75b8b3b25c
flexible process_fork, process_exec, and process_exit eventhandlers. This reduces code duplication and also means that I don't have to go duplicate the eventhandler locking three more times for each of at_fork, at_exec, and at_exit. Reviewed by: phk, jake, almost complete silence on arch@
848 lines
18 KiB
C
848 lines
18 KiB
C
/*
|
|
* Copyright (c) 2002 Alfred Perlstein <alfred@FreeBSD.org>
|
|
* All rights reserved.
|
|
*
|
|
* 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include "opt_posix.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/sysproto.h>
|
|
#include <sys/eventhandler.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/condvar.h>
|
|
#include <sys/sem.h>
|
|
#include <sys/uio.h>
|
|
#include <sys/syscall.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/sysent.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/jail.h>
|
|
#include <sys/fcntl.h>
|
|
|
|
#include <posix4/posix4.h>
|
|
#include <posix4/semaphore.h>
|
|
#include <posix4/_semaphore.h>
|
|
|
|
static struct ksem *sem_lookup_byname(const char *name);
|
|
static int sem_create(struct thread *td, const char *name,
|
|
struct ksem **ksret, mode_t mode, unsigned int value);
|
|
static void sem_free(struct ksem *ksnew);
|
|
static int sem_perm(struct thread *td, struct ksem *ks);
|
|
static void sem_enter(struct proc *p, struct ksem *ks);
|
|
static int sem_leave(struct proc *p, struct ksem *ks);
|
|
static void sem_exithook(void *arg, struct proc *p);
|
|
static int sem_hasopen(struct thread *td, struct ksem *ks);
|
|
|
|
static int kern_sem_close(struct thread *td, semid_t id);
|
|
static int kern_sem_post(struct thread *td, semid_t id);
|
|
static int kern_sem_wait(struct thread *td, semid_t id, int tryflag);
|
|
static int kern_sem_init(struct thread *td, int dir, unsigned int value,
|
|
semid_t *idp);
|
|
static int kern_sem_open(struct thread *td, int dir, const char *name,
|
|
int oflag, mode_t mode, unsigned int value, semid_t *idp);
|
|
static int kern_sem_unlink(struct thread *td, const char *name);
|
|
|
|
#ifndef SEM_MAX
|
|
#define SEM_MAX 30
|
|
#endif
|
|
|
|
#define SEM_MAX_NAMELEN 14
|
|
|
|
#define SEM_TO_ID(x) ((intptr_t)(x))
|
|
#define ID_TO_SEM(x) id_to_sem(x)
|
|
|
|
struct kuser {
|
|
pid_t ku_pid;
|
|
LIST_ENTRY(kuser) ku_next;
|
|
};
|
|
|
|
struct ksem {
|
|
LIST_ENTRY(ksem) ks_entry; /* global list entry */
|
|
int ks_onlist; /* boolean if on a list (ks_entry) */
|
|
char *ks_name; /* if named, this is the name */
|
|
int ks_ref; /* number of references */
|
|
mode_t ks_mode; /* protection bits */
|
|
uid_t ks_uid; /* creator uid */
|
|
gid_t ks_gid; /* creator gid */
|
|
unsigned int ks_value; /* current value */
|
|
struct cv ks_cv; /* waiters sleep here */
|
|
int ks_waiters; /* number of waiters */
|
|
LIST_HEAD(, kuser) ks_users; /* pids using this sem */
|
|
};
|
|
|
|
/*
|
|
* available semaphores go here, this includes sem_init and any semaphores
|
|
* created via sem_open that have not yet been unlinked.
|
|
*/
|
|
LIST_HEAD(, ksem) ksem_head = LIST_HEAD_INITIALIZER(&ksem_head);
|
|
/*
|
|
* semaphores still in use but have been sem_unlink()'d go here.
