[PATCH V2] x86/Hyper-V: Fix definition HV_MAX_FLUSH_REP_COUNT

[PATCH V2] x86/Hyper-V: Fix definition HV_MAX_FLUSH_REP_COUNT

[lantianyu1986]

From: Lan Tianyu <Tianyu.Lan@microsoft.com>

The max flush rep count of HvFlushGuestPhysicalAddressList hypercall
is equal with how many entries of union hv_gpa_page_range can be populated
into the input parameter page. The origin code lacks parenthesis around
PAGE_SIZE - 2 * sizeof(u64). This patch is to fix it.

Cc: <stable@vger.kernel.org>
Fixes: cc4edae4b924 ("x86/hyper-v: Add HvFlushGuestAddressList hypercall support")
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
---
Change since v1
	- Update change log

 arch/x86/include/asm/hyperv-tlfs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 705dafc2d11a..2bdbbbcfa393 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -841,7 +841,7 @@ union hv_gpa_page_range {
  * count is equal with how many entries of union hv_gpa_page_range can
  * be populated into the input parameter page.
  */
-#define HV_MAX_FLUSH_REP_COUNT (PAGE_SIZE - 2 * sizeof(u64) /	\
+#define HV_MAX_FLUSH_REP_COUNT ((PAGE_SIZE - 2 * sizeof(u64)) /	\
 				sizeof(union hv_gpa_page_range))
 
 struct hv_guest_mapping_flush_list {
-- 
2.14.4

[tip:x86/urgent] x86/hyper-v: Fix definition of HV_MAX_FLUSH_REP_COUNT

[tip-bot for Lan Tianyu]

Commit-ID:  9cd05ad2910b55238e3c720c99ad896dc538301b
Gitweb:     https://git.kernel.org/tip/9cd05ad2910b55238e3c720c99ad896dc538301b
Author:     Lan Tianyu <Tianyu.Lan@microsoft.com>
AuthorDate: Mon, 25 Feb 2019 22:31:14 +0800
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 28 Feb 2019 11:58:29 +0100

x86/hyper-v: Fix definition of HV_MAX_FLUSH_REP_COUNT

The max flush rep count of HvFlushGuestPhysicalAddressList hypercall is
equal with how many entries of union hv_gpa_page_range can be populated
into the input parameter page.

The code lacks parenthesis around PAGE_SIZE - 2 * sizeof(u64) which results
in bogus computations. Add them.

Fixes: cc4edae4b924 ("x86/hyper-v: Add HvFlushGuestAddressList hypercall support")
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: kys@microsoft.com
Cc: haiyangz@microsoft.com
Cc: sthemmin@microsoft.com
Cc: sashal@kernel.org
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: gregkh@linuxfoundation.org
Cc: devel@linuxdriverproject.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190225143114.5149-1-Tianyu.Lan@microsoft.com
---
 arch/x86/include/asm/hyperv-tlfs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 705dafc2d11a..2bdbbbcfa393 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -841,7 +841,7 @@ union hv_gpa_page_range {
  * count is equal with how many entries of union hv_gpa_page_range can
  * be populated into the input parameter page.
  */
-#define HV_MAX_FLUSH_REP_COUNT (PAGE_SIZE - 2 * sizeof(u64) /	\
+#define HV_MAX_FLUSH_REP_COUNT ((PAGE_SIZE - 2 * sizeof(u64)) /	\
 				sizeof(union hv_gpa_page_range))
 
 struct hv_guest_mapping_flush_list {