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path: root/drivers/gpu/drm/i915/i915_user_extensions.c
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Diffstat (limited to 'drivers/gpu/drm/i915/i915_user_extensions.c')
-rw-r--r--drivers/gpu/drm/i915/i915_user_extensions.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_user_extensions.c b/drivers/gpu/drm/i915/i915_user_extensions.c
new file mode 100644
index 000000000000..c822d0aafd2d
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_user_extensions.c
@@ -0,0 +1,61 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2018 Intel Corporation
+ */
+
+#include <linux/nospec.h>
+#include <linux/sched/signal.h>
+#include <linux/uaccess.h>
+
+#include <uapi/drm/i915_drm.h>
+
+#include "i915_user_extensions.h"
+#include "i915_utils.h"
+
+int i915_user_extensions(struct i915_user_extension __user *ext,
+ const i915_user_extension_fn *tbl,
+ unsigned int count,
+ void *data)
+{
+ unsigned int stackdepth = 512;
+
+ while (ext) {
+ int i, err;
+ u32 name;
+ u64 next;
+
+ if (!stackdepth--) /* recursion vs useful flexibility */
+ return -E2BIG;
+
+ err = check_user_mbz(&ext->flags);
+ if (err)
+ return err;
+
+ for (i = 0; i < ARRAY_SIZE(ext->rsvd); i++) {
+ err = check_user_mbz(&ext->rsvd[i]);
+ if (err)
+ return err;
+ }
+
+ if (get_user(name, &ext->name))
+ return -EFAULT;
+
+ err = -EINVAL;
+ if (name < count) {
+ name = array_index_nospec(name, count);
+ if (tbl[name])
+ err = tbl[name](ext, data);
+ }
+ if (err)
+ return err;
+
+ if (get_user(next, &ext->next_extension) ||
+ overflows_type(next, ext))
+ return -EFAULT;
+
+ ext = u64_to_user_ptr(next);
+ }
+
+ return 0;
+}