ComputerSurge/bind9
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Address unbalanced lock/unlock

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Also address race between reading and testing mpctx->allocated
and incrementing mpctx->allocated.
This commit is contained in:
Mark Andrews
2021-02-25 13:08:07 +11:00
parent 965848a11a
commit 3ac53daa06
1 changed files with 6 additions and 6 deletions
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lib/isc/mem.c
+6 -6
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@@ -1306,15 +1306,15 @@ isc__mempool_get(isc_mempool_t *mpctx FLARG) {
element *item;
unsigned int i;
size_t allocated = atomic_load_acquire(&mpctx->allocated);
size_t allocated = atomic_fetch_add_release(&mpctx->allocated, 1);
size_t maxalloc = atomic_load_acquire(&mpctx->maxalloc);
/*
* Don't let the caller go over quota
*/
if (ISC_UNLIKELY(allocated >= maxalloc)) {
item = NULL;
goto out;
atomic_fetch_sub_release(&mpctx->allocated, 1);
return (NULL);
}
MPCTXLOCK(mpctx);
@@ -1339,6 +1339,7 @@ isc__mempool_get(isc_mempool_t *mpctx FLARG) {
*/
item = mpctx->items;
if (ISC_UNLIKELY(item == NULL)) {
atomic_fetch_sub_release(&mpctx->allocated, 1);
goto out;
}
@@ -1346,13 +1347,12 @@ isc__mempool_get(isc_mempool_t *mpctx FLARG) {
INSIST(atomic_fetch_sub_release(&mpctx->freecount, 1) > 0);
atomic_fetch_add_relaxed(&mpctx->gets, 1);
atomic_fetch_add_relaxed(&mpctx->allocated, 1);
ADD_TRACE(mpctx->mctx, item, mpctx->size, file, line);
out:
MPCTXUNLOCK(mpctx);
ADD_TRACE(mpctx->mctx, item, mpctx->size, file, line);
return (item);
}