drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable@vger.kernel.org
Signed-off-by: Haojie Li <lihaojie@kylinos.cn>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/lib/clz_ctz.c b/lib/clz_ctz.c
new file mode 100644
index 000000000..8778ec44b
--- /dev/null
+++ b/lib/clz_ctz.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * lib/clz_ctz.c
+ *
+ * Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
+ *
+ * The functions in this file aren't called directly, but are required by
+ * GCC builtins such as __builtin_ctz, and therefore they can't be removed
+ * despite appearing unreferenced in kernel source.
+ *
+ * __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+
+int __weak __ctzsi2(int val);
+int __weak __attribute_const__ __ctzsi2(int val)
+{
+	return __ffs(val);
+}
+EXPORT_SYMBOL(__ctzsi2);
+
+int __weak __clzsi2(int val);
+int __weak __attribute_const__ __clzsi2(int val)
+{
+	return 32 - fls(val);
+}
+EXPORT_SYMBOL(__clzsi2);
+
+int __weak __clzdi2(u64 val);
+int __weak __attribute_const__ __clzdi2(u64 val)
+{
+	return 64 - fls64(val);
+}
+EXPORT_SYMBOL(__clzdi2);
+
+int __weak __ctzdi2(u64 val);
+int __weak __attribute_const__ __ctzdi2(u64 val)
+{
+	return __ffs64(val);
+}
+EXPORT_SYMBOL(__ctzdi2);