|
|
*/
|
|
LIST_HEAD(, ksem) ksem_deadhead = LIST_HEAD_INITIALIZER(&ksem_deadhead);
|
|
|
|
static struct mtx sem_lock;
|
|
static MALLOC_DEFINE(M_SEM, "sems", "semaphore data");
|
|
|
|
static int nsems = 0;
|
|
SYSCTL_DECL(_p1003_1b);
|
|
SYSCTL_INT(_p1003_1b, OID_AUTO, nsems, CTLFLAG_RD, &nsems, 0, "");
|
|
|
|
static eventhandler_tag sem_exit_tag, sem_exec_tag;
|
|
|
|
#ifdef SEM_DEBUG
|
|
#define DP(x) printf x
|
|
#else
|
|
#define DP(x)
|
|
#endif
|
|
|
|
static __inline
|
|
void
|
|
sem_ref(struct ksem *ks)
|
|
{
|
|
|
|
ks->ks_ref++;
|
|
DP(("sem_ref: ks = %p, ref = %d\n", ks, ks->ks_ref));
|
|
}
|
|
|
|
static __inline
|
|
void
|
|
sem_rel(struct ksem *ks)
|
|
{
|
|
|
|
DP(("sem_rel: ks = %p, ref = %d\n", ks, ks->ks_ref - 1));
|
|
if (--ks->ks_ref == 0)
|
|
sem_free(ks);
|
|
}
|
|
|
|
static __inline struct ksem *id_to_sem(semid_t id);
|
|
|
|
static __inline
|
|
struct ksem *
|
|
id_to_sem(id)
|
|
semid_t id;
|
|
{
|
|
struct ksem *ks;
|
|
|
|
DP(("id_to_sem: id = %0x,%p\n", id, (struct ksem *)id));
|
|
LIST_FOREACH(ks, &ksem_head, ks_entry) {
|
|
DP(("id_to_sem: ks = %p\n", ks));
|
|
if (ks == (struct ksem *)id)
|
|
return (ks);
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
static struct ksem *
|
|
sem_lookup_byname(name)
|
|
const char *name;
|
|
{
|
|
struct ksem *ks;
|
|
|
|
LIST_FOREACH(ks, &ksem_head, ks_entry)
|
|
if (ks->ks_name != NULL && strcmp(ks->ks_name, name) == 0)
|
|
return (ks);
|
|
return (NULL);
|
|
}
|
|
|
|
static int
|
|
sem_create(td, name, ksret, mode, value)
|
|
struct thread *td;
|
|
const char *name;
|
|
struct ksem **ksret;
|
|
mode_t mode;
|
|
unsigned int value;
|
|
{
|
|
struct ksem *ret;
|
|
struct proc *p;
|
|
struct ucred *uc;
|
|
size_t len;
|
|
int error;
|
|
|
|
DP(("sem_create\n"));
|
|
p = td->td_proc;
|
|
uc = td->td_ucred;
|
|
if (value > SEM_VALUE_MAX)
|
|
return (EINVAL);
|
|
ret = malloc(sizeof(*ret), M_SEM, M_WAITOK | M_ZERO);
|
|
if (name != NULL) {
|
|
len = strlen(name);
|
|
if (len > SEM_MAX_NAMELEN) {
|
|
free(ret, M_SEM);
|
|
return (ENAMETOOLONG);
|
|
}
|
|
/* name must start with a '/' but not contain one. */
|
|
if (*name != '/' || len < 2 || index(name + 1, '/') != NULL) {
|
|
free(ret, M_SEM);
|
|
return (EINVAL);
|
|
}
|
|
ret->ks_name = malloc(len + 1, M_SEM, M_WAITOK);
|
|
strcpy(ret->ks_name, name);
|
|
} else {
|
|
ret->ks_name = NULL;
|
|
}
|
|
ret->ks_mode = mode;
|
|
ret->ks_value = value;
|
|
ret->ks_ref = 1;
|
|
ret->ks_waiters = 0;
|
|
ret->ks_uid = uc->cr_uid;
|
|
ret->ks_gid = uc->cr_gid;
|
|
ret->ks_onlist = 0;
|
|
cv_init(&ret->ks_cv, "sem");
|
|
LIST_INIT(&ret->ks_users);
|
|
if (name != NULL)
|
|
sem_enter(td->td_proc, ret);
|
|
*ksret = ret;
|
|
mtx_lock(&sem_lock);
