File: [local] / src / sys / sys / proc.h (download)
Revision 1.68, Sat Nov 8 06:11:11 2003 UTC (20 years, 7 months ago) by nordin
Branch: MAIN
CVS Tags: OPENBSD_3_5_BASE, OPENBSD_3_5 Changes since 1.67: +2 -1 lines
Avoid a race condition while swapping in a process.
Tested by mickey@, henning@, ericj@, and beck@.
ok mickey@
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/* $OpenBSD: proc.h,v 1.68 2003/11/08 06:11:11 nordin Exp $ */
/* $NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $ */
/*-
* Copyright (c) 1986, 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)proc.h 8.8 (Berkeley) 1/21/94
*/
#ifndef _SYS_PROC_H_
#define _SYS_PROC_H_
#include <machine/proc.h> /* Machine-dependent proc substruct. */
#include <sys/select.h> /* For struct selinfo. */
#include <sys/queue.h>
#include <sys/timeout.h> /* For struct timeout. */
#include <sys/event.h> /* For struct klist */
/*
* One structure allocated per session.
*/
struct session {
int s_count; /* Ref cnt; pgrps in session. */
struct proc *s_leader; /* Session leader. */
struct vnode *s_ttyvp; /* Vnode of controlling terminal. */
struct tty *s_ttyp; /* Controlling terminal. */
char s_login[MAXLOGNAME]; /* Setlogin() name. */
};
/*
* One structure allocated per process group.
*/
struct pgrp {
LIST_ENTRY(pgrp) pg_hash; /* Hash chain. */
LIST_HEAD(, proc) pg_members; /* Pointer to pgrp members. */
struct session *pg_session; /* Pointer to session. */
pid_t pg_id; /* Pgrp id. */
int pg_jobc; /* # procs qualifying pgrp for job control */
};
/*
* One structure allocated per emulation.
*/
struct exec_package;
struct ps_strings;
struct uvm_object;
union sigval;
struct emul {
char e_name[8]; /* Symbolic name */
int *e_errno; /* Errno array */
/* Signal sending function */
void (*e_sendsig)(sig_t, int, int, u_long, int, union sigval);
int e_nosys; /* Offset of the nosys() syscall */
int e_nsysent; /* Number of system call entries */
struct sysent *e_sysent; /* System call array */
char **e_syscallnames; /* System call name array */
int e_arglen; /* Extra argument size in words */
/* Copy arguments on the stack */
void *(*e_copyargs)(struct exec_package *, struct ps_strings *,
void *, void *);
/* Set registers before execution */
void (*e_setregs)(struct proc *, struct exec_package *,
u_long, register_t *);
int (*e_fixup)(struct proc *, struct exec_package *);
char *e_sigcode; /* Start of sigcode */
char *e_esigcode; /* End of sigcode */
int e_flags; /* Flags, see below */
struct uvm_object *e_sigobject; /* shared sigcode object */
/* Per-process hooks */
void (*e_proc_exec)(struct proc *, struct exec_package *);
void (*e_proc_fork)(struct proc *p, struct proc *parent);
void (*e_proc_exit)(struct proc *);
};
/* Flags for e_flags */
#define EMUL_ENABLED 0x0001 /* Allow exec to continue */
#define EMUL_NATIVE 0x0002 /* Always enabled */
extern struct emul *emulsw[]; /* All emuls in system */
extern int nemuls; /* Number of emuls */
/*
* Description of a process.
*
* This structure contains the information needed to manage a thread of
* control, known in UN*X as a process; it has references to substructures
* containing descriptions of things that the process uses, but may share
* with related processes. The process structure and the substructures
* are always addressable except for those marked "(PROC ONLY)" below,
* which might be addressable only on a processor on which the process
* is running.
