[RFC][PATCH 4/6] sysvsem: containerize

From: Dave Hansen
Date: Mon Mar 06 2006 - 18:51:58 EST


Same thing as the msgs.

Take all of the global sysv sem context and put it inside of
a special structure. This allows future work to give different
containers completely different views into the sysv space.

Signed-off-by: Dave Hansen <haveblue@xxxxxxxxxx>
---

work-dave/ipc/sem.c | 194 ++++++++++++++++++++++++++-------------------------
work-dave/ipc/util.c | 2
work-dave/ipc/util.h | 15 ++-
3 files changed, 114 insertions(+), 97 deletions(-)

diff -puN ipc/sem.c~sysvsem-container ipc/sem.c
--- work/ipc/sem.c~sysvsem-container 2006-03-06 15:41:58.000000000 -0800
+++ work-dave/ipc/sem.c 2006-03-06 15:41:58.000000000 -0800
@@ -79,17 +79,19 @@
#include "util.h"


-#define sem_lock(id) ((struct sem_array*)ipc_lock(&sem_ids,id))
-#define sem_unlock(sma) ipc_unlock(&(sma)->sem_perm)
-#define sem_rmid(id) ((struct sem_array*)ipc_rmid(&sem_ids,id))
-#define sem_checkid(sma, semid) \
- ipc_checkid(&sem_ids,&sma->sem_perm,semid)
-#define sem_buildid(id, seq) \
- ipc_buildid(&sem_ids, id, seq)
-static struct ipc_ids sem_ids;
+#define sem_lock(context, id) \
+ ((struct sem_array*)ipc_lock(&context->ids,id))
+#define sem_unlock(context, sma) \
+ ipc_unlock(&(sma)->sem_perm)
+#define sem_rmid(context, id) \
+ ((struct sem_array*)ipc_rmid(&context->ids,id))
+#define sem_checkid(context, sma, semid) \
+ ipc_checkid(&context->ids,&sma->sem_perm,semid)
+#define sem_buildid(context, id, seq) \
+ ipc_buildid(&context->ids, id, seq)

-static int newary (key_t, int, int);
-static void freeary (struct sem_array *sma, int id);
+static int newary (struct ipc_sem_context *, key_t, int, int);
+static void freeary (struct ipc_sem_context *, struct sem_array *, int);
#ifdef CONFIG_PROC_FS
static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
#endif
@@ -112,15 +114,12 @@ int sem_ctls[4] = {SEMMSL, SEMMNS, SEMOP
#define sc_semopm (sem_ctls[2])
#define sc_semmni (sem_ctls[3])

-static int used_sems;
-
-void __init sem_init (void)
+void __init sem_init (struct ipc_sem_context *context)
{
- used_sems = 0;
- ipc_init_ids(&sem_ids,sc_semmni);
+ ipc_init_ids(&context->ids,sc_semmni);
ipc_init_proc_interface("sysvipc/sem",
" key semid perms nsems uid gid cuid cgid otime ctime\n",
- &sem_ids,
+ &context->ids,
sysvipc_sem_proc_show);
}

@@ -158,7 +157,8 @@ void __init sem_init (void)
*/
#define IN_WAKEUP 1

-static int newary (key_t key, int nsems, int semflg)
+static int newary (struct ipc_sem_context *context,
+ key_t key, int nsems, int semflg)
{
int id;
int retval;
@@ -167,7 +167,7 @@ static int newary (key_t key, int nsems,

if (!nsems)
return -EINVAL;
- if (used_sems + nsems > sc_semmns)
+ if (context->nr_used + nsems > sc_semmns)
return -ENOSPC;

size = sizeof (*sma) + nsems * sizeof (struct sem);
@@ -187,22 +187,22 @@ static int newary (key_t key, int nsems,
return retval;
}

- id = ipc_addid(&sem_ids, &sma->sem_perm, sc_semmni);
+ id = ipc_addid(&context->ids, &sma->sem_perm, sc_semmni);
if(id == -1) {
security_sem_free(sma);
ipc_rcu_putref(sma);
return -ENOSPC;
}
- used_sems += nsems;
+ context->nr_used += nsems;

