android: binder: Disable preemption while holding the global binder lock.

Change-Id: I90fe02cdedb8a5677b900a68528fb443b9204322
Signed-off-by: Riley Andrews <riandrews@google.com>
Git-repo: https://source.codeaurora.org/quic/la/kernel/msm-4.4
Git-commit: 5c9ce54ca3a66a57e4ebfe3ae71c5733b6bcc579
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

drivers/android/binder.c

@@ -427,6 +427,7 @@ static inline void binder_lock(const char *tag)
 {
 	trace_binder_lock(tag);
 	mutex_lock(&binder_main_lock);
+	preempt_disable();
 	trace_binder_locked(tag);
 }
 
@@ -434,8 +435,62 @@ static inline void binder_unlock(const char *tag)
 {
 	trace_binder_unlock(tag);
 	mutex_unlock(&binder_main_lock);
+	preempt_enable();
 }
 
+static inline void *kzalloc_preempt_disabled(size_t size)
+{
+	void *ptr;
+
+	ptr = kzalloc(size, GFP_NOWAIT);
+	if (ptr)
+		return ptr;
+
+	preempt_enable_no_resched();
+	ptr = kzalloc(size, GFP_KERNEL);
+	preempt_disable();
+
+	return ptr;
+}
+
+static inline long copy_to_user_preempt_disabled(void __user *to, const void *from, long n)
+{
+	long ret;
+
+	preempt_enable_no_resched();
+	ret = copy_to_user(to, from, n);
+	preempt_disable();
+	return ret;
+}
+
+static inline long copy_from_user_preempt_disabled(void *to, const void __user *from, long n)
+{
+	long ret;
+
+	preempt_enable_no_resched();
+	ret = copy_from_user(to, from, n);
+	preempt_disable();
+	return ret;
+}
+
+#define get_user_preempt_disabled(x, ptr)	\
+({						\
+	int __ret;				\
+	preempt_enable_no_resched();		\
+	__ret = get_user(x, ptr);		\
+	preempt_disable();			\
+	__ret;					\
+})
+
+#define put_user_preempt_disabled(x, ptr)	\
+({						\
+	int __ret;				\
+	preempt_enable_no_resched();		\
+	__ret = put_user(x, ptr);		\
+	preempt_disable();			\
+	__ret;					\
+})
+
 static void binder_set_nice(long nice)
 {
 	long min_nice;
@@ -568,6 +623,8 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate,
 	else
 		mm = get_task_mm(proc->tsk);
 
+	preempt_enable_no_resched();
+
 	if (mm) {
 		down_write(&mm->mmap_sem);
 		vma = proc->vma;
@@ -622,6 +679,9 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate,
 		up_write(&mm->mmap_sem);
 		mmput(mm);
 	}
+
+	preempt_disable();
+
 	return 0;
 
 free_range:
@@ -644,6 +704,9 @@ err_no_vma:
 		up_write(&mm->mmap_sem);
 		mmput(mm);
 	}
+
+	preempt_disable();
+	
 	return -ENOMEM;
 }
 
@@ -903,7 +966,7 @@ static struct binder_node *binder_new_node(struct binder_proc *proc,
 			return NULL;
 	}
 
-	node = kzalloc(sizeof(*node), GFP_KERNEL);
+	node = kzalloc_preempt_disabled(sizeof(*node));
 	if (node == NULL)
 		return NULL;
 	binder_stats_created(BINDER_STAT_NODE);
@@ -1040,7 +1103,7 @@ static struct binder_ref *binder_get_ref_for_node(struct binder_proc *proc,
 		else
 			return ref;
 	}
-	new_ref = kzalloc(sizeof(*ref), GFP_KERNEL);
+	new_ref = kzalloc_preempt_disabled(sizeof(*ref));
 	if (new_ref == NULL)
 		return NULL;
 	binder_stats_created(BINDER_STAT_REF);
@@ -1438,14 +1501,14 @@ static void binder_transaction(struct binder_proc *proc,
 	e->to_proc = target_proc->pid;
 
 	/* TODO: reuse incoming transaction for reply */
-	t = kzalloc(sizeof(*t), GFP_KERNEL);
+	t = kzalloc_preempt_disabled(sizeof(*t));
 	if (t == NULL) {
 		return_error = BR_FAILED_REPLY;
 		goto err_alloc_t_failed;
 	}
 	binder_stats_created(BINDER_STAT_TRANSACTION);
 