*/
struct proc {
struct proc *p_forw; /* Doubly-linked run/sleep queue. */
struct proc *p_back;
LIST_ENTRY(proc) p_list; /* List of all processes. */
/* substructures: */
struct pcred *p_cred; /* Process owner's identity. */
struct filedesc *p_fd; /* Ptr to open files structure. */
struct pstats *p_stats; /* Accounting/statistics (PROC ONLY). */
struct plimit *p_limit; /* Process limits. */
struct vmspace *p_vmspace; /* Address space. */
struct sigacts *p_sigacts; /* Signal actions, state (PROC ONLY). */
#define p_ucred p_cred->pc_ucred
#define p_rlimit p_limit->pl_rlimit
int p_exitsig; /* Signal to send to parent on exit. */
int p_flag; /* P_* flags. */
u_char p_os; /* OS tag */
char p_stat; /* S* process status. */
char p_pad1[2];
pid_t p_pid; /* Process identifier. */
LIST_ENTRY(proc) p_hash; /* Hash chain. */
LIST_ENTRY(proc) p_pglist; /* List of processes in pgrp. */
struct proc *p_pptr; /* Pointer to parent process. */
LIST_ENTRY(proc) p_sibling; /* List of sibling processes. */
LIST_HEAD(, proc) p_children; /* Pointer to list of children. */
/* The following fields are all zeroed upon creation in fork. */
#define p_startzero p_oppid
pid_t p_oppid; /* Save parent pid during ptrace. XXX */
int p_dupfd; /* Sideways return value from filedescopen. XXX */
/* scheduling */
u_int p_estcpu; /* Time averaged value of p_cpticks. */
int p_cpticks; /* Ticks of cpu time. */
fixpt_t p_pctcpu; /* %cpu for this process during p_swtime */
void *p_wchan; /* Sleep address. */
struct timeout p_sleep_to;/* timeout for tsleep() */
const char *p_wmesg; /* Reason for sleep. */
u_int p_swtime; /* Time swapped in or out. */
u_int p_slptime; /* Time since last blocked. */
int p_schedflags; /* PSCHED_* flags */
struct itimerval p_realtimer; /* Alarm timer. */
struct timeout p_realit_to; /* Alarm timeout. */
struct timeval p_rtime; /* Real time. */
u_quad_t p_uticks; /* Statclock hits in user mode. */
u_quad_t p_sticks; /* Statclock hits in system mode. */
u_quad_t p_iticks; /* Statclock hits processing intr. */
int p_traceflag; /* Kernel trace points. */
struct vnode *p_tracep; /* Trace to vnode. */
void *p_systrace; /* Back pointer to systrace */
int p_siglist; /* Signals arrived but not delivered. */
struct vnode *p_textvp; /* Vnode of executable. */
int p_holdcnt; /* If non-zero, don't swap. */
struct emul *p_emul; /* Emulation information */
void *p_emuldata; /* Per-process emulation data, or */
/* NULL. Malloc type M_EMULDATA */
struct klist p_klist; /* knotes attached to this process */
/* pad to 256, avoid shifting eproc. */
/* End area that is zeroed on creation. */
#define p_endzero p_startcopy
/* The following fields are all copied upon creation in fork. */
#define p_startcopy p_sigmask
sigset_t p_sigmask; /* Current signal mask. */
sigset_t p_sigignore; /* Signals being ignored. */
sigset_t p_sigcatch; /* Signals being caught by user. */
u_char p_priority; /* Process priority. */
u_char p_usrpri; /* User-priority based on p_cpu and p_nice. */
char p_nice; /* Process "nice" value. */
char p_comm[MAXCOMLEN+1];
struct pgrp *p_pgrp; /* Pointer to process group. */
vaddr_t p_sigcode; /* user pointer to the signal code. */
/* End area that is copied on creation. */
#define p_endcopy p_addr
struct user *p_addr; /* Kernel virtual addr of u-area (PROC ONLY). */
struct mdproc p_md; /* Any machine-dependent fields. */
u_short p_xstat; /* Exit status for wait; also stop signal. */
u_short p_acflag; /* Accounting flags. */
struct rusage *p_ru; /* Exit information. XXX */
};
#define p_session p_pgrp->pg_session
#define p_pgid p_pgrp->pg_id
/* Status values. */
#define SIDL 1 /* Process being created by fork. */
#define SRUN 2 /* Currently runnable. */
#define SSLEEP 3 /* Sleeping on an address. */