- sma->sem_id = sem_buildid(id, sma->sem_perm.seq);
+ sma->sem_id = sem_buildid(context, id, sma->sem_perm.seq);
sma->sem_base = (struct sem *) &sma[1];
/* sma->sem_pending = NULL; */
sma->sem_pending_last = &sma->sem_pending;
/* sma->undo = NULL; */
sma->sem_nsems = nsems;
sma->sem_ctime = get_seconds();
- sem_unlock(sma);
+ sem_unlock(context, sma);

return sma->sem_id;
}
@@ -211,22 +211,23 @@ asmlinkage long sys_semget (key_t key, i
{
int id, err = -EINVAL;
struct sem_array *sma;
+ struct ipc_sem_context *context = &current->ipc_context->sem;

if (nsems < 0 || nsems > sc_semmsl)
return -EINVAL;
- down(&sem_ids.sem);
+ down(&context->ids.sem);

if (key == IPC_PRIVATE) {
- err = newary(key, nsems, semflg);
- } else if ((id = ipc_findkey(&sem_ids, key)) == -1) { /* key not used */
+ err = newary(context, key, nsems, semflg);
+ } else if ((id = ipc_findkey(&context->ids, key)) == -1) { /* key not used */
if (!(semflg & IPC_CREAT))
err = -ENOENT;
else
- err = newary(key, nsems, semflg);
+ err = newary(context, key, nsems, semflg);
} else if (semflg & IPC_CREAT && semflg & IPC_EXCL) {
err = -EEXIST;
} else {
- sma = sem_lock(id);
+ sma = sem_lock(context, id);
if(sma==NULL)
BUG();
if (nsems > sma->sem_nsems)
@@ -234,15 +235,15 @@ asmlinkage long sys_semget (key_t key, i
else if (ipcperms(&sma->sem_perm, semflg))
err = -EACCES;
else {
- int semid = sem_buildid(id, sma->sem_perm.seq);
+ int semid = sem_buildid(context, id, sma->sem_perm.seq);
err = security_sem_associate(sma, semflg);
if (!err)
err = semid;
}
- sem_unlock(sma);
+ sem_unlock(context, sma);
}

- up(&sem_ids.sem);
+ up(&context->ids.sem);
return err;
}

@@ -437,11 +438,12 @@ static int count_semzcnt (struct sem_arr
return semzcnt;
}

-/* Free a semaphore set. freeary() is called with sem_ids.sem down and
- * the spinlock for this semaphore set hold. sem_ids.sem remains locked
+/* Free a semaphore set. freeary() is called with context->ids.sem down and
+ * the spinlock for this semaphore set hold. context->ids.sem remains locked
* on exit.
*/
-static void freeary (struct sem_array *sma, int id)
+static void freeary (struct ipc_sem_context *context,
+ struct sem_array *sma, int id)
{
struct sem_undo *un;
struct sem_queue *q;
@@ -469,10 +471,10 @@ static void freeary (struct sem_array *s
}

/* Remove the semaphore set from the ID array*/
- sma = sem_rmid(id);
- sem_unlock(sma);
+ sma = sem_rmid(context, id);
+ sem_unlock(context, sma);

- used_sems -= sma->sem_nsems;
+ context->nr_used -= sma->sem_nsems;
size = sizeof (*sma) + sma->sem_nsems * sizeof (struct sem);
security_sem_free(sma);
ipc_rcu_putref(sma);
@@ -500,7 +502,8 @@ static unsigned long copy_semid_to_user(
}
}

-static int semctl_nolock(int semid, int semnum, int cmd, int version, union semun arg)
+static int semctl_nolock(struct ipc_sem_context *context,
+ int semid, int semnum, int cmd, int version, union semun arg)
{
int err = -EINVAL;
struct sem_array *sma;
@@ -525,16 +528,16 @@ static int semctl_nolock(int semid, int
seminfo.semmnu = SEMMNU;
seminfo.semmap = SEMMAP;
seminfo.semume = SEMUME;
- down(&sem_ids.sem);
+ down(&context->ids.sem);
if (cmd == SEM_INFO) {
- seminfo.semusz = sem_ids.in_use;
- seminfo.semaem = used_sems;
+ seminfo.semusz = context->ids.in_use;
+ seminfo.semaem = context->nr_used;
} else {
seminfo.semusz = SEMUSZ;
seminfo.semaem = SEMAEM;
}
- max_id = sem_ids.max_id;
- up(&sem_ids.sem);
+ max_id = context->ids.max_id;
+ up(&context->ids.sem);
if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo)))
return -EFAULT;
return (max_id < 0) ? 0: max_id;
@@ -544,12 +547,12 @@ static int semctl_nolock(int semid, int
struct semid64_ds tbuf;
int id;

- if(semid >= sem_ids.entries->size)
+ if(semid >= context->ids.entries->size)
return -EINVAL;

memset(&tbuf,0,sizeof(tbuf));

