Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 265d9dd..89b590c 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -227,7 +227,7 @@
 struct binder_work {
 	struct list_head entry;
 
-	enum {
+	enum binder_work_type {
 		BINDER_WORK_TRANSACTION = 1,
 		BINDER_WORK_TRANSACTION_COMPLETE,
 		BINDER_WORK_RETURN_ERROR,
@@ -889,27 +889,6 @@
 	return w;
 }
 
-/**
- * binder_dequeue_work_head() - Dequeues the item at head of list
- * @proc:         binder_proc associated with list
- * @list:         list to dequeue head
- *
- * Removes the head of the list if there are items on the list
- *
- * Return: pointer dequeued binder_work, NULL if list was empty
- */
-static struct binder_work *binder_dequeue_work_head(
-					struct binder_proc *proc,
-					struct list_head *list)
-{
-	struct binder_work *w;
-
-	binder_inner_proc_lock(proc);
-	w = binder_dequeue_work_head_ilocked(list);
-	binder_inner_proc_unlock(proc);
-	return w;
-}
-
 static void
 binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer);
 static void binder_free_thread(struct binder_thread *thread);
@@ -2347,8 +2326,6 @@
 			 * file is done when the transaction is torn
 			 * down.
 			 */
-			WARN_ON(failed_at &&
-				proc->tsk == current->group_leader);
 		} break;
 		case BINDER_TYPE_PTR:
 			/*
@@ -2984,6 +2961,12 @@
 			goto err_dead_binder;
 		}
 		e->to_node = target_node->debug_id;
+		if (WARN_ON(proc == target_proc)) {
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EINVAL;
+			return_error_line = __LINE__;
+			goto err_invalid_target_handle;
+		}
 		if (security_binder_transaction(proc->tsk,
 						target_proc->tsk) < 0) {
 			return_error = BR_FAILED_REPLY;
@@ -3167,6 +3150,7 @@
 	t->buffer->debug_id = t->debug_id;
 	t->buffer->transaction = t;
 	t->buffer->target_node = target_node;
+	t->buffer->clear_on_free = !!(t->flags & TF_CLEAR_BUF);
 	trace_binder_transaction_alloc_buf(t->buffer);
 
 	if (binder_alloc_copy_user_to_buffer(
@@ -3314,7 +3298,7 @@
 			binder_size_t parent_offset;
 			struct binder_fd_array_object *fda =
 				to_binder_fd_array_object(hdr);
-			size_t num_valid = (buffer_offset - off_start_offset) *
+			size_t num_valid = (buffer_offset - off_start_offset) /
 						sizeof(binder_size_t);
 			struct binder_buffer_object *parent =
 				binder_validate_ptr(target_proc, t->buffer,
@@ -3388,7 +3372,7 @@
 				t->buffer->user_data + sg_buf_offset;
 			sg_buf_offset += ALIGN(bp->length, sizeof(u64));
 
-			num_valid = (buffer_offset - off_start_offset) *
+			num_valid = (buffer_offset - off_start_offset) /
 					sizeof(binder_size_t);
 			ret = binder_fixup_parent(t, thread, bp,
 						  off_start_offset,
@@ -3637,10 +3621,17 @@
 				struct binder_node *ctx_mgr_node;
 				mutex_lock(&context->context_mgr_node_lock);
 				ctx_mgr_node = context->binder_context_mgr_node;
-				if (ctx_mgr_node)
+				if (ctx_mgr_node) {
+					if (ctx_mgr_node->proc == proc) {
+						binder_user_error("%d:%d context manager tried to acquire desc 0\n",
+								  proc->pid, thread->pid);
+						mutex_unlock(&context->context_mgr_node_lock);
+						return -EINVAL;
+					}
 					ret = binder_inc_ref_for_node(
 							proc, ctx_mgr_node,
 							strong, NULL, &rdata);
+				}
 				mutex_unlock(&context->context_mgr_node_lock);
 			}
 			if (ret)
@@ -4578,13 +4569,17 @@
 				struct list_head *list)
 {
 	struct binder_work *w;
+	enum binder_work_type wtype;
 
 	while (1) {
-		w = binder_dequeue_work_head(proc, list);
+		binder_inner_proc_lock(proc);
+		w = binder_dequeue_work_head_ilocked(list);
+		wtype = w ? w->type : 0;
+		binder_inner_proc_unlock(proc);
 		if (!w)
 			return;
 
