4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jia-Ju Bai baijiaju1990@gmail.com
[ 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: Jia-Ju Bai baijiaju1990@gmail.com Reviewed-by: Javier González javier@cnexlabs.com Signed-off-by: Matias Bjørling mb@lightnvm.io Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/lightnvm/pblk-recovery.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/lightnvm/pblk-recovery.c +++ b/drivers/lightnvm/pblk-recovery.c @@ -956,12 +956,14 @@ 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) { @@ -969,8 +971,8 @@ 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);