From: Rich Felker <dalias@aerifal.cx>
Date: Fri, 7 Oct 2022 22:51:36 +0000 (-0400)
Subject: fix AS-safety of close when aio is in use and fd map is expanded
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=d8f35e29d0e35a90f44c04de585470c211afddf9;hp=d8f35e29d0e35a90f44c04de585470c211afddf9;p=musl

fix AS-safety of close when aio is in use and fd map is expanded

the aio operations that lead to calling __aio_get_queue with the
possibility to expand the fd map are not AS-safe, but if they are
interrupted by a signal handler, the signal handler may call close,
which is required to be AS-safe. due to __aio_get_queue taking the
write lock without blocking signals, such a call to close from a
signal handler could deadlock.

change __aio_get_queue to block signals if it needs to obtain a write
lock, and restore when finished.
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