-		switch (w->type) {
+		switch (wtype) {
 		case BINDER_WORK_TRANSACTION: {
 			struct binder_transaction *t;
 
@@ -4618,9 +4613,11 @@
 			kfree(death);
 			binder_stats_deleted(BINDER_STAT_DEATH);
 		} break;
+		case BINDER_WORK_NODE:
+			break;
 		default:
 			pr_err("unexpected work type, %d, not freed\n",
-			       w->type);
+			       wtype);
 			break;
 		}
 	}
@@ -4688,8 +4685,15 @@
 
 static void binder_free_proc(struct binder_proc *proc)
 {
+	struct binder_device *device;
+
 	BUG_ON(!list_empty(&proc->todo));
 	BUG_ON(!list_empty(&proc->delivered_death));
+	device = container_of(proc->context, struct binder_device, context);
+	if (refcount_dec_and_test(&device->ref)) {
+		kfree(proc->context->name);
+		kfree(device);
+	}
 	binder_alloc_deferred_release(&proc->alloc);
 	put_task_struct(proc->tsk);
 	binder_stats_deleted(BINDER_STAT_PROC);
@@ -5203,10 +5207,11 @@
 
 static int binder_open(struct inode *nodp, struct file *filp)
 {
-	struct binder_proc *proc;
+	struct binder_proc *proc, *itr;
 	struct binder_device *binder_dev;
 	struct binderfs_info *info;
 	struct dentry *binder_binderfs_dir_entry_proc = NULL;
+	bool existing_pid = false;
 
 	binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__,
 		     current->group_leader->pid, current->pid);
@@ -5229,6 +5234,7 @@
 		binder_dev = container_of(filp->private_data,
 					  struct binder_device, miscdev);
 	}
+	refcount_inc(&binder_dev->ref);
 	proc->context = &binder_dev->context;
 	binder_alloc_init(&proc->alloc);
 
@@ -5239,19 +5245,24 @@
 	filp->private_data = proc;
 
 	mutex_lock(&binder_procs_lock);
+	hlist_for_each_entry(itr, &binder_procs, proc_node) {
+		if (itr->pid == proc->pid) {
+			existing_pid = true;
+			break;
+		}
+	}
 	hlist_add_head(&proc->proc_node, &binder_procs);
 	mutex_unlock(&binder_procs_lock);
 
-	if (binder_debugfs_dir_entry_proc) {
+	if (binder_debugfs_dir_entry_proc && !existing_pid) {
 		char strbuf[11];
 
 		snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
 		/*
-		 * proc debug entries are shared between contexts, so
-		 * this will fail if the process tries to open the driver
-		 * again with a different context. The priting code will
-		 * anyway print all contexts that a given PID has, so this
-		 * is not a problem.
+		 * proc debug entries are shared between contexts.
+		 * Only create for the first PID to avoid debugfs log spamming
+		 * The printing code will anyway print all contexts for a given
+		 * PID so this is not a problem.
 		 */
 		proc->debugfs_entry = debugfs_create_file(strbuf, 0444,
 			binder_debugfs_dir_entry_proc,
@@ -5259,19 +5270,16 @@
 			&proc_fops);
 	}
 
-	if (binder_binderfs_dir_entry_proc) {
+	if (binder_binderfs_dir_entry_proc && !existing_pid) {
 		char strbuf[11];
 		struct dentry *binderfs_entry;
 
 		snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
 		/*
 		 * Similar to debugfs, the process specific log file is shared
-		 * between contexts. If the file has already been created for a
-		 * process, the following binderfs_create_file() call will
-		 * fail with error code EEXIST if another context of the same
-		 * process invoked binder_open(). This is ok since same as
-		 * debugfs, the log file will contain information on all
-		 * contexts of a given PID.
+		 * between contexts. Only create for the first PID.
+		 * This is ok since same as debugfs, the log file will contain
+		 * information on all contexts of a given PID.
 		 */
 		binderfs_entry = binderfs_create_file(binder_binderfs_dir_entry_proc,
 			strbuf, &proc_fops, (void *)(unsigned long)proc->pid);
@@ -5281,10 +5289,8 @@
 			int error;
 
 			error = PTR_ERR(binderfs_entry);
-			if (error != -EEXIST) {
-				pr_warn("Unable to create file %s in binderfs (error %d)\n",
-					strbuf, error);
-			}
+			pr_warn("Unable to create file %s in binderfs (error %d)\n",
+				strbuf, error);
 		}
 	}
 
