1 files changed, 24 insertions, 273 deletions

diff --git a/kernel/relay.c b/kernel/relay.c
index 72fe443ea78f..a8ae436dc77e 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -28,15 +28,6 @@ static DEFINE_MUTEX(relay_channels_mutex);
 static LIST_HEAD(relay_channels);
 
 /*
- * close() vm_op implementation for relay file mapping.
- */
-static void relay_file_mmap_close(struct vm_area_struct *vma)
-{
-	struct rchan_buf *buf = vma->vm_private_data;
-	buf->chan->cb->buf_unmapped(buf, vma->vm_file);
-}
-
-/*
  * fault() vm_op implementation for relay file mapping.
  */
 static vm_fault_t relay_buf_fault(struct vm_fault *vmf)
@@ -62,7 +53,6 @@ static vm_fault_t relay_buf_fault(struct vm_fault *vmf)
  */
 static const struct vm_operations_struct relay_file_mmap_ops = {
 	.fault = relay_buf_fault,
-	.close = relay_file_mmap_close,
 };
 
 /*
@@ -70,10 +60,7 @@ static const struct vm_operations_struct relay_file_mmap_ops = {
  */
 static struct page **relay_alloc_page_array(unsigned int n_pages)
 {
-	const size_t pa_size = n_pages * sizeof(struct page *);
-	if (pa_size > PAGE_SIZE)
-		return vzalloc(pa_size);
-	return kzalloc(pa_size, GFP_KERNEL);
+	return kvcalloc(n_pages, sizeof(struct page *), GFP_KERNEL);
 }
 
 /*
@@ -96,7 +83,6 @@ static void relay_free_page_array(struct page **array)
 static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
 {
 	unsigned long length = vma->vm_end - vma->vm_start;
-	struct file *filp = vma->vm_file;
 
 	if (!buf)
 		return -EBADF;
@@ -105,9 +91,8 @@ static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
 		return -EINVAL;
 
 	vma->vm_ops = &relay_file_mmap_ops;
-	vma->vm_flags |= VM_DONTEXPAND;
+	vm_flags_set(vma, VM_DONTEXPAND);
 	vma->vm_private_data = buf;
-	buf->chan->cb->buf_mapped(buf, filp);
 
 	return 0;
 }
@@ -163,13 +148,13 @@ static struct rchan_buf *relay_create_buf(struct rchan *chan)
 {
 	struct rchan_buf *buf;
 
-	if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t *))
+	if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t))
 		return NULL;
 
 	buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
 	if (!buf)
 		return NULL;
-	buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t *),
+	buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t),
 				     GFP_KERNEL);
 	if (!buf->padding)
 		goto free_buf;
@@ -197,6 +182,7 @@ free_buf:
 static void relay_destroy_channel(struct kref *kref)
 {
 	struct rchan *chan = container_of(kref, struct rchan, kref);
+	free_percpu(chan->buf);
 	kfree(chan);
 }
 
@@ -263,70 +249,16 @@ EXPORT_SYMBOL_GPL(relay_buf_full);
  * High-level relay kernel API and associated functions.
  */
 
-/*
- * rchan_callback implementations defining default channel behavior.  Used
- * in place of corresponding NULL values in client callback struct.
- */
-
-/*
- * subbuf_start() default callback.  Does nothing.
- */
-static int subbuf_start_default_callback (struct rchan_buf *buf,
-					  void *subbuf,
-					  void *prev_subbuf,
-					  size_t prev_padding)
+static int relay_subbuf_start(struct rchan_buf *buf, void *subbuf,
+			      void *prev_subbuf, size_t prev_padding)
 {
-	if (relay_buf_full(buf))
-		return 0;
+	if (!buf->chan->cb->subbuf_start)
+		return !relay_buf_full(buf);
 
-	return 1;
+	return buf->chan->cb->subbuf_start(buf, subbuf,
+					   prev_subbuf, prev_padding);
 }
 
