ipc: add definitions of USHORT_MAX and others
[safe/jmp/linux-2.6] / ipc / sem.c
index 84c701f..d56d3ab 100644 (file)
--- a/ipc/sem.c
+++ b/ipc/sem.c
 #include <asm/uaccess.h>
 #include "util.h"
 
-#define sem_ids(ns)    (*((ns)->ids[IPC_SEM_IDS]))
+#define sem_ids(ns)    ((ns)->ids[IPC_SEM_IDS])
 
 #define sem_unlock(sma)                ipc_unlock(&(sma)->sem_perm)
 #define sem_checkid(sma, semid)        ipc_checkid(&sma->sem_perm, semid)
-#define sem_buildid(id, seq)   ipc_buildid(id, seq)
-
-static struct ipc_ids init_sem_ids;
 
 static int newary(struct ipc_namespace *, struct ipc_params *);
-static void freeary(struct ipc_namespace *, struct sem_array *);
+static void freeary(struct ipc_namespace *, struct kern_ipc_perm *);
 #ifdef CONFIG_PROC_FS
 static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
 #endif
@@ -118,81 +115,32 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
 #define sc_semopm      sem_ctls[2]
 #define sc_semmni      sem_ctls[3]
 
-static void __sem_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+void sem_init_ns(struct ipc_namespace *ns)
 {
-       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);
+       ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
 }
 
 #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)
 {
-       struct sem_array *sma;
-       struct kern_ipc_perm *perm;
-       int next_id;
-       int total, in_use;
-
-       down_write(&sem_ids(ns).rw_mutex);
-
-       in_use = sem_ids(ns).in_use;
-
-       for (total = 0, next_id = 0; total < in_use; next_id++) {
-               perm = idr_find(&sem_ids(ns).ipcs_idr, next_id);
-               if (perm == NULL)
-                       continue;
-               ipc_lock_by_ptr(perm);
-               sma = container_of(perm, struct sem_array, sem_perm);
-               freeary(ns, sma);
-               total++;
-       }
-       up_write(&sem_ids(ns).rw_mutex);
-
-       kfree(ns->ids[IPC_SEM_IDS]);
-       ns->ids[IPC_SEM_IDS] = NULL;
+       free_ipcs(ns, &sem_ids(ns), freeary);
 }
 #endif
 
 void __init sem_init (void)
 {
-       __sem_init_ns(&init_ipc_ns, &init_sem_ids);
+       sem_init_ns(&init_ipc_ns);
        ipc_init_proc_interface("sysvipc/sem",
                                "       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
                                IPC_SEM_IDS, sysvipc_sem_proc_show);
 }
 
 /*
- * This routine is called in the paths where the rw_mutex is held to protect
- * access to the idr tree.
- */
-static inline struct sem_array *sem_lock_check_down(struct ipc_namespace *ns,
-                                               int id)
-{
-       struct kern_ipc_perm *ipcp = ipc_lock_check_down(&sem_ids(ns), id);
-
-       if (IS_ERR(ipcp))
-               return (struct sem_array *)ipcp;
-
-       return container_of(ipcp, struct sem_array, sem_perm);
-}
-
-/*
  * sem_lock_(check_) routines are called in the paths where the rw_mutex
  * is not held.
  */
@@ -217,6 +165,25 @@ static inline struct sem_array *sem_lock_check(struct ipc_namespace *ns,
        return container_of(ipcp, struct sem_array, sem_perm);
 }
 
+static inline void sem_lock_and_putref(struct sem_array *sma)
+{
+       ipc_lock_by_ptr(&sma->sem_perm);
+       ipc_rcu_putref(sma);
+}
+
+static inline void sem_getref_and_unlock(struct sem_array *sma)
+{
+       ipc_rcu_getref(sma);
+       ipc_unlock(&(sma)->sem_perm);
+}
+
+static inline void sem_putref(struct sem_array *sma)
+{
+       ipc_lock_by_ptr(&sma->sem_perm);
+       ipc_rcu_putref(sma);
+       ipc_unlock(&(sma)->sem_perm);
+}
+
 static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
 {
        ipc_rmid(&sem_ids(ns), &s->sem_perm);
@@ -304,7 +271,6 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
        }
        ns->used_sems += nsems;
 
-       sma->sem_perm.id = sem_buildid(id, sma->sem_perm.seq);
        sma->sem_base = (struct sem *) &sma[1];
        /* sma->sem_pending = NULL; */
        sma->sem_pending_last = &sma->sem_pending;
@@ -560,10 +526,11 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum)
  * as a writer and the spinlock for this semaphore set hold. sem_ids.rw_mutex
  * remains locked on exit.
  */
-static void freeary(struct ipc_namespace *ns, struct sem_array *sma)
+static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 {
        struct sem_undo *un;
        struct sem_queue *q;
+       struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
 
