diff options
Diffstat (limited to 'ipc/shm.c')
| -rw-r--r-- | ipc/shm.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/ipc/shm.c b/ipc/shm.c index 7e199fa1960f..c6b4ad5ce3b7 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -141,7 +141,7 @@ static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp) { rcu_read_lock(); - spin_lock(&ipcp->shm_perm.lock); + ipc_lock_object(&ipcp->shm_perm); } static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, @@ -491,10 +491,10 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) sprintf (name, "SYSV%08x", key); if (shmflg & SHM_HUGETLB) { - struct hstate *hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) - & SHM_HUGE_MASK); + struct hstate *hs; size_t hugesize; + hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK); if (!hs) { error = -EINVAL; goto no_file; @@ -535,6 +535,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) shp->shm_nattch = 0; shp->shm_file = file; shp->shm_creator = current; + /* * shmid gets reported as "inode#" in /proc/pid/maps. * proc-ps tools use this. Changing this will break them. @@ -543,7 +544,9 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) ns->shm_tot += numpages; error = shp->shm_perm.id; - shm_unlock(shp); + + ipc_unlock_object(&shp->shm_perm); + rcu_read_unlock(); return error; no_id: @@ -754,31 +757,42 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, return -EFAULT; } + down_write(&shm_ids(ns).rw_mutex); + rcu_read_lock(); + ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0); - if (IS_ERR(ipcp)) - return PTR_ERR(ipcp); + if (IS_ERR(ipcp)) { + err = PTR_ERR(ipcp); + /* the ipc lock is not held upon failure */ + goto out_unlock1; + } shp = container_of(ipcp, struct shmid_kernel, shm_perm); err = security_shm_shmctl(shp, cmd); if (err) - goto out_unlock; + goto out_unlock0; + switch (cmd) { case IPC_RMID: + /* do_shm_rmid unlocks the ipc object and rcu */ do_shm_rmid(ns, ipcp); goto out_up; case IPC_SET: err = ipc_update_perm(&shmid64.shm_perm, ipcp); if (err) - goto out_unlock; + goto out_unlock0; shp->shm_ctim = get_seconds(); break; default: err = -EINVAL; } -out_unlock: - shm_unlock(shp); + +out_unlock0: + ipc_unlock_object(&shp->shm_perm); +out_unlock1: + rcu_read_unlock(); out_up: up_write(&shm_ids(ns).rw_mutex); return err; |