-	tcomplete = kzalloc(sizeof(*tcomplete), GFP_KERNEL);
+	tcomplete = kzalloc_preempt_disabled(sizeof(*tcomplete));
 	if (tcomplete == NULL) {
 		return_error = BR_FAILED_REPLY;
 		goto err_alloc_tcomplete_failed;
@@ -1502,14 +1565,14 @@ static void binder_transaction(struct binder_proc *proc,
 	offp = (binder_size_t *)(t->buffer->data +
 				 ALIGN(tr->data_size, sizeof(void *)));
 
-	if (copy_from_user(t->buffer->data, (const void __user *)(uintptr_t)
+	if (copy_from_user_preempt_disabled(t->buffer->data, (const void __user *)(uintptr_t)
 			   tr->data.ptr.buffer, tr->data_size)) {
 		binder_user_error("%d:%d got transaction with invalid data ptr\n",
 				proc->pid, thread->pid);
 		return_error = BR_FAILED_REPLY;
 		goto err_copy_data_failed;
 	}
-	if (copy_from_user(offp, (const void __user *)(uintptr_t)
+	if (copy_from_user_preempt_disabled(offp, (const void __user *)(uintptr_t)
 			   tr->data.ptr.offsets, tr->offsets_size)) {
 		binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
 				proc->pid, thread->pid);
@@ -1778,7 +1841,7 @@ static int binder_thread_write(struct binder_proc *proc,
 	void __user *end = buffer + size;
 
 	while (ptr < end && thread->return_error == BR_OK) {
-		if (get_user(cmd, (uint32_t __user *)ptr))
+		if (get_user_preempt_disabled(cmd, (uint32_t __user *)ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
 		trace_binder_command(cmd);
@@ -1796,7 +1859,7 @@ static int binder_thread_write(struct binder_proc *proc,
 			struct binder_ref *ref;
 			const char *debug_string;
 
-			if (get_user(target, (uint32_t __user *)ptr))
+			if (get_user_preempt_disabled(target, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
 			if (target == 0 && binder_context_mgr_node &&
@@ -1846,10 +1909,10 @@ static int binder_thread_write(struct binder_proc *proc,
 			binder_uintptr_t cookie;
 			struct binder_node *node;
 
-			if (get_user(node_ptr, (binder_uintptr_t __user *)ptr))
+			if (get_user_preempt_disabled(node_ptr, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
-			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
+			if (get_user_preempt_disabled(cookie, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 			node = binder_get_node(proc, node_ptr);
@@ -1907,7 +1970,7 @@ static int binder_thread_write(struct binder_proc *proc,
 			binder_uintptr_t data_ptr;
 			struct binder_buffer *buffer;
 
-			if (get_user(data_ptr, (binder_uintptr_t __user *)ptr))
+			if (get_user_preempt_disabled(data_ptr, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 
@@ -1949,7 +2012,7 @@ static int binder_thread_write(struct binder_proc *proc,
 		case BC_REPLY: {
 			struct binder_transaction_data tr;
 
-			if (copy_from_user(&tr, ptr, sizeof(tr)))
+			if (copy_from_user_preempt_disabled(&tr, ptr, sizeof(tr)))
 				return -EFAULT;
 			ptr += sizeof(tr);
 			binder_transaction(proc, thread, &tr, cmd == BC_REPLY);
@@ -1999,10 +2062,10 @@ static int binder_thread_write(struct binder_proc *proc,
 			struct binder_ref *ref;
 			struct binder_ref_death *death;
 
-			if (get_user(target, (uint32_t __user *)ptr))
+			if (get_user_preempt_disabled(target, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
-			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
+			if (get_user_preempt_disabled(cookie, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 			ref = binder_get_ref(proc, target);
@@ -2031,7 +2094,7 @@ static int binder_thread_write(struct binder_proc *proc,
 						proc->pid, thread->pid);
 					break;
 				}
-				death = kzalloc(sizeof(*death), GFP_KERNEL);
+				death = kzalloc_preempt_disabled(sizeof(*death));
 				if (death == NULL) {
 					thread->return_error = BR_ERROR;
 					binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
@@ -2085,8 +2148,7 @@ static int binder_thread_write(struct binder_proc *proc,
 			struct binder_work *w;
 			binder_uintptr_t cookie;
 			struct binder_ref_death *death = NULL;
-
-			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
+			if (get_user_preempt_disabled(cookie, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 
 			ptr += sizeof(cookie);
@@ -2118,7 +2180,8 @@ static int binder_thread_write(struct binder_proc *proc,
 					wake_up_interruptible(&proc->wait);
 				}
 			}
-		} break;
+		}
+		break;
 
