[PATCH] IPC namespace - sem

IPC namespace support for IPC sem code.

Signed-off-by: Pavel Emelianiov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/ipc/sem.c b/ipc/sem.c
index 6013c751156fe81bee30536bef27bab7792eb1bb..69edeb1e2a65c5b67ac5a585577d4aeb1a7859de 100644 (file)
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -64,6 +64,10 @@
  *
  * support for audit of ipc object properties and permission changes
  * Dustin Kirkland <dustin.kirkland@us.ibm.com>
+ *
+ * namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
  */
 
 #include <linux/slab.h>
@@ -78,22 +82,25 @@
 #include <linux/capability.h>
 #include <linux/seq_file.h>
 #include <linux/mutex.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 #include "util.h"
 
+#define sem_ids(ns)    (*((ns)->ids[IPC_SEM_IDS]))
+
+#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) \
+       ipc_buildid(&sem_ids(ns), id, seq)
 
-#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;
+static struct ipc_ids init_sem_ids;
 
-static int newary (key_t, int, int);
-static void freeary (struct sem_array *sma, int id);
+static int newary(struct ipc_namespace *, key_t, int, int);
+static void freeary(struct ipc_namespace *ns, struct sem_array *sma, int id);
 #ifdef CONFIG_PROC_FS
 static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
 #endif
@@ -110,22 +117,61 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
  *     
  */
 
-int sem_ctls[4] = {SEMMSL, SEMMNS, SEMOPM, SEMMNI};
-#define sc_semmsl      (sem_ctls[0])
-#define sc_semmns      (sem_ctls[1])
-#define sc_semopm      (sem_ctls[2])
-#define sc_semmni      (sem_ctls[3])
+#define sc_semmsl      sem_ctls[0]
+#define sc_semmns      sem_ctls[1]
+#define sc_semopm      sem_ctls[2]
+#define sc_semmni      sem_ctls[3]
+
+static void __ipc_init __sem_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+{
+       ns->ids[IPC_SEM_IDS] = ids;
+       ns->sc_semmsl = SEMMSL;
+       ns->sc_semmns = SEMMNS;
+       ns->sc_semopm = SEMOPM;
+       ns->sc_semmni = SEMMNI;
+       ns->used_sems = 0;
+       ipc_init_ids(ids, ns->sc_semmni);
+}
+
+#ifdef CONFIG_IPC_NS
+int sem_init_ns(struct ipc_namespace *ns)
+{
+       struct ipc_ids *ids;
+
+       ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
+       if (ids == NULL)
+               return -ENOMEM;
+
+       __sem_init_ns(ns, ids);
+       return 0;
+}
+
+void sem_exit_ns(struct ipc_namespace *ns)
+{
+       int i;
+       struct sem_array *sma;
+
+       mutex_lock(&sem_ids(ns).mutex);
+       for (i = 0; i <= sem_ids(ns).max_id; i++) {
+               sma = sem_lock(ns, i);
+               if (sma == NULL)
+                       continue;
+
+               freeary(ns, sma, i);
+       }
+       mutex_unlock(&sem_ids(ns).mutex);
 
-static int used_sems;
+       kfree(ns->ids[IPC_SEM_IDS]);
+       ns->ids[IPC_SEM_IDS] = NULL;
+}
+#endif
 
 void __init sem_init (void)
 {
-       used_sems = 0;
-       ipc_init_ids(&sem_ids,sc_semmni);
+       __sem_init_ns(&init_ipc_ns, &init_sem_ids);
        ipc_init_proc_interface("sysvipc/sem",
                                "       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
-                               &sem_ids,
-                               sysvipc_sem_proc_show);
+                               IPC_SEM_IDS, sysvipc_sem_proc_show);
 }
 
 /*
@@ -162,7 +208,7 @@ void __init sem_init (void)
  */
 #define IN_WAKEUP      1
 
-static int newary (key_t key, int nsems, int semflg)
+static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
 {
        int id;
        int retval;
@@ -171,7 +217,7 @@ static int newary (key_t key, int nsems, int semflg)
 
        if (!nsems)
                return -EINVAL;
-       if (used_sems + nsems > sc_semmns)
+       if (ns->used_sems + nsems > ns->sc_semmns)
                return -ENOSPC;
 
        size = sizeof (*sma) + nsems * sizeof (struct sem);
@@ -191,15 +237,15 @@ static int newary (key_t key, int nsems, int semflg)
                return retval;
        }
 
