android: binder: Revert fixes for preemption and locking issues

  These were hacks and no longer needed as next binder from
  android-4.4@59ff2e1 (v4.4.78) has been reworked to use
  fine-grained locking.

  This is a preparation for clean merge of binder changes from
  android-4.4@59ff2e1 (v4.4.78), which follows right after this
  commit.

Reverted changes:
=================

  773fc2f android: binder: use copy_from_user_preempt_disabled

  To keep the driver consistent, and until we have
  fine-grained locking in place.

  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>

  821e02f CHROMIUM: android: binder: Fix potential scheduling-while-atomica

  Commit f1e7f0a724f6 ("android: binder: Disable preemption while holding
  the global binder lock.") re-enabled preemption around most of the sites
  where calls to potentially sleeping functions were made, but missed
  __alloc_fd(), which can sleep if the fdtable needs to be resized.
  Re-enable preemption around __alloc_fd() as well as __fd_install() which
  can now sleep in upstream kernels as of commit 8a81252b774b ("fs/file.c:
  don't acquire files->file_lock in fd_install()").

  BUG=chrome-os-partner:44012
  TEST=Build and boot on Smaug.

  Change-Id: I9819c4b95876f697e75b1b84810b6c520d9c33ec
  Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
  Reviewed-on: https://chromium-review.googlesource.com/308582
  Reviewed-by: Stephen Barber <smbarber@chromium.org>
  Reviewed-by: Riley Andrews <riandrews@google.com>
  Git-repo: https://source.codeaurora.org/quic/la/kernel/msm-4.4
  Git-commit: c267ff1d548ed1bdad6a08f1c70776c5e60d569e
  Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

  e4045d6 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>

Change-Id: Id97e04f3694d76c2b6a1e7c0dc39da15d83c2867
Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>

1 files changed, 49 insertions, 130 deletions

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 0c3cf182e351..573e9795b236 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -417,7 +417,6 @@ static int task_get_unused_fd_flags(struct binder_proc *proc, int flags)
 	struct files_struct *files = proc->files;
 	unsigned long rlim_cur;
 	unsigned long irqs;
-	int ret;
 
 	if (files == NULL)
 		return -ESRCH;
@@ -428,11 +427,7 @@ static int task_get_unused_fd_flags(struct binder_proc *proc, int flags)
 	rlim_cur = task_rlimit(proc->tsk, RLIMIT_NOFILE);
 	unlock_task_sighand(proc->tsk, &irqs);
 
-	preempt_enable_no_resched();
-	ret = __alloc_fd(files, 0, rlim_cur, flags);
-	preempt_disable();
-
-	return ret;
+	return __alloc_fd(files, 0, rlim_cur, flags);
 }
 
 /*
@@ -441,11 +436,8 @@ static int task_get_unused_fd_flags(struct binder_proc *proc, int flags)
 static void task_fd_install(
 	struct binder_proc *proc, unsigned int fd, struct file *file)
 {
-	if (proc->files) {
-		preempt_enable_no_resched();
+	if (proc->files)
 		__fd_install(proc->files, fd, file);
-		preempt_disable();
-	}
 }
 
 /*
@@ -473,7 +465,6 @@ static inline void binder_lock(struct binder_context *context, const char *tag)
 {
 	trace_binder_lock(tag);
 	mutex_lock(&context->binder_main_lock);
-	preempt_disable();
 	trace_binder_locked(tag);
 }
 
@@ -482,62 +473,8 @@ static inline void binder_unlock(struct binder_context *context,
 {
 	trace_binder_unlock(tag);
 	mutex_unlock(&context->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;
@@ -670,8 +607,6 @@ 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;
@@ -726,9 +661,6 @@ 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:
@@ -751,9 +683,6 @@ err_no_vma:
 		up_write(&mm->mmap_sem);
 		mmput(mm);
 	}
-
-	preempt_disable();
-	
 	return -ENOMEM;
 }
 
@@ -1022,7 +951,7 @@ static struct binder_node *binder_new_node(struct binder_proc *proc,
 			return NULL;
 	}
 
