Files
erofs-linux/drivers/android
Carlos Llamas 31643d84b8 binder: fix hang of unregistered readers
With the introduction of binder_available_for_proc_work_ilocked() in
commit 1b77e9dcc3 ("ANDROID: binder: remove proc waitqueue") a binder
thread can only "wait_for_proc_work" after its thread->looper has been
marked as BINDER_LOOPER_STATE_{ENTERED|REGISTERED}.

This means an unregistered reader risks waiting indefinitely for work
since it never gets added to the proc->waiting_threads. If there are no
further references to its waitqueue either the task will hang. The same
applies to readers using the (e)poll interface.

I couldn't find the rationale behind this restriction. So this patch
restores the previous behavior of allowing unregistered threads to
"wait_for_proc_work". Note that an error message for this scenario,
which had previously become unreachable, is now re-enabled.

Fixes: 1b77e9dcc3 ("ANDROID: binder: remove proc waitqueue")
Cc: [email protected]
Cc: Martijn Coenen <[email protected]>
Cc: Arve Hjønnevåg <[email protected]>
Signed-off-by: Carlos Llamas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
2024-07-12 11:31:37 +02:00
..
2022-07-01 10:41:09 +02:00
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