 		default:
 			pr_err("%d:%d unknown command %d\n",
@@ -2167,7 +2230,7 @@ static int binder_thread_read(struct binder_proc *proc,
 	int wait_for_proc_work;
 
 	if (*consumed == 0) {
-		if (put_user(BR_NOOP, (uint32_t __user *)ptr))
+		if (put_user_preempt_disabled(BR_NOOP, (uint32_t __user *)ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
 	}
@@ -2178,7 +2241,7 @@ retry:
 
 	if (thread->return_error != BR_OK && ptr < end) {
 		if (thread->return_error2 != BR_OK) {
-			if (put_user(thread->return_error2, (uint32_t __user *)ptr))
+			if (put_user_preempt_disabled(thread->return_error2, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
 			binder_stat_br(proc, thread, thread->return_error2);
@@ -2186,7 +2249,7 @@ retry:
 				goto done;
 			thread->return_error2 = BR_OK;
 		}
-		if (put_user(thread->return_error, (uint32_t __user *)ptr))
+		if (put_user_preempt_disabled(thread->return_error, (uint32_t __user *)ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
 		binder_stat_br(proc, thread, thread->return_error);
@@ -2264,7 +2327,7 @@ retry:
 		} break;
 		case BINDER_WORK_TRANSACTION_COMPLETE: {
 			cmd = BR_TRANSACTION_COMPLETE;
-			if (put_user(cmd, (uint32_t __user *)ptr))
+				if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
 
@@ -2306,14 +2369,14 @@ retry:
 				node->has_weak_ref = 0;
 			}
 			if (cmd != BR_NOOP) {
-				if (put_user(cmd, (uint32_t __user *)ptr))
+					if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
 					return -EFAULT;
 				ptr += sizeof(uint32_t);
-				if (put_user(node->ptr,
+					if (put_user_preempt_disabled(node->ptr, (binder_uintptr_t __user *)
 					     (binder_uintptr_t __user *)ptr))
 					return -EFAULT;
 				ptr += sizeof(binder_uintptr_t);
-				if (put_user(node->cookie,
+					if (put_user_preempt_disabled(node->cookie, (binder_uintptr_t __user *)
 					     (binder_uintptr_t __user *)ptr))
 					return -EFAULT;
 				ptr += sizeof(binder_uintptr_t);
@@ -2357,11 +2420,10 @@ retry:
 				cmd = BR_CLEAR_DEATH_NOTIFICATION_DONE;
 			else
 				cmd = BR_DEAD_BINDER;
-			if (put_user(cmd, (uint32_t __user *)ptr))
+				if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
-			if (put_user(death->cookie,
-				     (binder_uintptr_t __user *)ptr))
+			if (put_user_preempt_disabled(death->cookie, (binder_uintptr_t __user *) ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 			binder_stat_br(proc, thread, cmd);
@@ -2428,10 +2490,10 @@ retry:
 					ALIGN(t->buffer->data_size,
 					    sizeof(void *));
 
-		if (put_user(cmd, (uint32_t __user *)ptr))
+		if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
-		if (copy_to_user(ptr, &tr, sizeof(tr)))
+		if (copy_to_user_preempt_disabled(ptr, &tr, sizeof(tr)))
 			return -EFAULT;
 		ptr += sizeof(tr);
 
