Provides a userspace interface to trigger a CMA allocation.
Usage:
echo [pages] > alloc
This would provide testing/fuzzing access to the CMA allocation paths.
Signed-off-by: Sasha Levin <sasha.le...@oracle.com>
---
mm/cma_debug.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 58 insertions(+), 2 deletions(-)
diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index 3a25413..39c7116 100644
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -7,9 +7,22 @@
#include <linux/debugfs.h>
#include <linux/cma.h>
+#include <linux/list.h>
+#include <linux/kernel.h>
+#include <linux/dma-contiguous.h>
+#include <linux/slab.h>
#include "cma.h"
+struct cma_mem {
+ struct hlist_node node;
+ struct page *p;
+ unsigned long n;
+};
+
+static HLIST_HEAD(cma_mem_head);
+static DEFINE_SPINLOCK(cma_mem_head_lock);
+
static struct dentry *cma_debugfs_root;
static int cma_debugfs_get(void *data, u64 *val)
@@ -23,8 +36,48 @@ static int cma_debugfs_get(void *data, u64 *val)
DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");
-static void cma_debugfs_add_one(struct cma *cma, int idx)
+static void cma_add_to_cma_mem_list(struct cma_mem *mem)
+{
+ spin_lock(&cma_mem_head_lock);
+ hlist_add_head(&mem->node, &cma_mem_head);
+ spin_unlock(&cma_mem_head_lock);
+}
+
+static int cma_alloc_mem(struct cma *cma, int count)
{
+ struct cma_mem *mem;
+ struct page *p;
+
+ mem = kzalloc(sizeof(*mem), GFP_KERNEL);
+ if (!mem)
+ return -ENOMEM;
+
+ p = cma_alloc(cma, count, CONFIG_CMA_ALIGNMENT);
+ if (!p) {
+ kfree(mem);
+ return -ENOMEM;
+ }
+
+ mem->p = p;
+ mem->n = count;
+
+ cma_add_to_cma_mem_list(mem);
+
+ return 0;
+}
+
+static int cma_alloc_write(void *data, u64 val)
+{
+ int pages = val;
+ struct cma *cma = data;
+
+ return cma_alloc_mem(cma, pages);
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
+
+static void cma_debugfs_add_one(struct cma *cma, int idx)
+{
struct dentry *tmp;
char name[16];
int u32s;
@@ -33,12 +86,15 @@ static void cma_debugfs_add_one(struct cma *cma, int idx)
tmp = debugfs_create_dir(name, cma_debugfs_root);
+ debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma,
+ &cma_alloc_fops);
+
debugfs_create_file("base_pfn", S_IRUGO, tmp,
&cma->base_pfn, &cma_debugfs_fops);
debugfs_create_file("count", S_IRUGO, tmp,
&cma->count, &cma_debugfs_fops);
debugfs_create_file("order_per_bit", S_IRUGO, tmp,
- &cma->order_per_bit, &cma_debugfs_fops);
+ &cma->order_per_bit, &cma_debugfs_fops);
u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32));
debugfs_create_u32_array("bitmap", S_IRUGO, tmp, (u32*)cma->bitmap,
u32s);
--
1.7.10.4
--
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