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[v3] KVM: arm64: fix compile error because of shift overflow

Message ID 20220810013435.1525363-1-yangyingliang@huawei.com (mailing list archive)
State New, archived
Headers show
Series [v3] KVM: arm64: fix compile error because of shift overflow | expand

Commit Message

Yang Yingliang Aug. 10, 2022, 1:34 a.m. UTC
Using GENMASK() to generate the masks of device type and device id, it makes
code unambiguous, also it can fix the following fix compile error because of
shift overflow when using low verison gcc(mine version is 7.5):

In function ‘kvm_vm_ioctl_set_device_addr.isra.38’,
    inlined from ‘kvm_arch_vm_ioctl’ at arch/arm64/kvm/arm.c:1454:10:
././include/linux/compiler_types.h:354:38: error: call to ‘__compiletime_assert_599’ \
declared with attribute error: FIELD_GET: mask is not constant
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

Fixes: 9f968c9266aa ("KVM: arm64: vgic-v2: Add helper for legacy dist/cpuif base address setting")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
v3:
 replace '15/31' with 'SHIFT + 15' to make it more readable.
v2:
  Using GENMASK() to generate the masks.
---
 arch/arm64/include/uapi/asm/kvm.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Marc Zyngier Aug. 10, 2022, 9:08 a.m. UTC | #1
On Wed, 10 Aug 2022 09:34:35 +0800, Yang Yingliang wrote:
> Using GENMASK() to generate the masks of device type and device id, it makes
> code unambiguous, also it can fix the following fix compile error because of
> shift overflow when using low verison gcc(mine version is 7.5):
> 
> In function ‘kvm_vm_ioctl_set_device_addr.isra.38’,
>     inlined from ‘kvm_arch_vm_ioctl’ at arch/arm64/kvm/arm.c:1454:10:
> ././include/linux/compiler_types.h:354:38: error: call to ‘__compiletime_assert_599’ \
> declared with attribute error: FIELD_GET: mask is not constant
>   _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

Applied to fixes, thanks!

[1/1] KVM: arm64: fix compile error because of shift overflow
      commit: ae3b1da95413614f96ffa23d200929c6f809c807

Cheers,

	M.
diff mbox series

Patch

diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 3bb134355874..316917b98707 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -75,9 +75,11 @@  struct kvm_regs {
 
 /* KVM_ARM_SET_DEVICE_ADDR ioctl id encoding */
 #define KVM_ARM_DEVICE_TYPE_SHIFT	0
-#define KVM_ARM_DEVICE_TYPE_MASK	(0xffff << KVM_ARM_DEVICE_TYPE_SHIFT)
+#define KVM_ARM_DEVICE_TYPE_MASK	GENMASK(KVM_ARM_DEVICE_TYPE_SHIFT + 15, \
+						KVM_ARM_DEVICE_TYPE_SHIFT)
 #define KVM_ARM_DEVICE_ID_SHIFT		16
-#define KVM_ARM_DEVICE_ID_MASK		(0xffff << KVM_ARM_DEVICE_ID_SHIFT)
+#define KVM_ARM_DEVICE_ID_MASK		GENMASK(KVM_ARM_DEVICE_ID_SHIFT + 15, \
+						KVM_ARM_DEVICE_ID_SHIFT)
 
 /* Supported device IDs */
 #define KVM_ARM_DEVICE_VGIC_V2		0