-       id = ipc_addid(&sem_ids, &sma->sem_perm, sc_semmni);
+       id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni);
        if(id == -1) {
                security_sem_free(sma);
                ipc_rcu_putref(sma);
                return -ENOSPC;
        }
-       used_sems += nsems;
+       ns->used_sems += nsems;
 
-       sma->sem_id = sem_buildid(id, sma->sem_perm.seq);
+       sma->sem_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;
@@ -215,29 +261,32 @@ asmlinkage long sys_semget (key_t key, int nsems, int semflg)
 {
        int id, err = -EINVAL;
        struct sem_array *sma;
+       struct ipc_namespace *ns;
+
+       ns = current->nsproxy->ipc_ns;
 
-       if (nsems < 0 || nsems > sc_semmsl)
+       if (nsems < 0 || nsems > ns->sc_semmsl)
                return -EINVAL;
-       mutex_lock(&sem_ids.mutex);
+       mutex_lock(&sem_ids(ns).mutex);
        
        if (key == IPC_PRIVATE) {
-               err = newary(key, nsems, semflg);
-       } else if ((id = ipc_findkey(&sem_ids, key)) == -1) {  /* key not used */
+               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(key, nsems, semflg);
+                       err = newary(ns, key, nsems, semflg);
        } else if (semflg & IPC_CREAT && semflg & IPC_EXCL) {
                err = -EEXIST;
        } else {
-               sma = sem_lock(id);
+               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;
                else {
-                       int semid = sem_buildid(id, sma->sem_perm.seq);
+                       int semid = sem_buildid(ns, id, sma->sem_perm.seq);
                        err = security_sem_associate(sma, semflg);
                        if (!err)
                                err = semid;
@@ -245,7 +294,7 @@ asmlinkage long sys_semget (key_t key, int nsems, int semflg)
                sem_unlock(sma);
        }
 
-       mutex_unlock(&sem_ids.mutex);
+       mutex_unlock(&sem_ids(ns).mutex);
        return err;
 }
 
@@ -444,7 +493,7 @@ 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 sem_array *sma, int id)
+static void freeary (struct ipc_namespace *ns, struct sem_array *sma, int id)
 {
        struct sem_undo *un;
        struct sem_queue *q;
@@ -472,10 +521,10 @@ static void freeary (struct sem_array *sma, int id)
        }
 
        /* Remove the semaphore set from the ID array*/
-       sma = sem_rmid(id);
+       sma = sem_rmid(ns, id);
        sem_unlock(sma);
 
-       used_sems -= sma->sem_nsems;
+       ns->used_sems -= sma->sem_nsems;
        size = sizeof (*sma) + sma->sem_nsems * sizeof (struct sem);
        security_sem_free(sma);
        ipc_rcu_putref(sma);
@@ -503,7 +552,8 @@ static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in,
        }
 }
 
-static int semctl_nolock(int semid, int semnum, int cmd, int version, union semun arg)
+static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
+               int cmd, int version, union semun arg)
 {
        int err = -EINVAL;
        struct sem_array *sma;
@@ -520,24 +570,24 @@ static int semctl_nolock(int semid, int semnum, int cmd, int version, union semu
                        return err;
                
                memset(&seminfo,0,sizeof(seminfo));
-               seminfo.semmni = sc_semmni;
-               seminfo.semmns = sc_semmns;
-               seminfo.semmsl = sc_semmsl;
-               seminfo.semopm = sc_semopm;
+               seminfo.semmni = ns->sc_semmni;
+               seminfo.semmns = ns->sc_semmns;
+               seminfo.semmsl = ns->sc_semmsl;
+               seminfo.semopm = ns->sc_semopm;
                seminfo.semvmx = SEMVMX;
                seminfo.semmnu = SEMMNU;
                seminfo.semmap = SEMMAP;
                seminfo.semume = SEMUME;
-               mutex_lock(&sem_ids.mutex);
+               mutex_lock(&sem_ids(ns).mutex);
                if (cmd == SEM_INFO) {
-                       seminfo.semusz = sem_ids.in_use;
-                       seminfo.semaem = used_sems;
+                       seminfo.semusz = sem_ids(ns).in_use;
+                       seminfo.semaem = ns->used_sems;
                } else {
                        seminfo.semusz = SEMUSZ;
                        seminfo.semaem = SEMAEM;
                }
-               max_id = sem_ids.max_id;
-               mutex_unlock(&sem_ids.mutex);
+               max_id = sem_ids(ns).max_id;
+               mutex_unlock(&sem_ids(ns).mutex);
                if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo))) 
                        return -EFAULT;
                return (max_id < 0) ? 0: max_id;
@@ -547,12 +597,12 @@ static int semctl_nolock(int semid, int semnum, int cmd, int version, union semu
                struct semid64_ds tbuf;
                int id;
 