        /* Invalidate the existing undo structures for this semaphore set.
         * (They will be freed without any further action in exit_sem()
@@ -617,8 +584,8 @@ static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in,
        }
 }
 
-static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
-               int cmd, int version, union semun arg)
+static int semctl_nolock(struct ipc_namespace *ns, int semid,
+                        int cmd, int version, union semun arg)
 {
        int err = -EINVAL;
        struct sem_array *sma;
@@ -657,14 +624,23 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
                        return -EFAULT;
                return (max_id < 0) ? 0: max_id;
        }
+       case IPC_STAT:
        case SEM_STAT:
        {
                struct semid64_ds tbuf;
                int id;
 
-               sma = sem_lock(ns, semid);
-               if (IS_ERR(sma))
-                       return PTR_ERR(sma);
+               if (cmd == SEM_STAT) {
+                       sma = sem_lock(ns, semid);
+                       if (IS_ERR(sma))
+                               return PTR_ERR(sma);
+                       id = sma->sem_perm.id;
+               } else {
+                       sma = sem_lock_check(ns, semid);
+                       if (IS_ERR(sma))
+                               return PTR_ERR(sma);
+                       id = 0;
+               }
 
                err = -EACCES;
                if (ipcperms (&sma->sem_perm, S_IRUGO))
@@ -674,8 +650,6 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
                if (err)
                        goto out_unlock;
 
-               id = sma->sem_perm.id;
-
                memset(&tbuf, 0, sizeof(tbuf));
 
                kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
@@ -728,19 +702,15 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
                int i;
 
                if(nsems > SEMMSL_FAST) {
-                       ipc_rcu_getref(sma);
-                       sem_unlock(sma);                        
+                       sem_getref_and_unlock(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_putref(sma);
                                return -ENOMEM;
                        }
 
-                       ipc_lock_by_ptr(&sma->sem_perm);
-                       ipc_rcu_putref(sma);
+                       sem_lock_and_putref(sma);
                        if (sma->sem_perm.deleted) {
                                sem_unlock(sma);
                                err = -EIDRM;
@@ -761,38 +731,30 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
                int i;
                struct sem_undo *un;
 
-               ipc_rcu_getref(sma);
-               sem_unlock(sma);
+               sem_getref_and_unlock(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_putref(sma);
                                return -ENOMEM;
                        }
                }
 
                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_putref(sma);
                        err = -EFAULT;
                        goto out_free;
                }
 
                for (i = 0; i < nsems; i++) {
                        if (sem_io[i] > SEMVMX) {
-                               ipc_lock_by_ptr(&sma->sem_perm);
-                               ipc_rcu_putref(sma);
-                               sem_unlock(sma);
+                               sem_putref(sma);
                                err = -ERANGE;
                                goto out_free;
                        }
                }
-               ipc_lock_by_ptr(&sma->sem_perm);
-               ipc_rcu_putref(sma);
+               sem_lock_and_putref(sma);
                if (sma->sem_perm.deleted) {
                        sem_unlock(sma);
                        err = -EIDRM;
@@ -810,19 +772,6 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
                err = 0;
                goto out_unlock;
        }
-       case IPC_STAT:
-       {
-               struct semid64_ds tbuf;
-               memset(&tbuf,0,sizeof(tbuf));
-               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);
-               if (copy_semid_to_user (arg.buf, &tbuf, version))
-                       return -EFAULT;
-               return 0;
-       }
        /* GETVAL, GETPID, GETNCTN, GETZCNT, SETVAL: fall-through */
        }
        err = -EINVAL;
@@ -871,28 +820,14 @@ out_free:
        return err;
 }
 
-struct sem_setbuf {
-       uid_t   uid;
-       gid_t   gid;
-       mode_t  mode;
-};
-
-static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
 {
        switch(version) {
        case IPC_64:
-           {
-               struct semid64_ds tbuf;
-
-               if(copy_from_user(&tbuf, buf, sizeof(tbuf)))
+               if (copy_from_user(out, buf, sizeof(*out)))
                        return -EFAULT;
-
-               out->uid        = tbuf.sem_perm.uid;
-               out->gid        = tbuf.sem_perm.gid;
-               out->mode       = tbuf.sem_perm.mode;
-
                return 0;
-           }
        case IPC_OLD:
            {
                struct semid_ds tbuf_old;
@@ -900,9 +835,9 @@ static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __
                if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
                        return -EFAULT;
 
-               out->uid        = tbuf_old.sem_perm.uid;
-               out->gid        = tbuf_old.sem_perm.gid;
-               out->mode       = tbuf_old.sem_perm.mode;
+               out->sem_perm.uid       = tbuf_old.sem_perm.uid;
+               out->sem_perm.gid       = tbuf_old.sem_perm.gid;
+               out->sem_perm.mode      = tbuf_old.sem_perm.mode;
 
                return 0;
            }
@@ -911,38 +846,29 @@ static inline unsigned long copy_semid_from_user(struct sem_setbuf *out, void __
        }
 }
 