|
|
if (nsems >= p31b_getcfg(CTL_P1003_1B_SEM_NSEMS_MAX)) {
|
|
sem_leave(td->td_proc, ret);
|
|
sem_free(ret);
|
|
error = ENFILE;
|
|
} else {
|
|
nsems++;
|
|
error = 0;
|
|
}
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_init_args {
|
|
unsigned int value;
|
|
semid_t *idp;
|
|
};
|
|
int ksem_init(struct thread *td, struct ksem_init_args *uap);
|
|
#endif
|
|
int
|
|
ksem_init(td, uap)
|
|
struct thread *td;
|
|
struct ksem_init_args *uap;
|
|
{
|
|
int error;
|
|
|
|
error = kern_sem_init(td, UIO_USERSPACE, uap->value, uap->idp);
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
kern_sem_init(td, dir, value, idp)
|
|
struct thread *td;
|
|
int dir;
|
|
unsigned int value;
|
|
semid_t *idp;
|
|
{
|
|
struct ksem *ks;
|
|
semid_t id;
|
|
int error;
|
|
|
|
error = sem_create(td, NULL, &ks, S_IRWXU | S_IRWXG, value);
|
|
if (error)
|
|
return (error);
|
|
id = SEM_TO_ID(ks);
|
|
if (dir == UIO_USERSPACE) {
|
|
error = copyout(&id, idp, sizeof(id));
|
|
if (error) {
|
|
mtx_lock(&sem_lock);
|
|
sem_rel(ks);
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
} else {
|
|
*idp = id;
|
|
}
|
|
mtx_lock(&sem_lock);
|
|
LIST_INSERT_HEAD(&ksem_head, ks, ks_entry);
|
|
ks->ks_onlist = 1;
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_open_args {
|
|
char *name;
|
|
int oflag;
|
|
mode_t mode;
|
|
unsigned int value;
|
|
semid_t *idp;
|
|
};
|
|
int ksem_open(struct thread *td, struct ksem_open_args *uap);
|
|
#endif
|
|
int
|
|
ksem_open(td, uap)
|
|
struct thread *td;
|
|
struct ksem_open_args *uap;
|
|
{
|
|
char name[SEM_MAX_NAMELEN + 1];
|
|
size_t done;
|
|
int error;
|
|
|
|
error = copyinstr(uap->name, name, SEM_MAX_NAMELEN + 1, &done);
|
|
if (error)
|
|
return (error);
|
|
DP((">>> sem_open start\n"));
|
|
error = kern_sem_open(td, UIO_USERSPACE,
|
|
name, uap->oflag, uap->mode, uap->value, uap->idp);
|
|
DP(("<<< sem_open end\n"));
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
kern_sem_open(td, dir, name, oflag, mode, value, idp)
|
|
struct thread *td;
|
|
int dir;
|
|
const char *name;
|
|
int oflag;
|
|
mode_t mode;
|
|
unsigned int value;
|
|
semid_t *idp;
|
|
{
|
|
struct ksem *ksnew, *ks;
|
|
int error;
|
|
semid_t id;
|
|
|
|
ksnew = NULL;
|
|
mtx_lock(&sem_lock);
|
|
ks = sem_lookup_byname(name);
|
|
/*
|
|
* If we found it but O_EXCL is set, error.
|
|
*/
|
|
if (ks != NULL && (oflag & O_EXCL) != 0) {
|
|
mtx_unlock(&sem_lock);
|
|
return (EEXIST);
|
|
}
|
|
/*
|
|
* If we didn't find it...
|
|
*/
|
|
if (ks == NULL) {
|
|
/*
|
|
* didn't ask for creation? error.
|
|
*/
|
|
if ((oflag & O_CREAT) == 0) {
|
|
mtx_unlock(&sem_lock);
|
|
return (ENOENT);
|
|
}
|
|
/*
|
|
* We may block during creation, so drop the lock.
