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, 79 insertions, 0 deletions

diff --git a/tools/perf/util/path.c b/tools/perf/util/path.c
new file mode 100644
index 000000000..2e62f272f
--- /dev/null
+++ b/tools/perf/util/path.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "path.h"
+#include "cache.h"
+#include <linux/kernel.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <unistd.h>
+
+static char *cleanup_path(char *path)
+{
+	/* Clean it up */
+	if (!memcmp(path, "./", 2)) {
+		path += 2;
+		while (*path == '/')
+			path++;
+	}
+	return path;
+}
+
+char *mkpath(char *path_buf, size_t sz, const char *fmt, ...)
+{
+	va_list args;
+	unsigned len;
+
+	va_start(args, fmt);
+	len = vsnprintf(path_buf, sz, fmt, args);
+	va_end(args);
+	if (len >= sz)
+		strncpy(path_buf, "/bad-path/", sz);
+	return cleanup_path(path_buf);
+}
+
+int path__join(char *bf, size_t size, const char *path1, const char *path2)
+{
+	return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
+}
+
+int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
+{
+	return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
+			 path2, path2[0] ? "/" : "", path3);
+}
+
+bool is_regular_file(const char *file)
+{
+	struct stat st;
+
+	if (stat(file, &st))
+		return false;
+
+	return S_ISREG(st.st_mode);
+}
+
+/* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */
+bool is_directory(const char *base_path, const struct dirent *dent)
+{
+	char path[PATH_MAX];
+	struct stat st;
+
+	snprintf(path, sizeof(path), "%s/%s", base_path, dent->d_name);
+	if (stat(path, &st))
+		return false;
+
+	return S_ISDIR(st.st_mode);
+}
+
+bool is_directory_at(int dir_fd, const char *path)
+{
+	struct stat st;
+
+	if (fstatat(dir_fd, path, &st, /*flags=*/0))
+		return false;
+
+	return S_ISDIR(st.st_mode);
+}