diff --git a/drivers/android/binder.c b/drivers/android/binder.c index d58763b6b009..0d475a17089b 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -73,6 +73,7 @@ #include #include +#include #include @@ -350,10 +351,14 @@ struct binder_error { * and by @lock) * @has_async_transaction: async transaction to node in progress * (protected by @lock) + * @sched_policy: minimum scheduling policy for node + * (invariant after initialized) * @accept_fds: file descriptor operations supported for node * (invariant after initialized) * @min_priority: minimum scheduling priority * (invariant after initialized) + * @inherit_rt: inherit RT scheduling policy from caller + * (invariant after initialized) * @async_todo: list of async work items * (protected by @proc->inner_lock) * @@ -389,6 +394,8 @@ struct binder_node { /* * invariant after initialization */ + u8 sched_policy:2; + u8 inherit_rt:1; u8 accept_fds:1; u8 min_priority; }; @@ -462,6 +469,22 @@ enum binder_deferred_state { BINDER_DEFERRED_RELEASE = 0x04, }; +/** + * struct binder_priority - scheduler policy and priority + * @sched_policy scheduler policy + * @prio [100..139] for SCHED_NORMAL, [0..99] for FIFO/RT + * + * The binder driver supports inheriting the following scheduler policies: + * SCHED_NORMAL + * SCHED_BATCH + * SCHED_FIFO + * SCHED_RR + */ +struct binder_priority { + unsigned int sched_policy; + int prio; +}; + /** * struct binder_proc - binder process bookkeeping * @proc_node: element for binder_procs list @@ -540,7 +563,7 @@ struct binder_proc { int requested_threads; int requested_threads_started; int tmp_ref; - long default_priority; + struct binder_priority default_priority; struct dentry *debugfs_entry; struct binder_alloc alloc; struct binder_context *context; @@ -590,6 +613,7 @@ enum { * @is_dead: thread is dead and awaiting free * when outstanding transactions are cleaned up * (protected by @proc->inner_lock) + * @task: struct task_struct for this thread * * Bookkeeping structure for binder threads. */ @@ -609,6 +633,7 @@ struct binder_thread { struct binder_stats stats; atomic_t tmp_ref; bool is_dead; + struct task_struct *task; }; struct binder_transaction { @@ -625,8 +650,9 @@ struct binder_transaction { struct binder_buffer *buffer; unsigned int code; unsigned int flags; - long priority; - long saved_priority; + struct binder_priority priority; + struct binder_priority saved_priority; + bool set_priority_called; kuid_t sender_euid; /** * @lock: protects @from, @to_proc, and @to_thread @@ -1107,22 +1133,145 @@ static void binder_wakeup_proc_ilocked(struct binder_proc *proc) binder_wakeup_thread_ilocked(proc, thread, /* sync = */false); } -static void binder_set_nice(long nice) +static bool is_rt_policy(int policy) { - long min_nice; + return policy == SCHED_FIFO || policy == SCHED_RR; +} - if (can_nice(current, nice)) { - set_user_nice(current, nice); +static bool is_fair_policy(int policy) +{ + return policy == SCHED_NORMAL || policy == SCHED_BATCH; +} + +static bool binder_supported_policy(int policy) +{ + return is_fair_policy(policy) || is_rt_policy(policy); +} + +static int to_userspace_prio(int policy, int kernel_priority) +{ + if (is_fair_policy(policy)) + return PRIO_TO_NICE(kernel_priority); + else + return MAX_USER_RT_PRIO - 1 - kernel_priority; +} + +static int to_kernel_prio(int policy, int user_priority) +{ + if (is_fair_policy(policy)) + return NICE_TO_PRIO(user_priority); + else + return