#define SSTOP 4 /* Process debugging or suspension. */
#define SZOMB 5 /* Awaiting collection by parent. */
#define SDEAD 6 /* Process is almost a zombie. */
#define P_ZOMBIE(p) ((p)->p_stat == SZOMB || (p)->p_stat == SDEAD)
/* These flags are kept in p_flag. */
#define P_ADVLOCK 0x000001 /* Proc may hold a POSIX adv. lock. */
#define P_CONTROLT 0x000002 /* Has a controlling terminal. */
#define P_INMEM 0x000004 /* Loaded into memory. */
#define P_NOCLDSTOP 0x000008 /* No SIGCHLD when children stop. */
#define P_PPWAIT 0x000010 /* Parent waits for child exec/exit. */
#define P_PROFIL 0x000020 /* Has started profiling. */
#define P_SELECT 0x000040 /* Selecting; wakeup/waiting danger. */
#define P_SINTR 0x000080 /* Sleep is interruptible. */
#define P_SUGID 0x000100 /* Had set id privs since last exec. */
#define P_SYSTEM 0x000200 /* No sigs, stats or swapping. */
#define P_TIMEOUT 0x000400 /* Timing out during sleep. */
#define P_TRACED 0x000800 /* Debugged process being traced. */
#define P_WAITED 0x001000 /* Debugging proc has waited for child. */
/* XXX - Should be merged with INEXEC */
#define P_WEXIT 0x002000 /* Working on exiting. */
#define P_EXEC 0x004000 /* Process called exec. */
/* Should be moved to machine-dependent areas. */
#define P_OWEUPC 0x008000 /* Owe proc an addupc() at next ast. */
/* XXX Not sure what to do with these, yet. */
#define P_FSTRACE 0x010000 /* tracing via fs (elsewhere?) */
#define P_SSTEP 0x020000 /* proc needs single-step fixup ??? */
#define P_SUGIDEXEC 0x040000 /* last execve() was set[ug]id */
#define P_NOCLDWAIT 0x080000 /* Let pid 1 wait for my children */
#define P_NOZOMBIE 0x100000 /* Pid 1 waits for me instead of dad */
#define P_INEXEC 0x200000 /* Process is doing an exec right now */
#define P_SYSTRACE 0x400000 /* Process system call tracing active*/
#define P_CONTINUED 0x800000 /* Proc has continued from a stopped state. */
#define P_SWAPIN 0x1000000 /* Swapping in right now */
#define P_BITS \
("\20\01ADVLOCK\02CTTY\03INMEM\04NOCLDSTOP\05PPWAIT\06PROFIL\07SELECT" \
"\010SINTR\011SUGID\012SYSTEM\013TIMEOUT\014TRACED\015WAITED\016WEXIT" \
"\017EXEC\020PWEUPC\021FSTRACE\022SSTEP\023SUGIDEXEC\024NOCLDWAIT" \
"\025NOZOMBIE\026INEXEC\027SYSTRACE\030CONTINUED")
/* Macro to compute the exit signal to be delivered. */
#define P_EXITSIG(p) \
(((p)->p_flag & (P_TRACED | P_FSTRACE)) ? SIGCHLD : (p)->p_exitsig)
/*
* These flags are kept in p_schedflags. p_schedflags may be modified
* only at splstatclock().
*/
#define PSCHED_SEENRR 0x0001 /* process has been in roundrobin() */
#define PSCHED_SHOULDYIELD 0x0002 /* process should yield */
#define PSCHED_SWITCHCLEAR (PSCHED_SEENRR|PSCHED_SHOULDYIELD)
/*
* MOVE TO ucred.h?
*
* Shareable process credentials (always resident). This includes a reference
* to the current user credentials as well as real and saved ids that may be
* used to change ids.
*/
struct pcred {
struct ucred *pc_ucred; /* Current credentials. */
uid_t p_ruid; /* Real user id. */
uid_t p_svuid; /* Saved effective user id. */
gid_t p_rgid; /* Real group id. */
gid_t p_svgid; /* Saved effective group id. */
int p_refcnt; /* Number of references. */
};
#ifdef _KERNEL
/*
* We use process IDs <= PID_MAX; PID_MAX + 1 must also fit in a pid_t,
* as it is used to represent "no process group".
* We set PID_MAX to (SHRT_MAX - 1) so we don't break sys/compat.
*/
#define PID_MAX 32766
#define NO_PID (PID_MAX+1)
#define SESS_LEADER(p) ((p)->p_session->s_leader == (p))
#define SESSHOLD(s) ((s)->s_count++)
#define SESSRELE(s) { \
if (--(s)->s_count == 0) \
pool_put(&session_pool, s); \
}
#define PHOLD(p) { \
if ((p)->p_holdcnt++ == 0 && ((p)->p_flag & P_INMEM) == 0) \
uvm_swapin(p); \
}
#define PRELE(p) (--(p)->p_holdcnt)
/*
* Flags to fork1().
