Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Three cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 5 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 529cc50d7243..81279c6602ff 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4386,15 +4386,19 @@ EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
  * the page that was allocated, with the read page of the buffer.
  *
  * Returns:
- *  The page allocated, or NULL on error.
+ *  The page allocated, or ERR_PTR
  */
 void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu)
 {
-	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_data_page *bpage = NULL;
 	unsigned long flags;
 	struct page *page;
 
+	if (!cpumask_test_cpu(cpu, buffer->cpumask))
+		return ERR_PTR(-ENODEV);
+
+	cpu_buffer = buffer->buffers[cpu];
 	local_irq_save(flags);
 	arch_spin_lock(&cpu_buffer->lock);
 
@@ -4412,7 +4416,7 @@ void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu)
 	page = alloc_pages_node(cpu_to_node(cpu),
 				GFP_KERNEL | __GFP_NORETRY, 0);
 	if (!page)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	bpage = page_address(page);
 
@@ -4467,8 +4471,8 @@ EXPORT_SYMBOL_GPL(ring_buffer_free_read_page);
  *
  * for example:
  *	rpage = ring_buffer_alloc_read_page(buffer, cpu);
- *	if (!rpage)
- *		return error;
+ *	if (IS_ERR(rpage))
+ *		return PTR_ERR(rpage);
  *	ret = ring_buffer_read_page(buffer, &rpage, len, cpu, 0);
  *	if (ret >= 0)
  *		process_page(rpage, ret);