From: Li Li <dualli@xxxxxxxxxx> It's a known issue that neither the frozen processes nor the system administration process of the OS can correctly deal with failed binder transactions. The reason is that there's no reliable way for the user space administration process to fetch the binder errors from the kernel binder driver. Android is such an OS suffering from this issue. Since cgroup freezer was used to freeze user applications to save battery, innocent frozen apps have to be killed when they receive sync binder transactions or when their async binder buffer is running out. This patch introduces the Linux generic netlink messages into the binder driver so that the Linux/Android system administration process can listen to important events and take corresponding actions, like stopping a broken app from attacking the OS by sending huge amount of spamming binder transactiions. The first version uses a global generic netlink for all binder contexts, raising potential security concerns. There were a few other feedbacks like request to kernel docs and test code. The thread can be found at https://lore.kernel.org/lkml/20240812211844.4107494-1-dualli@xxxxxxxxxxxx/ The second version fixes those issues and has been tested on the latest version of AOSP. See https://r.android.com/3305462 for how userspace is going to use this feature and the test code. It can be found at https://lore.kernel.org/lkml/20241011064427.1565287-1-dualli@xxxxxxxxxxxx/ The third version replaces the handcrafted netlink source code with the netlink protocal specs in YAML. It also fixes the documentation issues. https://lore.kernel.org/lkml/20241021182821.1259487-1-dualli@xxxxxxxxxxxx/ This version just containsi trivial fixes, making the subject of the patch aligned with the subject of the cover letter. v1: add a global binder genl socket for all contexts v2: change to per-context binder genl for security reason replace the new ioctl with a netlink command add corresponding doc Documentation/admin-guide/binder_genl.rst add user space test code in AOSP v3: use YNL spec (./tools/net/ynl/ynl-regen.sh) fix documentation index v4: change the subject of the patch and remove unsed #if 0 Li Li (1): binder: report txn errors via generic netlink (genl) Documentation/admin-guide/binder_genl.rst | 92 ++++++ Documentation/admin-guide/index.rst | 1 + Documentation/netlink/specs/binder_genl.yaml | 59 ++++ drivers/android/Kconfig | 1 + drivers/android/Makefile | 2 +- drivers/android/binder.c | 287 ++++++++++++++++++- drivers/android/binder_genl.c | 38 +++ drivers/android/binder_genl.h | 18 ++ drivers/android/binder_internal.h | 22 ++ drivers/android/binder_trace.h | 37 +++ drivers/android/binderfs.c | 4 + include/uapi/linux/android/binder.h | 31 ++ include/uapi/linux/android/binder_genl.h | 37 +++ 13 files changed, 625 insertions(+), 4 deletions(-) create mode 100644 Documentation/admin-guide/binder_genl.rst create mode 100644 Documentation/netlink/specs/binder_genl.yaml create mode 100644 drivers/android/binder_genl.c create mode 100644 drivers/android/binder_genl.h create mode 100644 include/uapi/linux/android/binder_genl.h -- 2.47.0.105.g07ac214952-goog