-	node = kzalloc_preempt_disabled(sizeof(*node));
+	node = kzalloc(sizeof(*node), GFP_KERNEL);
 	if (node == NULL)
 		return NULL;
 	binder_stats_created(BINDER_STAT_NODE);
@@ -1166,7 +1095,7 @@ static struct binder_ref *binder_get_ref_for_node(struct binder_proc *proc,
 		else
 			return ref;
 	}
-	new_ref = kzalloc_preempt_disabled(sizeof(*ref));
+	new_ref = kzalloc(sizeof(*ref), GFP_KERNEL);
 	if (new_ref == NULL)
 		return NULL;
 	binder_stats_created(BINDER_STAT_REF);
@@ -2039,14 +1968,14 @@ static void binder_transaction(struct binder_proc *proc,
 	e->to_proc = target_proc->pid;
 
 	/* TODO: reuse incoming transaction for reply */
-	t = kzalloc_preempt_disabled(sizeof(*t));
+	t = kzalloc(sizeof(*t), GFP_KERNEL);
 	if (t == NULL) {
 		return_error = BR_FAILED_REPLY;
 		goto err_alloc_t_failed;
 	}
 	binder_stats_created(BINDER_STAT_TRANSACTION);
 
-	tcomplete = kzalloc_preempt_disabled(sizeof(*tcomplete));
+	tcomplete = kzalloc(sizeof(*tcomplete), GFP_KERNEL);
 	if (tcomplete == NULL) {
 		return_error = BR_FAILED_REPLY;
 		goto err_alloc_tcomplete_failed;
@@ -2107,14 +2036,14 @@ static void binder_transaction(struct binder_proc *proc,
 				      ALIGN(tr->data_size, sizeof(void *)));
 	offp = off_start;
 
-	if (copy_from_user_preempt_disabled(t->buffer->data, (const void __user *)(uintptr_t)
+	if (copy_from_user(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_preempt_disabled(offp, (const void __user *)(uintptr_t)
+	if (copy_from_user(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);
@@ -2232,10 +2161,9 @@ static void binder_transaction(struct binder_proc *proc,
 				return_error = BR_FAILED_REPLY;
 				goto err_bad_offset;
 			}
-			if (copy_from_user_preempt_disabled(
-					sg_bufp,
-					(const void __user *)(uintptr_t)
-					bp->buffer, bp->length)) {
+			if (copy_from_user(sg_bufp,
+					   (const void __user *)(uintptr_t)
+					   bp->buffer, bp->length)) {
 				binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
 						  proc->pid, thread->pid);
 				return_error = BR_FAILED_REPLY;
@@ -2351,7 +2279,7 @@ 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_preempt_disabled(cmd, (uint32_t __user *)ptr))
+		if (get_user(cmd, (uint32_t __user *)ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
 		trace_binder_command(cmd);
@@ -2369,7 +2297,7 @@ static int binder_thread_write(struct binder_proc *proc,
 			struct binder_ref *ref;
 			const char *debug_string;
 
-			if (get_user_preempt_disabled(target, (uint32_t __user *)ptr))
+			if (get_user(target, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
 			if (target == 0 && context->binder_context_mgr_node &&
@@ -2421,10 +2349,10 @@ static int binder_thread_write(struct binder_proc *proc,
 			binder_uintptr_t cookie;
 			struct binder_node *node;
 
-			if (get_user_preempt_disabled(node_ptr, (binder_uintptr_t __user *)ptr))
+			if (get_user(node_ptr, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
-			if (get_user_preempt_disabled(cookie, (binder_uintptr_t __user *)ptr))
+			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 			node = binder_get_node(proc, node_ptr);
@@ -2482,7 +2410,7 @@ static int binder_thread_write(struct binder_proc *proc,
 			binder_uintptr_t data_ptr;
 			struct binder_buffer *buffer;
 
-			if (get_user_preempt_disabled(data_ptr, (binder_uintptr_t __user *)ptr))
+			if (get_user(data_ptr, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 
@@ -2524,8 +2452,7 @@ static int binder_thread_write(struct binder_proc *proc,
 		case BC_REPLY_SG: {
 			struct binder_transaction_data_sg tr;
 
-			if (copy_from_user_preempt_disabled(&tr, ptr,
-							    sizeof(tr)))
+			if (copy_from_user(&tr, ptr, sizeof(tr)))
 				return -EFAULT;
 			ptr += sizeof(tr);
 			binder_transaction(proc, thread, &tr.transaction_data,
@@ -2536,7 +2463,7 @@ static int binder_thread_write(struct binder_proc *proc,
 		case BC_REPLY: {
 			struct binder_transaction_data tr;
 