-/*
- * buf_mapped() default callback.  Does nothing.
- */
-static void buf_mapped_default_callback(struct rchan_buf *buf,
-					struct file *filp)
-{
-}
-
-/*
- * buf_unmapped() default callback.  Does nothing.
- */
-static void buf_unmapped_default_callback(struct rchan_buf *buf,
-					  struct file *filp)
-{
-}
-
-/*
- * create_buf_file_create() default callback.  Does nothing.
- */
-static struct dentry *create_buf_file_default_callback(const char *filename,
-						       struct dentry *parent,
-						       umode_t mode,
-						       struct rchan_buf *buf,
-						       int *is_global)
-{
-	return NULL;
-}
-
-/*
- * remove_buf_file() default callback.  Does nothing.
- */
-static int remove_buf_file_default_callback(struct dentry *dentry)
-{
-	return -EINVAL;
-}
-
-/* relay channel default callbacks */
-static struct rchan_callbacks default_channel_callbacks = {
-	.subbuf_start = subbuf_start_default_callback,
-	.buf_mapped = buf_mapped_default_callback,
-	.buf_unmapped = buf_unmapped_default_callback,
-	.create_buf_file = create_buf_file_default_callback,
-	.remove_buf_file = remove_buf_file_default_callback,
-};
-
 /**
  *	wakeup_readers - wake up readers waiting on a channel
  *	@work: contains the channel buffer
@@ -370,7 +302,7 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init)
 	for (i = 0; i < buf->chan->n_subbufs; i++)
 		buf->padding[i] = 0;
 
-	buf->chan->cb->subbuf_start(buf, buf->data, NULL, 0);
+	relay_subbuf_start(buf, buf->data, NULL, 0);
 }
 
 /**
@@ -443,7 +375,7 @@ static struct dentry *relay_create_buf_file(struct rchan *chan,
  */
 static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
 {
- 	struct rchan_buf *buf = NULL;
+	struct rchan_buf *buf;
 	struct dentry *dentry;
 
  	if (chan->is_global)
@@ -498,27 +430,6 @@ static void relay_close_buf(struct rchan_buf *buf)
 	kref_put(&buf->kref, relay_remove_buf);
 }
 
-static void setup_callbacks(struct rchan *chan,
-				   struct rchan_callbacks *cb)
-{
-	if (!cb) {
-		chan->cb = &default_channel_callbacks;
-		return;
-	}
-
-	if (!cb->subbuf_start)
-		cb->subbuf_start = subbuf_start_default_callback;
-	if (!cb->buf_mapped)
-		cb->buf_mapped = buf_mapped_default_callback;
-	if (!cb->buf_unmapped)
-		cb->buf_unmapped = buf_unmapped_default_callback;
-	if (!cb->create_buf_file)
-		cb->create_buf_file = create_buf_file_default_callback;
-	if (!cb->remove_buf_file)
-		cb->remove_buf_file = remove_buf_file_default_callback;
-	chan->cb = cb;
-}
-
 int relay_prepare_cpu(unsigned int cpu)
 {
 	struct rchan *chan;
@@ -526,7 +437,7 @@ int relay_prepare_cpu(unsigned int cpu)
 
 	mutex_lock(&relay_channels_mutex);
 	list_for_each_entry(chan, &relay_channels, list) {
-		if ((buf = *per_cpu_ptr(chan->buf, cpu)))
+		if (*per_cpu_ptr(chan->buf, cpu))
 			continue;
 		buf = relay_open_buf(chan, cpu);
 		if (!buf) {
@@ -564,7 +475,7 @@ struct rchan *relay_open(const char *base_filename,
 			 struct dentry *parent,
 			 size_t subbuf_size,
 			 size_t n_subbufs,
-			 struct rchan_callbacks *cb,
+			 const struct rchan_callbacks *cb,
 			 void *private_data)
 {
 	unsigned int i;
@@ -575,6 +486,8 @@ struct rchan *relay_open(const char *base_filename,
 		return NULL;
 	if (subbuf_size > UINT_MAX / n_subbufs)
 		return NULL;
+	if (!cb || !cb->create_buf_file || !cb->remove_buf_file)
+		return NULL;
 
