Commit 208b201a authored by Manfred Spraul's avatar Manfred Spraul Committed by Linus Torvalds

[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: default avatarManfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 3a4262a0
...@@ -241,25 +241,6 @@ asmlinkage long sys_semget (key_t key, int nsems, int semflg) ...@@ -241,25 +241,6 @@ asmlinkage long sys_semget (key_t key, int nsems, int semflg)
return err; 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: /* Manage the doubly linked list sma->sem_pending as a FIFO:
* insert new queue elements at the tail sma->sem_pending_last. * insert new queue elements at the tail sma->sem_pending_last.
*/ */
...@@ -614,14 +595,25 @@ static int semctl_main(int semid, int semnum, int cmd, int version, union semun ...@@ -614,14 +595,25 @@ static int semctl_main(int semid, int semnum, int cmd, int version, union semun
int i; int i;
if(nsems > SEMMSL_FAST) { if(nsems > SEMMSL_FAST) {
ipc_rcu_getref(sma);
sem_unlock(sma); sem_unlock(sma);
sem_io = ipc_alloc(sizeof(ushort)*nsems); 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; 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; goto out_free;
} }
}
for (i = 0; i < sma->sem_nsems; i++) for (i = 0; i < sma->sem_nsems; i++)
sem_io[i] = sma->sem_base[i].semval; sem_io[i] = sma->sem_base[i].semval;
...@@ -636,28 +628,43 @@ static int semctl_main(int semid, int semnum, int cmd, int version, union semun ...@@ -636,28 +628,43 @@ static int semctl_main(int semid, int semnum, int cmd, int version, union semun
int i; int i;
struct sem_undo *un; struct sem_undo *un;
ipc_rcu_getref(sma);
sem_unlock(sma); sem_unlock(sma);
if(nsems > SEMMSL_FAST) { if(nsems > SEMMSL_FAST) {
sem_io = ipc_alloc(sizeof(ushort)*nsems); 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; return -ENOMEM;
} }
}
if (copy_from_user (sem_io, arg.array, nsems*sizeof(ushort))) { 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; err = -EFAULT;
goto out_free; goto out_free;
} }
for (i = 0; i < nsems; i++) { for (i = 0; i < nsems; i++) {
if (sem_io[i] > SEMVMX) { if (sem_io[i] > SEMVMX) {
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
sem_unlock(sma);
err = -ERANGE; err = -ERANGE;
goto out_free; goto out_free;
} }
} }
err = sem_revalidate(semid, sma, nsems, S_IWUGO); ipc_lock_by_ptr(&sma->sem_perm);
if(err) ipc_rcu_putref(sma);
if (sma->sem_perm.deleted) {
sem_unlock(sma);
err = -EIDRM;
goto out_free; goto out_free;
}
for (i = 0; i < nsems; i++) for (i = 0; i < nsems; i++)
sma->sem_base[i].semval = sem_io[i]; sma->sem_base[i].semval = sem_io[i];
...@@ -977,11 +984,16 @@ static struct sem_undo *find_undo(int semid) ...@@ -977,11 +984,16 @@ static struct sem_undo *find_undo(int semid)
goto out; goto out;
} }
nsems = sma->sem_nsems; nsems = sma->sem_nsems;
ipc_rcu_getref(sma);
sem_unlock(sma); sem_unlock(sma);
new = (struct sem_undo *) kmalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL); 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); return ERR_PTR(-ENOMEM);
}
memset(new, 0, sizeof(struct sem_undo) + sizeof(short)*nsems); memset(new, 0, sizeof(struct sem_undo) + sizeof(short)*nsems);
new->semadj = (short *) &new[1]; new->semadj = (short *) &new[1];
new->semid = semid; new->semid = semid;
...@@ -991,13 +1003,18 @@ static struct sem_undo *find_undo(int semid) ...@@ -991,13 +1003,18 @@ static struct sem_undo *find_undo(int semid)
if (un) { if (un) {
unlock_semundo(); unlock_semundo();
kfree(new); kfree(new);
ipc_lock_by_ptr(&sma->sem_perm);
ipc_rcu_putref(sma);
sem_unlock(sma);
goto out; goto out;
} }
error = sem_revalidate(semid, sma, nsems, 0); ipc_lock_by_ptr(&sma->sem_perm);
if (error) { ipc_rcu_putref(sma);
if (sma->sem_perm.deleted) {
sem_unlock(sma);
unlock_semundo(); unlock_semundo();
kfree(new); kfree(new);
un = ERR_PTR(error); un = ERR_PTR(-EIDRM);
goto out; goto out;
} }
new->proc_next = ulp->proc_list; new->proc_next = ulp->proc_list;
......
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