[PATCH 2/3] zsmalloc: prevent mappping in interrupt context

From: Seth Jennings
Date: Wed Jul 18 2012 - 13:25:34 EST


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@xxxxxxxxxxxxxxxxxx>
---
drivers/staging/zsmalloc/zsmalloc-main.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c
index 3c83c65..b86133f 100644
--- 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];
--
1.7.9.5

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