+/*
+ * do_background_thread
+ * Returns: 0 Success
+ * XXX - todo - does this need a MACF hook?
+ *
+ * NOTE: To maintain binary compatibility with PRIO_DARWIN_THREAD with respect
+ * to network traffic management, UT_BACKGROUND_TRAFFIC_MGT is set/cleared
+ * along with UT_BACKGROUND flag, as the latter alone no longer implies
+ * any form of traffic regulation (it simply means that the thread is
+ * background.) With PRIO_DARWIN_PROCESS, any form of network traffic
+ * management must be explicitly requested via whatever means appropriate,
+ * and only TRAFFIC_MGT_SO_BACKGROUND is set via do_background_socket().
+ */
+static int
+do_background_thread(struct proc *curp __unused, thread_t thread, int priority)
+{
+ struct uthread *ut;
+#if !CONFIG_EMBEDDED
+ int error = 0;
+#else /* !CONFIG_EMBEDDED */
+ thread_precedence_policy_data_t policy;
+#endif /* !CONFIG_EMBEDDED */
+
+ ut = get_bsdthread_info(thread);
+
+ /* Backgrounding is unsupported for threads in vfork */
+ if ( (ut->uu_flag & UT_VFORK) != 0) {
+ return(EPERM);
+ }
+
+#if !CONFIG_EMBEDDED
+ error = proc_set1_bgthreadpolicy(curp->task, thread_tid(thread), priority);
+ return(error);
+#else /* !CONFIG_EMBEDDED */
+ if ( (priority & PRIO_DARWIN_BG) == 0 ) {
+ /* turn off backgrounding of thread */
+ if ( (ut->uu_flag & UT_BACKGROUND) == 0 ) {
+ /* already off */
+ return(0);
+ }
+
+ /*
+ * Clear background bit in thread and disable disk IO
+ * throttle as well as network traffic management.
+ * The corresponding socket flags for sockets created by
+ * this thread will be cleared in do_background_socket().
+ */
+ ut->uu_flag &= ~(UT_BACKGROUND | UT_BACKGROUND_TRAFFIC_MGT);
+ ut->uu_iopol_disk = IOPOL_NORMAL;
+
+ /* reset thread priority (we did not save previous value) */
+ policy.importance = 0;
+ thread_policy_set( thread, THREAD_PRECEDENCE_POLICY,
+ (thread_policy_t)&policy,
+ THREAD_PRECEDENCE_POLICY_COUNT );
+ return(0);
+ }
+
+ /* background this thread */
+ if ( (ut->uu_flag & UT_BACKGROUND) != 0 ) {
+ /* already backgrounded */
+ return(0);
+ }
+
+ /*
+ * Tag thread as background and throttle disk IO, as well
+ * as regulate network traffics. Future sockets created
+ * by this thread will have their corresponding socket
+ * flags set at socket create time.
+ */
+ ut->uu_flag |= (UT_BACKGROUND | UT_BACKGROUND_TRAFFIC_MGT);
+ ut->uu_iopol_disk = IOPOL_THROTTLE;
+
+ policy.importance = INT_MIN;
+ thread_policy_set( thread, THREAD_PRECEDENCE_POLICY,
+ (thread_policy_t)&policy,
+ THREAD_PRECEDENCE_POLICY_COUNT );
+
+ /* throttle networking IO happens in socket( ) syscall.
+ * If UT_{BACKGROUND,BACKGROUND_TRAFFIC_MGT} is set in the current
+ * thread then TRAFFIC_MGT_SO_{BACKGROUND,BG_REGULATE} is set.
+ * Existing sockets are taken care of by do_background_socket().
+ */
+#endif /* !CONFIG_EMBEDDED */
+ return(0);
+}
+
+#if CONFIG_EMBEDDED
+int mach_do_background_thread(thread_t thread, int prio);
+
+int
+mach_do_background_thread(thread_t thread, int prio)
+{
+ int error = 0;
+ struct proc *curp = NULL;
+ struct proc *targetp = NULL;
+ kauth_cred_t ucred;
+
+ targetp = get_bsdtask_info(get_threadtask(thread));
+ if (!targetp) {
+ return KERN_INVALID_ARGUMENT;
+ }
+
+ curp = proc_self();
+ if (curp == PROC_NULL) {
+ return KERN_FAILURE;
+ }
+
+ ucred = kauth_cred_proc_ref(curp);
+
+ if (suser(ucred, NULL) && curp != targetp) {
+ error = KERN_PROTECTION_FAILURE;
+ goto out;
+ }
+
+ error = do_background_thread(curp, thread, prio);
+ if (!error) {
+ (void) do_background_socket(curp, thread, prio);
+ } else {
+ if (error == EPERM) {
+ error = KERN_PROTECTION_FAILURE;
+ } else {
+ error = KERN_FAILURE;
+ }
+ }
+
+out:
+ proc_rele(curp);
+ kauth_cred_unref(&ucred);
+ return error;
+}
+#endif /* CONFIG_EMBEDDED */
+
+#if CONFIG_EMBEDDED
+/*
+ * If the thread or its proc has been put into the background
+ * with setpriority(PRIO_DARWIN_{THREAD,PROCESS}, *, PRIO_DARWIN_BG),
+ * report that status.
+ *
+ * Returns: PRIO_DARWIN_BG if background
+ * 0 if foreground
+ */
+int
+uthread_get_background_state(uthread_t uth)
+{
+ proc_t p = uth->uu_proc;
+ if (p && (p->p_lflag & P_LBACKGROUND))
+ return PRIO_DARWIN_BG;
+
+ if (uth->uu_flag & UT_BACKGROUND)
+ return PRIO_DARWIN_BG;
+
+ return 0;
+}
+#endif /* CONFIG_EMBEDDED */
+
+/*
+ * Returns: 0 Success
+ * copyin:EFAULT
+ * dosetrlimit:
+ */
projects / apple / xnu.git / blobdiff