@@ -6078,6 +6084,7 @@
 	binder_device->miscdev.minor = MISC_DYNAMIC_MINOR;
 	binder_device->miscdev.name = name;
 
+	refcount_set(&binder_device->ref, 1);
 	binder_device->context.binder_context_mgr_uid = INVALID_UID;
 	binder_device->context.name = name;
 	mutex_init(&binder_device->context.context_mgr_node_lock);
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index eb76a82..3526bb1 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -277,8 +277,7 @@
 	return 0;
 
 free_range:
-	for (page_addr = end - PAGE_SIZE; page_addr >= start;
-	     page_addr -= PAGE_SIZE) {
+	for (page_addr = end - PAGE_SIZE; 1; page_addr -= PAGE_SIZE) {
 		bool ret;
 		size_t index;
 
@@ -291,6 +290,8 @@
 		WARN_ON(!ret);
 
 		trace_binder_free_lru_end(alloc, index);
+		if (page_addr == start)
+			break;
 		continue;
 
 err_vm_insert_page_failed:
@@ -298,7 +299,8 @@
 		page->page_ptr = NULL;
 err_alloc_page_failed:
 err_page_ptr_cleared:
-		;
+		if (page_addr == start)
+			break;
 	}
 err_no_vma:
 	if (mm) {
@@ -645,6 +647,8 @@
 	binder_insert_free_buffer(alloc, buffer);
 }
 
+static void binder_alloc_clear_buf(struct binder_alloc *alloc,
+				   struct binder_buffer *buffer);
 /**
  * binder_alloc_free_buf() - free a binder buffer
  * @alloc:	binder_alloc for this proc
@@ -655,6 +659,18 @@
 void binder_alloc_free_buf(struct binder_alloc *alloc,
 			    struct binder_buffer *buffer)
 {
+	/*
+	 * We could eliminate the call to binder_alloc_clear_buf()
+	 * from binder_alloc_deferred_release() by moving this to
+	 * binder_alloc_free_buf_locked(). However, that could
+	 * increase contention for the alloc mutex if clear_on_free
+	 * is used frequently for large buffers. The mutex is not
+	 * needed for correctness here.
+	 */
+	if (buffer->clear_on_free) {
+		binder_alloc_clear_buf(alloc, buffer);
+		buffer->clear_on_free = false;
+	}
 	mutex_lock(&alloc->mutex);
 	binder_free_buf_locked(alloc, buffer);
 	mutex_unlock(&alloc->mutex);
@@ -681,17 +697,17 @@
 	struct binder_buffer *buffer;
 
 	mutex_lock(&binder_alloc_mmap_lock);
-	if (alloc->buffer) {
+	if (alloc->buffer_size) {
 		ret = -EBUSY;
 		failure_string = "already mapped";
 		goto err_already_mapped;
 	}
-
-	alloc->buffer = (void __user *)vma->vm_start;
-	mutex_unlock(&binder_alloc_mmap_lock);
-
 	alloc->buffer_size = min_t(unsigned long, vma->vm_end - vma->vm_start,
 				   SZ_4M);
+	mutex_unlock(&binder_alloc_mmap_lock);
+
+	alloc->buffer = (void __user *)vma->vm_start;
+
 	alloc->pages = kcalloc(alloc->buffer_size / PAGE_SIZE,
 			       sizeof(alloc->pages[0]),
 			       GFP_KERNEL);
@@ -722,8 +738,9 @@
 	kfree(alloc->pages);
 	alloc->pages = NULL;
 err_alloc_pages_failed:
-	mutex_lock(&binder_alloc_mmap_lock);
 	alloc->buffer = NULL;
+	mutex_lock(&binder_alloc_mmap_lock);
+	alloc->buffer_size = 0;
 err_already_mapped:
 	mutex_unlock(&binder_alloc_mmap_lock);
 	binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
@@ -750,6 +767,10 @@
 		/* Transaction should already have been freed */
 		BUG_ON(buffer->transaction);
 