MAX_USER_RT_PRIO - 1 - user_priority; +} + +static void binder_do_set_priority(struct task_struct *task, + struct binder_priority desired, + bool verify) +{ + int priority; /* user-space prio value */ + bool has_cap_nice; + unsigned int policy = desired.sched_policy; + + if (task->policy == policy && task->normal_prio == desired.prio) return; + + has_cap_nice = has_capability_noaudit(task, CAP_SYS_NICE); + + priority = to_userspace_prio(policy, desired.prio); + + if (verify && is_rt_policy(policy) && !has_cap_nice) { + long max_rtprio = task_rlimit(task, RLIMIT_RTPRIO); + + if (max_rtprio == 0) { + policy = SCHED_NORMAL; + priority = MIN_NICE; + } else if (priority > max_rtprio) { + priority = max_rtprio; + } } - min_nice = rlimit_to_nice(rlimit(RLIMIT_NICE)); - binder_debug(BINDER_DEBUG_PRIORITY_CAP, - "%d: nice value %ld not allowed use %ld instead\n", - current->pid, nice, min_nice); - set_user_nice(current, min_nice); - if (min_nice <= MAX_NICE) + + if (verify && is_fair_policy(policy) && !has_cap_nice) { + long min_nice = rlimit_to_nice(task_rlimit(task, RLIMIT_NICE)); + + if (min_nice > MAX_NICE) { + binder_user_error("%d RLIMIT_NICE not set\n", + task->pid); + return; + } else if (priority < min_nice) { + priority = min_nice; + } + } + + if (policy != desired.sched_policy || + to_kernel_prio(policy, priority) != desired.prio) + binder_debug(BINDER_DEBUG_PRIORITY_CAP, + "%d: priority %d not allowed, using %d instead\n", + task->pid, desired.prio, + to_kernel_prio(policy, priority)); + + trace_binder_set_priority(task->tgid, task->pid, task->normal_prio, + to_kernel_prio(policy, priority), + desired.prio); + + /* Set the actual priority */ + if (task->policy != policy || is_rt_policy(policy)) { + struct sched_param params; + + params.sched_priority = is_rt_policy(policy) ? priority : 0; + + sched_setscheduler_nocheck(task, + policy | SCHED_RESET_ON_FORK, + ¶ms); + } + if (is_fair_policy(policy)) + set_user_nice(task, priority); +} + +static void binder_set_priority(struct task_struct *task, + struct binder_priority desired) +{ + binder_do_set_priority(task, desired, /* verify = */ true); +} + +static void binder_restore_priority(struct task_struct *task, + struct binder_priority desired) +{ + binder_do_set_priority(task, desired, /* verify = */ false); +} + +static void binder_transaction_priority(struct task_struct *task, + struct binder_transaction *t, + struct binder_priority node_prio, + bool inherit_rt) +{ + struct binder_priority desired_prio = t->priority; + + if (t->set_priority_called) return; - binder_user_error("%d RLIMIT_NICE not set\n", current->pid); + + t->set_priority_called = true; + t->saved_priority.sched_policy = task->policy; + t->saved_priority.prio = task->normal_prio; + + if (!inherit_rt && is_rt_policy(desired_prio.sched_policy)) { + desired_prio.prio = NICE_TO_PRIO(0); + desired_prio.sched_policy = SCHED_NORMAL; + } + + if (node_prio.prio < t->priority.prio || + (node_prio.prio == t->priority.prio && + node_prio.sched_policy == SCHED_FIFO)) { + /* + * In case the minimum priority on the node is + * higher (lower value), use that priority. If + * the priority is the same, but the node uses + * SCHED_FIFO, prefer SCHED_FIFO, since it can + * run unbounded, unlike SCHED_RR. + */ + desired_prio = node_prio; + } + + binder_set_priority(task, desired_prio); } static struct binder_node *binder_get_node_ilocked(struct binder_proc *proc, @@ -1175,6 +1324,7 @@ static struct binder_node *binder_init_node_ilocked( binder_uintptr_t ptr = fp ? fp->binder : 0; binder_uintptr_t cookie = fp ? fp->cookie : 0; __u32 flags = fp ? fp->flags : 0; + s8 priority; assert_spin_locked(&proc->inner_lock); @@ -1207,8 +1357,12 @@ static struct binder_node *binder_init_node_ilocked( node->ptr = ptr; node->cookie = cookie; node->work.type = BINDER_WORK_NODE; - node->min_priority = flags & FLAT_BINDER_FLAG_PRIORITY_MASK; + priority = flags & FLAT_BINDER_FLAG_PRIORITY_MASK; + node->sched_policy = (flags & FLAT_BINDER_FLAG_SCHED_POLICY_MASK) >> + FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT; + node->min_priority = to_kernel_prio(node->sched_policy, priority); node->accept_fds = !!(flags & FLAT_BINDER_FLAG_ACCEPTS_FDS); + node->inherit_rt = !!(flags & FLAT_BINDER_FLAG_INHERIT_RT); spin_lock_init(&node->lock); INIT_LIST_HEAD(&node->work.entry); INIT_LIST_HEAD(&node->async_todo); @@ -2633,11 +2787,15 @@ static bool binder_proc_transaction(struct binder_transaction *t, struct binder_thread *thread) { struct binder_node *node = t->buffer->target_node; + struct binder_priority node_prio; bool oneway = !!(t->flags & TF_ONE_WAY); bool pending_async = false; BUG_ON(!node); binder_node_lock(node); + node_prio.prio = node->min_priority; + node_prio.sched_policy = node->sched_policy; + if (oneway) { BUG_ON(thread); if (node->has_async_transaction) { @@ -2658,12 +2816,15 @@ static bool binder_proc_transaction(struct binder_transaction *t, if (!thread && !pending_async) thread = binder_select_thread_ilocked(proc); - if (thread) + if (thread) { + binder_transaction_priority(thread->task, t, node_prio, + node->inherit_rt); binder_enqueue_thread_work_ilocked(thread, &t->work); - else if (!pending_async) + } else if (!pending_async) { binder_enqueue_work_ilocked(&t->work, &proc->todo); - else + } else { binder_enqueue_work_ilocked(&t->work, &node->async_todo); + } if (!pending_async) binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */); @@ -2780,7 +2941,6 @@ static void binder_transaction(struct binder_proc *proc, } thread->transaction_stack = in_reply_to->to_parent; binder_inner_proc_unlock(proc); - binder_set_nice(in_reply_to->saved_priority); target_thread = binder_get_txn_from_and_acq_inner(in_reply_to); if (target_thread == NULL) { return_error = BR_DEAD_REPLY; @@ -2953,7 +3113,15 @@ static void binder_transaction(struct binder_proc *proc, t->to_thread = target_thread; t->code = tr->code; t->flags = tr->flags; - t->priority = task_nice(current); + if (!(t->flags & TF_ONE_WAY) && + binder_supported_policy(current->policy)) { + /* Inherit supported policies for synchronous transactions */ + t->priority.sched_policy = current->policy; + t->priority.prio = current->normal_prio; + } else { + /* Otherwise, fall back to the default priority */ + t->priority = target_proc->default_priority; + } trace_binder_transaction(reply, t, target_node); @@ -3182,6 +3350,7 @@ static void binder_transaction(struct binder_proc *proc, binder_enqueue_thread_work_ilocked(target_thread, &t->work); binder_inner_proc_unlock(target_proc); wake_up_interruptible_sync(&target_thread->wait); + binder_restore_priority(current, in_reply_to->saved_priority); binder_free_transaction(in_reply_to); } else if (!