[PATCH 6.0 12/34] scsi: qla2xxx: Fix response queue handler reading stale packets

Greg Kroah-Hartman
2022-10-13T19:06:09Z

From: Arun Easi <aeasi@marvell.com>

commit e4f8a29deb3ba30e414dfb6b09e3ae3bf6dbe74a upstream.

On some platforms, the current logic of relying on finding new packet
solely based on signature pattern can lead to driver reading stale
packets. Though this is a bug in those platforms, reduce such exposures by
limiting reading packets until the IN pointer.

Link: https://lore.kernel.org/r/20220826102559.17474-3-njavali@marvell.com
Cc: stable@vger.kernel.org
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/qla2xxx/qla_isr.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -3763,7 +3763,8 @@ void qla24xx_process_response_queue(stru
struct qla_hw_data *ha = vha->hw;
struct purex_entry_24xx *purex_entry;
struct purex_item *pure_item;
- u16 cur_ring_index;
+ u16 rsp_in = 0, cur_ring_index;
+ int is_shadow_hba;

if (!ha->flags.fw_started)
return;
@@ -3773,7 +3774,18 @@ void qla24xx_process_response_queue(stru
qla_cpu_update(rsp->qpair, smp_processor_id());
}

- while (rsp->ring_ptr->signature != RESPONSE_PROCESSED) {
+#define __update_rsp_in(_is_shadow_hba, _rsp, _rsp_in) \
+ do { \
+ _rsp_in = _is_shadow_hba ? *(_rsp)->in_ptr : \
+ rd_reg_dword_relaxed((_rsp)->rsp_q_in); \
+ } while (0)
+
+ is_shadow_hba = IS_SHADOW_REG_CAPABLE(ha);
+
+ __update_rsp_in(is_shadow_hba, rsp, rsp_in);
+
+ while (rsp->ring_index != rsp_in &&
+ rsp->ring_ptr->signature != RESPONSE_PROCESSED) {
pkt = (struct sts_entry_24xx *)rsp->ring_ptr;
cur_ring_index = rsp->ring_index;

@@ -3887,6 +3899,7 @@ process_err:
}
pure_item = qla27xx_copy_fpin_pkt(vha,
(void **)&pkt, &rsp);
+ __update_rsp_in(is_shadow_hba, rsp, rsp_in);
if (!pure_item)
break;
qla24xx_queue_purex_item(vha, pure_item,