[PATCH V2 11/15] hv: don't reset hv_context.tsc_page on crash

From: kys
Date: Sat Dec 03 2016 - 13:43:16 EST


From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/hv.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 4ece040..04a0fd8 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -309,9 +309,10 @@ 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
}
--
1.7.4.1