| From 56ef6718a1d8d77745033c5291e025ce18504159 Mon Sep 17 00:00:00 2001 |
| From: Vitaly Kuznetsov <vkuznets@redhat.com> |
| Date: Wed, 7 Dec 2016 01:16:27 -0800 |
| Subject: hv: don't reset hv_context.tsc_page on crash |
| |
| From: Vitaly Kuznetsov <vkuznets@redhat.com> |
| |
| commit 56ef6718a1d8d77745033c5291e025ce18504159 upstream. |
| |
| It may happen that secondary CPUs are still alive and resetting |
| hv_context.tsc_page will cause a consequent crash in read_hv_clock_tsc() |
| as we don't check for it being not NULL there. It is safe as we're not |
| freeing this page anyways. |
| |
| Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> |
| Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> |
| Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/hv/hv.c | 5 +++-- |
| 1 file changed, 3 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/hv/hv.c |
| +++ b/drivers/hv/hv.c |
| @@ -305,9 +305,10 @@ void hv_cleanup(bool crash) |
| |
| hypercall_msr.as_uint64 = 0; |
| wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64); |
| - if (!crash) |
| + if (!crash) { |
| vfree(hv_context.tsc_page); |
| - hv_context.tsc_page = NULL; |
| + hv_context.tsc_page = NULL; |
| + } |
| } |
| #endif |
| } |
