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ipc: store ipcs into IDRs

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This patch introduces ipcs storage into IDRs. The main changes are:
  . This ipc_ids structure is changed: the entries array is changed into a
    root idr structure.
  . The grow_ary() routine is removed: it is not needed anymore when adding
    an ipc structure, since we are now using the IDR facility.
  . The ipc_rmid() routine interface is changed:
       . there is no need for this routine to return the pointer passed in as
         argument: it is now declared as a void
       . since the id is now part of the kern_ipc_perm structure, no need to
         have it as an argument to the routine

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nadia Derbey 2007-10-18 23:40:48 -07:00 committed by Linus Torvalds
parent d2b20b1154
commit 7ca7e564e0
9 changed files with 332 additions and 314 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
include/linux/ipc.h
View file

@ -89,6 +89,7 @@ struct kern_ipc_perm
{
spinlock_t lock;
int deleted;
int id;
key_t key;
uid_t uid;
gid_t gid;

1
include/linux/msg.h
View file

@ -77,7 +77,6 @@ struct msg_msg {
/* one msq_queue structure for each present queue on the system */
struct msg_queue {
struct kern_ipc_perm q_perm;
int q_id;
time_t q_stime; /* last msgsnd time */
time_t q_rtime; /* last msgrcv time */
time_t q_ctime; /* last change time */

1
include/linux/sem.h
View file

@ -90,7 +90,6 @@ struct sem {
/* One sem_array data structure for each set of semaphores in the system. */
struct sem_array {
struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
int sem_id;
time_t sem_otime; /* last semop time */
time_t sem_ctime; /* last change time */
struct sem *sem_base; /* ptr to first semaphore in array */

1
include/linux/shm.h
View file

@ -79,7 +79,6 @@ struct shmid_kernel /* private to the kernel */
{
struct kern_ipc_perm shm_perm;
struct file * shm_file;
int id;
unsigned long shm_nattch;
unsigned long shm_segsz;
time_t shm_atim;