-			if (copy_from_user_preempt_disabled(&tr, ptr, sizeof(tr)))
+			if (copy_from_user(&tr, ptr, sizeof(tr)))
 				return -EFAULT;
 			ptr += sizeof(tr);
 			binder_transaction(proc, thread, &tr,
@@ -2587,10 +2514,10 @@ static int binder_thread_write(struct binder_proc *proc,
 			struct binder_ref *ref;
 			struct binder_ref_death *death;
 
-			if (get_user_preempt_disabled(target, (uint32_t __user *)ptr))
+			if (get_user(target, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
-			if (get_user_preempt_disabled(cookie, (binder_uintptr_t __user *)ptr))
+			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 			ref = binder_get_ref(proc, target, false);
@@ -2619,7 +2546,7 @@ static int binder_thread_write(struct binder_proc *proc,
 						proc->pid, thread->pid);
 					break;
 				}
-				death = kzalloc_preempt_disabled(sizeof(*death));
+				death = kzalloc(sizeof(*death), GFP_KERNEL);
 				if (death == NULL) {
 					thread->return_error = BR_ERROR;
 					binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
@@ -2673,7 +2600,8 @@ 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_preempt_disabled(cookie, (binder_uintptr_t __user *)ptr))
+
+			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 
 			ptr += sizeof(cookie);
@@ -2705,8 +2633,7 @@ 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",
@@ -2755,7 +2682,7 @@ static int binder_thread_read(struct binder_proc *proc,
 	int wait_for_proc_work;
 
 	if (*consumed == 0) {
-		if (put_user_preempt_disabled(BR_NOOP, (uint32_t __user *)ptr))
+		if (put_user(BR_NOOP, (uint32_t __user *)ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
 	}
@@ -2766,7 +2693,7 @@ retry:
 
 	if (thread->return_error != BR_OK && ptr < end) {
 		if (thread->return_error2 != BR_OK) {
-			if (put_user_preempt_disabled(thread->return_error2, (uint32_t __user *)ptr))
+			if (put_user(thread->return_error2, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
 			binder_stat_br(proc, thread, thread->return_error2);
@@ -2774,7 +2701,7 @@ retry:
 				goto done;
 			thread->return_error2 = BR_OK;
 		}
-		if (put_user_preempt_disabled(thread->return_error, (uint32_t __user *)ptr))
+		if (put_user(thread->return_error, (uint32_t __user *)ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
 		binder_stat_br(proc, thread, thread->return_error);
@@ -2852,7 +2779,7 @@ retry:
 		} break;
 		case BINDER_WORK_TRANSACTION_COMPLETE: {
 			cmd = BR_TRANSACTION_COMPLETE;
-				if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
+			if (put_user(cmd, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
 
@@ -2894,14 +2821,14 @@ retry:
 				node->has_weak_ref = 0;
 			}
 			if (cmd != BR_NOOP) {
-					if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
+				if (put_user(cmd, (uint32_t __user *)ptr))
 					return -EFAULT;
 				ptr += sizeof(uint32_t);
-					if (put_user_preempt_disabled(node->ptr, (binder_uintptr_t __user *)
+				if (put_user(node->ptr,
 					     (binder_uintptr_t __user *)ptr))
 					return -EFAULT;
 				ptr += sizeof(binder_uintptr_t);
-					if (put_user_preempt_disabled(node->cookie, (binder_uintptr_t __user *)
+				if (put_user(node->cookie,
 					     (binder_uintptr_t __user *)ptr))
 					return -EFAULT;
 				ptr += sizeof(binder_uintptr_t);
@@ -2945,10 +2872,11 @@ retry:
 				cmd = BR_CLEAR_DEATH_NOTIFICATION_DONE;
 			else
 				cmd = BR_DEAD_BINDER;
-				if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
+			if (put_user(cmd, (uint32_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(uint32_t);
-			if (put_user_preempt_disabled(death->cookie, (binder_uintptr_t __user *) ptr))
+			if (put_user(death->cookie,
+				     (binder_uintptr_t __user *)ptr))
 				return -EFAULT;
 			ptr += sizeof(binder_uintptr_t);
 			binder_stat_br(proc, thread, cmd);
@@ -3015,10 +2943,10 @@ retry:
 					ALIGN(t->buffer->data_size,
 					    sizeof(void *));
 
-		if (put_user_preempt_disabled(cmd, (uint32_t __user *) ptr))
+		if (put_user(cmd, (uint32_t __user *)ptr))
 			return -EFAULT;
 		ptr += sizeof(uint32_t);
-		if (copy_to_user_preempt_disabled(ptr, &tr, sizeof(tr)))
+		if (copy_to_user(ptr, &tr, sizeof(tr)))
 			return -EFAULT;
 		ptr += sizeof(tr);
 
