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author | Manfred Spraul <manfred@colorfullife.com> | 2004-08-22 22:40:49 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-22 22:40:49 -0700 |
commit | 208b201a7a507a1e08424f0eb1e7be7073490a95 (patch) | |
tree | 48e5c19c4ce4c9fdf9c7705cbe6bee4e8f27e1a0 /ipc | |
parent | 3a4262a016085f178811ec2459b93f63127e6280 (diff) | |
download | history-208b201a7a507a1e08424f0eb1e7be7073490a95.tar.gz |
[PATCH] ipc: remove sem_revalidate
The attached patch removes sem_revalidate and replaces it with
ipc_rcu_getref() calls followed by ipc_lock_by_ptr().
Signed-Off-By: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'ipc')
-rw-r--r-- | ipc/sem.c | 75 |
1 files changed, 46 insertions, 29 deletions
diff --git a/ipc/sem.c b/ipc/sem.c index e7af623f63171f..475b437d498091 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -241,25 +241,6 @@ asmlinkage long sys_semget (key_t key, int nsems, int semflg) return err; } -/* doesn't acquire the sem_lock on error! */ -static int sem_revalidate(int semid, struct sem_array* sma, int nsems, short flg) -{ - struct sem_array* smanew; - - smanew = sem_lock(semid); - if(smanew==NULL) - return -EIDRM; - if(smanew != sma || sem_checkid(sma,semid) || sma->sem_nsems != nsems) { - sem_unlock(smanew); - return -EIDRM; - } - - if (flg && ipcperms(&sma->sem_perm, flg)) { - sem_unlock(smanew); - return -EACCES; - } - return 0; -} /* Manage the doubly linked list sma->sem_pending as a FIFO: * insert new queue elements at the tail sma->sem_pending_last. */ @@ -614,13 +595,24 @@ static int semctl_main(int semid, int semnum, int cmd, int version, union semun int i; if(nsems > SEMMSL_FAST) { + ipc_rcu_getref(sma); sem_unlock(sma); + sem_io = ipc_alloc(sizeof(ushort)*nsems); - if(sem_io == NULL) + if(sem_io == NULL) { + ipc_lock_by_ptr(&sma->sem_perm); + ipc_rcu_putref(sma); + sem_unlock(sma); return -ENOMEM; - err = sem_revalidate(semid, sma, nsems, S_IRUGO); - if(err) + } + + ipc_lock_by_ptr(&sma->sem_perm); + ipc_rcu_putref(sma); + if (sma->sem_perm.deleted) { + sem_unlock(sma); + err = -EIDRM; goto out_free; + } } for (i = 0; i < sma->sem_nsems; i++) @@ -636,28 +628,43 @@ static int semctl_main(int semid, int semnum, int cmd, int version, union semun int i; struct sem_undo *un; + ipc_rcu_getref(sma); sem_unlock(sma); if(nsems > SEMMSL_FAST) { sem_io = ipc_alloc(sizeof(ushort)*nsems); - if(sem_io == NULL) + if(sem_io == NULL) { + ipc_lock_by_ptr(&sma->sem_perm); + ipc_rcu_putref(sma); + sem_unlock(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); 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); err = -ERANGE; goto out_free; } } - err = sem_revalidate(semid, sma, nsems, S_IWUGO); - if(err) + ipc_lock_by_ptr(&sma->sem_perm); + ipc_rcu_putref(sma); + if (sma->sem_perm.deleted) { + sem_unlock(sma); + err = -EIDRM; goto out_free; + } for (i = 0; i < nsems; i++) sma->sem_base[i].semval = sem_io[i]; @@ -977,11 +984,16 @@ static struct sem_undo *find_undo(int semid) goto out; } nsems = sma->sem_nsems; + ipc_rcu_getref(sma); sem_unlock(sma); new = (struct sem_undo *) kmalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL); - if (!new) + if (!new) { + ipc_lock_by_ptr(&sma->sem_perm); + ipc_rcu_putref(sma); + sem_unlock(sma); return ERR_PTR(-ENOMEM); + } memset(new, 0, sizeof(struct sem_undo) + sizeof(short)*nsems); new->semadj = (short *) &new[1]; new->semid = semid; @@ -991,13 +1003,18 @@ static struct sem_undo *find_undo(int semid) if (un) { unlock_semundo(); kfree(new); + ipc_lock_by_ptr(&sma->sem_perm); + ipc_rcu_putref(sma); + sem_unlock(sma); goto out; } - error = sem_revalidate(semid, sma, nsems, 0); - if (error) { + ipc_lock_by_ptr(&sma->sem_perm); + ipc_rcu_putref(sma); + if (sma->sem_perm.deleted) { + sem_unlock(sma); unlock_semundo(); kfree(new); - un = ERR_PTR(error); + un = ERR_PTR(-EIDRM); goto out; } new->proc_next = ulp->proc_list; |