117
ipc/msg.c
View file

@ -75,13 +75,12 @@ static struct ipc_ids init_msg_ids;
#define msg_lock(ns, id) ((struct msg_queue*)ipc_lock(&msg_ids(ns), id))
#define msg_unlock(msq) ipc_unlock(&(msq)->q_perm)
#define msg_rmid(ns, id) ((struct msg_queue*)ipc_rmid(&msg_ids(ns), id))
#define msg_checkid(ns, msq, msgid) \
ipc_checkid(&msg_ids(ns), &msq->q_perm, msgid)
#define msg_buildid(ns, id, seq) \
ipc_buildid(&msg_ids(ns), id, seq)
static void freeque (struct ipc_namespace *ns, struct msg_queue *msq, int id);
static void freeque(struct ipc_namespace *, struct msg_queue *);
static int newque (struct ipc_namespace *ns, key_t key, int msgflg);
#ifdef CONFIG_PROC_FS
static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
@ -93,7 +92,7 @@ static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
ns->msg_ctlmax = MSGMAX;
ns->msg_ctlmnb = MSGMNB;
ns->msg_ctlmni = MSGMNI;
ipc_init_ids(ids, ns->msg_ctlmni);
ipc_init_ids(ids);
}
int msg_init_ns(struct ipc_namespace *ns)
@ -110,20 +109,24 @@ int msg_init_ns(struct ipc_namespace *ns)
void msg_exit_ns(struct ipc_namespace *ns)
{
int i;
struct msg_queue *msq;
int next_id;
int total, in_use;
mutex_lock(&msg_ids(ns).mutex);
for (i = 0; i <= msg_ids(ns).max_id; i++) {
msq = msg_lock(ns, i);
in_use = msg_ids(ns).in_use;
for (total = 0, next_id = 0; total < in_use; next_id++) {
msq = idr_find(&msg_ids(ns).ipcs_idr, next_id);
if (msq == NULL)
continue;
freeque(ns, msq, i);
ipc_lock_by_ptr(&msq->q_perm);
freeque(ns, msq);
total++;
}
mutex_unlock(&msg_ids(ns).mutex);
ipc_fini_ids(ns->ids[IPC_MSG_IDS]);
kfree(ns->ids[IPC_MSG_IDS]);
ns->ids[IPC_MSG_IDS] = NULL;
}
@ -136,6 +139,11 @@ void __init msg_init(void)
IPC_MSG_IDS, sysvipc_msg_proc_show);
}
static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
{
ipc_rmid(&msg_ids(ns), &s->q_perm);
}
static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
{
struct msg_queue *msq;
@ -155,6 +163,9 @@ static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
return retval;
}
/*
* ipc_addid() locks msq
*/
id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
if (id == -1) {
security_msg_queue_free(msq);
@ -162,7 +173,7 @@ static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
return -ENOSPC;
}
msq->q_id = msg_buildid(ns, id, msq->q_perm.seq);
msq->q_perm.id = msg_buildid(ns, id, msq->q_perm.seq);
msq->q_stime = msq->q_rtime = 0;
msq->q_ctime = get_seconds();
msq->q_cbytes = msq->q_qnum = 0;
@ -171,9 +182,10 @@ static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
INIT_LIST_HEAD(&msq->q_messages);
INIT_LIST_HEAD(&msq->q_receivers);
INIT_LIST_HEAD(&msq->q_senders);
msg_unlock(msq);
return msq->q_id;
return msq->q_perm.id;
}
static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
@ -225,18 +237,18 @@ static void expunge_all(struct msg_queue *msq, int res)
/*
* freeque() wakes up waiters on the sender and receiver waiting queue,
* removes the message queue from message queue ID
* array, and cleans up all the messages associated with this queue.
* IDR, and cleans up all the messages associated with this queue.
*
* msg_ids.mutex and the spinlock for this message queue is hold
* msg_ids.mutex and the spinlock for this message queue are held
* before freeque() is called. msg_ids.mutex remains locked on exit.
*/