|
|
*/
|
|
mtx_unlock(&sem_lock);
|
|
error = sem_create(td, name, &ksnew, mode, value);
|
|
if (error != 0)
|
|
return (error);
|
|
id = SEM_TO_ID(ksnew);
|
|
if (dir == UIO_USERSPACE) {
|
|
DP(("about to copyout! %d to %p\n", id, idp));
|
|
error = copyout(&id, idp, sizeof(id));
|
|
if (error) {
|
|
mtx_lock(&sem_lock);
|
|
sem_leave(td->td_proc, ksnew);
|
|
sem_rel(ksnew);
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
} else {
|
|
DP(("about to set! %d to %p\n", id, idp));
|
|
*idp = id;
|
|
}
|
|
/*
|
|
* We need to make sure we haven't lost a race while
|
|
* allocating during creation.
|
|
*/
|
|
mtx_lock(&sem_lock);
|
|
ks = sem_lookup_byname(name);
|
|
if (ks != NULL) {
|
|
/* we lost... */
|
|
sem_leave(td->td_proc, ksnew);
|
|
sem_rel(ksnew);
|
|
/* we lost and we can't loose... */
|
|
if ((oflag & O_EXCL) != 0) {
|
|
mtx_unlock(&sem_lock);
|
|
return (EEXIST);
|
|
}
|
|
} else {
|
|
DP(("sem_create: about to add to list...\n"));
|
|
LIST_INSERT_HEAD(&ksem_head, ksnew, ks_entry);
|
|
DP(("sem_create: setting list bit...\n"));
|
|
ksnew->ks_onlist = 1;
|
|
DP(("sem_create: done, about to unlock...\n"));
|
|
}
|
|
mtx_unlock(&sem_lock);
|
|
} else {
|
|
/*
|
|
* if we aren't the creator, then enforce permissions.
|
|
*/
|
|
error = sem_perm(td, ks);
|
|
if (!error)
|
|
sem_ref(ks);
|
|
mtx_unlock(&sem_lock);
|
|
if (error)
|
|
return (error);
|
|
id = SEM_TO_ID(ks);
|
|
if (dir == UIO_USERSPACE) {
|
|
error = copyout(&id, idp, sizeof(id));
|
|
if (error) {
|
|
mtx_lock(&sem_lock);
|
|
sem_rel(ks);
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
} else {
|
|
*idp = id;
|
|
}
|
|
sem_enter(td->td_proc, ks);
|
|
mtx_lock(&sem_lock);
|
|
sem_rel(ks);
|
|
mtx_unlock(&sem_lock);
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
sem_perm(td, ks)
|
|
struct thread *td;
|
|
struct ksem *ks;
|
|
{
|
|
struct ucred *uc;
|
|
|
|
uc = td->td_ucred;
|
|
DP(("sem_perm: uc(%d,%d) ks(%d,%d,%o)\n",
|
|
uc->cr_uid, uc->cr_gid,
|
|
ks->ks_uid, ks->ks_gid, ks->ks_mode));
|
|
if ((uc->cr_uid == ks->ks_uid && (ks->ks_mode & S_IWUSR) != 0) ||
|
|
(uc->cr_gid == ks->ks_gid && (ks->ks_mode & S_IWGRP) != 0) ||
|
|
(ks->ks_mode & S_IWOTH) != 0 || suser(td) == 0)
|
|
return (0);
|
|
return (EPERM);
|
|
}
|
|
|
|
static void
|
|
sem_free(struct ksem *ks)
|
|
{
|
|
|
|
nsems--;
|
|
if (ks->ks_onlist)
|
|
LIST_REMOVE(ks, ks_entry);
|
|
if (ks->ks_name != NULL)
|
|
free(ks->ks_name, M_SEM);
|
|
cv_destroy(&ks->ks_cv);
|
|
free(ks, M_SEM);
|
|
}
|
|
|
|
static __inline struct kuser *sem_getuser(struct proc *p, struct ksem *ks);
|
|
|
|
static __inline struct kuser *
|
|
sem_getuser(p, ks)
|
|
struct proc *p;
|
|
struct ksem *ks;
|
|
{
|
|
struct kuser *k;
|
|
|
|
LIST_FOREACH(k, &ks->ks_users, ku_next)