(t->flags & TF_ONE_WAY)) { BUG_ON(t->buffer->async_transaction != 0); @@ -3285,6 +3454,7 @@ err_invalid_target_handle: BUG_ON(thread->return_error.cmd != BR_OK); if (in_reply_to) { + binder_restore_priority(current, in_reply_to->saved_priority); thread->return_error.cmd = BR_TRANSACTION_COMPLETE; binder_enqueue_thread_work(thread, &thread->return_error.work); binder_send_failed_reply(in_reply_to, return_error); @@ -3865,7 +4035,7 @@ retry: wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2); } - binder_set_nice(proc->default_priority); + binder_restore_priority(current, proc->default_priority); } if (non_block) { @@ -4080,16 +4250,14 @@ retry: BUG_ON(t->buffer == NULL); if (t->buffer->target_node) { struct binder_node *target_node = t->buffer->target_node; + struct binder_priority node_prio; tr.target.ptr = target_node->ptr; tr.cookie = target_node->cookie; - t->saved_priority = task_nice(current); - if (t->priority < target_node->min_priority && - !(t->flags & TF_ONE_WAY)) - binder_set_nice(t->priority); - else if (!(t->flags & TF_ONE_WAY) || - t->saved_priority > target_node->min_priority) - binder_set_nice(target_node->min_priority); + node_prio.sched_policy = target_node->sched_policy; + node_prio.prio = target_node->min_priority; + binder_transaction_priority(current, t, node_prio, + target_node->inherit_rt); cmd = BR_TRANSACTION; } else { tr.target.ptr = 0; @@ -4267,6 +4435,8 @@ static struct binder_thread *binder_get_thread_ilocked( binder_stats_created(BINDER_STAT_THREAD); thread->proc = proc; thread->pid = current->pid; + get_task_struct(current); + thread->task = current; atomic_set(&thread->tmp_ref, 0); init_waitqueue_head(&thread->wait); INIT_LIST_HEAD(&thread->todo); @@ -4317,6 +4487,7 @@ static void binder_free_thread(struct binder_thread *thread) BUG_ON(!list_empty(&thread->todo)); binder_stats_deleted(BINDER_STAT_THREAD); binder_proc_dec_tmpref(thread->proc); + put_task_struct(thread->task); kfree(thread); } @@ -4767,7 +4938,14 @@ static int binder_open(struct inode *nodp, struct file *filp) proc->tsk = current->group_leader; mutex_init(&proc->files_lock); INIT_LIST_HEAD(&proc->todo); - proc->default_priority = task_nice(current); + if (binder_supported_policy(current->policy)) { + proc->default_priority.sched_policy = current->policy; + proc->default_priority.prio = current->normal_prio; + } else { + proc->default_priority.sched_policy = SCHED_NORMAL; + proc->default_priority.prio = NICE_TO_PRIO(0); + } + binder_dev = container_of(filp->private_data, struct binder_device, miscdev); proc->context = &binder_dev->context; @@ -5061,13 +5239,14 @@ static void print_binder_transaction_ilocked(struct seq_file *m, spin_lock(&t->lock); to_proc = t->to_proc; seq_printf(m, - "%s %d: %pK from %d:%d to %d:%d code %x flags %x pri %ld r%d", + "%s %d: %pK from %d:%d to %d:%d code %x flags %x pri %d:%d r%d", prefix, t->debug_id, t, t->from ? t->from->proc->pid : 0, t->from ? t->from->pid : 0, to_proc ? to_proc->pid : 0, t->to_thread ? t->to_thread->pid : 0, - t->code, t->flags, t->priority, t->need_reply); + t->code, t->flags, t->priority.sched_policy, + t->priority.prio, t->need_reply); spin_unlock(&t->lock); if (proc != to_proc) { @@ -5185,8 +5364,9 @@ static void print_binder_node_nilocked(struct seq_file *m, hlist_for_each_entry(ref, &node->refs, node_entry) count++; - seq_printf(m, " node %d: u%016llx c%016llx hs %d hw %d ls %d lw %d is %d iw %d tr %d", + seq_printf(m, " node %d: u%016llx c%016llx pri %d:%d hs %d hw %d ls %d lw %d is %d iw %d tr %d", node->debug_id, (u64)node->ptr, (u64)node->cookie, + node->sched_policy, node->min_priority, node->has_strong_ref, node->has_weak_ref, node->local_strong_refs, node->local_weak_refs, node->internal_strong_refs, count, node->tmp_refs); diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h index 588eb3ec3507..7d8beb77f532 100644 --- a/drivers/android/binder_trace.h +++ b/drivers/android/binder_trace.h @@ -85,6 +85,30 @@ DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_ioctl_done); DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_write_done); DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_read_done); +TRACE_EVENT(binder_set_priority, + TP_PROTO(int proc, int thread, unsigned int old_prio, + unsigned int desired_prio, unsigned int new_prio), + TP_ARGS(proc, thread, old_prio, new_prio, desired_prio), + + TP_STRUCT__entry( + __field(int, proc) + __field(int, thread) + __field(unsigned int, old_prio) + __field(unsigned int, new_prio) + __field(unsigned int, desired_prio) + ), + TP_fast_assign( + __entry->proc = proc; + __entry->thread = thread; + __entry->old_prio = old_prio; + __entry->new_prio = new_prio; + __entry->desired_prio = desired_prio; + ), + TP_printk("proc=%d thread=%d old=%d => new=%d desired=%d", + __entry->proc, __entry->thread, __entry->old_prio, + __entry->new_prio, __entry->desired_prio) +); + TRACE_EVENT(binder_wait_for_work, TP_PROTO(bool proc_work, bool transaction_stack, bool thread_todo), TP_ARGS(proc_work, transaction_stack, thread_todo), diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h index bfaec6903b8b..b4723e36b6cf 100644 --- a/include/uapi/linux/android/binder.h +++ b/include/uapi/linux/android/binder.h @@ -38,9 +38,56 @@ enum { BINDER_TYPE_PTR = B_PACK_CHARS('p', 't', '*', B_TYPE_LARGE), }; -enum { +/** + * enum flat_binder_object_shifts: shift values for flat_binder_object_flags + * @FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT: shift for getting scheduler policy. + * + */ +enum flat_binder_object_shifts { + FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT = 9, +}; + +/** + * enum flat_binder_object_flags - flags for use in flat_binder_object.flags + */ +enum flat_binder_object_flags { + /** + * @FLAT_BINDER_FLAG_PRIORITY_MASK: bit-mask for min scheduler priority + * + * These bits can be used to set the minimum scheduler priority + * at which transactions into this node should run. Valid values + * in these bits depend on the scheduler policy encoded in + * @FLAT_BINDER_FLAG_SCHED_POLICY_MASK. + * + * For SCHED_NORMAL/SCHED_BATCH, the valid range is between [-20..19] + * For SCHED_FIFO/SCHED_RR, the value can run between [1..99] + */ FLAT_BINDER_FLAG_PRIORITY_MASK = 0xff, + /** + * @FLAT_BINDER_FLAG_ACCEPTS_FDS: whether the node accepts fds. + */ FLAT_BINDER_FLAG_ACCEPTS_FDS = 0x100, + /** + * @FLAT_BINDER_FLAG_SCHED_POLICY_MASK: bit-mask for scheduling policy + * + * These two bits can be used to set the min scheduling policy at which + * transactions on this node should run. These match the UAPI + * scheduler policy values, eg: + * 00b: SCHED_NORMAL + * 01b: SCHED_FIFO + * 10b: SCHED_RR + * 11b: SCHED_BATCH + */ + FLAT_BINDER_FLAG_SCHED_POLICY_MASK = + 3U << FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT, + + /** + * @FLAT_BINDER_FLAG_INHERIT_RT: whether the node inherits RT policy + * + * Only when set, calls into this node will inherit a real-time + * scheduling policy from the caller (for synchronous transactions). + */ + FLAT_BINDER_FLAG_INHERIT_RT = 0x800, }; #ifdef BINDER_IPC_32BIT