@@ -2473,7 +2535,7 @@ done:
 		binder_debug(BINDER_DEBUG_THREADS,
 			     "%d:%d BR_SPAWN_LOOPER\n",
 			     proc->pid, thread->pid);
-		if (put_user(BR_SPAWN_LOOPER, (uint32_t __user *)buffer))
+		if (put_user_preempt_disabled(BR_SPAWN_LOOPER, (uint32_t __user *) buffer))
 			return -EFAULT;
 		binder_stat_br(proc, thread, BR_SPAWN_LOOPER);
 	}
@@ -2548,7 +2610,7 @@ static struct binder_thread *binder_get_thread(struct binder_proc *proc)
 			break;
 	}
 	if (*p == NULL) {
-		thread = kzalloc(sizeof(*thread), GFP_KERNEL);
+		thread = kzalloc_preempt_disabled(sizeof(*thread));
 		if (thread == NULL)
 			return NULL;
 		binder_stats_created(BINDER_STAT_THREAD);
@@ -2652,7 +2714,7 @@ static int binder_ioctl_write_read(struct file *filp,
 		ret = -EINVAL;
 		goto out;
 	}
-	if (copy_from_user(&bwr, ubuf, sizeof(bwr))) {
+	if (copy_from_user_preempt_disabled(&bwr, ubuf, sizeof(bwr))) {
 		ret = -EFAULT;
 		goto out;
 	}
@@ -2670,7 +2732,7 @@ static int binder_ioctl_write_read(struct file *filp,
 		trace_binder_write_done(ret);
 		if (ret < 0) {
 			bwr.read_consumed = 0;
-			if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
+			if (copy_to_user_preempt_disabled(ubuf, &bwr, sizeof(bwr)))
 				ret = -EFAULT;
 			goto out;
 		}
@@ -2684,7 +2746,7 @@ static int binder_ioctl_write_read(struct file *filp,
 		if (!list_empty(&proc->todo))
 			wake_up_interruptible(&proc->wait);
 		if (ret < 0) {
-			if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
+			if (copy_to_user_preempt_disabled(ubuf, &bwr, sizeof(bwr)))
 				ret = -EFAULT;
 			goto out;
 		}
@@ -2694,7 +2756,7 @@ static int binder_ioctl_write_read(struct file *filp,
 		     proc->pid, thread->pid,
 		     (u64)bwr.write_consumed, (u64)bwr.write_size,
 		     (u64)bwr.read_consumed, (u64)bwr.read_size);
-	if (copy_to_user(ubuf, &bwr, sizeof(bwr))) {
+	if (copy_to_user_preempt_disabled(ubuf, &bwr, sizeof(bwr))) {
 		ret = -EFAULT;
 		goto out;
 	}
@@ -2772,7 +2834,7 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			goto err;
 		break;
 	case BINDER_SET_MAX_THREADS:
-		if (copy_from_user(&proc->max_threads, ubuf, sizeof(proc->max_threads))) {
+		if (copy_from_user_preempt_disabled(&proc->max_threads, ubuf, sizeof(proc->max_threads))) {
 			ret = -EINVAL;
 			goto err;
 		}
@@ -2795,9 +2857,8 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			ret = -EINVAL;
 			goto err;
 		}
-		if (put_user(BINDER_CURRENT_PROTOCOL_VERSION,
-			     &ver->protocol_version)) {
-			ret = -EINVAL;
+			if (put_user_preempt_disabled(BINDER_CURRENT_PROTOCOL_VERSION, &ver->protocol_version)) {
+				ret = -EINVAL;
 			goto err;
 		}
 		break;
@@ -2858,6 +2919,7 @@ static const struct vm_operations_struct binder_vm_ops = {
 static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	int ret;
+
 	struct vm_struct *area;
 	struct binder_proc *proc = filp->private_data;
 	const char *failure_string;
@@ -2918,7 +2980,11 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
 	vma->vm_ops = &binder_vm_ops;
 	vma->vm_private_data = proc;
 
-	if (binder_update_page_range(proc, 1, proc->buffer, proc->buffer + PAGE_SIZE, vma)) {
+	/* binder_update_page_range assumes preemption is disabled */
+	preempt_disable();
+	ret = binder_update_page_range(proc, 1, proc->buffer, proc->buffer + PAGE_SIZE, vma);
+	preempt_enable_no_resched();
+	if (ret) {
 		ret = -ENOMEM;
 		failure_string = "alloc small buf";
 		goto err_alloc_small_buf_failed;
@@ -3188,8 +3254,12 @@ static void binder_deferred_func(struct work_struct *work)
 	int defer;
 
 	do {
-		binder_lock(__func__);
+		trace_binder_lock(__func__);
+		mutex_lock(&binder_main_lock);
+		trace_binder_locked(__func__);
+
 		mutex_lock(&binder_deferred_lock);
+		preempt_disable();
 		if (!hlist_empty(&binder_deferred_list)) {
 			proc = hlist_entry(binder_deferred_list.first,
 					struct binder_proc, deferred_work_node);
@@ -3215,7 +3285,9 @@ static void binder_deferred_func(struct work_struct *work)
 		if (defer & BINDER_DEFERRED_RELEASE)
 			binder_deferred_release(proc); /* frees proc */
 
-		binder_unlock(__func__);
+		trace_binder_unlock(__func__);
+		mutex_unlock(&binder_main_lock);
+		preempt_enable_no_resched();
 		if (files)
 			put_files_struct(files);
 	} while (proc);