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authorJia-Ju Bai <baijiaju1990@gmail.com>2018-10-09 13:12:00 +0200
committerJens Axboe <axboe@kernel.dk>2018-10-09 16:25:07 +0200
commit7325b4bbe5952e3e939f15de812f2ee0c0d33ca9 (patch)
tree560d344890b628460494963269b45e917187113f /drivers
parentlightnvm: pblk: fix mapping issue on failed writes (diff)
downloadlinux-7325b4bbe5952e3e939f15de812f2ee0c0d33ca9.tar.xz
linux-7325b4bbe5952e3e939f15de812f2ee0c0d33ca9.zip
lightnvm: pblk: fix two sleep-in-atomic-context bugs
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/lightnvm/pblk-recovery.c6
1 files changed, 4 insertions, 2 deletions
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);