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| author | Arjun Shankar <arjun@redhat.com> | 2024-10-18 16:03:25 +0200 |
|---|---|---|
| committer | Arjun Shankar <arjun@redhat.com> | 2024-10-23 13:40:16 +0200 |
| commit | 9f0d2c0ee6c728643fcf9a4879e9f20f5e45ce5f (patch) | |
| tree | 86cff8d63944f5a0e573b1d0a72d3a669c4f124d /libio/Makefile | |
| parent | 81439a116cf48583127ddf1f09809440aa40969a (diff) | |
| download | glibc-9f0d2c0ee6c728643fcf9a4879e9f20f5e45ce5f.zip glibc-9f0d2c0ee6c728643fcf9a4879e9f20f5e45ce5f.tar.gz glibc-9f0d2c0ee6c728643fcf9a4879e9f20f5e45ce5f.tar.bz2 | |
libio: Fix a deadlock after fork in popen
popen modifies its file handler book-keeping under a lock that wasn't
being taken during fork. This meant that a concurrent popen and fork
could end up copying the lock in a "locked" state into the fork child,
where subsequently calling popen would lead to a deadlock due to the
already (spuriously) held lock.
This commit fixes the deadlock by appropriately taking the lock before
fork, and releasing/resetting it in the parent/child after the fork.
A new test for concurrent popen and fork is also added. It consistently
hangs (and therefore fails via timeout) without the fix applied.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Diffstat (limited to 'libio/Makefile')
| -rw-r--r-- | libio/Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/libio/Makefile b/libio/Makefile index ae704d8..018c26d 100644 --- a/libio/Makefile +++ b/libio/Makefile @@ -119,6 +119,7 @@ tests = \ tst-mmap-offend \ tst-mmap-setvbuf \ tst-mmap2-eofsync \ + tst-popen-fork \ tst-popen1 \ tst-setvbuf1 \ tst-sprintf-chk-ub \ |