- sma = sem_lock(semid);
+ sma = sem_lock(context, semid);
if(sma == NULL)
return -EINVAL;

@@ -561,13 +564,13 @@ static int semctl_nolock(int semid, int
if (err)
goto out_unlock;

- id = sem_buildid(semid, sma->sem_perm.seq);
+ id = sem_buildid(context, semid, sma->sem_perm.seq);

kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
tbuf.sem_otime = sma->sem_otime;
tbuf.sem_ctime = sma->sem_ctime;
tbuf.sem_nsems = sma->sem_nsems;
- sem_unlock(sma);
+ sem_unlock(context, sma);
if (copy_semid_to_user (arg.buf, &tbuf, version))
return -EFAULT;
return id;
@@ -577,11 +580,13 @@ static int semctl_nolock(int semid, int
}
return err;
out_unlock:
- sem_unlock(sma);
+ sem_unlock(context, sma);
return err;
}

-static int semctl_main(int semid, int semnum, int cmd, int version, union semun arg)
+static int semctl_main(struct ipc_sem_context *context,
+ int semid, int semnum, int cmd,
+ int version, union semun arg)
{
struct sem_array *sma;
struct sem* curr;
@@ -590,14 +595,14 @@ static int semctl_main(int semid, int se
ushort* sem_io = fast_sem_io;
int nsems;

- sma = sem_lock(semid);
+ sma = sem_lock(context, semid);
if(sma==NULL)
return -EINVAL;

nsems = sma->sem_nsems;

err=-EIDRM;
- if (sem_checkid(sma,semid))
+ if (sem_checkid(context, sma,semid))
goto out_unlock;

err = -EACCES;
@@ -617,20 +622,20 @@ static int semctl_main(int semid, int se

if(nsems > SEMMSL_FAST) {
ipc_rcu_getref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);

sem_io = ipc_alloc(sizeof(ushort)*nsems);
if(sem_io == NULL) {
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);
return -ENOMEM;
}

ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ sem_unlock(context, sma);
err = -EIDRM;
goto out_free;
}
@@ -638,7 +643,7 @@ static int semctl_main(int semid, int se

for (i = 0; i < sma->sem_nsems; i++)
sem_io[i] = sma->sem_base[i].semval;
- sem_unlock(sma);
+ sem_unlock(context, sma);
err = 0;
if(copy_to_user(array, sem_io, nsems*sizeof(ushort)))
err = -EFAULT;
@@ -650,14 +655,14 @@ static int semctl_main(int semid, int se
struct sem_undo *un;

ipc_rcu_getref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);

if(nsems > SEMMSL_FAST) {
sem_io = ipc_alloc(sizeof(ushort)*nsems);
if(sem_io == NULL) {
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);
return -ENOMEM;
}
}
@@ -665,7 +670,7 @@ static int semctl_main(int semid, int se
if (copy_from_user (sem_io, arg.array, nsems*sizeof(ushort))) {
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);
err = -EFAULT;
goto out_free;
}
@@ -674,7 +679,7 @@ static int semctl_main(int semid, int se
if (sem_io[i] > SEMVMX) {
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);
err = -ERANGE;
goto out_free;
}
@@ -682,7 +687,7 @@ static int semctl_main(int semid, int se
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ sem_unlock(context, sma);
err = -EIDRM;
goto out_free;
}
@@ -706,7 +711,7 @@ static int semctl_main(int semid, int se
tbuf.sem_otime = sma->sem_otime;
tbuf.sem_ctime = sma->sem_ctime;
tbuf.sem_nsems = sma->sem_nsems;
- sem_unlock(sma);
+ sem_unlock(context, sma);
if (copy_semid_to_user (arg.buf, &tbuf, version))
return -EFAULT;
return 0;
@@ -752,7 +757,7 @@ static int semctl_main(int semid, int se
}
}
out_unlock:
- sem_unlock(sma);
+ sem_unlock(context, sma);
out_free:
if(sem_io != fast_sem_io)
ipc_free(sem_io, sizeof(ushort)*nsems);
@@ -799,7 +804,9 @@ static inline unsigned long copy_semid_f
}
}

-static int semctl_down(int semid, int semnum, int cmd, int version, union semun arg)
+static int semctl_down(struct ipc_sem_context *context,
+ int semid, int semnum, int cmd,
+ int version, union semun arg)
{
struct sem_array *sma;
int err;
@@ -812,11 +819,11 @@ static int semctl_down(int semid, int se
if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid, setbuf.mode)))
return err;
}
- sma = sem_lock(semid);
+ sma = sem_lock(context, semid);
if(sma==NULL)
return -EINVAL;