-               if(semid >= sem_ids.entries->size)
+               if(semid >= sem_ids(ns).entries->size)
                        return -EINVAL;
 
                memset(&tbuf,0,sizeof(tbuf));
 
-               sma = sem_lock(semid);
+               sma = sem_lock(ns, semid);
                if(sma == NULL)
                        return -EINVAL;
 
@@ -564,7 +614,7 @@ static int semctl_nolock(int semid, int semnum, int cmd, int version, union semu
                if (err)
                        goto out_unlock;
 
-               id = sem_buildid(semid, sma->sem_perm.seq);
+               id = sem_buildid(ns, semid, sma->sem_perm.seq);
 
                kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
                tbuf.sem_otime  = sma->sem_otime;
@@ -584,7 +634,8 @@ out_unlock:
        return err;
 }
 
-static int semctl_main(int semid, int semnum, int cmd, int version, union semun arg)
+static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
+               int cmd, int version, union semun arg)
 {
        struct sem_array *sma;
        struct sem* curr;
@@ -593,14 +644,14 @@ static int semctl_main(int semid, int semnum, int cmd, int version, union semun
        ushort* sem_io = fast_sem_io;
        int nsems;
 
-       sma = sem_lock(semid);
+       sma = sem_lock(ns, semid);
        if(sma==NULL)
                return -EINVAL;
 
        nsems = sma->sem_nsems;
 
        err=-EIDRM;
-       if (sem_checkid(sma,semid))
+       if (sem_checkid(ns,sma,semid))
                goto out_unlock;
 
        err = -EACCES;
@@ -802,7 +853,8 @@ static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __
        }
 }
 
-static int semctl_down(int semid, int semnum, int cmd, int version, union semun arg)
+static int semctl_down(struct ipc_namespace *ns, int semid, int semnum,
+               int cmd, int version, union semun arg)
 {
        struct sem_array *sma;
        int err;
@@ -813,11 +865,11 @@ static int semctl_down(int semid, int semnum, int cmd, int version, union semun
                if(copy_semid_from_user (&setbuf, arg.buf, version))
                        return -EFAULT;
        }
-       sma = sem_lock(semid);
+       sma = sem_lock(ns, semid);
        if(sma==NULL)
                return -EINVAL;
 
-       if (sem_checkid(sma,semid)) {
+       if (sem_checkid(ns,sma,semid)) {
                err=-EIDRM;
                goto out_unlock;
        }       
@@ -844,7 +896,7 @@ static int semctl_down(int semid, int semnum, int cmd, int version, union semun
 
        switch(cmd){
        case IPC_RMID:
-               freeary(sma, semid);
+               freeary(ns, sma, semid);
                err = 0;
                break;
        case IPC_SET:
@@ -872,17 +924,19 @@ asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
 {
        int err = -EINVAL;
        int version;
+       struct ipc_namespace *ns;
 
        if (semid < 0)
                return -EINVAL;
 
        version = ipc_parse_version(&cmd);
+       ns = current->nsproxy->ipc_ns;
 
        switch(cmd) {
        case IPC_INFO:
        case SEM_INFO:
        case SEM_STAT:
-               err = semctl_nolock(semid,semnum,cmd,version,arg);
+               err = semctl_nolock(ns,semid,semnum,cmd,version,arg);
                return err;
        case GETALL:
        case GETVAL:
@@ -892,13 +946,13 @@ asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
        case IPC_STAT:
        case SETVAL:
        case SETALL:
-               err = semctl_main(semid,semnum,cmd,version,arg);
+               err = semctl_main(ns,semid,semnum,cmd,version,arg);
                return err;
        case IPC_RMID:
        case IPC_SET:
-               mutex_lock(&sem_ids.mutex);
-               err = semctl_down(semid,semnum,cmd,version,arg);
-               mutex_unlock(&sem_ids.mutex);
+               mutex_lock(&sem_ids(ns).mutex);
+               err = semctl_down(ns,semid,semnum,cmd,version,arg);
+               mutex_unlock(&sem_ids(ns).mutex);
                return err;
        default:
                return -EINVAL;
@@ -986,7 +1040,7 @@ static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
        return un;
 }
 
