diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2016-06-03 17:09:22 -0700 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2017-06-17 16:10:27 +0200 |
| commit | 81671f4d891831d6502dae4b280e34cdfe5abd29 (patch) | |
| tree | 54a9e8f5852c094615b5b00147abe55042461240 /drivers/hv | |
| parent | 9916ff18dbb21277e1dd7a661de77ae272f6abfd (diff) | |
Drivers: hv: avoid vfree() on crash
commit a9f61ca793becabdefab03b77568d6c6f8c1bc79 upstream.
When we crash from NMI context (e.g. after NMI injection from host when
'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit
kernel BUG at mm/vmalloc.c:1530!
as vfree() is denied. While the issue could be solved with in_nmi() check
instead I opted for skipping vfree on all sorts of crashes to reduce the
amount of work which can cause consequent crashes. We don't really need to
free anything on crash.
[js] no tsc and kexec in 3.12 yet
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'drivers/hv')
| -rw-r--r-- | drivers/hv/hv.c | 5 | ||||
| -rw-r--r-- | drivers/hv/hyperv_vmbus.h | 2 | ||||
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 4 |
3 files changed, 6 insertions, 5 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index ae4923756..b1039552b 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -193,7 +193,7 @@ cleanup: * * This routine is called normally during driver unloading or exiting. */ -void hv_cleanup(void) +void hv_cleanup(bool crash) { union hv_x64_msr_hypercall_contents hypercall_msr; @@ -203,7 +203,8 @@ void hv_cleanup(void) if (hv_context.hypercall_page) { hypercall_msr.as_uint64 = 0; wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); - vfree(hv_context.hypercall_page); + if (!crash) + vfree(hv_context.hypercall_page); hv_context.hypercall_page = NULL; } } diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 12f2f9e98..11d4e6222 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -519,7 +519,7 @@ extern struct hv_context hv_context; extern int hv_init(void); -extern void hv_cleanup(void); +extern void hv_cleanup(bool crash); extern int hv_post_message(union hv_connection_id connection_id, enum hv_message_type message_type, diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 80754e2d8..3190a1fc7 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -618,7 +618,7 @@ err_unregister: bus_unregister(&hv_bus); err_cleanup: - hv_cleanup(); + hv_cleanup(false); return ret; } @@ -841,7 +841,7 @@ static void __exit vmbus_exit(void) free_irq(irq, hv_acpi_dev); vmbus_free_channels(); bus_unregister(&hv_bus); - hv_cleanup(); + hv_cleanup(false); acpi_bus_unregister_driver(&vmbus_acpi_driver); hv_cpu_hotplug_quirk(false); } |