static void freeque(struct ipc_namespace *ns, struct msg_queue *msq, int id)
static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)
{
struct list_head *tmp;
expunge_all(msq, -EIDRM);
ss_wakeup(&msq->q_senders, 1);
msq = msg_rmid(ns, id);
msg_rmid(ns, msq);
msg_unlock(msq);
tmp = msq->q_messages.next;
@ -255,36 +267,51 @@ static void freeque(struct ipc_namespace *ns, struct msg_queue *msq, int id)
asmlinkage long sys_msgget(key_t key, int msgflg)
{
struct msg_queue *msq;
int id, ret = -EPERM;
int ret;
struct ipc_namespace *ns;
ns = current->nsproxy->ipc_ns;
mutex_lock(&msg_ids(ns).mutex);
if (key == IPC_PRIVATE)
ret = newque(ns, key, msgflg);
else if ((id = ipc_findkey(&msg_ids(ns), key)) == -1) { /* key not used */
if (!(msgflg & IPC_CREAT))
ret = -ENOENT;
else
ret = newque(ns, key, msgflg);
} else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) {
ret = -EEXIST;
} else {
msq = msg_lock(ns, id);
BUG_ON(msq == NULL);
if (ipcperms(&msq->q_perm, msgflg))
ret = -EACCES;
else {
int qid = msg_buildid(ns, id, msq->q_perm.seq);
ret = security_msg_queue_associate(msq, msgflg);
if (!ret)
ret = qid;
ret = idr_pre_get(&msg_ids(ns).ipcs_idr, GFP_KERNEL);
if (key == IPC_PRIVATE) {
if (!ret)
ret = -ENOMEM;
else {
mutex_lock(&msg_ids(ns).mutex);
ret = newque(ns, key, msgflg);
mutex_unlock(&msg_ids(ns).mutex);
}
msg_unlock(msq);
} else {
mutex_lock(&msg_ids(ns).mutex);
msq = (struct msg_queue *) ipc_findkey(&msg_ids(ns), key);
if (msq == NULL) {
/* key not used */
if (!(msgflg & IPC_CREAT))
ret = -ENOENT;
else if (!ret)
ret = -ENOMEM;
else
ret = newque(ns, key, msgflg);
} else {
/* msq has been locked by ipc_findkey() */
if (msgflg & IPC_CREAT && msgflg & IPC_EXCL)
ret = -EEXIST;
else {
if (ipcperms(&msq->q_perm, msgflg))
ret = -EACCES;
else {
ret = security_msg_queue_associate(
msq, msgflg);
if (!ret)
ret = msq->q_perm.id;
}
}
msg_unlock(msq);
}
mutex_unlock(&msg_ids(ns).mutex);
}
mutex_unlock(&msg_ids(ns).mutex);
return ret;
}
@ -430,13 +457,13 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
msginfo.msgpool = MSGPOOL;
msginfo.msgtql = MSGTQL;
}
max_id = msg_ids(ns).max_id;
max_id = ipc_get_maxid(&msg_ids(ns));
mutex_unlock(&msg_ids(ns).mutex);
if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
return -EFAULT;
return (max_id < 0) ? 0 : max_id;
}
case MSG_STAT:
case MSG_STAT: /* msqid is an index rather than a msg queue id */
case IPC_STAT:
{
struct msqid64_ds tbuf;
@ -444,8 +471,6 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
if (!buf)
return -EFAULT;
if (cmd == MSG_STAT && msqid >= msg_ids(ns).entries->size)
return -EINVAL;
memset(&tbuf, 0, sizeof(tbuf));
@ -454,7 +479,7 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
return -EINVAL;
if (cmd == MSG_STAT) {
success_return = msg_buildid(ns, msqid, msq->q_perm.seq);
success_return = msq->q_perm.id;
} else {
err = -EIDRM;
if (msg_checkid(ns, msq, msqid))
@ -552,7 +577,7 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
break;
}
case IPC_RMID:
freeque(ns, msq, msqid);
freeque(ns, msq);
break;
}
err = 0;
@ -926,7 +951,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
return seq_printf(s,
"%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
msq->q_perm.key,
msq->q_id,
msq->q_perm.id,
msq->q_perm.mode,
msq->q_cbytes,
msq->q_qnum,

