From: Michael Reed Date: Wed, 2 Dec 2009 15:11:16 +0000 (-0600) Subject: [SCSI] qla2xxx: dpc thread can execute before scsi host has been added X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1486400f7edd009d49550da968d5744e246dc7f8;p=linux-beck.git [SCSI] qla2xxx: dpc thread can execute before scsi host has been added 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: [] show_stack+0x50/0xa0 sp=e00000b07c59f930 bsp=e00000b07c591400 [] show_regs+0x820/0x860 sp=e00000b07c59fb00 bsp=e00000b07c5913a0 [] die+0x1a0/0x2e0 sp=e00000b07c59fb00 bsp=e00000b07c591360 [] ia64_do_page_fault+0x8c0/0x9e0 sp=e00000b07c59fb00 bsp=e00000b07c591310 [] ia64_native_leave_kernel+0x0/0x270 sp=e00000b07c59fb90 bsp=e00000b07c591310 [] qla2x00_fdmi_register+0x850/0xbe0 [qla2xxx] sp=e00000b07c59fd60 bsp=e00000b07c591290 [] qla2x00_configure_loop+0x1930/0x34c0 [qla2xxx] sp=e00000b07c59fd60 bsp=e00000b07c591128 [] qla2x00_loop_resync+0x1b0/0x2e0 [qla2xxx] sp=e00000b07c59fdf0 bsp=e00000b07c5910c0 [] qla2x00_do_dpc+0x9a0/0xce0 [qla2xxx] sp=e00000b07c59fdf0 bsp=e00000b07c590fa0 [] kthread+0x110/0x140 sp=e00000b07c59fe00 bsp=e00000b07c590f68 [] kernel_thread_helper+0xd0/0x100 sp=e00000b07c59fe30 bsp=e00000b07c590f40 [] start_kernel_thread+0x20/0x40 sp=e00000b07c59fe30 bsp=e00000b07c590f40 crash> dis a000000207197350 0xa000000207197350 : [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 Acked-by: Giridhar Malavali Cc: stable@kernel.org Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 41669357b186..58edc0deb74b 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -2003,13 +2003,13 @@ 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);