@@ -3060,7 +2988,7 @@ done:
 		binder_debug(BINDER_DEBUG_THREADS,
 			     "%d:%d BR_SPAWN_LOOPER\n",
 			     proc->pid, thread->pid);
-		if (put_user_preempt_disabled(BR_SPAWN_LOOPER, (uint32_t __user *) buffer))
+		if (put_user(BR_SPAWN_LOOPER, (uint32_t __user *)buffer))
 			return -EFAULT;
 		binder_stat_br(proc, thread, BR_SPAWN_LOOPER);
 	}
@@ -3135,7 +3063,7 @@ static struct binder_thread *binder_get_thread(struct binder_proc *proc)
 			break;
 	}
 	if (*p == NULL) {
-		thread = kzalloc_preempt_disabled(sizeof(*thread));
+		thread = kzalloc(sizeof(*thread), GFP_KERNEL);
 		if (thread == NULL)
 			return NULL;
 		binder_stats_created(BINDER_STAT_THREAD);
@@ -3239,7 +3167,7 @@ static int binder_ioctl_write_read(struct file *filp,
 		ret = -EINVAL;
 		goto out;
 	}
-	if (copy_from_user_preempt_disabled(&bwr, ubuf, sizeof(bwr))) {
+	if (copy_from_user(&bwr, ubuf, sizeof(bwr))) {
 		ret = -EFAULT;
 		goto out;
 	}
@@ -3257,7 +3185,7 @@ 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_preempt_disabled(ubuf, &bwr, sizeof(bwr)))
+			if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
 				ret = -EFAULT;
 			goto out;
 		}
@@ -3271,7 +3199,7 @@ 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_preempt_disabled(ubuf, &bwr, sizeof(bwr)))
+			if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
 				ret = -EFAULT;
 			goto out;
 		}
@@ -3281,7 +3209,7 @@ 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_preempt_disabled(ubuf, &bwr, sizeof(bwr))) {
+	if (copy_to_user(ubuf, &bwr, sizeof(bwr))) {
 		ret = -EFAULT;
 		goto out;
 	}
@@ -3362,7 +3290,7 @@ 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_preempt_disabled(&proc->max_threads, ubuf, sizeof(proc->max_threads))) {
+		if (copy_from_user(&proc->max_threads, ubuf, sizeof(proc->max_threads))) {
 			ret = -EINVAL;
 			goto err;
 		}
@@ -3385,8 +3313,9 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			ret = -EINVAL;
 			goto err;
 		}
-			if (put_user_preempt_disabled(BINDER_CURRENT_PROTOCOL_VERSION, &ver->protocol_version)) {
-				ret = -EINVAL;
+		if (put_user(BINDER_CURRENT_PROTOCOL_VERSION,
+			     &ver->protocol_version)) {
+			ret = -EINVAL;
 			goto err;
 		}
 		break;
@@ -3447,7 +3376,6 @@ 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;
@@ -3508,11 +3436,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
 	vma->vm_ops = &binder_vm_ops;
 	vma->vm_private_data = proc;
 
-	/* 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) {
+	if (binder_update_page_range(proc, 1, proc->buffer, proc->buffer + PAGE_SIZE, vma)) {
 		ret = -ENOMEM;
 		failure_string = "alloc small buf";
 		goto err_alloc_small_buf_failed;
@@ -3803,12 +3727,9 @@ static void binder_deferred_func(struct work_struct *work)
 	int defer;
 
 	do {
-		trace_binder_lock(__func__);
-		mutex_lock(&context->binder_main_lock);
-		trace_binder_locked(__func__);
+		binder_lock(context, __func__);
 
 		mutex_lock(&context->binder_deferred_lock);
-		preempt_disable();
 		if (!hlist_empty(&context->binder_deferred_list)) {
 			proc = hlist_entry(context->binder_deferred_list.first,
 					struct binder_proc, deferred_work_node);
@@ -3834,9 +3755,7 @@ static void binder_deferred_func(struct work_struct *work)
 		if (defer & BINDER_DEFERRED_RELEASE)
 			binder_deferred_release(proc); /* frees proc */
 
-		trace_binder_unlock(__func__);
-		mutex_unlock(&context->binder_main_lock);
-		preempt_enable_no_resched();
+		binder_unlock(context, __func__);
 		if (files)
 			put_files_struct(files);
 	} while (proc);