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Commit 3c5b1d33 authored by Jia-Ju Bai's avatar Jia-Ju Bai Committed by Greg Kroah-Hartman
Browse files

lightnvm: pblk: fix two sleep-in-atomic-context bugs 



[ Upstream commit 7325b4bbe5952e3e939f15de812f2ee0c0d33ca9 ]

The driver may sleep with holding a spinlock.

The function call paths (from bottom to top) in Linux-4.16 are:

[FUNC] nvm_dev_dma_alloc(GFP_KERNEL)
drivers/lightnvm/pblk-core.c, 754:
	nvm_dev_dma_alloc in pblk_line_submit_smeta_io
drivers/lightnvm/pblk-core.c, 1048:
	pblk_line_submit_smeta_io in pblk_line_init_bb
drivers/lightnvm/pblk-core.c, 1434:
	pblk_line_init_bb in pblk_line_replace_data
drivers/lightnvm/pblk-recovery.c, 980:
	pblk_line_replace_data in pblk_recov_l2p
drivers/lightnvm/pblk-recovery.c, 976:
	spin_lock in pblk_recov_l2p

[FUNC] bio_map_kern(GFP_KERNEL)
drivers/lightnvm/pblk-core.c, 762:
	bio_map_kern in pblk_line_submit_smeta_io
drivers/lightnvm/pblk-core.c, 1048:
	pblk_line_submit_smeta_io in pblk_line_init_bb
drivers/lightnvm/pblk-core.c, 1434:
	pblk_line_init_bb in pblk_line_replace_data
drivers/lightnvm/pblk-recovery.c, 980:
	pblk_line_replace_data in pblk_recov_l2p
drivers/lightnvm/pblk-recovery.c, 976:
	spin_lock in pblk_recov_l2p

To fix these bugs, the call to pblk_line_replace_data()
is moved out of the spinlock protection.

These bugs are found by my static analysis tool DSAC.

Signed-off-by: default avatarJia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: default avatarJavier González <javier@cnexlabs.com>
Signed-off-by: default avatarMatias Bjørling <mb@lightnvm.io>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bd206a06

drivers/lightnvm/pblk-recovery.c

+4 −2
Original line number Diff line number Diff line
@@ -956,12 +956,14 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk) 
		}

	}



	spin_lock(&l_mg->free_lock);

	if (!open_lines) {

		spin_lock(&l_mg->free_lock);

		WARN_ON_ONCE(!test_and_clear_bit(meta_line,

							&l_mg->meta_bitmap));

		spin_unlock(&l_mg->free_lock);

		pblk_line_replace_data(pblk);

	} else {

		spin_lock(&l_mg->free_lock);

		/* Allocate next line for preparation */

		l_mg->data_next = pblk_line_get(pblk);

		if (l_mg->data_next) {
@@ -969,8 +971,8 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk) 
			l_mg->data_next->type = PBLK_LINETYPE_DATA;

			is_next = 1;

		}

	}

		spin_unlock(&l_mg->free_lock);

	}



	if (is_next)

		pblk_line_erase(pblk, l_mg->data_next);