+ * There is a semaphore leak (i.e. memory leak) in this code.
+ * We should be deleting the IPC_PRIVATE semaphores when they are
+ * no longer needed, and we dont. We would have to track which processes
+ * know about which IPC_PRIVATE semaphores, updating the list after
+ * every fork. We can't just delete them semaphore when the process
+ * that created it dies, because that process may well have forked
+ * some children. So we need to wait until all of it's children have
+ * died, and so on. Maybe we should tag each IPC_PRIVATE sempahore
+ * with the creating group ID, count the number of processes left in
+ * that group, and delete the semaphore when the group is gone.
+ * Until that code gets implemented we will leak IPC_PRIVATE semaphores.
+ * There is an upper bound on the size of our semaphore array, so
+ * leaking the semaphores should not work as a DOS attack.
+ *
+ * Please note that the original BSD code this file is based on had the
+ * same leaky semaphore problem.
+ */
+
+ SYSV_SEM_SUBSYS_UNLOCK();
+}
+
+
+/* (struct sysctl_oid *oidp, void *arg1, int arg2, \
+ struct sysctl_req *req) */
+static int
+sysctl_seminfo(__unused struct sysctl_oid *oidp, void *arg1,
+ __unused int arg2, struct sysctl_req *req)
+{
+ int error = 0;
+
+ error = SYSCTL_OUT(req, arg1, sizeof(int));
+ if (error || req->newptr == USER_ADDR_NULL)
+ return(error);
+
+ SYSV_SEM_SUBSYS_LOCK();
+
+ /* Set the values only if shared memory is not initialised */
+ if ((sem_pool == NULL) &&
+ (sema == NULL) &&
+ (semu == NULL) &&
+ (semu_list_idx == -1)) {
+ if ((error = SYSCTL_IN(req, arg1, sizeof(int)))) {
+ goto out;
+ }
+ } else
+ error = EINVAL;
+out:
+ SYSV_SEM_SUBSYS_UNLOCK();
+ return(error);
+
+}
+
+/* SYSCTL_NODE(_kern, KERN_SYSV, sysv, CTLFLAG_RW, 0, "SYSV"); */
+extern struct sysctl_oid_list sysctl__kern_sysv_children;
+SYSCTL_PROC(_kern_sysv, OID_AUTO, semmni, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+ &limitseminfo.semmni, 0, &sysctl_seminfo ,"I","semmni");
+
+SYSCTL_PROC(_kern_sysv, OID_AUTO, semmns, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+ &limitseminfo.semmns, 0, &sysctl_seminfo ,"I","semmns");
+
+SYSCTL_PROC(_kern_sysv, OID_AUTO, semmnu, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+ &limitseminfo.semmnu, 0, &sysctl_seminfo ,"I","semmnu");
+
+SYSCTL_PROC(_kern_sysv, OID_AUTO, semmsl, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+ &limitseminfo.semmsl, 0, &sysctl_seminfo ,"I","semmsl");
+
+SYSCTL_PROC(_kern_sysv, OID_AUTO, semume, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
+ &limitseminfo.semume, 0, &sysctl_seminfo ,"I","semume");
+
+
+static int
+IPCS_sem_sysctl(__unused struct sysctl_oid *oidp, __unused void *arg1,
+ __unused int arg2, struct sysctl_req *req)
+{
+ int error;
+ int cursor;
+ union {
+ struct user32_IPCS_command u32;
+ struct user_IPCS_command u64;
+ } ipcs;
+ struct user32_semid_ds semid_ds32; /* post conversion, 32 bit version */
+ struct user64_semid_ds semid_ds64; /* post conversion, 64 bit version */
+ void *semid_dsp;
+ size_t ipcs_sz;
+ size_t semid_ds_sz;
+ struct proc *p = current_proc();
+
+ if (IS_64BIT_PROCESS(p)) {
+ ipcs_sz = sizeof(struct user_IPCS_command);
+ semid_ds_sz = sizeof(struct user64_semid_ds);
+ } else {
+ ipcs_sz = sizeof(struct user32_IPCS_command);
+ semid_ds_sz = sizeof(struct user32_semid_ds);
projects / apple / xnu.git / blobdiff