|
|
if (k->ku_pid == p->p_pid)
|
|
return (k);
|
|
return (NULL);
|
|
}
|
|
|
|
static int
|
|
sem_hasopen(td, ks)
|
|
struct thread *td;
|
|
struct ksem *ks;
|
|
{
|
|
|
|
return ((ks->ks_name == NULL && sem_perm(td, ks))
|
|
|| sem_getuser(td->td_proc, ks) != NULL);
|
|
}
|
|
|
|
static int
|
|
sem_leave(p, ks)
|
|
struct proc *p;
|
|
struct ksem *ks;
|
|
{
|
|
struct kuser *k;
|
|
|
|
DP(("sem_leave: ks = %p\n", ks));
|
|
k = sem_getuser(p, ks);
|
|
DP(("sem_leave: ks = %p, k = %p\n", ks, k));
|
|
if (k != NULL) {
|
|
LIST_REMOVE(k, ku_next);
|
|
sem_rel(ks);
|
|
DP(("sem_leave: about to free k\n"));
|
|
free(k, M_SEM);
|
|
DP(("sem_leave: returning\n"));
|
|
return (0);
|
|
}
|
|
return (EINVAL);
|
|
}
|
|
|
|
static void
|
|
sem_enter(p, ks)
|
|
struct proc *p;
|
|
struct ksem *ks;
|
|
{
|
|
struct kuser *ku, *k;
|
|
|
|
ku = malloc(sizeof(*ku), M_SEM, M_WAITOK);
|
|
ku->ku_pid = p->p_pid;
|
|
mtx_lock(&sem_lock);
|
|
k = sem_getuser(p, ks);
|
|
if (k != NULL) {
|
|
mtx_unlock(&sem_lock);
|
|
free(ku, M_TEMP);
|
|
return;
|
|
}
|
|
LIST_INSERT_HEAD(&ks->ks_users, ku, ku_next);
|
|
sem_ref(ks);
|
|
mtx_unlock(&sem_lock);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_unlink_args {
|
|
char *name;
|
|
};
|
|
int ksem_unlink(struct thread *td, struct ksem_unlink_args *uap);
|
|
#endif
|
|
|
|
int
|
|
ksem_unlink(td, uap)
|
|
struct thread *td;
|
|
struct ksem_unlink_args *uap;
|
|
{
|
|
char name[SEM_MAX_NAMELEN + 1];
|
|
size_t done;
|
|
int error;
|
|
|
|
error = copyinstr(uap->name, name, SEM_MAX_NAMELEN + 1, &done);
|
|
return (error ? error :
|
|
kern_sem_unlink(td, name));
|
|
}
|
|
|
|
static int
|
|
kern_sem_unlink(td, name)
|
|
struct thread *td;
|
|
const char *name;
|
|
{
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
mtx_lock(&sem_lock);
|
|
ks = sem_lookup_byname(name);
|
|
if (ks == NULL)
|
|
error = ENOENT;
|
|
else
|
|
error = sem_perm(td, ks);
|
|
DP(("sem_unlink: '%s' ks = %p, error = %d\n", name, ks, error));
|
|
if (error == 0) {
|
|
LIST_REMOVE(ks, ks_entry);
|
|
LIST_INSERT_HEAD(&ksem_deadhead, ks, ks_entry);
|
|
sem_rel(ks);
|
|
}
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_close_args {
|
|
semid_t id;
|
|
};
|
|
int ksem_close(struct thread *td, struct ksem_close_args *uap);
|
|
#endif
|
|
|
|
int
|
|
ksem_close(struct thread *td, struct ksem_close_args *uap)
|
|
{
|
|
|
|
return (kern_sem_close(td, uap->id));
|
|
}
|
|
|
|
static int
|
|
kern_sem_close(td, id)
|
|
struct thread *td;
|
|
semid_t id;
|
|
{
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
error = EINVAL;
|
|
mtx_lock(&sem_lock);
|
|
ks = ID_TO_SEM(id);
|
|
/* this is not a valid operation for unnamed sems */
|
|
if (ks != NULL && ks->ks_name != NULL)
