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Diffstat (limited to 'ipc')
-rw-r--r--ipc/shm.c75
1 files changed, 39 insertions, 36 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index 89fc354156cb..7fc9f9f3a26b 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -178,6 +178,7 @@ static void shm_rcu_free(struct rcu_head *head)
static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
{
+ list_del(&s->shm_clist);
ipc_rmid(&shm_ids(ns), &s->shm_perm);
}
@@ -268,37 +269,6 @@ static void shm_close(struct vm_area_struct *vma)
}
/* Called with ns->shm_ids(ns).rwsem locked */
-static int shm_try_destroy_current(int id, void *p, void *data)
-{
- struct ipc_namespace *ns = data;
- struct kern_ipc_perm *ipcp = p;
- struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
-
- if (shp->shm_creator != current)
- return 0;
-
- /*
- * Mark it as orphaned to destroy the segment when
- * kernel.shm_rmid_forced is changed.
- * It is noop if the following shm_may_destroy() returns true.
- */
- shp->shm_creator = NULL;
-
- /*
- * Don't even try to destroy it. If shm_rmid_forced=0 and IPC_RMID
- * is not set, it shouldn't be deleted here.
- */
- if (!ns->shm_rmid_forced)
- return 0;
-
- if (shm_may_destroy(ns, shp)) {
- shm_lock_by_ptr(shp);
- shm_destroy(ns, shp);
- }
- return 0;
-}
-
-/* Called with ns->shm_ids(ns).rwsem locked */
static int shm_try_destroy_orphaned(int id, void *p, void *data)
{
struct ipc_namespace *ns = data;
@@ -329,18 +299,50 @@ void shm_destroy_orphaned(struct ipc_namespace *ns)
up_write(&shm_ids(ns).rwsem);
}
-
+/* Locking assumes this will only be called with task == current */
void exit_shm(struct task_struct *task)
{
struct ipc_namespace *ns = task->nsproxy->ipc_ns;
+ struct shmid_kernel *shp, *n;
- if (shm_ids(ns).in_use == 0)
+ if (list_empty(&task->sysvshm.shm_clist))
return;
- /* Destroy all already created segments, but not mapped yet */
+ /*
+ * If kernel.shm_rmid_forced is not set then only keep track of
+ * which shmids are orphaned, so that a later set of the sysctl
+ * can clean them up.
+ */
+ if (!ns->shm_rmid_forced) {
+ down_read(&shm_ids(ns).rwsem);
+ list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
+ shp->shm_creator = NULL;
+ /*
+ * Only under read lock but we are only called on current
+ * so no entry on the list will be shared.
+ */
+ list_del(&task->sysvshm.shm_clist);
+ up_read(&shm_ids(ns).rwsem);
+ return;
+ }
+
+ /*
+ * Destroy all already created segments, that were not yet mapped,
+ * and mark any mapped as orphan to cover the sysctl toggling.
+ * Destroy is skipped if shm_may_destroy() returns false.
+ */
down_write(&shm_ids(ns).rwsem);
- if (shm_ids(ns).in_use)
- idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_current, ns);
+ list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
+ shp->shm_creator = NULL;
+
+ if (shm_may_destroy(ns, shp)) {
+ shm_lock_by_ptr(shp);
+ shm_destroy(ns, shp);
+ }
+ }
+
+ /* Remove the list head from any segments still attached. */
+ list_del(&task->sysvshm.shm_clist);
up_write(&shm_ids(ns).rwsem);
}
@@ -561,6 +563,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
shp->shm_nattch = 0;
shp->shm_file = file;
shp->shm_creator = current;
+ list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
/*
* shmid gets reported as "inode#" in /proc/pid/maps.