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05a05872c8
The lpfc_sli4_scmd_to_wqidx_distr() function expects the scsi_cmnd
'lpfc_cmd->pCmd' not to be null, and point to the midlayer command.
That's not true in the .eh_(device|target|bus)_reset_handler path,
because lpfc_send_taskmgmt() sends commands not from the midlayer, so
does not set 'lpfc_cmd->pCmd'.
That is true in the .queuecommand path because lpfc_queuecommand()
stores the scsi_cmnd from midlayer in lpfc_cmd->pCmd; and lpfc_cmd is
stored by lpfc_scsi_prep_cmnd() in piocbq->context1 -- which is passed
to lpfc_sli4_scmd_to_wqidx_distr() as lpfc_cmd parameter.
This problem can be hit on SCSI EH, and immediately with sg_reset.
These 2 test-cases demonstrate the problem/fix with next-20160601.
Test-case 1) sg_reset
# strace sg_reset --device /dev/sdm
<...>
open("/dev/sdm", O_RDWR|O_NONBLOCK) = 3
ioctl(3, SG_SCSI_RESET, 0x3fffde6d0994 <unfinished ...>
+++ killed by SIGSEGV +++
Segmentation fault
# dmesg
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xd00000001c88442c
Oops: Kernel access of bad area, sig: 11 [#1]
<...>
CPU: 104 PID: 16333 Comm: sg_reset Tainted: G W 4.7.0-rc1-next-20160601-00004-g95b89dc #6
<...>
NIP [d00000001c88442c] lpfc_sli4_scmd_to_wqidx_distr+0xc/0xd0 [lpfc]
LR [d00000001c826fe8] lpfc_sli_calc_ring.part.27+0x98/0xd0 [lpfc]
Call Trace:
[c000003c9ec876f0] [c000003c9ec87770] 0xc000003c9ec87770 (unreliable)
[c000003c9ec87720] [d00000001c82e004] lpfc_sli_issue_iocb+0xd4/0x260 [lpfc]
[c000003c9ec87780] [d00000001c831a3c] lpfc_sli_issue_iocb_wait+0x15c/0x5b0 [lpfc]
[c000003c9ec87880] [d00000001c87f27c] lpfc_send_taskmgmt+0x24c/0x650 [lpfc]
[c000003c9ec87950] [d00000001c87fd7c] lpfc_device_reset_handler+0x10c/0x200 [lpfc]
[c000003c9ec87a10] [c000000000610694] scsi_try_bus_device_reset+0x44/0xc0
[c000003c9ec87a40] [c0000000006113e8] scsi_ioctl_reset+0x198/0x2c0
[c000003c9ec87bf0] [c00000000060fe5c] scsi_ioctl+0x13c/0x4b0
[c000003c9ec87c80] [c0000000006629b0] sd_ioctl+0xf0/0x120
[c000003c9ec87cd0] [c00000000046e4f8] blkdev_ioctl+0x248/0xb70
[c000003c9ec87d30] [c0000000002a1f60] block_ioctl+0x70/0x90
[c000003c9ec87d50] [c00000000026d334] do_vfs_ioctl+0xc4/0x890
[c000003c9ec87de0] [c00000000026db60] SyS_ioctl+0x60/0xc0
[c000003c9ec87e30] [c000000000009120] system_call+0x38/0x108
Instruction dump:
<...>
With fix:
# strace sg_reset --device /dev/sdm
<...>
open("/dev/sdm", O_RDWR|O_NONBLOCK) = 3
ioctl(3, SG_SCSI_RESET, 0x3fffe103c554) = 0
close(3) = 0
exit_group(0) = ?
