[PATCH v3 0/1] binder: return pending info for frozen async txns

From: Li Li
Date: Wed Nov 23 2022 - 15:18:31 EST


From: Li Li <dualli@xxxxxxxxxx>

User applications need to know if their binder transactions reach a
frozen process or not. For sync binder calls, Linux kernel already
has a dedicated return value BR_FROZEN_REPLY, indicating this sync
binder transaction will be rejected (similar to BR_DEAD_REPLY) as the
target process is frozen. But for async binder calls, the user space
application doesn't have a way to know if the target process is frozen.

This patch adds a new return value, BR_TRANSACTION_PENDING_FROZEN, to
fix this issue. Similar to BR_TRANSACTION_COMPLETE, it means the async
binder transaction has been put in the queue of the target process, but
it's waiting for the target process to be unfrozen.

v1: checkpatch.pl --strict passed
v2: protect proc->is_frozen with lock, fix typo in comments
v3: rename BR_TRANSACTION_PENDING to BR_TRANSACTION_PENDING_FROZEN to
signify the frozen scenario and avoid potential confusion

Li Li (1):
binder: return pending info for frozen async txns

drivers/android/binder.c | 32 +++++++++++++++++++++++------
drivers/android/binder_internal.h | 3 ++-
include/uapi/linux/android/binder.h | 7 ++++++-
3 files changed, 34 insertions(+), 8 deletions(-)

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2.38.1.584.g0f3c55d4c2-goog