 	chan = kzalloc(sizeof(struct rchan), GFP_KERNEL);
 	if (!chan)
@@ -594,9 +507,9 @@ struct rchan *relay_open(const char *base_filename,
 	chan->private_data = private_data;
 	if (base_filename) {
 		chan->has_base_filename = 1;
-		strlcpy(chan->base_filename, base_filename, NAME_MAX);
+		strscpy(chan->base_filename, base_filename, NAME_MAX);
 	}
-	setup_callbacks(chan, cb);
+	chan->cb = cb;
 	kref_init(&chan->kref);
 
 	mutex_lock(&relay_channels_mutex);
@@ -665,7 +578,7 @@ int relay_late_setup_files(struct rchan *chan,
 	if (!chan || !base_filename)
 		return -EINVAL;
 
-	strlcpy(chan->base_filename, base_filename, NAME_MAX);
+	strscpy(chan->base_filename, base_filename, NAME_MAX);
 
 	mutex_lock(&relay_channels_mutex);
 	/* Is chan already set up? */
@@ -779,7 +692,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
 	new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
 	new = buf->start + new_subbuf * buf->chan->subbuf_size;
 	buf->offset = 0;
-	if (!buf->chan->cb->subbuf_start(buf, new, old, buf->prev_padding)) {
+	if (!relay_subbuf_start(buf, new, old, buf->prev_padding)) {
 		buf->offset = buf->chan->subbuf_size + 1;
 		return 0;
 	}
@@ -1001,7 +914,7 @@ static int relay_file_read_avail(struct rchan_buf *buf)
 	size_t subbuf_size = buf->chan->subbuf_size;
 	size_t n_subbufs = buf->chan->n_subbufs;
 	size_t produced = buf->subbufs_produced;
-	size_t consumed = buf->subbufs_consumed;
+	size_t consumed;
 
 	relay_file_read_consume(buf, 0, 0);
 
@@ -1076,7 +989,8 @@ static size_t relay_file_read_start_pos(struct rchan_buf *buf)
 	size_t subbuf_size = buf->chan->subbuf_size;
 	size_t n_subbufs = buf->chan->n_subbufs;
 	size_t consumed = buf->subbufs_consumed % n_subbufs;
-	size_t read_pos = consumed * subbuf_size + buf->bytes_consumed;
+	size_t read_pos = (consumed * subbuf_size + buf->bytes_consumed)
+			% (n_subbufs * subbuf_size);
 
 	read_subbuf = read_pos / subbuf_size;
 	padding = buf->padding[read_subbuf];
@@ -1159,175 +1073,12 @@ static ssize_t relay_file_read(struct file *filp,
 	return written;
 }
 
