| Message ID | 20220404045547.579887-1-damien.lemoal@opensource.wdc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | scsi: scsi_debug: Fix sdebug_blk_mq_poll() in_use_bm bitmap use | expand |
On 2022-04-04 00:55, Damien Le Moal wrote: > The in_use_bm bitmap of struct sdebug_queue should be accessed under > protection of the qc_lock spinlock. Make sure that this lock is taken > before calling find_first_bit() at the beginning of the function > sdebug_blk_mq_poll(). > > Fixes: 3fd07aecb750 ("scsi: scsi_debug: Fix qc_lock use in sdebug_blk_mq_poll()") > Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Douglas Gilbert <dgilbert@interlog.com> > --- > drivers/scsi/scsi_debug.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c > index c607755cce00..ff78ef702f22 100644 > --- a/drivers/scsi/scsi_debug.c > +++ b/drivers/scsi/scsi_debug.c > @@ -7519,12 +7519,13 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) > struct sdebug_defer *sd_dp; > > sqp = sdebug_q_arr + queue_num; > - qc_idx = find_first_bit(sqp->in_use_bm, sdebug_max_queue); > - if (qc_idx >= sdebug_max_queue) > - return 0; > > spin_lock_irqsave(&sqp->qc_lock, iflags); > > + qc_idx = find_first_bit(sqp->in_use_bm, sdebug_max_queue); > + if (qc_idx >= sdebug_max_queue) > + goto unlock; > + > for (first = true; first || qc_idx + 1 < sdebug_max_queue; ) { > if (first) { > first = false; > @@ -7589,6 +7590,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) > break; > } > > +unlock: > spin_unlock_irqrestore(&sqp->qc_lock, iflags); > > if (num_entries > 0)
Damien, > The in_use_bm bitmap of struct sdebug_queue should be accessed under > protection of the qc_lock spinlock. Make sure that this lock is taken > before calling find_first_bit() at the beginning of the function > sdebug_blk_mq_poll(). Applied to 5.18/scsi-fixes, thanks!
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index c607755cce00..ff78ef702f22 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -7519,12 +7519,13 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) struct sdebug_defer *sd_dp; sqp = sdebug_q_arr + queue_num; - qc_idx = find_first_bit(sqp->in_use_bm, sdebug_max_queue); - if (qc_idx >= sdebug_max_queue) - return 0; spin_lock_irqsave(&sqp->qc_lock, iflags); + qc_idx = find_first_bit(sqp->in_use_bm, sdebug_max_queue); + if (qc_idx >= sdebug_max_queue) + goto unlock; + for (first = true; first || qc_idx + 1 < sdebug_max_queue; ) { if (first) { first = false; @@ -7589,6 +7590,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) break; } +unlock: spin_unlock_irqrestore(&sqp->qc_lock, iflags); if (num_entries > 0)
The in_use_bm bitmap of struct sdebug_queue should be accessed under protection of the qc_lock spinlock. Make sure that this lock is taken before calling find_first_bit() at the beginning of the function sdebug_blk_mq_poll(). Fixes: 3fd07aecb750 ("scsi: scsi_debug: Fix qc_lock use in sdebug_blk_mq_poll()") Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> --- drivers/scsi/scsi_debug.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)