|
|
error = sem_leave(td->td_proc, ks);
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_post_args {
|
|
semid_t id;
|
|
};
|
|
int ksem_post(struct thread *td, struct ksem_post_args *uap);
|
|
#endif
|
|
int
|
|
ksem_post(td, uap)
|
|
struct thread *td;
|
|
struct ksem_post_args *uap;
|
|
{
|
|
|
|
return (kern_sem_post(td, uap->id));
|
|
}
|
|
|
|
static int
|
|
kern_sem_post(td, id)
|
|
struct thread *td;
|
|
semid_t id;
|
|
{
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
mtx_lock(&sem_lock);
|
|
ks = ID_TO_SEM(id);
|
|
if (ks == NULL || !sem_hasopen(td, ks)) {
|
|
error = EINVAL;
|
|
goto err;
|
|
}
|
|
if (ks->ks_value == SEM_VALUE_MAX) {
|
|
error = EOVERFLOW;
|
|
goto err;
|
|
}
|
|
++ks->ks_value;
|
|
if (ks->ks_waiters > 0)
|
|
cv_signal(&ks->ks_cv);
|
|
error = 0;
|
|
err:
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_wait_args {
|
|
semid_t id;
|
|
};
|
|
int ksem_wait(struct thread *td, struct ksem_wait_args *uap);
|
|
#endif
|
|
|
|
int
|
|
ksem_wait(td, uap)
|
|
struct thread *td;
|
|
struct ksem_wait_args *uap;
|
|
{
|
|
|
|
return (kern_sem_wait(td, uap->id, 0));
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_trywait_args {
|
|
semid_t id;
|
|
};
|
|
int ksem_trywait(struct thread *td, struct ksem_trywait_args *uap);
|
|
#endif
|
|
int
|
|
ksem_trywait(td, uap)
|
|
struct thread *td;
|
|
struct ksem_trywait_args *uap;
|
|
{
|
|
|
|
return (kern_sem_wait(td, uap->id, 1));
|
|
}
|
|
|
|
static int
|
|
kern_sem_wait(td, id, tryflag)
|
|
struct thread *td;
|
|
semid_t id;
|
|
int tryflag;
|
|
{
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
DP((">>> kern_sem_wait entered!\n"));
|
|
mtx_lock(&sem_lock);
|
|
ks = ID_TO_SEM(id);
|
|
if (ks == NULL) {
|
|
DP(("kern_sem_wait ks == NULL\n"));
|
|
error = EINVAL;
|
|
goto err;
|
|
}
|
|
sem_ref(ks);
|
|
if (!sem_hasopen(td, ks)) {
|
|
DP(("kern_sem_wait hasopen failed\n"));
|
|
error = EINVAL;
|
|
goto err;
|
|
}
|
|
DP(("kern_sem_wait value = %d, tryflag %d\n", ks->ks_value, tryflag));
|
|
if (ks->ks_value == 0) {
|
|
ks->ks_waiters++;
|
|
error = tryflag ? EAGAIN : cv_wait_sig(&ks->ks_cv, &sem_lock);
|
|
ks->ks_waiters--;
|
|
if (error)
|
|
goto err;
|
|
}
|
|
ks->ks_value--;
|
|
error = 0;
|
|
err:
|
|
if (ks != NULL)
|
|
sem_rel(ks);
|
|
mtx_unlock(&sem_lock);
|
|
DP(("<<< kern_sem_wait leaving, error = %d\n", error));
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_getvalue_args {
|
|
semid_t id;
|
|
int *val;
|
|
};
|
|
int ksem_getvalue(struct thread *td, struct ksem_getvalue_args *uap);
|
|
#endif
|
|
int
|
|
ksem_getvalue(td, uap)
|
|
struct thread *td;
|
|
struct ksem_getvalue_args *uap;
|
|
{
|
|
struct ksem *ks;
|
|
int error, val;
|
|
|
|
mtx_lock(&sem_lock);
