[for-4.4.y,09/10] scsi: qla2xxx: do not queue commands when unloading

Message ID 1543426149-7269-10-git-send-email-amit.pundir@linaro.org
State New
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Series
  • Stable candidates for linux-4.4.y
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Commit Message

Amit Pundir Nov. 28, 2018, 5:29 p.m.
From: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>


commit 04dfaa53a0b6e66b328a5bc549e3af8f8b6eac02 upstream.

When the driver is unloading, in qla2x00_remove_one(), there is a single
call/point in time to abort ongoing commands, qla2x00_abort_all_cmds(),
which is still several steps away from the call to scsi_remove_host().

If more commands continue to arrive and be processed during that
interval, when the driver is tearing down and releasing its structures,
it might potentially hit an oops due to invalid memory access:

    Unable to handle kernel paging request for data at address 0x00000138
    <...>
    NIP [d000000004700a40] qla2xxx_queuecommand+0x80/0x3f0 [qla2xxx]
    LR [d000000004700a10] qla2xxx_queuecommand+0x50/0x3f0 [qla2xxx]

So, fail commands in qla2xxx_queuecommand() if the UNLOADING bit is set.

Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>

Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

---
 drivers/scsi/qla2xxx/qla_os.c | 5 +++++
 1 file changed, 5 insertions(+)

-- 
2.7.4

Patch

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 18b19744398a..ff5df33fc740 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -685,6 +685,11 @@  qla2xxx_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 	srb_t *sp;
 	int rval;
 
+	if (unlikely(test_bit(UNLOADING, &base_vha->dpc_flags))) {
+		cmd->result = DID_NO_CONNECT << 16;
+		goto qc24_fail_command;
+	}
+
 	if (ha->flags.eeh_busy) {
 		if (ha->flags.pci_channel_io_perm_failure) {
 			ql_dbg(ql_dbg_aer, vha, 0x9010,