-static int semctl_down(struct ipc_namespace *ns, int semid, int semnum,
-               int cmd, int version, union semun arg)
+/*
+ * This function handles some semctl commands which require the rw_mutex
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rw_mutex is taken inside this function.
+ */
+static int semctl_down(struct ipc_namespace *ns, int semid,
+                      int cmd, int version, union semun arg)
 {
        struct sem_array *sma;
        int err;
-       struct sem_setbuf uninitialized_var(setbuf);
+       struct semid64_ds semid64;
        struct kern_ipc_perm *ipcp;
 
        if(cmd == IPC_SET) {
-               if(copy_semid_from_user (&setbuf, arg.buf, version))
+               if (copy_semid_from_user(&semid64, arg.buf, version))
                        return -EFAULT;
        }
-       sma = sem_lock_check_down(ns, semid);
-       if (IS_ERR(sma))
-               return PTR_ERR(sma);
-
-       ipcp = &sma->sem_perm;
 
-       err = audit_ipc_obj(ipcp);
-       if (err)
-               goto out_unlock;
+       ipcp = ipcctl_pre_down(&sem_ids(ns), semid, cmd, &semid64.sem_perm, 0);
+       if (IS_ERR(ipcp))
+               return PTR_ERR(ipcp);
 
-       if (cmd == IPC_SET) {
-               err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
-               if (err)
-                       goto out_unlock;
-       }
-       if (current->euid != ipcp->cuid && 
-           current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) {
-               err=-EPERM;
-               goto out_unlock;
-       }
+       sma = container_of(ipcp, struct sem_array, sem_perm);
 
        err = security_sem_semctl(sma, cmd);
        if (err)
@@ -950,27 +876,20 @@ static int semctl_down(struct ipc_namespace *ns, int semid, int semnum,
 
        switch(cmd){
        case IPC_RMID:
-               freeary(ns, sma);
-               err = 0;
-               break;
+               freeary(ns, ipcp);
+               goto out_up;
        case IPC_SET:
-               ipcp->uid = setbuf.uid;
-               ipcp->gid = setbuf.gid;
-               ipcp->mode = (ipcp->mode & ~S_IRWXUGO)
-                               | (setbuf.mode & S_IRWXUGO);
+               ipc_update_perm(&semid64.sem_perm, ipcp);
                sma->sem_ctime = get_seconds();
-               sem_unlock(sma);
-               err = 0;
                break;
        default:
-               sem_unlock(sma);
                err = -EINVAL;
-               break;
        }
-       return err;
 
 out_unlock:
        sem_unlock(sma);
+out_up:
+       up_write(&sem_ids(ns).rw_mutex);
        return err;
 }
 
@@ -989,24 +908,22 @@ asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
        switch(cmd) {
        case IPC_INFO:
        case SEM_INFO:
+       case IPC_STAT:
        case SEM_STAT:
-               err = semctl_nolock(ns,semid,semnum,cmd,version,arg);
+               err = semctl_nolock(ns, semid, cmd, version, arg);
                return err;
        case GETALL:
        case GETVAL:
        case GETPID:
        case GETNCNT:
        case GETZCNT:
-       case IPC_STAT:
        case SETVAL:
        case SETALL:
                err = semctl_main(ns,semid,semnum,cmd,version,arg);
                return err;
        case IPC_RMID:
        case IPC_SET:
-               down_write(&sem_ids(ns).rw_mutex);
-               err = semctl_down(ns,semid,semnum,cmd,version,arg);
-               up_write(&sem_ids(ns).rw_mutex);
+               err = semctl_down(ns, semid, cmd, version, arg);
                return err;
        default:
                return -EINVAL;
@@ -1085,14 +1002,11 @@ static struct sem_undo *find_undo(struct ipc_namespace *ns, int semid)
                return ERR_PTR(PTR_ERR(sma));
 
        nsems = sma->sem_nsems;
-       ipc_rcu_getref(sma);
-       sem_unlock(sma);
+       sem_getref_and_unlock(sma);
 
        new = kzalloc(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_putref(sma);
                return ERR_PTR(-ENOMEM);
        }
        new->semadj = (short *) &new[1];
@@ -1103,13 +1017,10 @@ static struct sem_undo *find_undo(struct ipc_namespace *ns, int semid)
        if (un) {
                spin_unlock(&ulp->lock);
                kfree(new);
-               ipc_lock_by_ptr(&sma->sem_perm);
-               ipc_rcu_putref(sma);
-               sem_unlock(sma);
+               sem_putref(sma);
                goto out;
        }
-       ipc_lock_by_ptr(&sma->sem_perm);
-       ipc_rcu_putref(sma);
+       sem_lock_and_putref(sma);
        if (sma->sem_perm.deleted) {
                sem_unlock(sma);
                spin_unlock(&ulp->lock);