Module Name: src
Committed By: riastradh
Date: Sun Feb 27 14:16:43 UTC 2022
Modified Files:
src/sys/kern: subr_pool.c
Log Message:
pool(9): Membar audit.
- Use atomic_store_release and atomic_load_consume for associating a
freshly constructed pool_cache with its underlying pool. The pool
gets published in various ways before the pool cache is fully
constructed.
=> Nix membar_sync -- no store-before-load is needed here.
- Take pool_head_lock around sysctl kern.pool TAILQ_FOREACH. Then take
a reference count, and drop the lock, around copyout.
=> Otherwise, pools could be partially initialized or freed while
we're still trying to read from them -- and in the worst case,
we might see a corrupted view of the tailq.
=> If we kept the lock around copyout, this could deadlock in memory
allocation.
=> If we didn't take a reference count while releasing the lock, the
pool could be destroyed while we're trying to traverse the list,
sending us into oblivion instead of the next element.
To generate a diff of this commit:
cvs rdiff -u -r1.280 -r1.281 src/sys/kern/subr_pool.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
