Commit 3f01e667 authored by Tahsin Erdogan's avatar Tahsin Erdogan Committed by Greg Kroah-Hartman

percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pages

commit 320661b0 upstream.

Update to pcpu_nr_empty_pop_pages in pcpu_alloc() is currently done
without holding pcpu_lock. This can lead to bad updates to the variable.
Add missing lock calls.

Fixes: b539b87f ("percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated")
Signed-off-by: default avatarTahsin Erdogan <tahsin@google.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 824b5f14
......@@ -1012,8 +1012,11 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,
mutex_unlock(&pcpu_alloc_mutex);
}
if (chunk != pcpu_reserved_chunk)
if (chunk != pcpu_reserved_chunk) {
spin_lock_irqsave(&pcpu_lock, flags);
pcpu_nr_empty_pop_pages -= occ_pages;
spin_unlock_irqrestore(&pcpu_lock, flags);
}
if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW)
pcpu_schedule_balance_work();
......
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