113
ipc/sem.c
View file

@ -90,7 +90,6 @@
#define sem_lock(ns, id) ((struct sem_array*)ipc_lock(&sem_ids(ns), id))
#define sem_unlock(sma) ipc_unlock(&(sma)->sem_perm)
#define sem_rmid(ns, id) ((struct sem_array*)ipc_rmid(&sem_ids(ns), id))
#define sem_checkid(ns, sma, semid) \
ipc_checkid(&sem_ids(ns),&sma->sem_perm,semid)
#define sem_buildid(ns, id, seq) \
@ -99,7 +98,7 @@
static struct ipc_ids init_sem_ids;
static int newary(struct ipc_namespace *, key_t, int, int);
static void freeary(struct ipc_namespace *ns, struct sem_array *sma, int id);
static void freeary(struct ipc_namespace *, struct sem_array *);
#ifdef CONFIG_PROC_FS
static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
#endif
@ -129,7 +128,7 @@ static void __sem_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
ns->sc_semopm = SEMOPM;
ns->sc_semmni = SEMMNI;
ns->used_sems = 0;
ipc_init_ids(ids, ns->sc_semmni);
ipc_init_ids(ids);
}
int sem_init_ns(struct ipc_namespace *ns)
@ -146,20 +145,24 @@ int sem_init_ns(struct ipc_namespace *ns)
void sem_exit_ns(struct ipc_namespace *ns)
{
int i;
struct sem_array *sma;
int next_id;
int total, in_use;
mutex_lock(&sem_ids(ns).mutex);
for (i = 0; i <= sem_ids(ns).max_id; i++) {
sma = sem_lock(ns, i);
in_use = sem_ids(ns).in_use;
for (total = 0, next_id = 0; total < in_use; next_id++) {
sma = idr_find(&sem_ids(ns).ipcs_idr, next_id);
if (sma == NULL)
continue;
freeary(ns, sma, i);
ipc_lock_by_ptr(&sma->sem_perm);
freeary(ns, sma);
total++;
}
mutex_unlock(&sem_ids(ns).mutex);
ipc_fini_ids(ns->ids[IPC_SEM_IDS]);
kfree(ns->ids[IPC_SEM_IDS]);
ns->ids[IPC_SEM_IDS] = NULL;
}
@ -172,6 +175,11 @@ void __init sem_init (void)
IPC_SEM_IDS, sysvipc_sem_proc_show);
}
static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
{
ipc_rmid(&sem_ids(ns), &s->sem_perm);
}
/*
* Lockless wakeup algorithm:
* Without the check/retry algorithm a lockless wakeup is possible:
@ -243,7 +251,7 @@ static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
}
ns->used_sems += nsems;
sma->sem_id = sem_buildid(ns, id, sma->sem_perm.seq);
sma->sem_perm.id = sem_buildid(ns, id, sma->sem_perm.seq);
sma->sem_base = (struct sem *) &sma[1];
/* sma->sem_pending = NULL; */
sma->sem_pending_last = &sma->sem_pending;
@ -252,12 +260,12 @@ static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
sma->sem_ctime = get_seconds();
sem_unlock(sma);
return sma->sem_id;
return sma->sem_perm.id;
}
asmlinkage long sys_semget (key_t key, int nsems, int semflg)
{
int id, err = -EINVAL;
int err;
struct sem_array *sma;
struct ipc_namespace *ns;
@ -265,34 +273,50 @@ asmlinkage long sys_semget (key_t key, int nsems, int semflg)
if (nsems < 0 || nsems > ns->sc_semmsl)
return -EINVAL;
mutex_lock(&sem_ids(ns).mutex);
err = idr_pre_get(&sem_ids(ns).ipcs_idr, GFP_KERNEL);
if (key == IPC_PRIVATE) {
err = newary(ns, key, nsems, semflg);
} else if ((id = ipc_findkey(&sem_ids(ns), key)) == -1) { /* key not used */
if (!(semflg & IPC_CREAT))
err = -ENOENT;
else
err = newary(ns, key, nsems, semflg);
} else if (semflg & IPC_CREAT && semflg & IPC_EXCL) {
err = -EEXIST;
} else {
sma = sem_lock(ns, id);
BUG_ON(sma==NULL);
if (nsems > sma->sem_nsems)
err = -EINVAL;
else if (ipcperms(&sma->sem_perm, semflg))
err = -EACCES;
if (!err)
err = -ENOMEM;
else {
int semid = sem_buildid(ns, id, sma->sem_perm.seq);
err = security_sem_associate(sma, semflg);
if (!err)
err = semid;
mutex_lock(&sem_ids(ns).mutex);
err = newary(ns, key, nsems, semflg);
mutex_unlock(&sem_ids(ns).mutex);
}
sem_unlock(sma);
} else {
mutex_lock(&sem_ids(ns).mutex);
sma = (struct sem_array *) ipc_findkey(&sem_ids(ns), key);
if (sma == NULL) {
/* key not used */
if (!(semflg & IPC_CREAT))
err = -ENOENT;
else if (!err)
err = -ENOMEM;
else
err = newary(ns, key, nsems, semflg);
} else {
/* sma has been locked by ipc_findkey() */
if (semflg & IPC_CREAT && semflg & IPC_EXCL)
err = -EEXIST;
else {
if (nsems > sma->sem_nsems)
err = -EINVAL;
else if (ipcperms(&sma->sem_perm, semflg))
err = -EACCES;
else {
err = security_sem_associate(sma,
semflg);
if (!err)
err = sma->sem_perm.id;
}
}
sem_unlock(sma);
}
mutex_unlock(&sem_ids(ns).mutex);
}
mutex_unlock(&sem_ids(ns).mutex);
return err;
}
@ -491,11 +515,10 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum)
* the spinlock for this semaphore set hold. sem_ids.mutex remains locked
* on exit.
*/
static void freeary (struct ipc_namespace *ns, struct sem_array *sma, int id)
static void freeary(struct ipc_namespace *ns, struct sem_array *sma)
{
struct sem_undo *un;
struct sem_queue *q;
int size;
/* Invalidate the existing undo structures for this semaphore set.
* (They will be freed without any further action in exit_sem()
@ -518,12 +541,11 @@ static void freeary (struct ipc_namespace *ns, struct sem_array *sma, int id)
q = n;
}
/* Remove the semaphore set from the ID array*/
sma = sem_rmid(ns, id);
/* Remove the semaphore set from the IDR */
sem_rmid(ns, sma);
sem_unlock(sma);
ns->used_sems -= sma->sem_nsems;
size = sizeof (*sma) + sma->sem_nsems * sizeof (struct sem);
security_sem_free(sma);
ipc_rcu_putref(sma);
}
@ -584,7 +606,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
seminfo.semusz = SEMUSZ;
seminfo.semaem = SEMAEM;
}
max_id = sem_ids(ns).max_id;
max_id = ipc_get_maxid(&sem_ids(ns));
mutex_unlock(&sem_ids(ns).mutex);
if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo)))
return -EFAULT;
@ -595,9 +617,6 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
struct semid64_ds tbuf;
int id;
if(semid >= sem_ids(ns).entries->size)
return -EINVAL;
memset(&tbuf,0,sizeof(tbuf));
sma = sem_lock(ns, semid);
@ -612,7 +631,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
if (err)
goto out_unlock;
id = sem_buildid(ns, semid, sma->sem_perm.seq);
id = sma->sem_perm.id;
kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
tbuf.sem_otime = sma->sem_otime;
@ -894,7 +913,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid, int semnum,
switch(cmd){
case IPC_RMID:
freeary(ns, sma, semid);
freeary(ns, sma);
err = 0;
break;
case IPC_SET:
@ -1402,7 +1421,7 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
return seq_printf(s,
"%10d %10d %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
sma->sem_perm.key,
sma->sem_id,
sma->sem_perm.id,
sma->sem_perm.mode,
sma->sem_nsems,
sma->sem_perm.uid,