-static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed)
-{
-	rbuf->bytes_consumed += bytes_consumed;
-
-	if (rbuf->bytes_consumed >= rbuf->chan->subbuf_size) {
-		relay_subbufs_consumed(rbuf->chan, rbuf->cpu, 1);
-		rbuf->bytes_consumed %= rbuf->chan->subbuf_size;
-	}
-}
-
-static void relay_pipe_buf_release(struct pipe_inode_info *pipe,
-				   struct pipe_buffer *buf)
-{
-	struct rchan_buf *rbuf;
-
-	rbuf = (struct rchan_buf *)page_private(buf->page);
-	relay_consume_bytes(rbuf, buf->private);
-}
-
-static const struct pipe_buf_operations relay_pipe_buf_ops = {
-	.release	= relay_pipe_buf_release,
-	.try_steal	= generic_pipe_buf_try_steal,
-	.get		= generic_pipe_buf_get,
-};
-
-static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i)
-{
-}
-
-/*
- *	subbuf_splice_actor - splice up to one subbuf's worth of data
- */
-static ssize_t subbuf_splice_actor(struct file *in,
-			       loff_t *ppos,
-			       struct pipe_inode_info *pipe,
-			       size_t len,
-			       unsigned int flags,
-			       int *nonpad_ret)
-{
-	unsigned int pidx, poff, total_len, subbuf_pages, nr_pages;
-	struct rchan_buf *rbuf = in->private_data;
-	unsigned int subbuf_size = rbuf->chan->subbuf_size;
-	uint64_t pos = (uint64_t) *ppos;
-	uint32_t alloc_size = (uint32_t) rbuf->chan->alloc_size;
-	size_t read_start = (size_t) do_div(pos, alloc_size);
-	size_t read_subbuf = read_start / subbuf_size;
-	size_t padding = rbuf->padding[read_subbuf];
-	size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding;
-	struct page *pages[PIPE_DEF_BUFFERS];
-	struct partial_page partial[PIPE_DEF_BUFFERS];
-	struct splice_pipe_desc spd = {
-		.pages = pages,
-		.nr_pages = 0,
-		.nr_pages_max = PIPE_DEF_BUFFERS,
-		.partial = partial,
-		.ops = &relay_pipe_buf_ops,
-		.spd_release = relay_page_release,
-	};
-	ssize_t ret;
-
-	if (rbuf->subbufs_produced == rbuf->subbufs_consumed)
-		return 0;
-	if (splice_grow_spd(pipe, &spd))
-		return -ENOMEM;
-
-	/*
-	 * Adjust read len, if longer than what is available
-	 */
-	if (len > (subbuf_size - read_start % subbuf_size))
-		len = subbuf_size - read_start % subbuf_size;
-
-	subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;
-	pidx = (read_start / PAGE_SIZE) % subbuf_pages;
-	poff = read_start & ~PAGE_MASK;
-	nr_pages = min_t(unsigned int, subbuf_pages, spd.nr_pages_max);
-
-	for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) {
-		unsigned int this_len, this_end, private;
-		unsigned int cur_pos = read_start + total_len;
-
-		if (!len)
-			break;
-
-		this_len = min_t(unsigned long, len, PAGE_SIZE - poff);
-		private = this_len;
-
-		spd.pages[spd.nr_pages] = rbuf->page_array[pidx];
-		spd.partial[spd.nr_pages].offset = poff;
-
-		this_end = cur_pos + this_len;
-		if (this_end >= nonpad_end) {
-			this_len = nonpad_end - cur_pos;
-			private = this_len + padding;
-		}
-		spd.partial[spd.nr_pages].len = this_len;
-		spd.partial[spd.nr_pages].private = private;
-
-		len -= this_len;
-		total_len += this_len;
-		poff = 0;
-		pidx = (pidx + 1) % subbuf_pages;
-
-		if (this_end >= nonpad_end) {
-			spd.nr_pages++;
-			break;
-		}
-	}
-
-	ret = 0;
-	if (!spd.nr_pages)
-		goto out;
-
-	ret = *nonpad_ret = splice_to_pipe(pipe, &spd);
-	if (ret < 0 || ret < total_len)
-		goto out;
-
-        if (read_start + ret == nonpad_end)
-                ret += padding;
-
-out:
-	splice_shrink_spd(&spd);
-	return ret;
-}
-
-static ssize_t relay_file_splice_read(struct file *in,
-				      loff_t *ppos,
-				      struct pipe_inode_info *pipe,
-				      size_t len,
-				      unsigned int flags)
-{
-	ssize_t spliced;
-	int ret;
-	int nonpad_ret = 0;
-
-	ret = 0;
-	spliced = 0;
-
-	while (len && !spliced) {
-		ret = subbuf_splice_actor(in, ppos, pipe, len, flags, &nonpad_ret);
-		if (ret < 0)
-			break;
-		else if (!ret) {
-			if (flags & SPLICE_F_NONBLOCK)
-				ret = -EAGAIN;
-			break;
-		}
-
-		*ppos += ret;
-		if (ret > len)
-			len = 0;
-		else
-			len -= ret;
-		spliced += nonpad_ret;
-		nonpad_ret = 0;
-	}
-
-	if (spliced)
-		return spliced;
-
-	return ret;
-}
 
 const struct file_operations relay_file_operations = {
 	.open		= relay_file_open,
 	.poll		= relay_file_poll,
 	.mmap		= relay_file_mmap,
 	.read		= relay_file_read,
-	.llseek		= no_llseek,
 	.release	= relay_file_release,
-	.splice_read	= relay_file_splice_read,
 };
 EXPORT_SYMBOL_GPL(relay_file_operations);