
{
handle_vfs_reply();
result= SUSPEND; /* don't reply */
}
else
result= ENOSYS;
break;
case COMMON_GETSYSINFO:
result = do_getsysinfo();
break;
default:
/* Else, if the system call number is valid, perform the
* call.
*/
if ((unsigned) call_nr >= NCALLS) {
result = ENOSYS;
} else {
#if ENABLE_SYSCALL_STATS
calls_stats[call_nr]++;
#endif
result = (*call_vec[call_nr])();
}
break;
}
/* Send reply. */
if (result != SUSPEND) setreply(who_p, result);
sendreply();
}
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(sef_cb_signal_manager);
/* 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.
* Memory use info is collected from the boot monitor, the kernel, and
* all processes compiled into the system image. Initially this information
* is put into an array mem_chunks. Elements of mem_chunks are struct memory,
* and hold base, size pairs in units of clicks. This array is small, there
* should be no more than 8 chunks. After the array of chunks has been built
* the contents are used to initialize the hole list. Space for the hole list
* is reserved as an array with twice as many elements as the maximum number
* of processes allowed. It is managed as a linked list, and elements of the
* array are struct hole, which, in addition to storage for a base and size in
* click units also contain space for a link, a pointer to another element.
*/
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 };
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 and the kernel info struct.
* Parse the list of free memory chunks. This list is what the boot monitor
* reported, but it must be corrected for the kernel and system processes.
*/
if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK)
panic("get monitor params failed: %d", s);
if ((s=sys_getkinfo(&kinfo)) != OK)
panic("get kernel info 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. */
mess.m_type = PM_INIT;
mess.PM_SLOT = ip->proc_nr;
mess.PM_PID = rmp->mp_pid;
mess.PM_PROC = rmp->mp_endpoint;
if (OK != (s=send(VFS_PROC_NR, &mess)))
panic("can't sync up with VFS: %d", s);
}
}
/* Tell VFS that no more system processes follow and synchronize. */
mess.PR_ENDPT = NONE;
if (sendrec(VFS_PROC_NR, &mess) != OK || mess.m_type != OK)
panic("can't sync up with VFS");
#if defined(__i386__)
uts_val.machine[0] = 'i';
strcpy(uts_val.machine + 1, itoa(getprocessor()));
#elif defined(__arm__)
strcpy(uts_val.machine, "arm");
#endif
system_hz = sys_hz();
/* Initialize user-space scheduling. */
sched_init();
return(OK);
}
/*===========================================================================*
* sef_cb_signal_manager *
*===========================================================================*/
static int sef_cb_signal_manager(endpoint_t target, int signo)
{
/* Process signal on behalf of the kernel. */
int r;
r = process_ksig(target, signo);
sendreply();
return r;
}
/*===========================================================================*
* setreply *
*===========================================================================*/
void setreply(proc_nr, result)
int proc_nr; /* process to reply to */
int result; /* result of call (usually OK or error #) */
{
/* Fill in a reply message to be sent later to a user process. System calls
* may occasionally fill in other fields, this is only for the main return
* value, and for setting the "must send reply" flag.
*/
register struct mproc *rmp = &mproc[proc_nr];
if(proc_nr < 0 || proc_nr >= NR_PROCS)
panic("setreply arg out of range: %d", proc_nr);
rmp->mp_reply.reply_res = result;
rmp->mp_flags |= REPLY; /* reply pending */
}
/*===========================================================================*
* sendreply *
*===========================================================================*/
static void sendreply()
{
int proc_nr;
int s;
struct mproc *rmp;
/* Send out all pending reply messages, including the answer to
* the call just made above.
*/
for (proc_nr=0, rmp=mproc; proc_nr < NR_PROCS; proc_nr++, rmp++) {
/* In the meantime, the process may have been killed by a
* signal (e.g. if a lethal pending signal was unblocked)
* without the PM realizing it. If the slot is no longer in
* use or the process is exiting, don't try to reply.
*/
if ((rmp->mp_flags & (REPLY | IN_USE | EXITING)) ==
(REPLY | IN_USE)) {
s=sendnb(rmp->mp_endpoint, &rmp->mp_reply);
if (s != OK) {
printf("PM can't reply to %d (%s): %d\n",
rmp->mp_endpoint, rmp->mp_name, s);
}
rmp->mp_flags &= ~REPLY;
}
}
}
/*===========================================================================*
* 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;
/* PM_REBOOT is the only request not associated with a process.
* Handle its reply first.
*/
if (call_nr == 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.PM_PROC;
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);
rmp->mp_flags &= ~VFS_CALL;
if (rmp->mp_flags & UNPAUSED)
panic("handle_vfs_reply: UNPAUSED set on entry: %d", call_nr);
/* Call-specific handler code */
switch (call_nr) {
case PM_SETUID_REPLY:
case PM_SETGID_REPLY:
case PM_SETGROUPS_REPLY:
/* Wake up the original caller */
setreply(rmp-mproc, OK);
break;
case PM_SETSID_REPLY:
/* Wake up the original caller */
setreply(rmp-mproc, rmp->mp_procgrp);
break;
case PM_EXEC_REPLY:
exec_restart(rmp, m_in.PM_STATUS, (vir_bytes)m_in.PM_PC,
(vir_bytes)m_in.PM_NEWSP);
break;
case PM_EXIT_REPLY:
exit_restart(rmp, FALSE /*dump_core*/);
break;
case PM_CORE_REPLY:
if (m_in.PM_STATUS == OK)
rmp->mp_sigstatus |= DUMPED;
if (m_in.PM_PROC == m_in.PM_TRACED_PROC)
/* The reply is to a core dump request
* for a killed process */
exit_restart(rmp, TRUE /*dump_core*/);
else
/* The reply is to a core dump request
* for a traced process (T_DUMPCORE) */
/* Wake up the original caller */
setreply(rmp-mproc, rmp->mp_procgrp);
break;
case 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 */
setreply(rmp->mp_parent, -1);
}
else {
/* Wake up the child */
setreply(proc_n, OK);
/* Wake up the parent */
setreply(rmp->mp_parent, rmp->mp_pid);
}
break;
case PM_SRV_FORK_REPLY:
/* Nothing to do */
break;
case PM_UNPAUSE_REPLY:
/* 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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