+		if (buffer->clear_on_free) {
+			binder_alloc_clear_buf(alloc, buffer);
+			buffer->clear_on_free = false;
+		}
 		binder_free_buf_locked(alloc, buffer);
 		buffers++;
 	}
@@ -841,14 +862,20 @@
 	int free = 0;
 
 	mutex_lock(&alloc->mutex);
-	for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
-		page = &alloc->pages[i];
-		if (!page->page_ptr)
-			free++;
-		else if (list_empty(&page->lru))
-			active++;
-		else
-			lru++;
+	/*
+	 * Make sure the binder_alloc is fully initialized, otherwise we might
+	 * read inconsistent state.
+	 */
+	if (binder_alloc_get_vma(alloc) != NULL) {
+		for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+			page = &alloc->pages[i];
+			if (!page->page_ptr)
+				free++;
+			else if (list_empty(&page->lru))
+				active++;
+			else
+				lru++;
+		}
 	}
 	mutex_unlock(&alloc->mutex);
 	seq_printf(m, "  pages: %d:%d:%d\n", active, lru, free);
@@ -939,7 +966,7 @@
 		trace_binder_unmap_user_end(alloc, index);
 	}
 	up_read(&mm->mmap_sem);
-	mmput(mm);
+	mmput_async(mm);
 
 	trace_binder_unmap_kernel_start(alloc, index);
 
@@ -1078,6 +1105,36 @@
 }
 
 /**
+ * binder_alloc_clear_buf() - zero out buffer
+ * @alloc: binder_alloc for this proc
+ * @buffer: binder buffer to be cleared
+ *
+ * memset the given buffer to 0
+ */
+static void binder_alloc_clear_buf(struct binder_alloc *alloc,
+				   struct binder_buffer *buffer)
+{
+	size_t bytes = binder_alloc_buffer_size(alloc, buffer);
+	binder_size_t buffer_offset = 0;
+
+	while (bytes) {
+		unsigned long size;
+		struct page *page;
+		pgoff_t pgoff;
+		void *kptr;
+
+		page = binder_alloc_get_page(alloc, buffer,
+					     buffer_offset, &pgoff);
+		size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
+		kptr = kmap(page) + pgoff;
+		memset(kptr, 0, size);
+		kunmap(page);
+		bytes -= size;
+		buffer_offset += size;
+	}
+}
+
+/**
  * binder_alloc_copy_user_to_buffer() - copy src user to tgt user
  * @alloc: binder_alloc for this proc
  * @buffer: binder buffer to be accessed
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h
index db9c1b9..288d0f4 100644
--- a/drivers/android/binder_alloc.h
+++ b/drivers/android/binder_alloc.h
@@ -23,6 +23,7 @@
  * @entry:              entry alloc->buffers
  * @rb_node:            node for allocated_buffers/free_buffers rb trees
  * @free:               %true if buffer is free
+ * @clear_on_free:      %true if buffer must be zeroed after use
  * @allow_user_free:    %true if user is allowed to free buffer
  * @async_transaction:  %true if buffer is in use for an async txn
  * @debug_id:           unique ID for debugging
@@ -40,9 +41,10 @@
 	struct rb_node rb_node; /* free entry by size or allocated entry */
 				/* by address */
 	unsigned free:1;
+	unsigned clear_on_free:1;
 	unsigned allow_user_free:1;
 	unsigned async_transaction:1;
-	unsigned debug_id:29;
+	unsigned debug_id:28;
 
 	struct binder_transaction *transaction;
 
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
index ae99109..283d3cb 100644
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -8,6 +8,7 @@
 #include <linux/list.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
+#include <linux/refcount.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
 #include <linux/uidgid.h>
@@ -33,6 +34,7 @@
 	struct miscdevice miscdev;
 	struct binder_context context;
 	struct inode *binderfs_inode;
+	refcount_t ref;
 };
 
 /**
diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index e2580e5..f303106 100644
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -154,6 +154,7 @@
 	if (!name)
 		goto err;
 
+	refcount_set(&device->ref, 1);
 	device->binderfs_inode = inode;
 	device->context.binder_context_mgr_uid = INVALID_UID;
 	device->context.name = name;
@@ -257,8 +258,10 @@
 	ida_free(&binderfs_minors, device->miscdev.minor);
 	mutex_unlock(&binderfs_minors_mutex);
 
-	kfree(device->context.name);
-	kfree(device);
+	if (refcount_dec_and_test(&device->ref)) {
+		kfree(device->context.name);
+		kfree(device);
+	}
 }
 
 /**
@@ -445,6 +448,7 @@
 	inode->i_uid = info->root_uid;
 	inode->i_gid = info->root_gid;
 
+	refcount_set(&device->ref, 1);
 	device->binderfs_inode = inode;
 	device->miscdev.minor = minor;