diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2016-06-04 02:09:22 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-31 13:05:40 +0200 |
| commit | a9f61ca793becabdefab03b77568d6c6f8c1bc79 (patch) | |
| tree | 422f0e2eb47880341e6ebe69a1afa918458c4dd4 /drivers/hv/hv.c | |
| parent | tile-srom: avoid krealloc(... __GFP_ZERO) pattern (diff) | |
| download | linux-a9f61ca793becabdefab03b77568d6c6f8c1bc79.tar.xz linux-a9f61ca793becabdefab03b77568d6c6f8c1bc79.zip | |
Drivers: hv: avoid vfree() on crash
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.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/hv.c')
| -rw-r--r-- | drivers/hv/hv.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index a1c086ba3b9a..60dbd6cb4640 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -278,7 +278,7 @@ 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; @@ -288,7 +288,8 @@ 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; } @@ -308,7 +309,8 @@ void hv_cleanup(void) hypercall_msr.as_uint64 = 0; wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64); - vfree(hv_context.tsc_page); + if (!crash) + vfree(hv_context.tsc_page); hv_context.tsc_page = NULL; } #endif |