staging: zsmalloc: prevent mappping in interrupt context

Because we use per-cpu mapping areas shared among the
pools/users, we can't allow mapping in interrupt context
because it can corrupt another users mappings.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c
index 3c83c65..b86133f 100644 (file)
--- a/drivers/staging/zsmalloc/zsmalloc-main.c
+++ b/drivers/staging/zsmalloc/zsmalloc-main.c
@@ -75,6 +75,7 @@
 #include <linux/cpumask.h>
 #include <linux/cpu.h>
 #include <linux/vmalloc.h>
+#include <linux/hardirq.h>
 
 #include "zsmalloc.h"
 #include "zsmalloc_int.h"
@@ -761,6 +762,13 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
 
        BUG_ON(!handle);
 
+       /*
+        * Because we use per-cpu mapping areas shared among the
+        * pools/users, we can't allow mapping in interrupt context
+        * because it can corrupt another users mappings.
+        */
+       BUG_ON(in_interrupt());
+
        obj_handle_to_location(handle, &page, &obj_idx);
        get_zspage_mapping(get_first_page(page), &class_idx, &fg);
        class = &pool->size_class[class_idx];