|
|
ks = ID_TO_SEM(uap->id);
|
|
if (ks == NULL || !sem_hasopen(td, ks)) {
|
|
mtx_unlock(&sem_lock);
|
|
return (EINVAL);
|
|
}
|
|
val = ks->ks_value;
|
|
mtx_unlock(&sem_lock);
|
|
error = copyout(&val, uap->val, sizeof(val));
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ksem_destroy_args {
|
|
semid_t id;
|
|
};
|
|
int ksem_destroy(struct thread *td, struct ksem_destroy_args *uap);
|
|
#endif
|
|
int
|
|
ksem_destroy(td, uap)
|
|
struct thread *td;
|
|
struct ksem_destroy_args *uap;
|
|
{
|
|
struct ksem *ks;
|
|
int error;
|
|
|
|
mtx_lock(&sem_lock);
|
|
ks = ID_TO_SEM(uap->id);
|
|
if (ks == NULL || !sem_hasopen(td, ks) ||
|
|
ks->ks_name != NULL) {
|
|
error = EINVAL;
|
|
goto err;
|
|
}
|
|
if (ks->ks_waiters != 0) {
|
|
error = EBUSY;
|
|
goto err;
|
|
}
|
|
sem_rel(ks);
|
|
error = 0;
|
|
err:
|
|
mtx_unlock(&sem_lock);
|
|
return (error);
|
|
}
|
|
|
|
static void
|
|
sem_exithook(arg, p)
|
|
void *arg;
|
|
struct proc *p;
|
|
{
|
|
struct ksem *ks, *ksnext;
|
|
|
|
mtx_lock(&sem_lock);
|
|
ks = LIST_FIRST(&ksem_head);
|
|
while (ks != NULL) {
|
|
ksnext = LIST_NEXT(ks, ks_entry);
|
|
sem_leave(p, ks);
|
|
ks = ksnext;
|
|
}
|
|
ks = LIST_FIRST(&ksem_deadhead);
|
|
while (ks != NULL) {
|
|
ksnext = LIST_NEXT(ks, ks_entry);
|
|
sem_leave(p, ks);
|
|
ks = ksnext;
|
|
}
|
|
mtx_unlock(&sem_lock);
|
|
}
|
|
|
|
static int
|
|
sem_modload(struct module *module, int cmd, void *arg)
|
|
{
|
|
int error = 0;
|
|
|
|
switch (cmd) {
|
|
case MOD_LOAD:
|
|
mtx_init(&sem_lock, "sem", "semaphore", MTX_DEF);
|
|
p31b_setcfg(CTL_P1003_1B_SEM_NSEMS_MAX, SEM_MAX);
|
|
p31b_setcfg(CTL_P1003_1B_SEM_VALUE_MAX, SEM_VALUE_MAX);
|
|
sem_exit_tag = EVENTHANDLER_REGISTER(process_exit, sem_exithook,
|
|
NULL, EVENTHANDLER_PRI_ANY);
|
|
sem_exec_tag = EVENTHANDLER_REGISTER(process_exec, sem_exithook,
|
|
NULL, EVENTHANDLER_PRI_ANY);
|
|
break;
|
|
case MOD_UNLOAD:
|
|
if (nsems != 0) {
|
|
error = EOPNOTSUPP;
|
|
break;
|
|
}
|
|
EVENTHANDLER_DEREGISTER(process_exit, sem_exit_tag);
|
|
EVENTHANDLER_DEREGISTER(process_exec, sem_exec_tag);
|
|
mtx_destroy(&sem_lock);
|
|
break;
|
|
case MOD_SHUTDOWN:
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
static moduledata_t sem_mod = {
|
|
"sem",
|
|
&sem_modload,
|
|
NULL
|
|
};
|
|
|
|
SYSCALL_MODULE_HELPER(ksem_init);
|
|
SYSCALL_MODULE_HELPER(ksem_open);
|
|
SYSCALL_MODULE_HELPER(ksem_unlink);
|
|
SYSCALL_MODULE_HELPER(ksem_close);
|
|
SYSCALL_MODULE_HELPER(ksem_post);
|
|
SYSCALL_MODULE_HELPER(ksem_wait);
|
|
SYSCALL_MODULE_HELPER(ksem_trywait);
|
|
SYSCALL_MODULE_HELPER(ksem_getvalue);
|
|
SYSCALL_MODULE_HELPER(ksem_destroy);
|
|
|
|
DECLARE_MODULE(sem, sem_mod, SI_SUB_SYSV_SEM, SI_ORDER_FIRST);
|
|
MODULE_VERSION(sem, 1);
|