1 files changed, 48 insertions, 12 deletions

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index ffb59a4ef4ff..7ffd5c763f93 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -562,6 +562,42 @@ void *perf_get_aux(struct perf_output_handle *handle)
 }
 EXPORT_SYMBOL_GPL(perf_get_aux);
 
+/*
+ * Copy out AUX data from an AUX handle.
+ */
+long perf_output_copy_aux(struct perf_output_handle *aux_handle,
+			  struct perf_output_handle *handle,
+			  unsigned long from, unsigned long to)
+{
+	unsigned long tocopy, remainder, len = 0;
+	struct ring_buffer *rb = aux_handle->rb;
+	void *addr;
+
+	from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
+	to &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
+
+	do {
+		tocopy = PAGE_SIZE - offset_in_page(from);
+		if (to > from)
+			tocopy = min(tocopy, to - from);
+		if (!tocopy)
+			break;
+
+		addr = rb->aux_pages[from >> PAGE_SHIFT];
+		addr += offset_in_page(from);
+
+		remainder = perf_output_copy(handle, addr, tocopy);
+		if (remainder)
+			return -EFAULT;
+
+		len += tocopy;
+		from += tocopy;
+		from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
+	} while (to != from);
+
+	return len;
+}
+
 #define PERF_AUX_GFP	(GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY)
 
 static struct page *rb_alloc_aux_page(int node, int order)
@@ -754,6 +790,14 @@ static void *perf_mmap_alloc_page(int cpu)
 	return page_address(page);
 }
 
+static void perf_mmap_free_page(void *addr)
+{
+	struct page *page = virt_to_page(addr);
+
+	page->mapping = NULL;
+	__free_page(page);
+}
+
 struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 {
 	struct ring_buffer *rb;
@@ -788,9 +832,9 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
 
 fail_data_pages:
 	for (i--; i >= 0; i--)
-		free_page((unsigned long)rb->data_pages[i]);
+		perf_mmap_free_page(rb->data_pages[i]);
 
-	free_page((unsigned long)rb->user_page);
+	perf_mmap_free_page(rb->user_page);
 
 fail_user_page:
 	kfree(rb);
@@ -799,21 +843,13 @@ fail:
 	return NULL;
 }
 
-static void perf_mmap_free_page(unsigned long addr)
-{
-	struct page *page = virt_to_page((void *)addr);
-
-	page->mapping = NULL;
-	__free_page(page);
-}
-
 void rb_free(struct ring_buffer *rb)
 {
 	int i;
 
-	perf_mmap_free_page((unsigned long)rb->user_page);
+	perf_mmap_free_page(rb->user_page);
 	for (i = 0; i < rb->nr_pages; i++)
-		perf_mmap_free_page((unsigned long)rb->data_pages[i]);
+		perf_mmap_free_page(rb->data_pages[i]);
 	kfree(rb);
 }