Fix crash in qla2x00_fdmi_register() due to the dpc
thread executing before the scsi host has been fully
added.
Unable to handle kernel NULL pointer dereference (address 00000000000001d0)
qla2xxx_7_dpc[4140]: Oops 8813272891392 [1]
Call Trace:
[<a000000100016910>] show_stack+0x50/0xa0
sp=e00000b07c59f930 bsp=e00000b07c591400
[<a000000100017180>] show_regs+0x820/0x860
sp=e00000b07c59fb00 bsp=e00000b07c5913a0
[<a00000010003bd60>] die+0x1a0/0x2e0
sp=e00000b07c59fb00 bsp=e00000b07c591360
[<a0000001000681a0>] ia64_do_page_fault+0x8c0/0x9e0
sp=e00000b07c59fb00 bsp=e00000b07c591310
[<a00000010000c8e0>] ia64_native_leave_kernel+0x0/0x270
sp=e00000b07c59fb90 bsp=e00000b07c591310
[<a000000207197350>] qla2x00_fdmi_register+0x850/0xbe0 [qla2xxx]
sp=e00000b07c59fd60 bsp=e00000b07c591290
[<a000000207171570>] qla2x00_configure_loop+0x1930/0x34c0 [qla2xxx]
sp=e00000b07c59fd60 bsp=e00000b07c591128
[<a0000002071732b0>] qla2x00_loop_resync+0x1b0/0x2e0 [qla2xxx]
sp=e00000b07c59fdf0 bsp=e00000b07c5910c0
[<a000000207166d40>] qla2x00_do_dpc+0x9a0/0xce0 [qla2xxx]
sp=e00000b07c59fdf0 bsp=e00000b07c590fa0
[<a0000001000d5bb0>] kthread+0x110/0x140
sp=e00000b07c59fe00 bsp=e00000b07c590f68
[<a000000100014a30>] kernel_thread_helper+0xd0/0x100
sp=e00000b07c59fe30 bsp=e00000b07c590f40
[<a00000010000a4c0>] start_kernel_thread+0x20/0x40
sp=e00000b07c59fe30 bsp=e00000b07c590f40
crash> dis a000000207197350
0xa000000207197350 <qla2x00_fdmi_register+2128>: [MMI] ld1 r45=[r14];;
crash> scsi_qla_host.host 0xe00000b058c73ff8
host = 0xe00000b058c73be0,
crash> Scsi_Host.shost_data 0xe00000b058c73be0
shost_data = 0x0, <<<<<<<<<<<
The fc_transport fc_* workqueue threads have yet to be created.
crash> ps | grep _7
3891 2 2 e00000b075c80000 IN 0.0 0 0 [scsi_eh_7]
4140 2 3 e00000b07c590000 RU 0.0 0 0 [qla2xxx_7_dpc]
The thread creating adding the Scsi_Host is blocked due to other
activity in sysfs.
crash> bt 3762
PID: 3762 TASK: e00000b071e70000 CPU: 3 COMMAND: "modprobe"
#0 [BSP:e00000b071e71548] schedule at a000000100727e00
#1 [BSP:e00000b071e714c8] __mutex_lock_slowpath at a0000001007295a0
#2 [BSP:e00000b071e714a8] mutex_lock at a000000100729830
#3 [BSP:e00000b071e71478] sysfs_addrm_start at a0000001002584f0
#4 [BSP:e00000b071e71440] create_dir at a000000100259350
#5 [BSP:e00000b071e71410] sysfs_create_subdir at a000000100259510
#6 [BSP:e00000b071e713b0] internal_create_group at a00000010025c880
#7 [BSP:e00000b071e71388] sysfs_create_group at a00000010025cc50
#8 [BSP:e00000b071e71368] dpm_sysfs_add at a000000100425050
#9 [BSP:e00000b071e71310] device_add at a000000100417d90
#10 [BSP:e00000b071e712d8] scsi_add_host at a00000010045a380
#11 [BSP:e00000b071e71268] qla2x00_probe_one at a0000002071be950
#12 [BSP:e00000b071e71248] local_pci_probe at a00000010032e490
#13 [BSP:e00000b071e71218] pci_device_probe at a00000010032ecd0
#14 [BSP:e00000b071e711d8] driver_probe_device at a00000010041d480
#15 [BSP:e00000b071e711a8] __driver_attach at a00000010041d6e0
#16 [BSP:e00000b071e71170] bus_for_each_dev at a00000010041c240
#17 [BSP:e00000b071e71150] driver_attach at a00000010041d0a0
#18 [BSP:e00000b071e71108] bus_add_driver at a00000010041b080
#19 [BSP:e00000b071e710c0] driver_register at a00000010041dea0
#20 [BSP:e00000b071e71088] __pci_register_driver at a00000010032f610
#21 [BSP:e00000b071e71058] (unknown) at a000000207200270
#22 [BSP:e00000b071e71018] do_one_initcall at a00000010000a9c0
#23 [BSP:e00000b071e70f98] sys_init_module at a0000001000fef00
#24 [BSP:e00000b071e70f98] ia64_ret_from_syscall at a00000010000c740
So, it appears that qla2xxx dpc thread is moving forward before the
scsi host has been completely added.
This patch moves the setting of the init_done (and online) flag to
after the call to scsi_add_host() to hold off the dpc thread.
Found via large lun count testing using 2.6.31.
Signed-off-by: Michael Reed <mdr@xxxxxxx>
--- linux-2.6.32-rc8/drivers/scsi/qla2xxx/qla_os.c 2009-11-19 16:32:38.000000000 -0600
+++ linux-2.6.32-rc8-modified/drivers/scsi/qla2xxx/qla_os.c 2009-12-02 08:46:04.962724212 -0600
@@ -2016,13 +2016,13 @@ skip_dpc:
DEBUG2(printk("DEBUG: detect hba %ld at address = %p\n",
base_vha->host_no, ha));
- base_vha->flags.init_done = 1;
- base_vha->flags.online = 1;
-
ret = scsi_add_host(host, &pdev->dev);
if (ret)
goto probe_failed;
+ base_vha->flags.init_done = 1;
+ base_vha->flags.online = 1;
+
ha->isp_ops->enable_intrs(ha);
scsi_scan_host(host);
--
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