118
ipc/shm.c
View file

@ -84,7 +84,7 @@ static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
ns->shm_ctlall = SHMALL;
ns->shm_ctlmni = SHMMNI;
ns->shm_tot = 0;
ipc_init_ids(ids, 1);
ipc_init_ids(ids);
}
static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
@ -112,20 +112,24 @@ int shm_init_ns(struct ipc_namespace *ns)
void shm_exit_ns(struct ipc_namespace *ns)
{
int i;
struct shmid_kernel *shp;
int next_id;
int total, in_use;
mutex_lock(&shm_ids(ns).mutex);
for (i = 0; i <= shm_ids(ns).max_id; i++) {
shp = shm_lock(ns, i);
in_use = shm_ids(ns).in_use;
for (total = 0, next_id = 0; total < in_use; next_id++) {
shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
if (shp == NULL)
continue;
ipc_lock_by_ptr(&shp->shm_perm);
do_shm_rmid(ns, shp);
total++;
}
mutex_unlock(&shm_ids(ns).mutex);
ipc_fini_ids(ns->ids[IPC_SHM_IDS]);
kfree(ns->ids[IPC_SHM_IDS]);
ns->ids[IPC_SHM_IDS] = NULL;
}
@ -146,9 +150,9 @@ static inline int shm_checkid(struct ipc_namespace *ns,
return 0;
}
static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id)
static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
{
return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id);
ipc_rmid(&shm_ids(ns), &s->shm_perm);
}
static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
@ -184,7 +188,7 @@ static void shm_open(struct vm_area_struct *vma)
static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
{
ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
shm_rmid(ns, shp->id);
shm_rmid(ns, shp);
shm_unlock(shp);
if (!is_file_hugepages(shp->shm_file))
shmem_lock(shp->shm_file, 0, shp->mlock_user);
@ -398,17 +402,18 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
shp->shm_ctim = get_seconds();
shp->shm_segsz = size;
shp->shm_nattch = 0;
shp->id = shm_buildid(ns, id, shp->shm_perm.seq);
shp->shm_perm.id = shm_buildid(ns, id, shp->shm_perm.seq);
shp->shm_file = file;
/*
* shmid gets reported as "inode#" in /proc/pid/maps.
* proc-ps tools use this. Changing this will break them.
*/
file->f_dentry->d_inode->i_ino = shp->id;
file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
ns->shm_tot += numpages;
error = shp->shm_perm.id;
shm_unlock(shp);
return shp->id;
return error;
no_id:
fput(file);
@ -421,37 +426,52 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
{
struct shmid_kernel *shp;
int err, id = 0;
int err;
struct ipc_namespace *ns;
ns = current->nsproxy->ipc_ns;
mutex_lock(&shm_ids(ns).mutex);
err = idr_pre_get(&shm_ids(ns).ipcs_idr, GFP_KERNEL);
if (key == IPC_PRIVATE) {
err = newseg(ns, key, shmflg, size);
} else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
if (!(shmflg & IPC_CREAT))
err = -ENOENT;
else
err = newseg(ns, key, shmflg, size);
} else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
err = -EEXIST;
} else {
shp = shm_lock(ns, id);
BUG_ON(shp==NULL);
if (shp->shm_segsz < size)
err = -EINVAL;
else if (ipcperms(&shp->shm_perm, shmflg))
err = -EACCES;
if (!err)
err = -ENOMEM;
else {
int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
err = security_shm_associate(shp, shmflg);
if (!err)
err = shmid;
mutex_lock(&shm_ids(ns).mutex);
err = newseg(ns, key, shmflg, size);
mutex_unlock(&shm_ids(ns).mutex);
}
shm_unlock(shp);
} else {
mutex_lock(&shm_ids(ns).mutex);
shp = (struct shmid_kernel *) ipc_findkey(&shm_ids(ns), key);
if (shp == NULL) {
if (!(shmflg & IPC_CREAT))
err = -ENOENT;
else if (!err)
err = -ENOMEM;
else
err = newseg(ns, key, shmflg, size);
} else {
/* shp has been locked by ipc_findkey() */
if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL))
err = -EEXIST;
else {
if (shp->shm_segsz < size)
err = -EINVAL;
else if (ipcperms(&shp->shm_perm, shmflg))
err = -EACCES;
else {
err = security_shm_associate(shp,
shmflg);
if (!err)
err = shp->shm_perm.id;
}
}
shm_unlock(shp);
}
mutex_unlock(&shm_ids(ns).mutex);
}
mutex_unlock(&shm_ids(ns).mutex);
return err;
}
@ -550,17 +570,20 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
unsigned long *swp)
{
int i;
int next_id;
int total, in_use;
*rss = 0;
*swp = 0;
for (i = 0; i <= shm_ids(ns).max_id; i++) {
in_use = shm_ids(ns).in_use;
for (total = 0, next_id = 0; total < in_use; next_id++) {
struct shmid_kernel *shp;
struct inode *inode;
shp = shm_get(ns, i);
if(!shp)
shp = shm_get(ns, next_id);
if (shp == NULL)
continue;
inode = shp->shm_file->f_path.dentry->d_inode;
@ -575,6 +598,8 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
*swp += info->swapped;
spin_unlock(&info->lock);
}
total++;
}
}
@ -611,7 +636,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
if(copy_shminfo_to_user (buf, &shminfo, version))
return -EFAULT;
/* reading a integer is always atomic */
err= shm_ids(ns).max_id;
err = ipc_get_maxid(&shm_ids(ns));
if(err<0)
err = 0;
goto out;
@ -631,7 +656,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
shm_info.shm_tot = ns->shm_tot;
shm_info.swap_attempts = 0;
shm_info.swap_successes = 0;
err = shm_ids(ns).max_id;
err = ipc_get_maxid(&shm_ids(ns));
mutex_unlock(&shm_ids(ns).mutex);
if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
err = -EFAULT;
@ -651,11 +676,8 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
if(shp==NULL) {
err = -EINVAL;
goto out;
} else if(cmd==SHM_STAT) {
err = -EINVAL;
if (shmid > shm_ids(ns).max_id)
goto out_unlock;
result = shm_buildid(ns, shmid, shp->shm_perm.seq);
} else if (cmd == SHM_STAT) {
result = shp->shm_perm.id;
} else {
err = shm_checkid(ns, shp,shmid);
if(err)
@ -925,7 +947,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
file->private_data = sfd;
file->f_mapping = shp->shm_file->f_mapping;
sfd->id = shp->id;
sfd->id = shp->shm_perm.id;
sfd->ns = get_ipc_ns(ns);
sfd->file = shp->shm_file;
sfd->vm_ops = NULL;
@ -1094,7 +1116,7 @@ static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
format = BIG_STRING;
return seq_printf(s, format,
shp->shm_perm.key,
shp->id,
shp->shm_perm.id,
shp->shm_perm.mode,
shp->shm_segsz,
shp->shm_cprid,