- if (sem_checkid(sma,semid)) {
+ if (sem_checkid(context, sma,semid)) {
err=-EIDRM;
goto out_unlock;
}
@@ -834,7 +841,7 @@ static int semctl_down(int semid, int se

switch(cmd){
case IPC_RMID:
- freeary(sma, semid);
+ freeary(context, sma, semid);
err = 0;
break;
case IPC_SET:
@@ -843,18 +850,18 @@ static int semctl_down(int semid, int se
ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
| (setbuf.mode & S_IRWXUGO);
sma->sem_ctime = get_seconds();
- sem_unlock(sma);
+ sem_unlock(context, sma);
err = 0;
break;
default:
- sem_unlock(sma);
+ sem_unlock(context, sma);
err = -EINVAL;
break;
}
return err;

out_unlock:
- sem_unlock(sma);
+ sem_unlock(context, sma);
return err;
}

@@ -862,6 +869,7 @@ asmlinkage long sys_semctl (int semid, i
{
int err = -EINVAL;
int version;
+ struct ipc_sem_context *context = &current->ipc_context->sem;

if (semid < 0)
return -EINVAL;
@@ -872,7 +880,7 @@ asmlinkage long sys_semctl (int semid, i
case IPC_INFO:
case SEM_INFO:
case SEM_STAT:
- err = semctl_nolock(semid,semnum,cmd,version,arg);
+ err = semctl_nolock(context, semid,semnum,cmd,version,arg);
return err;
case GETALL:
case GETVAL:
@@ -882,13 +890,13 @@ asmlinkage long sys_semctl (int semid, i
case IPC_STAT:
case SETVAL:
case SETALL:
- err = semctl_main(semid,semnum,cmd,version,arg);
+ err = semctl_main(context, semid,semnum,cmd,version,arg);
return err;
case IPC_RMID:
case IPC_SET:
- down(&sem_ids.sem);
- err = semctl_down(semid,semnum,cmd,version,arg);
- up(&sem_ids.sem);
+ down(&context->ids.sem);
+ err = semctl_down(context, semid,semnum,cmd,version,arg);
+ up(&context->ids.sem);
return err;
default:
return -EINVAL;
@@ -976,7 +984,7 @@ static struct sem_undo *lookup_undo(stru
return un;
}

-static struct sem_undo *find_undo(int semid)
+static struct sem_undo *find_undo(struct ipc_sem_context *context, int semid)
{
struct sem_array *sma;
struct sem_undo_list *ulp;
@@ -995,24 +1003,24 @@ static struct sem_undo *find_undo(int se
goto out;

/* no undo structure around - allocate one. */
- sma = sem_lock(semid);
+ sma = sem_lock(context, semid);
un = ERR_PTR(-EINVAL);
if(sma==NULL)
goto out;
un = ERR_PTR(-EIDRM);
- if (sem_checkid(sma,semid)) {
- sem_unlock(sma);
+ if (sem_checkid(context, sma,semid)) {
+ sem_unlock(context, sma);
goto out;
}
nsems = sma->sem_nsems;
ipc_rcu_getref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);

new = (struct sem_undo *) kmalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
if (!new) {
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);
return ERR_PTR(-ENOMEM);
}
memset(new, 0, sizeof(struct sem_undo) + sizeof(short)*nsems);
@@ -1026,13 +1034,13 @@ static struct sem_undo *find_undo(int se
kfree(new);
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
- sem_unlock(sma);
+ sem_unlock(context, sma);
goto out;
}
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
if (sma->sem_perm.deleted) {
- sem_unlock(sma);
+ sem_unlock(context, sma);
unlock_semundo();
kfree(new);
un = ERR_PTR(-EIDRM);
@@ -1042,7 +1050,7 @@ static struct sem_undo *find_undo(int se
ulp->proc_list = new;
new->id_next = sma->undo;
sma->undo = new;
- sem_unlock(sma);
+ sem_unlock(context, sma);
un = new;
unlock_semundo();
out:
@@ -1052,6 +1060,7 @@ out:
asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
unsigned nsops, const struct timespec __user *timeout)
{
+ struct ipc_sem_context *context = &current->ipc_context->sem;
int error = -EINVAL;
struct sem_array *sma;
struct sembuf fast_sops[SEMOPM_FAST];
@@ -1099,7 +1108,7 @@ asmlinkage long sys_semtimedop(int semid

retry_undos:
if (undos) {
- un = find_undo(semid);
+ un = find_undo(context, semid);
if (IS_ERR(un)) {
error = PTR_ERR(un);
goto out_free;
@@ -1107,12 +1116,12 @@ retry_undos:
} else
un = NULL;

