The kernel may sleep with holding a spinlock. The function call path (from bottom to top) in Linux-4.16.7 is:
[FUNC] remove_element(GFP_KERNEL) mm/mempool.c, 250: remove_element in mempool_resize mm/mempool.c, 247: _raw_spin_lock_irqsave in mempool_resize To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC. This bug is found by my static analysis tool (DSAC-2) and checked by my code review. Signed-off-by: Jia-Ju Bai <[email protected]> --- mm/mempool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mempool.c b/mm/mempool.c index 5c9dce34719b..d33bd5d622e7 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -247,7 +247,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr) spin_lock_irqsave(&pool->lock, flags); if (new_min_nr <= pool->min_nr) { while (new_min_nr < pool->curr_nr) { - element = remove_element(pool, GFP_KERNEL); + element = remove_element(pool, GFP_ATOMIC); spin_unlock_irqrestore(&pool->lock, flags); pool->free(element, pool->pool_data); spin_lock_irqsave(&pool->lock, flags); -- 2.17.0