262
ipc/util.c
View file

@ -129,23 +129,16 @@ __initcall(ipc_init);
/**
* ipc_init_ids - initialise IPC identifiers
* @ids: Identifier set
* @size: Number of identifiers
*
* Given a size for the ipc identifier range (limited below IPCMNI)
* set up the sequence range to use then allocate and initialise the
* array itself.
* Set up the sequence range to use for the ipc identifier range (limited
* below IPCMNI) then initialise the ids idr.
*/
void ipc_init_ids(struct ipc_ids* ids, int size)
void ipc_init_ids(struct ipc_ids *ids)
{
int i;
mutex_init(&ids->mutex);
if(size > IPCMNI)
size = IPCMNI;
ids->in_use = 0;
ids->max_id = -1;
ids->seq = 0;
{
int seq_limit = INT_MAX/SEQ_MULTIPLIER;
@ -155,17 +148,7 @@ void ipc_init_ids(struct ipc_ids* ids, int size)
ids->seq_max = seq_limit;
}
ids->entries = ipc_rcu_alloc(sizeof(struct kern_ipc_perm *)*size +
sizeof(struct ipc_id_ary));
if(ids->entries == NULL) {
printk(KERN_ERR "ipc_init_ids() failed, ipc service disabled.\n");
size = 0;
ids->entries = &ids->nullentry;
}
ids->entries->size = size;
for(i=0;i<size;i++)
ids->entries->p[i] = NULL;
idr_init(&ids->ipcs_idr);
}
#ifdef CONFIG_PROC_FS
@ -209,72 +192,73 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
* @key: The key to find
*
* Requires ipc_ids.mutex locked.
* Returns the identifier if found or -1 if not.
* Returns the LOCKED pointer to the ipc structure if found or NULL
* if not.
* If key is found ipc contains its ipc structure
*/
int ipc_findkey(struct ipc_ids* ids, key_t key)
struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
{
int id;
struct kern_ipc_perm* p;
int max_id = ids->max_id;
struct kern_ipc_perm *ipc;
int next_id;
int total;
/*
* rcu_dereference() is not needed here
* since ipc_ids.mutex is held
*/
for (id = 0; id <= max_id; id++) {
p = ids->entries->p[id];
if(p==NULL)
for (total = 0, next_id = 0; total < ids->in_use; next_id++) {
ipc = idr_find(&ids->ipcs_idr, next_id);
if (ipc == NULL)
continue;
if (key == p->key)
return id;
if (ipc->key != key) {
total++;
continue;
}
ipc_lock_by_ptr(ipc);
return ipc;
}
return -1;
return NULL;
}
/*
* Requires ipc_ids.mutex locked
/**
* ipc_get_maxid - get the last assigned id
* @ids: IPC identifier set
*
* Called with ipc_ids.mutex held.
*/
static int grow_ary(struct ipc_ids* ids, int newsize)
int ipc_get_maxid(struct ipc_ids *ids)
{
struct ipc_id_ary* new;
struct ipc_id_ary* old;
int i;
int size = ids->entries->size;
struct kern_ipc_perm *ipc;
int max_id = -1;
int total, id;
if(newsize > IPCMNI)
newsize = IPCMNI;
if(newsize <= size)
return newsize;
if (ids->in_use == 0)
return -1;
new = ipc_rcu_alloc(sizeof(struct kern_ipc_perm *)*newsize +
sizeof(struct ipc_id_ary));
if(new == NULL)
return size;
new->size = newsize;
memcpy(new->p, ids->entries->p, sizeof(struct kern_ipc_perm *)*size);
for(i=size;i<newsize;i++) {
new->p[i] = NULL;
if (ids->in_use == IPCMNI)
return IPCMNI - 1;
/* Look for the last assigned id */
total = 0;
for (id = 0; id < IPCMNI && total < ids->in_use; id++) {
ipc = idr_find(&ids->ipcs_idr, id);
if (ipc != NULL) {
max_id = id;
total++;
}
}
old = ids->entries;
/*
* Use rcu_assign_pointer() to make sure the memcpyed contents
* of the new array are visible before the new array becomes visible.
*/
rcu_assign_pointer(ids->entries, new);
__ipc_fini_ids(ids, old);
return newsize;
return max_id;
}
/**
* ipc_addid - add an IPC identifier
* @ids: IPC identifier set
* @new: new IPC permission set
* @size: new size limit for the id array
* @size: limit for the number of used ids
*
* Add an entry 'new' to the IPC arrays. The permissions object is
* Add an entry 'new' to the IPC idr. The permissions object is
* initialised and the first free entry is set up and the id assigned
* is returned. The list is returned in a locked state on success.
* On failure the list is not locked and -1 is returned.
@ -284,23 +268,23 @@ static int grow_ary(struct ipc_ids* ids, int newsize)
int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
{
int id;
size = grow_ary(ids,size);
int id, err;
/*
* rcu_dereference()() is not needed here since
* ipc_ids.mutex is held
*/
for (id = 0; id < size; id++) {
if(ids->entries->p[id] == NULL)
goto found;
}
return -1;
found:
if (size > IPCMNI)
size = IPCMNI;
if (ids->in_use >= size)
return -1;
err = idr_get_new(&ids->ipcs_idr, new, &id);
if (err)
return -1;
ids->in_use++;
if (id > ids->max_id)
ids->max_id = id;
new->cuid = new->uid = current->euid;
new->gid = new->cgid = current->egid;
@ -313,48 +297,32 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
new->deleted = 0;
rcu_read_lock();
spin_lock(&new->lock);
ids->entries->p[id] = new;
return id;
}
/**
* ipc_rmid - remove an IPC identifier
* @ids: identifier set
* @id: Identifier to remove
