From 7325b4bbe5952e3e939f15de812f2ee0c0d33ca9 Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Tue, 9 Oct 2018 13:12:00 +0200 Subject: lightnvm: pblk: fix two sleep-in-atomic-context bugs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Jia-Ju Bai Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe --- drivers/lightnvm/pblk-recovery.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/lightnvm') diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c index 8036c3eb6372..2526722304bb 100644 --- a/drivers/lightnvm/pblk-recovery.c +++ b/drivers/lightnvm/pblk-recovery.c @@ -966,12 +966,14 @@ next: } } - 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) { @@ -979,8 +981,8 @@ next: l_mg->data_next->type = PBLK_LINETYPE_DATA; is_next = 1; } + spin_unlock(&l_mg->free_lock); } - spin_unlock(&l_mg->free_lock); if (is_next) pblk_line_erase(pblk, l_mg->data_next); -- cgit v1.2.3