X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=ipc%2Fshm.c;h=3f5b14365f33e54408c5e89d3b15aacbc2c1435b;hp=ab3385a21b27ac9b528ea270f2d4567522d2c966;hb=38da590bef19f23d4b610aecaad4f32de483890d;hpb=5f127133ee432d0b83ee26e8e3a3d7828ab5f2b1

diff --git a/ipc/shm.c b/ipc/shm.c
index ab3385a21b27..3f5b14365f33 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -74,6 +74,7 @@ void shm_init_ns(struct ipc_namespace *ns)
 	ns->shm_ctlmax = SHMMAX;
 	ns->shm_ctlall = SHMALL;
 	ns->shm_ctlmni = SHMMNI;
+	ns->shm_rmid_forced = 0;
 	ns->shm_tot = 0;
 	ipc_init_ids(&shm_ids(ns));
 }
@@ -186,6 +187,23 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 	ipc_rcu_putref(shp);
 }
 
+/*
+ * shm_may_destroy - identifies whether shm segment should be destroyed now
+ *
+ * Returns true if and only if there are no active users of the segment and
+ * one of the following is true:
+ *
+ * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
+ *
+ * 2) sysctl kernel.shm_rmid_forced is set to 1.
+ */
+static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+{
+	return (shp->shm_nattch == 0) &&
+	       (ns->shm_rmid_forced ||
+		(shp->shm_perm.mode & SHM_DEST));
+}
+
 /*
  * remove the attach descriptor vma.
  * free memory for segment if it is marked destroyed.
@@ -206,11 +224,83 @@ static void shm_close(struct vm_area_struct *vma)
 	shp->shm_lprid = task_tgid_vnr(current);
 	shp->shm_dtim = get_seconds();
 	shp->shm_nattch--;
-	if(shp->shm_nattch == 0 &&
-	   shp->shm_perm.mode & SHM_DEST)
+	if (shm_may_destroy(ns, shp))
+		shm_destroy(ns, shp);
+	else
+		shm_unlock(shp);
+	up_write(&shm_ids(ns).rw_mutex);
+}
+
+static int shm_try_destroy_current(int id, void *p, void *data)
+{
+	struct ipc_namespace *ns = data;
+	struct shmid_kernel *shp = shm_lock(ns, id);
+
+	if (IS_ERR(shp))
+		return 0;
+
+	if (shp->shm_cprid != task_tgid_vnr(current)) {
+		shm_unlock(shp);
+		return 0;
+	}
+
+	if (shm_may_destroy(ns, shp))
+		shm_destroy(ns, shp);
+	else
+		shm_unlock(shp);
+	return 0;
+}
+
+static int shm_try_destroy_orphaned(int id, void *p, void *data)
+{
+	struct ipc_namespace *ns = data;
+	struct shmid_kernel *shp = shm_lock(ns, id);
+	struct task_struct *task;
+
+	if (IS_ERR(shp))
+		return 0;
+
+	/*
+	 * We want to destroy segments without users and with already
+	 * exit'ed originating process.
+	 *
+	 * XXX: the originating process may exist in another pid namespace.
+	 */
+	task = find_task_by_vpid(shp->shm_cprid);
+	if (task != NULL) {
+		shm_unlock(shp);
+		return 0;
+	}
+
+	if (shm_may_destroy(ns, shp))
 		shm_destroy(ns, shp);
 	else
 		shm_unlock(shp);
+	return 0;
+}
+
+void shm_destroy_orphaned(struct ipc_namespace *ns)
+{
+	down_write(&shm_ids(ns).rw_mutex);
+	idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
+	up_write(&shm_ids(ns).rw_mutex);
+}
+
+
+void exit_shm(struct task_struct *task)
+{
+	struct nsproxy *nsp = task->nsproxy;
+	struct ipc_namespace *ns;
+
+	if (!nsp)
+		return;
+	ns = nsp->ipc_ns;
+	if (!ns || !ns->shm_rmid_forced)
+		return;
+
+	/* Destroy all already created segments, but not mapped yet */
+	down_write(&shm_ids(ns).rw_mutex);
+	idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_current, ns);
 	up_write(&shm_ids(ns).rw_mutex);
 }
 
@@ -277,13 +367,13 @@ static int shm_release(struct inode *ino, struct file *file)
 	return 0;
 }
 
-static int shm_fsync(struct file *file, int datasync)
+static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
 	struct shm_file_data *sfd = shm_file_data(file);
 
 	if (!sfd->file->f_op->fsync)
 		return -EINVAL;
-	return sfd->file->f_op->fsync(sfd->file, datasync);
+	return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
 }
 
 static unsigned long shm_get_unmapped_area(struct file *file,
@@ -950,8 +1040,7 @@ out_nattch:
 	shp = shm_lock(ns, shmid);
 	BUG_ON(IS_ERR(shp));
 	shp->shm_nattch--;
-	if(shp->shm_nattch == 0 &&
-	   shp->shm_perm.mode & SHM_DEST)
+	if (shm_may_destroy(ns, shp))
 		shm_destroy(ns, shp);
 	else
 		shm_unlock(shp);