* @id: ipc perm structure containing the identifier to remove
*
* The identifier must be valid, and in use. The kernel will panic if
* fed an invalid identifier. The entry is removed and internal
* variables recomputed. The object associated with the identifier
* is returned.
* ipc_ids.mutex and the spinlock for this ID is hold before this function
* is called, and remain locked on the exit.
* variables recomputed.
* ipc_ids.mutex and the spinlock for this ID are held before this
* function is called, and remain locked on the exit.
*/
struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id)
void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
{
struct kern_ipc_perm* p;
int lid = id % SEQ_MULTIPLIER;
BUG_ON(lid >= ids->entries->size);
int lid = ipcp->id % SEQ_MULTIPLIER;
idr_remove(&ids->ipcs_idr, lid);
/*
* do not need a rcu_dereference()() here to force ordering
* on Alpha, since the ipc_ids.mutex is held.
*/
p = ids->entries->p[lid];
ids->entries->p[lid] = NULL;
BUG_ON(p==NULL);
ids->in_use--;
if (lid == ids->max_id) {
do {
lid--;
if(lid == -1)
break;
} while (ids->entries->p[lid] == NULL);
ids->max_id = lid;
}
p->deleted = 1;
return p;
ipcp->deleted = 1;
return;
}
/**
@ -613,33 +581,26 @@ void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
* if in the future ipc_get() is used by other places without ipc_ids.mutex
* down, then ipc_get() needs read memery barriers as ipc_lock() does.
*/
struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id)
struct kern_ipc_perm *ipc_get(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm* out;
struct kern_ipc_perm *out;
int lid = id % SEQ_MULTIPLIER;
if(lid >= ids->entries->size)
return NULL;
out = ids->entries->p[lid];
out = idr_find(&ids->ipcs_idr, lid);
return out;
}
struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id)
struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm* out;
struct kern_ipc_perm *out;
int lid = id % SEQ_MULTIPLIER;
struct ipc_id_ary* entries;
rcu_read_lock();
entries = rcu_dereference(ids->entries);
if(lid >= entries->size) {
rcu_read_unlock();
return NULL;
}
out = entries->p[lid];
if(out == NULL) {
out = idr_find(&ids->ipcs_idr, lid);
if (out == NULL) {
rcu_read_unlock();
return NULL;
}
spin_lock(&out->lock);
/* ipc_rmid() may have already freed the ID while ipc_lock
@ -650,6 +611,7 @@ struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id)
rcu_read_unlock();
return NULL;
}
return out;
}
@ -707,27 +669,30 @@ struct ipc_proc_iter {
struct ipc_proc_iface *iface;
};
static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
/*
* This routine locks the ipc structure found at least at position pos.
*/
struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
loff_t *new_pos)
{
struct ipc_proc_iter *iter = s->private;
struct ipc_proc_iface *iface = iter->iface;
struct kern_ipc_perm *ipc = it;
loff_t p;
struct ipc_ids *ids;
struct kern_ipc_perm *ipc;
int total, id;
ids = iter->ns->ids[iface->ids];
total = 0;
for (id = 0; id < pos && total < ids->in_use; id++) {
ipc = idr_find(&ids->ipcs_idr, id);
if (ipc != NULL)
total++;
}
/* If we had an ipc id locked before, unlock it */
if (ipc && ipc != SEQ_START_TOKEN)
ipc_unlock(ipc);
if (total >= ids->in_use)
return NULL;
/*
* p = *pos - 1 (because id 0 starts at position 1)
* + 1 (because we increment the position by one)
*/
for (p = *pos; p <= ids->max_id; p++) {
if ((ipc = ipc_lock(ids, p)) != NULL) {
*pos = p + 1;
for ( ; pos < IPCMNI; pos++) {
ipc = idr_find(&ids->ipcs_idr, pos);
if (ipc != NULL) {
*new_pos = pos + 1;
ipc_lock_by_ptr(ipc);
return ipc;
}
}
@ -736,6 +701,19 @@ static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
return NULL;
}
static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
{
struct ipc_proc_iter *iter = s->private;
struct ipc_proc_iface *iface = iter->iface;
struct kern_ipc_perm *ipc = it;
/* If we had an ipc id locked before, unlock it */
if (ipc && ipc != SEQ_START_TOKEN)
ipc_unlock(ipc);
return sysvipc_find_ipc(iter->ns->ids[iface->ids], *pos, pos);
}
/*
* File positions: pos 0 -> header, pos n -> ipc id + 1.
* SeqFile iterator: iterator value locked shp or SEQ_TOKEN_START.
@ -744,8 +722,6 @@ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
{
struct ipc_proc_iter *iter = s->private;
struct ipc_proc_iface *iface = iter->iface;
struct kern_ipc_perm *ipc;
loff_t p;
struct ipc_ids *ids;
ids = iter->ns->ids[iface->ids];
@ -765,13 +741,7 @@ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
return SEQ_START_TOKEN;
/* Find the (pos-1)th ipc */
for (p = *pos - 1; p <= ids->max_id; p++) {
if ((ipc = ipc_lock(ids, p)) != NULL) {
*pos = p + 1;
return ipc;
}
}
return NULL;
return sysvipc_find_ipc(ids, *pos - 1, pos);
}
static void sysvipc_proc_stop(struct seq_file *s, void *it)

