[PATCH V2 5/7] Correcting truncation error for constant HV_CRASH_CTL_CRASH_NOTIFY

K. Y. Srinivasan kys at microsoft.com
Sat Mar 7 07:04:32 UTC 2015


From: Nick Meier <nmeier at microsoft.com>

HV_CRASH_CTL_CRASH_NOTIFY is a 64 bit number.  Depending on the usage context,
the value may be truncated. This patch is in response from the following
email from Intel:

    [char-misc:char-misc-testing 25/45] drivers/hv/vmbus_drv.c:67:9: sparse:
                   constant 0x8000000000000000 is so big it is unsigned long

    tree:   git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git char-misc-testing
    head:   b3de8e3719e582f3182bb504295e4a8e43c8c96f
    commit: 96c1d0581d00f7abe033350edb021a9d947d8d81 [25/45] Drivers: hv: vmbus: Add support for VMBus panic notifier handler
    reproduce:
      # apt-get install sparse
      git checkout 96c1d0581d00f7abe033350edb021a9d947d8d81
      make ARCH=x86_64 allmodconfig
      make C=1 CF=-D__CHECK_ENDIAN__

    sparse warnings: (new ones prefixed by >>)

    drivers/hv/vmbus_drv.c:67:9: sparse: constant 0x8000000000000000 is so big it is unsigned long
    ...

Signed-off-by: Nick Meier <nmeier at microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
---
 drivers/hv/hyperv_vmbus.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 6339589..c8e27e0 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -58,7 +58,7 @@ enum hv_cpuid_function {
 #define HV_X64_MSR_CRASH_P4   0x40000104
 #define HV_X64_MSR_CRASH_CTL  0x40000105
 
-#define HV_CRASH_CTL_CRASH_NOTIFY 0x8000000000000000
+#define HV_CRASH_CTL_CRASH_NOTIFY (1ULL << 63)
 
 /* Define version of the synthetic interrupt controller. */
 #define HV_SYNIC_VERSION		(1)
-- 
1.7.4.1



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