+++ exited with 0 +++
# dmesg
[ 424.658649] lpfc 0006:01:00.4: 4:(0):0713 SCSI layer issued Device Reset (1, 0) return x2002
Test-case 2) SCSI EH
Using this debug patch to wire an SCSI EH trigger, for lpfc_scsi_cmd_iocb_cmpl():
- cmd->scsi_done(cmd);
+ if ((phba->pport ? phba->pport->cfg_log_verbose : phba->cfg_log_verbose) == 0x32100000)
+ printk(KERN_ALERT "lpfc: skip scsi_done()\n");
+ else
+ cmd->scsi_done(cmd);
# echo 0x32100000 > /sys/class/scsi_host/host11/lpfc_log_verbose
# dd if=/dev/sdm of=/dev/null iflag=direct &
<...>
After a while:
# dmesg
lpfc 0006:01:00.4: 4:(0):3053 lpfc_log_verbose changed from 0 (x0) to 839909376 (x32100000)
lpfc: skip scsi_done()
<...>
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xd0000000199e448c
Oops: Kernel access of bad area, sig: 11 [#1]
<...>
CPU: 96 PID: 28556 Comm: scsi_eh_11 Tainted: G W 4.7.0-rc1-next-20160601-00004-g95b89dc #6
<...>
NIP [d0000000199e448c] lpfc_sli4_scmd_to_wqidx_distr+0xc/0xd0 [lpfc]
LR [d000000019986fe8] lpfc_sli_calc_ring.part.27+0x98/0xd0 [lpfc]
Call Trace:
[c000000ff0d0b890] [c000000ff0d0b900] 0xc000000ff0d0b900 (unreliable)
[c000000ff0d0b8c0] [d00000001998e004] lpfc_sli_issue_iocb+0xd4/0x260 [lpfc]
[c000000ff0d0b920] [d000000019991a3c] lpfc_sli_issue_iocb_wait+0x15c/0x5b0 [lpfc]
[c000000ff0d0ba20] [d0000000199df27c] lpfc_send_taskmgmt+0x24c/0x650 [lpfc]
[c000000ff0d0baf0] [d0000000199dfd7c] lpfc_device_reset_handler+0x10c/0x200 [lpfc]
[c000000ff0d0bbb0] [c000000000610694] scsi_try_bus_device_reset+0x44/0xc0
[c000000ff0d0bbe0] [c0000000006126cc] scsi_eh_ready_devs+0x49c/0x9c0
[c000000ff0d0bcb0] [c000000000614160] scsi_error_handler+0x580/0x680
[c000000ff0d0bd80] [c0000000000ae848] kthread+0x108/0x130
[c000000ff0d0be30] [c0000000000094a8] ret_from_kernel_thread+0x5c/0xb4
Instruction dump:
<...>
With fix:
# dmesg
lpfc 0006:01:00.4: 4:(0):3053 lpfc_log_verbose changed from 0 (x0) to 839909376 (x32100000)
lpfc: skip scsi_done()
<...>
lpfc 0006:01:00.4: 4:(0):0713 SCSI layer issued Device Reset (0, 0) return x2002
<...>
lpfc 0006:01:00.4: 4:(0):0723 SCSI layer issued Target Reset (1, 0) return x2002
<...>
lpfc 0006:01:00.4: 4:(0):0714 SCSI layer issued Bus Reset Data: x2002
<...>
lpfc 0006:01:00.4: 4:(0):3172 SCSI layer issued Host Reset Data:
<...>
Fixes:
|
||
|---|---|---|
| .. | ||
| accessibility | ||
| acpi | ||
| amba | ||
| android | ||
| ata | ||
| atm | ||
| auxdisplay | ||
| base | ||
| bcma | ||
| block | ||
| bluetooth | ||
| bus | ||
| cdrom | ||
| char | ||
| clk | ||
| clocksource | ||
| connector | ||
| cpufreq | ||
| cpuidle | ||
| crypto | ||
| dax | ||
| dca | ||
| devfreq | ||
| dio | ||
| dma | ||
| dma-buf | ||
| edac | ||
| eisa | ||
| extcon | ||
| firewire | ||
| firmware | ||
| fmc | ||
| fpga | ||
| gpio | ||
| gpu | ||
| hid | ||
| hsi | ||
| hv | ||
| hwmon | ||
| hwspinlock | ||
| hwtracing | ||
| i2c | ||
| ide | ||
| idle | ||
| iio | ||
| infiniband | ||
| input | ||
| iommu | ||
| ipack | ||
| irqchip | ||
| isdn | ||
| leds | ||
| lguest | ||
| lightnvm | ||
| macintosh | ||
| mailbox | ||
| mcb | ||
| md | ||
| media | ||
| memory | ||
| memstick | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| mtd | ||
| net | ||
| nfc | ||
| ntb | ||
| nubus | ||
| nvdimm | ||
| nvme | ||
| nvmem | ||
| of | ||
| oprofile | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| perf | ||
| phy | ||
| pinctrl | ||
| platform | ||
| pnp | ||
| power | ||
| powercap | ||
| pps | ||
| ps3 | ||
| ptp | ||
| pwm | ||
| rapidio | ||
| ras | ||
| regulator | ||
| remoteproc | ||
| reset | ||
| rpmsg | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| sfi | ||
| sh | ||
| sn | ||
| soc | ||
| spi | ||
| spmi | ||
| ssb | ||
| staging | ||
| target | ||
| tc | ||
| thermal | ||
| thunderbolt | ||
| tty | ||
| uio | ||
| usb | ||
| uwb | ||
| vfio | ||
| vhost | ||
| video | ||
| virt | ||
| virtio | ||
| vlynq | ||
| vme | ||
| w1 | ||
| watchdog | ||
| xen | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||