32
ipc/util.h
View file

@ -10,6 +10,8 @@
#ifndef _IPC_UTIL_H
#define _IPC_UTIL_H
#include <linux/idr.h>
#define USHRT_MAX 0xffff
#define SEQ_MULTIPLIER (IPCMNI)
@ -25,24 +27,17 @@ void sem_exit_ns(struct ipc_namespace *ns);
void msg_exit_ns(struct ipc_namespace *ns);
void shm_exit_ns(struct ipc_namespace *ns);
struct ipc_id_ary {
int size;
struct kern_ipc_perm *p[0];
};
struct ipc_ids {
int in_use;
int max_id;
unsigned short seq;
unsigned short seq_max;
struct mutex mutex;
struct ipc_id_ary nullentry;
struct ipc_id_ary* entries;
struct idr ipcs_idr;
};
struct seq_file;
void ipc_init_ids(struct ipc_ids *ids, int size);
void ipc_init_ids(struct ipc_ids *);
#ifdef CONFIG_PROC_FS
void __init ipc_init_proc_interface(const char *path, const char *header,
int ids, int (*show)(struct seq_file *, void *));
@ -55,11 +50,12 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
#define IPC_SHM_IDS 2
/* must be called with ids->mutex acquired.*/
int ipc_findkey(struct ipc_ids* ids, key_t key);
int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key);
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
int ipc_get_maxid(struct ipc_ids *);
/* must be called with both locks acquired. */
struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
int ipcperms (struct kern_ipc_perm *ipcp, short flg);
@ -79,18 +75,6 @@ void* ipc_rcu_alloc(int size);
void ipc_rcu_getref(void *ptr);
void ipc_rcu_putref(void *ptr);
static inline void __ipc_fini_ids(struct ipc_ids *ids,
struct ipc_id_ary *entries)
{
if (entries != &ids->nullentry)
ipc_rcu_putref(entries);
}
static inline void ipc_fini_ids(struct ipc_ids *ids)
{
__ipc_fini_ids(ids, ids->entries);
}
struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);