[PATCH v2 0/5] Drivers: hv: vmbus: fix crashes on hv_vmbus load/unload path

From: Vitaly Kuznetsov
Date: Tue Jan 27 2015 - 11:44:40 EST


Changes since v1:
- '[PATCH 2/3] Drivers: hv: vmbus: introduce vmbus_acpi_remove' was dropped in
favor of Jake's '[PATCH v2 1/1] drivers:hv:vmbus drivers:hv:vmbus Allow for
more than one MMIO range for children'. It is required to make unload/load
work on Gen2 instances.

- Added '[PATCH v2 3/5] drivers: hv: Teardown synthetic interrupt controllers
on module unload' to deal with synic.

- Added '[PATCH v2 4/5] clockevents: export clockevents_unbind_device instead
of clockevents_unbind'. It is not for Hyper-V subsystem, however, it is a
pre-requisite for 'PATCH 5/5' and a natural part of this series. CC: Thomas
Gleixner as the subsystem maintainer.

- Added '[PATCH v2 5/5] Drivers: hv: vmbus: Teardown clockevent devices on
module unload' to deal with clockevent devices.

Patches are supposed to be applied on top of current char-misc-next tree.

Original description:

It is possible (since 93e5bd06a953: "Drivers: hv: Make the vmbus driver
unloadable") to unload hv_vmbus driver if no other devices are connected.
1aec169673d7: "x86: Hyperv: Cleanup the irq mess" fixed doulble interrupt
gate setup. However, if we try to unload hv_vmbus and then load it back
crashes in different places of vmbus driver occur on both unload and second
load paths. Address those I saw in my testing.

Not everything is fixed though. MCE was hit once on Generation2 instance and
I neither understand what caused it nor do I know the way to reproduce it.
Anyway, here is the log:

[ 204.846255] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0020001
[ 204.846675] mce: [Hardware Error]: TSC 6b5cd64bc8
[ 204.846675] mce: [Hardware Error]: PROCESSOR 0:306e4 TIME 1421944123 SOCKET 0 APIC 0 microcode ffffffff
[ 204.846675] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
[ 204.846675] mce: [Hardware Error]: Machine check: Processor context corrupt
[ 204.846675] Kernel panic - not syncing: Fatal Machine check
[ 204.846675] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff)
[ 204.846675] Rebooting in 30 seconds..
[ 204.846675] ACPI MEMORY or I/O RESET_REG.

Vitaly Kuznetsov (5):
Drivers: hv: vmbus: avoid double kfree for device_obj
Drivers: hv: vmbus: teardown hv_vmbus_con workqueue and
vmbus_connection pages on shutdown
drivers: hv: Teardown synthetic interrupt controllers on module unload
clockevents: export clockevents_unbind_device instead of
clockevents_unbind
Drivers: hv: vmbus: Teardown clockevent devices on module unload

drivers/hv/channel_mgmt.c | 1 -
drivers/hv/connection.c | 17 ++++++++++++-----
drivers/hv/hv.c | 34 +++++++++++++++++++++++++++++++---
drivers/hv/hyperv_vmbus.h | 3 +++
drivers/hv/vmbus_drv.c | 11 +++++++++++
kernel/time/clockevents.c | 2 +-
6 files changed, 58 insertions(+), 10 deletions(-)

--
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/