-static struct sem_undo *find_undo(int semid)
+static struct sem_undo *find_undo(struct ipc_namespace *ns, int semid)
 {
        struct sem_array *sma;
        struct sem_undo_list *ulp;
@@ -1005,12 +1059,12 @@ static struct sem_undo *find_undo(int semid)
                goto out;
 
        /* no undo structure around - allocate one. */
-       sma = sem_lock(semid);
+       sma = sem_lock(ns, semid);
        un = ERR_PTR(-EINVAL);
        if(sma==NULL)
                goto out;
        un = ERR_PTR(-EIDRM);
-       if (sem_checkid(sma,semid)) {
+       if (sem_checkid(ns,sma,semid)) {
                sem_unlock(sma);
                goto out;
        }
@@ -1070,10 +1124,13 @@ asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
        int undos = 0, alter = 0, max;
        struct sem_queue queue;
        unsigned long jiffies_left = 0;
+       struct ipc_namespace *ns;
+
+       ns = current->nsproxy->ipc_ns;
 
        if (nsops < 1 || semid < 0)
                return -EINVAL;
-       if (nsops > sc_semopm)
+       if (nsops > ns->sc_semopm)
                return -E2BIG;
        if(nsops > SEMOPM_FAST) {
                sops = kmalloc(sizeof(*sops)*nsops,GFP_KERNEL);
@@ -1109,7 +1166,7 @@ asmlinkage long sys_semtimedop(int semid, struct sembuf __user *tsops,
 
 retry_undos:
        if (undos) {
-               un = find_undo(semid);
+               un = find_undo(ns, semid);
                if (IS_ERR(un)) {
                        error = PTR_ERR(un);
                        goto out_free;
@@ -1117,12 +1174,12 @@ retry_undos:
        } else
                un = NULL;
 
-       sma = sem_lock(semid);
+       sma = sem_lock(ns, semid);
        error=-EINVAL;
        if(sma==NULL)
                goto out_free;
        error = -EIDRM;
-       if (sem_checkid(sma,semid))
+       if (sem_checkid(ns,sma,semid))
                goto out_unlock_free;
        /*
         * semid identifies are not unique - find_undo may have
@@ -1190,7 +1247,7 @@ retry_undos:
                goto out_free;
        }
 
-       sma = sem_lock(semid);
+       sma = sem_lock(ns, semid);
        if(sma==NULL) {
                BUG_ON(queue.prev != NULL);
                error = -EIDRM;
@@ -1267,6 +1324,7 @@ void exit_sem(struct task_struct *tsk)
 {
        struct sem_undo_list *undo_list;
        struct sem_undo *u, **up;
+       struct ipc_namespace *ns;
 
        undo_list = tsk->sysvsem.undo_list;
        if (!undo_list)
@@ -1275,6 +1333,7 @@ void exit_sem(struct task_struct *tsk)
        if (!atomic_dec_and_test(&undo_list->refcnt))
                return;
 
+       ns = tsk->nsproxy->ipc_ns;
        /* There's no need to hold the semundo list lock, as current
          * is the last task exiting for this undo list.
         */
@@ -1288,14 +1347,14 @@ void exit_sem(struct task_struct *tsk)
 
                if(semid == -1)
                        continue;
-               sma = sem_lock(semid);
+               sma = sem_lock(ns, semid);
                if (sma == NULL)
                        continue;
 
                if (u->semid == -1)
                        goto next_entry;
 
-               BUG_ON(sem_checkid(sma,u->semid));
+               BUG_ON(sem_checkid(ns,sma,u->semid));
 
                /* remove u from the sma->undo list */
                for (unp = &sma->undo; (un = *unp); unp = &un->id_next) {