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, 75 insertions, 0 deletions

diff --git a/tools/tracing/rtla/README.txt b/tools/tracing/rtla/README.txt
new file mode 100644
index 000000000..13b4a798b
--- /dev/null
+++ b/tools/tracing/rtla/README.txt
@@ -0,0 +1,75 @@
+RTLA: Real-Time Linux Analysis tools
+
+The rtla meta-tool includes a set of commands that aims to analyze
+the real-time properties of Linux. Instead of testing Linux as a black box,
+rtla leverages kernel tracing capabilities to provide precise information
+about the properties and root causes of unexpected results.
+
+Installing RTLA
+
+RTLA depends on the following libraries and tools:
+
+ - libtracefs
+ - libtraceevent
+ - libcpupower (optional, for --deepest-idle-state)
+ - libcheck (optional, for unit tests)
+
+For BPF sample collection support, the following extra dependencies are
+required:
+
+ - libbpf 1.0.0 or later
+ - bpftool with skeleton support
+ - clang with BPF CO-RE support
+
+It also depends on python3-docutils to compile man pages.
+
+For development, we suggest the following steps for compiling rtla:
+
+  $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git
+  $ cd libtraceevent/
+  $ make
+  $ sudo make install
+  $ cd ..
+  $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git
+  $ cd libtracefs/
+  $ make
+  $ sudo make install
+  $ cd ..
+  $ cd $libcpupower_src
+  $ make
+  $ sudo make install
+  $ cd $rtla_src
+  $ make
+  $ sudo make install
+
+Running tests
+
+RTLA has two test suites: a runtime test suite and a unit test suite.
+
+The runtime test suite is available as "make check" (root required) and has
+the following dependencies, in addition to RTLA build dependencies:
+
+- Perl
+- Test::Harness (libtest-harness-perl on Debian/Ubuntu, perl-Test-Harness on Fedora/RHEL)
+- bash
+- coreutils
+- ldd
+- util-linux
+- procps(-ng)
+- bpftool (if rtla is built against libbpf)
+
+as well as the following required system configuration:
+
+- CONFIG_OSNOISE_TRACER=y
+- CONFIG_TIMERLAT_TRACER=y
+- tracefs mounted and readable at /sys/kernel/tracing
+
+The unit test suite is available as "make unit-tests" and has the following
+dependencies:
+
+- libcheck
+
+Unlike the runtime test suite, root is not required to run unit tests, nor is
+a tracefs/osnoise/timerlat-capable kernel required.
+
+For further information, please refer to the rtla man page.