*/
#define FORK_FORK 0x00000001
#define FORK_VFORK 0x00000002
#define FORK_RFORK 0x00000004
#define FORK_PPWAIT 0x00000008
#define FORK_SHAREFILES 0x00000010
#define FORK_CLEANFILES 0x00000020
#define FORK_NOZOMBIE 0x00000040
#define FORK_SHAREVM 0x00000080
#define FORK_VMNOSTACK 0x00000100
#define FORK_SIGHAND 0x00000200
#define PIDHASH(pid) (&pidhashtbl[(pid) & pidhash])
extern LIST_HEAD(pidhashhead, proc) *pidhashtbl;
extern u_long pidhash;
#define PGRPHASH(pgid) (&pgrphashtbl[(pgid) & pgrphash])
extern LIST_HEAD(pgrphashhead, pgrp) *pgrphashtbl;
extern u_long pgrphash;
#ifndef curproc
extern struct proc *curproc; /* Current running proc. */
#endif
extern struct proc proc0; /* Process slot for swapper. */
extern int nprocs, maxproc; /* Current and max number of procs. */
extern int randompid; /* fork() should create random pid's */
LIST_HEAD(proclist, proc);
extern struct proclist allproc; /* List of all processes. */
extern struct proclist zombproc; /* List of zombie processes. */
extern struct proclist deadproc; /* List of dead processes. */
extern struct simplelock deadproc_slock;
extern struct proc *initproc; /* Process slots for init, pager. */
extern struct proc *syncerproc; /* filesystem syncer daemon */
extern struct pool proc_pool; /* memory pool for procs */
extern struct pool rusage_pool; /* memory pool for zombies */
extern struct pool ucred_pool; /* memory pool for ucreds */
extern struct pool session_pool; /* memory pool for sessions */
extern struct pool pcred_pool; /* memory pool for pcreds */
#define NQS 32 /* 32 run queues. */
extern int whichqs; /* Bit mask summary of non-empty Q's. */
struct prochd {
struct proc *ph_link; /* Linked list of running processes. */
struct proc *ph_rlink;
};
extern struct prochd qs[NQS];
struct simplelock;
struct proc *pfind(pid_t); /* Find process by id. */
struct pgrp *pgfind(pid_t); /* Find process group by id. */
void proc_printit(struct proc *p, const char *modif,
int (*pr)(const char *, ...));
int chgproccnt(uid_t uid, int diff);
int enterpgrp(struct proc *p, pid_t pgid, int mksess);
void fixjobc(struct proc *p, struct pgrp *pgrp, int entering);
int inferior(struct proc *p);
int leavepgrp(struct proc *p);
void yield(void);
void preempt(struct proc *);
void mi_switch(void);
void pgdelete(struct pgrp *pgrp);
void procinit(void);
#if !defined(remrunqueue)
void remrunqueue(struct proc *);
#endif
void resetpriority(struct proc *);
void setrunnable(struct proc *);
#if !defined(setrunqueue)
void setrunqueue(struct proc *);
#endif
void sleep(void *chan, int pri);
void uvm_swapin(struct proc *); /* XXX: uvm_extern.h? */
int ltsleep(void *chan, int pri, const char *wmesg, int timo,
volatile struct simplelock *);
#define tsleep(chan, pri, wmesg, timo) ltsleep(chan, pri, wmesg, timo, NULL)
void unsleep(struct proc *);
void wakeup_n(void *chan, int);
void wakeup(void *chan);
#define wakeup_one(c) wakeup_n((c), 1)
void reaper(void);
void exit1(struct proc *, int);
void exit2(struct proc *);
int fork1(struct proc *, int, int, void *, size_t, void (*)(void *),
void *, register_t *);
void rqinit(void);
int groupmember(gid_t, struct ucred *);
#if !defined(cpu_switch)
void cpu_switch(struct proc *);
#endif
#if !defined(cpu_wait)
void cpu_wait(struct proc *);
#endif
void cpu_exit(struct proc *);
void child_return(void *);
int proc_cansugid(struct proc *);
void proc_zap(struct proc *);
#endif /* _KERNEL */
#endif /* !_SYS_PROC_H_ */