- sma = sem_lock(semid);
+ sma = sem_lock(context, semid);
error=-EINVAL;
if(sma==NULL)
goto out_free;
error = -EIDRM;
- if (sem_checkid(sma,semid))
+ if (sem_checkid(context, sma,semid))
goto out_unlock_free;
/*
* semid identifies are not unique - find_undo may have
@@ -1120,7 +1129,7 @@ retry_undos:
* and now a new array with received the same id. Check and retry.
*/
if (un && un->semid == -1) {
- sem_unlock(sma);
+ sem_unlock(context, sma);
goto retry_undos;
}
error = -EFBIG;
@@ -1161,7 +1170,7 @@ retry_undos:
queue.status = -EINTR;
queue.sleeper = current;
current->state = TASK_INTERRUPTIBLE;
- sem_unlock(sma);
+ sem_unlock(context, sma);

if (timeout)
jiffies_left = schedule_timeout(jiffies_left);
@@ -1180,7 +1189,7 @@ retry_undos:
goto out_free;
}

- sma = sem_lock(semid);
+ sma = sem_lock(context, semid);
if(sma==NULL) {
if(queue.prev != NULL)
BUG();
@@ -1205,7 +1214,7 @@ retry_undos:
goto out_unlock_free;

out_unlock_free:
- sem_unlock(sma);
+ sem_unlock(context, sma);
out_free:
if(sops != fast_sops)
kfree(sops);
@@ -1258,6 +1267,7 @@ void exit_sem(struct task_struct *tsk)
{
struct sem_undo_list *undo_list;
struct sem_undo *u, **up;
+ struct ipc_sem_context *context = &tsk->ipc_context->sem;

undo_list = tsk->sysvsem.undo_list;
if (!undo_list)
@@ -1279,14 +1289,14 @@ void exit_sem(struct task_struct *tsk)

if(semid == -1)
continue;
- sma = sem_lock(semid);
+ sma = sem_lock(context, semid);
if (sma == NULL)
continue;

if (u->semid == -1)
goto next_entry;

- BUG_ON(sem_checkid(sma,u->semid));
+ BUG_ON(sem_checkid(context, sma,u->semid));

/* remove u from the sma->undo list */
for (unp = &sma->undo; (un = *unp); unp = &un->id_next) {
@@ -1327,7 +1337,7 @@ found:
/* maybe some queued-up processes were waiting for this */
update_queue(sma);
next_entry:
- sem_unlock(sma);
+ sem_unlock(context, sma);
}
kfree(undo_list);
}
diff -puN ipc/util.c~sysvsem-container ipc/util.c
--- work/ipc/util.c~sysvsem-container 2006-03-06 15:41:58.000000000 -0800
+++ work-dave/ipc/util.c 2006-03-06 15:41:58.000000000 -0800
@@ -52,7 +52,7 @@ static int __init ipc_init(void)
if (!init_task.ipc_context)
return -ENOMEM;

- sem_init();
+ sem_init(&init_task.ipc_context->sem);
msg_init(&init_task.ipc_context->msg);
shm_init();
return 0;
diff -puN ipc/util.h~sysvsem-container ipc/util.h
--- work/ipc/util.h~sysvsem-container 2006-03-06 15:41:58.000000000 -0800
+++ work-dave/ipc/util.h 2006-03-06 15:41:58.000000000 -0800
@@ -11,10 +11,6 @@
#define USHRT_MAX 0xffff
#define SEQ_MULTIPLIER (IPCMNI)

-void sem_init (void);
-void msg_init (struct ipc_msg_context *context);
-void shm_init (void);
-
struct ipc_id_ary {
int size;
struct kern_ipc_perm *p[0];
@@ -42,10 +38,21 @@ struct ipc_msg_context {
struct kref count;
};

+struct ipc_sem_context {
+ struct ipc_ids ids;
+
+ int nr_used;
+};
+
struct ipc_context {
struct ipc_msg_context msg;
+ struct ipc_sem_context sem;
};

+void sem_init (struct ipc_sem_context *context);
+void msg_init (struct ipc_msg_context *context);
+void shm_init (void);
+
struct seq_file;
void __init ipc_init_ids(struct ipc_ids* ids, int size);
#ifdef CONFIG_PROC_FS
_
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