[PATCH V2 04/10] Drivers: hv: vmbus: Correcting truncation error for constant HV_CRASH_CTL_CRASH_NOTIFY

From: K. Y. Srinivasan
Date: Wed Mar 18 2015 - 14:13:16 EST


From: Nick Meier <nmeier@xxxxxxxxxxxxx>

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 Wu Fengguang <fengguang.wu@xxxxxxxxx>:

From: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Subject: [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@xxxxxxxxxxxxx>
Reported-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
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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